Sharon Wahl - Academia.edu (original) (raw)

Papers by Sharon Wahl

Blood, Aug 1, 1997

Infection of monocytes with human immunodeficiency virus the C-terminal domain contains the prote... more Infection of monocytes with human immunodeficiency virus the C-terminal domain contains the protease inhibiting retype 1 Ba-L (HIV-1 Ba-L) is significantly inhibited by treatment gion. However, when tested independently, neither domain with the serine protease inhibitor, secretory leukocyte protehad potent anti-HIV-1 activity. SLPI binding neither prease inhibitor (SLPI). SLPI does not appear to act on virus vented virus binding to monocytes nor attenuated the infecdirectly, but rather the inhibitory activity is most likely due tivity of any virus progeny that escaped inhibition by SLPI. to interaction with the host cell. The current study was initi-A polymerase chain reaction (PCR)-based assay for newly ated to investigate how SLPI interacts with monocytes to generated viral DNA demonstrated that SLPI blocks at or inhibit infection. SLPI was found to bind to monocytes with before viral DNA synthesis. Therefore, it most likely inhibits high affinity to a single class of receptor sites (Ò7,000 recepa step of viral infection that occurs after virus binding but tors per monocyte, K D ! 3.6 nmol/L). The putative SLPI rebefore reverse transcription. Taken together, the unique ceptor was identified as a surface protein with a molecular antiviral activity of SLPI, which may be independent of its weight of 55 Ô 5 kD. A well-characterized function of SLPI previously characterized antiprotease activity, appears to reis inhibition of neutrophil elastase and cathepsin G. Howside in disruption of the viral infection process soon after ever, two SLPI mutants (or muteins) that contain single virus binding. amino acid substitutions and exhibit greatly reduced prote-This is a US government work. There are no restrictions on ase inhibitory activity still bound to monocytes and retained its use. anti-HIV-1 activity. SLPI consists of two domains, of which

Journal of Clinical Investigation, Mar 1, 1997

Secretory leukocyte protease inhibitor (SLPI) is a serine protease inhibitor found in fluids lini... more Secretory leukocyte protease inhibitor (SLPI) is a serine protease inhibitor found in fluids lining mucosal surfaces. In addition to its primary function as an antiprotease, SLPI may also influence cellular functions associated with enzyme synthesis and retroviral infection. In this study, SLPI was examined for its effect on signaling events involved in the production of matrix metalloproteinases (MMPs) by monocytes. Addition of SLPI before stimulation with concanavalin A or LPS resulted in a significant inhibition of monocyte prostaglandin H synthase-2 (PGHS-2), a pivotal enzyme in the PGE 2-cAMP dependent pathway of monocyte MMP synthesis. Suppression of PGHS-2 was detected with 0.1 g/ml of SLPI with a substantial inhibition at 1 and 10 g/ml. Attenuation of PGHS-2 by SLPI was accompanied by decreased production of PGE 2 resulting in the suppression of interstitial collagenase (MMP-1) and gelatinase B (MMP-9) that was reversed by PGE 2 or Bt 2 cAMP. The inhibitory effect of SLPI was largely independent of its antiprotease activity because SLPI muteins, with significantly lower antiprotease activity, also suppressed the induction of PGHS-2 and MMPs. The inhibitory effects of SLPI did not involve the modulation of monokine production since TNF-␣ and IL-10 were unaffected. These findings demonstrate that SLPI also functions as a potent antiinflammatory agent by interfering with the signal transduction pathway leading to monocyte MMP production.

The Journal of Immunology

Oral administration of autoantigens can influence the outcome of experimental autoimmune diseases... more Oral administration of autoantigens can influence the outcome of experimental autoimmune diseases, yet little is known about nonself Ag-induced tolerance. In this study, we administered group A streptococcal cell wall (SCW) peptidoglycan-polysaccharide complexes orally and monitored the impact on SCW-induced erosive polyarthritis. Oral administration of low dose SCW (3 μg/day), initiated 7 days before an arthritogenic dose of systemic SCW, virtually eliminated the joint swelling and destruction typically observed during both the acute and chronic phases of the arthritis. High (300 μg), but not intermediate (30 μg), dose regimens also profoundly inhibited the disease. Most previous studies have demonstrated that prior feeding is required for efficacy, yet oral feeding of low dose SCW suppressed the evolution of arthritis even when administration was begun 10–15 days after induction of the arthritis. While the synovial inflammatory cell infiltration and expression of proinflammatory c...

The Journal of Immunology

Peripheral blood monocytes from AIDS patients exhibit defective migratory responses to chemotacti... more Peripheral blood monocytes from AIDS patients exhibit defective migratory responses to chemotactic stimuli in vitro and to inflammatory sites in vivo. In studies presented here, normal monocytes were infected with the HIV-1/HTLV-IIIBa-L isolate in vitro and evaluated for chemotactic responsiveness. Within 2 days after viral exposure, but before evidence of virus production in the monocytes, chemotactic activity was significantly impaired. Decreased chemotactic activity was associated with modulation of receptors for the chemotactic ligands, C5a and FMLP, on the monocyte cell surface. In addition to HIV-1, monocytes treated with purified HIV-1 envelope glycoprotein gp120 demonstrated a comparable modulation of chemotactic ligand receptors and migratory function. In addition, the HIV-1 or HIV-1 gp120-treated monocytes were induced to undergo differentiation as monitored by HLA-DR expression. Immunoprecipitation of the gp120 with a specific antibody reversed its effects on monocyte che...

