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Papers by Keith Crawford

The Journal of Immunology

Low levels of CD2 have been described on subsets of monocytes, macrophages, and dendritic cells. ... more Low levels of CD2 have been described on subsets of monocytes, macrophages, and dendritic cells. CD2 is expressed on about one-third of circulating monocytes, at levels one-half log lower than on T or NK cells, representing 2–4% of PBMC. FACS analysis of CD2+ and CD2− monocytes revealed no significant difference in the expression of adhesion molecules (CD11a/b/c), class II Ags (HLA-DR, -DQ, -DP), myeloid Ags (CD13, CD14, CD33), or costimulatory molecules (CD80, CD86). Freshly isolated CD2+ and CD2− monocytes were morphologically indistinguishable by phase contrast microscopy. However, scanning electron microscopy revealed large prominent ruffles on CD2+ monocytes in contrast to small knob-like projections on CD2− monocytes. After 2 days of culture, the CD2+ monocytes largely lost CD14 expression and developed distinct dendrites, whereas the CD2− monocytes retained surface CD14 and remained round or oval. Freshly isolated CD2+ monocytes were more potent inducers of the allogeneic MLR...

Level of Cathepsin S, whose expression was previously validated in atherosclerosis, was also exam... more Level of Cathepsin S, whose expression was previously validated in atherosclerosis, was also examined in femoral atherosclerotic lesions. Beta – actin served as a loading control.<b>Copyright information:</b>Taken from "Peripheral arterial occlusive disease: Global gene expression analyses suggest a major role for