Journal of Leukocyte Biology

Immunodeficiency, the consequence of HIV-1 infection, predisposes the host to opportunistic infec... more Immunodeficiency, the consequence of HIV-1 infection, predisposes the host to opportunistic infections. In turn, opportunistic pathogens influence target cell susceptibility to HIV-1 infection and replication. Although the advent of highly active antiretroviral therapy (HAART) has altered these sequelae, co-infections may prevail in some parts of the world and in failed HAART regimens. Moreover, immune activation as occurs in tonsil and non-infectious mucosal inflammatory lesions may also be associated with proximal sites of viral replication. These connections between enhancement of HIV-1 infection and activation/inflammation warrant further elucidation of the factors promoting permissiveness to HIV-1 infection. Using the opportunistic pathogen Mycobacterium avium as an in vitro model, we demonstrated that co-infection facilitated HIV-1 infection of monocyte-macrophages by multiple pathways. M. avium activated NF-κB, the downstream consequences of which included augmented expressio...

Journal of Virology, 1991

The induction of interferon (IFN) by human immunodeficiency virus type 1 (HIV-1) in primary, nons... more The induction of interferon (IFN) by human immunodeficiency virus type 1 (HIV-1) in primary, nonstimulated monocyte-macrophage cultures was studied. HIV-1 infection, as confirmed by p24 antigen levels in the cell supernatant, led to the production of alpha interferon (IFN-alpha) over 7 to 21 days following infection. In two of seven experiments, the IFN detected was acid labile. Coupled reverse transcription-polymerase chain reaction analysis confirmed the induction of IFN-alpha mRNA in cells of HIV-1-infected cultures.

Journal of Leukocyte Biology, 2014

ABSTRACTSLPI, a potent epithelial and myeloid-derived serine protease inhibitor with antimicrobia... more ABSTRACTSLPI, a potent epithelial and myeloid-derived serine protease inhibitor with antimicrobial and anti-inflammatory functions, is induced by the intracellular parasite Leishmania major, and increased SLPI expression is evident within lesions that follow L. major infection. In contrast to self-resolving infection in C57Bl/6 WT mice, Slpi−/− mice launch a strong Th1 response to L. major, yet fail to control infection and develop destructive, nonhealing lesions with systemic spread of parasites. Because SLPI is both produced by murine macrophages and antagonizes their function, we examined the contribution of macrophage polarization to the defective host response in the absence of SLPI. Slpi−/− and Slpi+/+ macrophages were first primed with either IFNγ or IL-4 to generate classically activated M1 or alternatively activated M2 macrophages. After infection with L. major, Slpi−/− M1 macrophages expressed elevated iNOS RNA, whereas arginase was more highly expressed in WT than Slpi−/−...

Proceedings of the National Academy of Sciences, 1998

Infection with HIV-1 results in pronounced immune suppression and susceptibility to opportunistic... more Infection with HIV-1 results in pronounced immune suppression and susceptibility to opportunistic infections (OI). Reciprocally, OI augment HIV-1 replication. As we have shown forMycobacterium aviumcomplex (MAC) andPneumocystis carinii, macrophages infected with opportunistic pathogens and within lymphoid tissues containing OI, exhibit striking levels of viral replication. To explore potential underlying mechanisms for increased HIV-1 replication associated with coinfection, blood monocytes were exposed to MAC antigens (MAg) or viable MAC and their levels of tumor necrosis factor α (TNFα) and HIV-1 coreceptors monitored. MAC enhanced TNFα productionin vitro, consistent with its expression in coinfected lymph nodes. Using a polyclonal antibody to the CCR5 coreceptor that mediates viral entry of macrophage tropic HIV-1, a subset of unstimulated monocytes was shown to be CCR5-positive by fluorescence-activated cell sorter analysis. After stimulation with MAg or infection with MAC, CCR5...

Proceedings of the National Academy of Sciences, 1989

Dipyridamole (DPM) is commonly used as a coronary vasodilator and inhibitor of platelet aggregati... more Dipyridamole (DPM) is commonly used as a coronary vasodilator and inhibitor of platelet aggregation in the treatment of cardiovascular diseases. We report here that DPM potentiates the inhibitory effects of 3'-azido-3'-deoxythymidine (AZT) and 2',3'-dideoxycytidine against human immunodeficiency virus type 1 (HIV-1) in human monocyte-macrophages. At the same concentrations, DPM does not potentiate the toxic effects of AZT on these cells or on human bone marrow (granulocyte-monocyte) progenitor cells. Since monocyte-macrophage lineage cells appear to be the major reservoir for HIV-1 in vivo, these findings suggest the possibility of using DPM or its analogues in combination chemotherapy of HIV infections.

Journal of Virology, 2005

ABSTRACTIn contrast to CD4+T cells, human immunodeficiency virus type 1 (HIV-1)-infected macropha... more ABSTRACTIn contrast to CD4+T cells, human immunodeficiency virus type 1 (HIV-1)-infected macrophages typically resist cell death, support viral replication, and consequently, may facilitate HIV-1 transmission. To elucidate how the virus commandeers the macrophage's intracellular machinery for its benefit, we analyzed HIV-1-infected human macrophages for virus-induced gene transcription by using multiple parameters, including cDNA expression arrays. HIV-1 infection induced the transcriptional regulation of genes associated with host defense, signal transduction, apoptosis, and the cell cycle, among which the cyclin-dependent kinase inhibitor 1A (CDKN1A/p21) gene was the most prominent. p21 mRNA and protein expression followed a bimodal pattern which was initially evident during the early stages of infection, and maximum levels occurred concomitant with active HIV-1 replication. Mechanistically, viral protein R (Vpr) independently regulates p21 expression, consistent with the redu...

Journal of Leukocyte Biology, 2003

Human immunodeficiency virus type 1 (HIV-1) infection of CD4+ T lymphocytes leads to their progre... more Human immunodeficiency virus type 1 (HIV-1) infection of CD4+ T lymphocytes leads to their progressive loss, whereas HIV-1-infected macrophages appear to resist HIV-1-mediated apoptotic death. The differential response of these two host-cell populations may be critical in the development of immunodeficiency and long-term persistence of the virus. Multiple contributing factors may favor the macrophage as a resilient host, not only supporting infection by HIV-1 but also promoting replication and persistence of this member of the lentivirus subfamily of primate retroviruses. An encounter between macrophages and R5 virus engages a signal cascade eventuating in transcriptional regulation of multiple genes including those associated with host defense, cell cycle, nuclear factor-κB regulation, and apoptosis. It is important that enhanced gene expression is transient, declining to near control levels, and during this quiescent state, the virus continues its life cycle unimpeded. However, wh...

Journal of Leukocyte Biology, 2006

Cell surface and intracellular proteins in macrophages influence various steps in the life cycle ... more Cell surface and intracellular proteins in macrophages influence various steps in the life cycle of lentiviruses. Characterization of these restriction and/or cofactors is essential to understanding how macrophages become unwitting HIV hosts and in fact, can coexist with a heavy viral burden. Although many of the cellular pathways co-opted by HIV in macrophages mimic those seen in CD4+ T cells, emerging evidence reveals cellular constituents of the macrophage, which may be uniquely usurped by HIV. For example, in addition to CD4 and CCR5, membrane annexin II facilitates early steps in infection of macrophages, but not in T cells. Blockade of this pathway effectively diminishes macrophage infection. Viral binding engages a macrophage-centric signaling pathway and a transcriptional profile, including genes such as p21, which benefit the virus. Once inside the cell, multiple host cell molecules are engaged to facilitate virus replication and assembly. Although the macrophage is an enab...

Journal of Leukocyte Biology, 2006

Mycobacterium avium is an opportunistic pathogen that commonly infects individuals colonized with... more Mycobacterium avium is an opportunistic pathogen that commonly infects individuals colonized with HIV-1, although it is less frequent in the post-HAART era. These microorganisms invade macrophages after interacting with TLR2 and/or CD14 co-receptors, but signaling pathways promoting survival in macrophages are not well defined. Although IFN-γ plays an important role in protective immunity against bacterial infections, IFN-γ responses are compromised in AIDS patients and evidence suggests that exogenous IFN-γ is inadequate to clear the mycobacteria. To determine the mechanism by which M. avium survives intracellularly, even in the presence of IFN-γ, we studied the effect of mycobacteria infection in macrophages during early IFN-γ signaling events. M. avium infected cells exhibited a reduced response to IFN-γ, with suppressed phosphorylation of STAT-1 compared with uninfected cells. Interaction of M. avium with macrophage receptors increased gene expression of the suppressors of cytok...

The Journal of Infectious Diseases, 1999

Human immunodeficiency virus type 1 (HIV-1) infection is dependent on susceptible host cells that... more Human immunodeficiency virus type 1 (HIV-1) infection is dependent on susceptible host cells that express both CD4 and chemokine co-receptors. The co-receptor CCR5 is associated with primary infection by macrophage-tropic virus isolates, whereas CXCR4 is commonly associated with T cell-and dual-tropic viruses. Once infected, lymphocytes and macrophages may replicate HIV-1 or harbor latent virus, depending on environmental factors and cellular activation. Immune activation is often associated with viremia, which is consistent with enhanced infection and viral replication in activated cells harboring virus. In this regard, opportunistic infections activate the immune system with the detrimental sequelae of enhanced viral replication and viremia. Under these conditions, viral expansion extends beyond T cells to tissue macrophages, many of which are co-infected with opportunistic pathogens. The opportunistic infections promote macrophage susceptibility to HIV-1 through cytokine modulation and altered chemokine co-receptors, potential targets for intervention.

The Journal of Immunology, 2002

In lymphoid tissues coinfected with Mycobacterium avium complex (MAC) and HIV-1, increased viral ... more In lymphoid tissues coinfected with Mycobacterium avium complex (MAC) and HIV-1, increased viral replication has been observed. This study investigates the role of MAC in perpetuating both infections through the recruitment of monocytes as potential new hosts for bacteria and HIV-1. Increased numbers of macrophages were present in the lymph nodes of patients with dual infection as compared with lymph nodes from HIV+ patients with no known opportunistic pathogens. In a coculture system, monocyte-derived macrophages were treated with HIV-1 or M. avium and its constituents to further define the mechanism whereby MAC infection of macrophages initiates monocyte migration. Monocyte-derived macrophages treated with bacteria or bacterial products, but not HIV-1, induced a rapid 2- to 3-fold increase in recruitment of monocytes. Pretreatment of the monocytes with pertussis toxin inhibited the migration of these cells, indicating a G protein-linked pathway is necessary for induction of chemot...

The Journal of Immunology, 2002

Mycobacterium avium is a facultative intracellular pathogen cleared rapidly via intact host defen... more Mycobacterium avium is a facultative intracellular pathogen cleared rapidly via intact host defense mechanisms. In the absence of adequate T cell function, as occurs in HIV-1-induced immunodeficiency, M. avium becomes an opportunistic infection with uncontrolled replication and reinfection of macrophage hosts. How M. avium infects, survives, and replicates in macrophages without signaling an effective microbicidal counterattack is unresolved. To address whether M. avium signals the expression of molecules, which influence mycobacterial survival or clearance, human monocyte-derived macrophage cultures were exposed to M. avium. Within minutes, M. avium, or its cell wall lipoarabinomannan, binds to the adherent macrophages and induces a spectrum of gene expression. In this innate response, the most abundant genes detected within 2 h by cDNA expression array involved proinflammatory chemokines, cytokines including TNF-α and IL-1, and adhesion molecules. Associated with this rapid initia...

The Journal of experimental medicine, 1991

The multifunctional cytokine, transforming growth factor beta (TGF-beta), was identified by immun... more The multifunctional cytokine, transforming growth factor beta (TGF-beta), was identified by immunocytochemistry in the brain tissues of four patients with acquired immune deficiency syndrome (AIDS), but not in control brain tissue. The TGF-beta staining was localized to cells of monocytic lineage as well as astrocytes, especially in areas of brain pathology. In addition, the brain tissues from the AIDS patients contained transcripts for human immunodeficiency virus 1 (HIV-1) by in situ hybridization, suggesting a correlation between the presence of HIV-1 in the brain and the expression of TGF-beta. However, the expression of TGF-beta was not limited to HIV-1-positive cells, raising the possibility of alternative mechanisms for the induction of TGF-beta in these AIDS patients' brains. To investigate these mechanisms, purified human monocytes were infected in vitro with HIV-1 and were shown to secrete increased levels of TGF-beta. In addition, HIV-1-infected monocytes released a f...

Journal of Clinical Investigation, 1991

Monocytes in the circulation of normal individuals express two receptors for the constant region ... more Monocytes in the circulation of normal individuals express two receptors for the constant region of immunoglobulin, FcyRI and FcyRII. In contrast, we have observed that AIDS monocytes express significant levels of a third FcyR, Fc'yRIII (CD16), which is normally associated with activation or maturation of the monocyte population. By dual-fluorescence analysis using a monoclonal antibody specific for FcyRIII (MAb 3G8), 38.5±3.2% of the LeuM3 (CD14)-positive monocytes in AIDS patients were CD16 positive as compared to 10.4±1.0% for healthy individuals (n = 29; P < 0.005). Furthermore, AIDS monocytes expressed FcyRIII-specific mRNA which is expressed minimally or not at all in control monocytes. As a recently identified inducer of FcyRIII expression on blood monocytes, transforming growth factor-,8 (TGF-0) was found to be elevated in the serum and/or plasma of AIDS patients. Moreover, incubation of normal monocytes with AIDS serum or plasma induced CD16 expression which correlated with serum TGF-ft levels (r = 0.74, P < 0.001) and was inhibited with a neutralizing antibody to TGF-ft. Thus, the increased CD16 expression on peripheral blood monocytes in AIDS patients may be the consequence ofelevated circulating levels ofthe polypeptide hormone TGF-ft.

Journal of Clinical Investigation, 1990

A population of circulating mononuclear cells from patients with AIDS was identified which expres... more A population of circulating mononuclear cells from patients with AIDS was identified which expressed interleukin 2 receptors (IL-2R). By dual-fluorescence flow microfluorometry, the patients' IL-2R' cells were further identified as Leu M3' monocytes (29.4±5.2% of the Leu M3' cells were IL-2R', n = 15), whereas Leu M3' monocytes from normal subjects were IL-2R negative (2.0±0.42%; P < 0.001). By Northern analysis, monocytes from AIDS patients, but not control subjects, constitutively expressed steady-state levels of IL-2R mRNA. Functionally, the IL-2R' monocytes were capable of depleting IL-2 from culture supernatants, suggesting a mechanism for the reduced IL-2 levels commonly seen in AIDS patients. IL-2R+ monocytes also expressed increased levels of surface HLA-DR which may favor monocyte T-cell interactions and the transmission of human immunodeficiency virus (HIV). In additional studies, normal monocytes were infected with a macrophage-tropic HIV isolate in vitro and monitored for IL-2R and HLA-DR expression. Within 24-48 h after exposure to HIV in vitro, but before evidence of productive infection, > 25% of the monocytes became IL-2R+ with increasing numbers of IL-2R+ cells and HLA-DR levels through day 6. These early signaling effects of HIV could be mimicked by adding purified HIV envelope glycoprotein gpl20 to the monocytes. This stimulation of monocytes before or independent of productive infection of the cells by HIV is consistent with in vivo observations of activated and/or abnormal functions by monocytes that do not appear to be infected with HIV in AIDS patients. (J. Clin. Invest. 1990. 85:192-199.) acquired immunodeficiency syndrome * human immunodeficiency virus * interleukin 2-interleukin 2 receptor * monocyte/macrophage

Journal of Autoimmunity, 2012

In periodontitis, a common chronic inflammatory condition, gram negative-rich bacterial biofilms ... more In periodontitis, a common chronic inflammatory condition, gram negative-rich bacterial biofilms trigger, in susceptible individuals, perpetuating inflammation that results in extensive tissue damage of tooth supporting structures. To delineate immune cell-dependent mechanisms whereby bacterial challenge drives persistent destructive inflammation in periodontitis and other inflammatory diseases, we studied involved tissues ex vivo and investigated host cell responses to the periodontal pathogen P. gingivalis, in vitro. Diseased lesions were populated by abundant Th17 cells, linked to infection, chronic inflammation/autoimmunity and tissue pathology. In vitro, P. gingivalis, particularly the more virulent strain W83, stimulated myeloid antigen presenting cells (APC) to drive Th17 polarization. Supernatants from myeloid APC exposed to P. gingivalis were capable of enhancing Th17 but not Th1 polarization. P. gingivalis favored the generation of Th17 responses by stimulating the production of Th17 related cytokines IL-1β, IL-6 and IL-23, but not Th1 related IL-12. By inducing NFκB activation, P. gingivalis promoted IL-1β, IL-6 and IL-12p40 production, but not IRF-3 phosphorylation, connected to generation of the IL-12p35 chain, ultimately restricting formation of the intact IL-12 molecule. Promotion of Th17 lineage responses was also aided by P. gingivalis proteases, which appeared to differentially degrade pivotal cytokines. In this regard, IL-12 was largely degraded by P. gingivalis, whereas IL-1β was more resistant to proteolysis. Our data unveil multiple pathways by which P. gingivalis may orchestrate chronic inflammation, providing insights into interventional strategies.

Blood, Aug 1, 1997

Infection of monocytes with human immunodeficiency virus the C-terminal domain contains the prote... more Infection of monocytes with human immunodeficiency virus the C-terminal domain contains the protease inhibiting retype 1 Ba-L (HIV-1 Ba-L) is significantly inhibited by treatment gion. However, when tested independently, neither domain with the serine protease inhibitor, secretory leukocyte protehad potent anti-HIV-1 activity. SLPI binding neither prease inhibitor (SLPI). SLPI does not appear to act on virus vented virus binding to monocytes nor attenuated the infecdirectly, but rather the inhibitory activity is most likely due tivity of any virus progeny that escaped inhibition by SLPI. to interaction with the host cell. The current study was initi-A polymerase chain reaction (PCR)-based assay for newly ated to investigate how SLPI interacts with monocytes to generated viral DNA demonstrated that SLPI blocks at or inhibit infection. SLPI was found to bind to monocytes with before viral DNA synthesis. Therefore, it most likely inhibits high affinity to a single class of receptor sites (Ò7,000 recepa step of viral infection that occurs after virus binding but tors per monocyte, K D ! 3.6 nmol/L). The putative SLPI rebefore reverse transcription. Taken together, the unique ceptor was identified as a surface protein with a molecular antiviral activity of SLPI, which may be independent of its weight of 55 Ô 5 kD. A well-characterized function of SLPI previously characterized antiprotease activity, appears to reis inhibition of neutrophil elastase and cathepsin G. Howside in disruption of the viral infection process soon after ever, two SLPI mutants (or muteins) that contain single virus binding. amino acid substitutions and exhibit greatly reduced prote-This is a US government work. There are no restrictions on ase inhibitory activity still bound to monocytes and retained its use. anti-HIV-1 activity. SLPI consists of two domains, of which

Journal of Clinical Investigation, Mar 1, 1997

Secretory leukocyte protease inhibitor (SLPI) is a serine protease inhibitor found in fluids lini... more Secretory leukocyte protease inhibitor (SLPI) is a serine protease inhibitor found in fluids lining mucosal surfaces. In addition to its primary function as an antiprotease, SLPI may also influence cellular functions associated with enzyme synthesis and retroviral infection. In this study, SLPI was examined for its effect on signaling events involved in the production of matrix metalloproteinases (MMPs) by monocytes. Addition of SLPI before stimulation with concanavalin A or LPS resulted in a significant inhibition of monocyte prostaglandin H synthase-2 (PGHS-2), a pivotal enzyme in the PGE 2-cAMP dependent pathway of monocyte MMP synthesis. Suppression of PGHS-2 was detected with 0.1 g/ml of SLPI with a substantial inhibition at 1 and 10 g/ml. Attenuation of PGHS-2 by SLPI was accompanied by decreased production of PGE 2 resulting in the suppression of interstitial collagenase (MMP-1) and gelatinase B (MMP-9) that was reversed by PGE 2 or Bt 2 cAMP. The inhibitory effect of SLPI was largely independent of its antiprotease activity because SLPI muteins, with significantly lower antiprotease activity, also suppressed the induction of PGHS-2 and MMPs. The inhibitory effects of SLPI did not involve the modulation of monokine production since TNF-␣ and IL-10 were unaffected. These findings demonstrate that SLPI also functions as a potent antiinflammatory agent by interfering with the signal transduction pathway leading to monocyte MMP production.

The Journal of Immunology

Oral administration of autoantigens can influence the outcome of experimental autoimmune diseases... more Oral administration of autoantigens can influence the outcome of experimental autoimmune diseases, yet little is known about nonself Ag-induced tolerance. In this study, we administered group A streptococcal cell wall (SCW) peptidoglycan-polysaccharide complexes orally and monitored the impact on SCW-induced erosive polyarthritis. Oral administration of low dose SCW (3 μg/day), initiated 7 days before an arthritogenic dose of systemic SCW, virtually eliminated the joint swelling and destruction typically observed during both the acute and chronic phases of the arthritis. High (300 μg), but not intermediate (30 μg), dose regimens also profoundly inhibited the disease. Most previous studies have demonstrated that prior feeding is required for efficacy, yet oral feeding of low dose SCW suppressed the evolution of arthritis even when administration was begun 10–15 days after induction of the arthritis. While the synovial inflammatory cell infiltration and expression of proinflammatory c...

The Journal of Immunology

Peripheral blood monocytes from AIDS patients exhibit defective migratory responses to chemotacti... more Peripheral blood monocytes from AIDS patients exhibit defective migratory responses to chemotactic stimuli in vitro and to inflammatory sites in vivo. In studies presented here, normal monocytes were infected with the HIV-1/HTLV-IIIBa-L isolate in vitro and evaluated for chemotactic responsiveness. Within 2 days after viral exposure, but before evidence of virus production in the monocytes, chemotactic activity was significantly impaired. Decreased chemotactic activity was associated with modulation of receptors for the chemotactic ligands, C5a and FMLP, on the monocyte cell surface. In addition to HIV-1, monocytes treated with purified HIV-1 envelope glycoprotein gp120 demonstrated a comparable modulation of chemotactic ligand receptors and migratory function. In addition, the HIV-1 or HIV-1 gp120-treated monocytes were induced to undergo differentiation as monitored by HLA-DR expression. Immunoprecipitation of the gp120 with a specific antibody reversed its effects on monocyte che...

Journal of Leukocyte Biology

Immunodeficiency, the consequence of HIV-1 infection, predisposes the host to opportunistic infec... more Immunodeficiency, the consequence of HIV-1 infection, predisposes the host to opportunistic infections. In turn, opportunistic pathogens influence target cell susceptibility to HIV-1 infection and replication. Although the advent of highly active antiretroviral therapy (HAART) has altered these sequelae, co-infections may prevail in some parts of the world and in failed HAART regimens. Moreover, immune activation as occurs in tonsil and non-infectious mucosal inflammatory lesions may also be associated with proximal sites of viral replication. These connections between enhancement of HIV-1 infection and activation/inflammation warrant further elucidation of the factors promoting permissiveness to HIV-1 infection. Using the opportunistic pathogen Mycobacterium avium as an in vitro model, we demonstrated that co-infection facilitated HIV-1 infection of monocyte-macrophages by multiple pathways. M. avium activated NF-κB, the downstream consequences of which included augmented expressio...

Journal of Virology, 1991

The induction of interferon (IFN) by human immunodeficiency virus type 1 (HIV-1) in primary, nons... more The induction of interferon (IFN) by human immunodeficiency virus type 1 (HIV-1) in primary, nonstimulated monocyte-macrophage cultures was studied. HIV-1 infection, as confirmed by p24 antigen levels in the cell supernatant, led to the production of alpha interferon (IFN-alpha) over 7 to 21 days following infection. In two of seven experiments, the IFN detected was acid labile. Coupled reverse transcription-polymerase chain reaction analysis confirmed the induction of IFN-alpha mRNA in cells of HIV-1-infected cultures.

Journal of Leukocyte Biology, 2014

ABSTRACTSLPI, a potent epithelial and myeloid-derived serine protease inhibitor with antimicrobia... more ABSTRACTSLPI, a potent epithelial and myeloid-derived serine protease inhibitor with antimicrobial and anti-inflammatory functions, is induced by the intracellular parasite Leishmania major, and increased SLPI expression is evident within lesions that follow L. major infection. In contrast to self-resolving infection in C57Bl/6 WT mice, Slpi−/− mice launch a strong Th1 response to L. major, yet fail to control infection and develop destructive, nonhealing lesions with systemic spread of parasites. Because SLPI is both produced by murine macrophages and antagonizes their function, we examined the contribution of macrophage polarization to the defective host response in the absence of SLPI. Slpi−/− and Slpi+/+ macrophages were first primed with either IFNγ or IL-4 to generate classically activated M1 or alternatively activated M2 macrophages. After infection with L. major, Slpi−/− M1 macrophages expressed elevated iNOS RNA, whereas arginase was more highly expressed in WT than Slpi−/−...

Proceedings of the National Academy of Sciences, 1998

Infection with HIV-1 results in pronounced immune suppression and susceptibility to opportunistic... more Infection with HIV-1 results in pronounced immune suppression and susceptibility to opportunistic infections (OI). Reciprocally, OI augment HIV-1 replication. As we have shown forMycobacterium aviumcomplex (MAC) andPneumocystis carinii, macrophages infected with opportunistic pathogens and within lymphoid tissues containing OI, exhibit striking levels of viral replication. To explore potential underlying mechanisms for increased HIV-1 replication associated with coinfection, blood monocytes were exposed to MAC antigens (MAg) or viable MAC and their levels of tumor necrosis factor α (TNFα) and HIV-1 coreceptors monitored. MAC enhanced TNFα productionin vitro, consistent with its expression in coinfected lymph nodes. Using a polyclonal antibody to the CCR5 coreceptor that mediates viral entry of macrophage tropic HIV-1, a subset of unstimulated monocytes was shown to be CCR5-positive by fluorescence-activated cell sorter analysis. After stimulation with MAg or infection with MAC, CCR5...

Proceedings of the National Academy of Sciences, 1989

Dipyridamole (DPM) is commonly used as a coronary vasodilator and inhibitor of platelet aggregati... more Dipyridamole (DPM) is commonly used as a coronary vasodilator and inhibitor of platelet aggregation in the treatment of cardiovascular diseases. We report here that DPM potentiates the inhibitory effects of 3'-azido-3'-deoxythymidine (AZT) and 2',3'-dideoxycytidine against human immunodeficiency virus type 1 (HIV-1) in human monocyte-macrophages. At the same concentrations, DPM does not potentiate the toxic effects of AZT on these cells or on human bone marrow (granulocyte-monocyte) progenitor cells. Since monocyte-macrophage lineage cells appear to be the major reservoir for HIV-1 in vivo, these findings suggest the possibility of using DPM or its analogues in combination chemotherapy of HIV infections.

Journal of Virology, 2005

ABSTRACTIn contrast to CD4+T cells, human immunodeficiency virus type 1 (HIV-1)-infected macropha... more ABSTRACTIn contrast to CD4+T cells, human immunodeficiency virus type 1 (HIV-1)-infected macrophages typically resist cell death, support viral replication, and consequently, may facilitate HIV-1 transmission. To elucidate how the virus commandeers the macrophage's intracellular machinery for its benefit, we analyzed HIV-1-infected human macrophages for virus-induced gene transcription by using multiple parameters, including cDNA expression arrays. HIV-1 infection induced the transcriptional regulation of genes associated with host defense, signal transduction, apoptosis, and the cell cycle, among which the cyclin-dependent kinase inhibitor 1A (CDKN1A/p21) gene was the most prominent. p21 mRNA and protein expression followed a bimodal pattern which was initially evident during the early stages of infection, and maximum levels occurred concomitant with active HIV-1 replication. Mechanistically, viral protein R (Vpr) independently regulates p21 expression, consistent with the redu...

Journal of Leukocyte Biology, 2003

Human immunodeficiency virus type 1 (HIV-1) infection of CD4+ T lymphocytes leads to their progre... more Human immunodeficiency virus type 1 (HIV-1) infection of CD4+ T lymphocytes leads to their progressive loss, whereas HIV-1-infected macrophages appear to resist HIV-1-mediated apoptotic death. The differential response of these two host-cell populations may be critical in the development of immunodeficiency and long-term persistence of the virus. Multiple contributing factors may favor the macrophage as a resilient host, not only supporting infection by HIV-1 but also promoting replication and persistence of this member of the lentivirus subfamily of primate retroviruses. An encounter between macrophages and R5 virus engages a signal cascade eventuating in transcriptional regulation of multiple genes including those associated with host defense, cell cycle, nuclear factor-κB regulation, and apoptosis. It is important that enhanced gene expression is transient, declining to near control levels, and during this quiescent state, the virus continues its life cycle unimpeded. However, wh...

Journal of Leukocyte Biology, 2006

Cell surface and intracellular proteins in macrophages influence various steps in the life cycle ... more Cell surface and intracellular proteins in macrophages influence various steps in the life cycle of lentiviruses. Characterization of these restriction and/or cofactors is essential to understanding how macrophages become unwitting HIV hosts and in fact, can coexist with a heavy viral burden. Although many of the cellular pathways co-opted by HIV in macrophages mimic those seen in CD4+ T cells, emerging evidence reveals cellular constituents of the macrophage, which may be uniquely usurped by HIV. For example, in addition to CD4 and CCR5, membrane annexin II facilitates early steps in infection of macrophages, but not in T cells. Blockade of this pathway effectively diminishes macrophage infection. Viral binding engages a macrophage-centric signaling pathway and a transcriptional profile, including genes such as p21, which benefit the virus. Once inside the cell, multiple host cell molecules are engaged to facilitate virus replication and assembly. Although the macrophage is an enab...

Journal of Leukocyte Biology, 2006

Mycobacterium avium is an opportunistic pathogen that commonly infects individuals colonized with... more Mycobacterium avium is an opportunistic pathogen that commonly infects individuals colonized with HIV-1, although it is less frequent in the post-HAART era. These microorganisms invade macrophages after interacting with TLR2 and/or CD14 co-receptors, but signaling pathways promoting survival in macrophages are not well defined. Although IFN-γ plays an important role in protective immunity against bacterial infections, IFN-γ responses are compromised in AIDS patients and evidence suggests that exogenous IFN-γ is inadequate to clear the mycobacteria. To determine the mechanism by which M. avium survives intracellularly, even in the presence of IFN-γ, we studied the effect of mycobacteria infection in macrophages during early IFN-γ signaling events. M. avium infected cells exhibited a reduced response to IFN-γ, with suppressed phosphorylation of STAT-1 compared with uninfected cells. Interaction of M. avium with macrophage receptors increased gene expression of the suppressors of cytok...

The Journal of Infectious Diseases, 1999

Human immunodeficiency virus type 1 (HIV-1) infection is dependent on susceptible host cells that... more Human immunodeficiency virus type 1 (HIV-1) infection is dependent on susceptible host cells that express both CD4 and chemokine co-receptors. The co-receptor CCR5 is associated with primary infection by macrophage-tropic virus isolates, whereas CXCR4 is commonly associated with T cell-and dual-tropic viruses. Once infected, lymphocytes and macrophages may replicate HIV-1 or harbor latent virus, depending on environmental factors and cellular activation. Immune activation is often associated with viremia, which is consistent with enhanced infection and viral replication in activated cells harboring virus. In this regard, opportunistic infections activate the immune system with the detrimental sequelae of enhanced viral replication and viremia. Under these conditions, viral expansion extends beyond T cells to tissue macrophages, many of which are co-infected with opportunistic pathogens. The opportunistic infections promote macrophage susceptibility to HIV-1 through cytokine modulation and altered chemokine co-receptors, potential targets for intervention.

The Journal of Immunology, 2002

In lymphoid tissues coinfected with Mycobacterium avium complex (MAC) and HIV-1, increased viral ... more In lymphoid tissues coinfected with Mycobacterium avium complex (MAC) and HIV-1, increased viral replication has been observed. This study investigates the role of MAC in perpetuating both infections through the recruitment of monocytes as potential new hosts for bacteria and HIV-1. Increased numbers of macrophages were present in the lymph nodes of patients with dual infection as compared with lymph nodes from HIV+ patients with no known opportunistic pathogens. In a coculture system, monocyte-derived macrophages were treated with HIV-1 or M. avium and its constituents to further define the mechanism whereby MAC infection of macrophages initiates monocyte migration. Monocyte-derived macrophages treated with bacteria or bacterial products, but not HIV-1, induced a rapid 2- to 3-fold increase in recruitment of monocytes. Pretreatment of the monocytes with pertussis toxin inhibited the migration of these cells, indicating a G protein-linked pathway is necessary for induction of chemot...

The Journal of Immunology, 2002

Mycobacterium avium is a facultative intracellular pathogen cleared rapidly via intact host defen... more Mycobacterium avium is a facultative intracellular pathogen cleared rapidly via intact host defense mechanisms. In the absence of adequate T cell function, as occurs in HIV-1-induced immunodeficiency, M. avium becomes an opportunistic infection with uncontrolled replication and reinfection of macrophage hosts. How M. avium infects, survives, and replicates in macrophages without signaling an effective microbicidal counterattack is unresolved. To address whether M. avium signals the expression of molecules, which influence mycobacterial survival or clearance, human monocyte-derived macrophage cultures were exposed to M. avium. Within minutes, M. avium, or its cell wall lipoarabinomannan, binds to the adherent macrophages and induces a spectrum of gene expression. In this innate response, the most abundant genes detected within 2 h by cDNA expression array involved proinflammatory chemokines, cytokines including TNF-α and IL-1, and adhesion molecules. Associated with this rapid initia...

The Journal of experimental medicine, 1991

The multifunctional cytokine, transforming growth factor beta (TGF-beta), was identified by immun... more The multifunctional cytokine, transforming growth factor beta (TGF-beta), was identified by immunocytochemistry in the brain tissues of four patients with acquired immune deficiency syndrome (AIDS), but not in control brain tissue. The TGF-beta staining was localized to cells of monocytic lineage as well as astrocytes, especially in areas of brain pathology. In addition, the brain tissues from the AIDS patients contained transcripts for human immunodeficiency virus 1 (HIV-1) by in situ hybridization, suggesting a correlation between the presence of HIV-1 in the brain and the expression of TGF-beta. However, the expression of TGF-beta was not limited to HIV-1-positive cells, raising the possibility of alternative mechanisms for the induction of TGF-beta in these AIDS patients' brains. To investigate these mechanisms, purified human monocytes were infected in vitro with HIV-1 and were shown to secrete increased levels of TGF-beta. In addition, HIV-1-infected monocytes released a f...

Journal of Clinical Investigation, 1991

Monocytes in the circulation of normal individuals express two receptors for the constant region ... more Monocytes in the circulation of normal individuals express two receptors for the constant region of immunoglobulin, FcyRI and FcyRII. In contrast, we have observed that AIDS monocytes express significant levels of a third FcyR, Fc'yRIII (CD16), which is normally associated with activation or maturation of the monocyte population. By dual-fluorescence analysis using a monoclonal antibody specific for FcyRIII (MAb 3G8), 38.5±3.2% of the LeuM3 (CD14)-positive monocytes in AIDS patients were CD16 positive as compared to 10.4±1.0% for healthy individuals (n = 29; P < 0.005). Furthermore, AIDS monocytes expressed FcyRIII-specific mRNA which is expressed minimally or not at all in control monocytes. As a recently identified inducer of FcyRIII expression on blood monocytes, transforming growth factor-,8 (TGF-0) was found to be elevated in the serum and/or plasma of AIDS patients. Moreover, incubation of normal monocytes with AIDS serum or plasma induced CD16 expression which correlated with serum TGF-ft levels (r = 0.74, P < 0.001) and was inhibited with a neutralizing antibody to TGF-ft. Thus, the increased CD16 expression on peripheral blood monocytes in AIDS patients may be the consequence ofelevated circulating levels ofthe polypeptide hormone TGF-ft.

Journal of Clinical Investigation, 1990

A population of circulating mononuclear cells from patients with AIDS was identified which expres... more A population of circulating mononuclear cells from patients with AIDS was identified which expressed interleukin 2 receptors (IL-2R). By dual-fluorescence flow microfluorometry, the patients' IL-2R' cells were further identified as Leu M3' monocytes (29.4±5.2% of the Leu M3' cells were IL-2R', n = 15), whereas Leu M3' monocytes from normal subjects were IL-2R negative (2.0±0.42%; P < 0.001). By Northern analysis, monocytes from AIDS patients, but not control subjects, constitutively expressed steady-state levels of IL-2R mRNA. Functionally, the IL-2R' monocytes were capable of depleting IL-2 from culture supernatants, suggesting a mechanism for the reduced IL-2 levels commonly seen in AIDS patients. IL-2R+ monocytes also expressed increased levels of surface HLA-DR which may favor monocyte T-cell interactions and the transmission of human immunodeficiency virus (HIV). In additional studies, normal monocytes were infected with a macrophage-tropic HIV isolate in vitro and monitored for IL-2R and HLA-DR expression. Within 24-48 h after exposure to HIV in vitro, but before evidence of productive infection, > 25% of the monocytes became IL-2R+ with increasing numbers of IL-2R+ cells and HLA-DR levels through day 6. These early signaling effects of HIV could be mimicked by adding purified HIV envelope glycoprotein gpl20 to the monocytes. This stimulation of monocytes before or independent of productive infection of the cells by HIV is consistent with in vivo observations of activated and/or abnormal functions by monocytes that do not appear to be infected with HIV in AIDS patients. (J. Clin. Invest. 1990. 85:192-199.) acquired immunodeficiency syndrome * human immunodeficiency virus * interleukin 2-interleukin 2 receptor * monocyte/macrophage

Journal of Autoimmunity, 2012

In periodontitis, a common chronic inflammatory condition, gram negative-rich bacterial biofilms ... more In periodontitis, a common chronic inflammatory condition, gram negative-rich bacterial biofilms trigger, in susceptible individuals, perpetuating inflammation that results in extensive tissue damage of tooth supporting structures. To delineate immune cell-dependent mechanisms whereby bacterial challenge drives persistent destructive inflammation in periodontitis and other inflammatory diseases, we studied involved tissues ex vivo and investigated host cell responses to the periodontal pathogen P. gingivalis, in vitro. Diseased lesions were populated by abundant Th17 cells, linked to infection, chronic inflammation/autoimmunity and tissue pathology. In vitro, P. gingivalis, particularly the more virulent strain W83, stimulated myeloid antigen presenting cells (APC) to drive Th17 polarization. Supernatants from myeloid APC exposed to P. gingivalis were capable of enhancing Th17 but not Th1 polarization. P. gingivalis favored the generation of Th17 responses by stimulating the production of Th17 related cytokines IL-1β, IL-6 and IL-23, but not Th1 related IL-12. By inducing NFκB activation, P. gingivalis promoted IL-1β, IL-6 and IL-12p40 production, but not IRF-3 phosphorylation, connected to generation of the IL-12p35 chain, ultimately restricting formation of the intact IL-12 molecule. Promotion of Th17 lineage responses was also aided by P. gingivalis proteases, which appeared to differentially degrade pivotal cytokines. In this regard, IL-12 was largely degraded by P. gingivalis, whereas IL-1β was more resistant to proteolysis. Our data unveil multiple pathways by which P. gingivalis may orchestrate chronic inflammation, providing insights into interventional strategies.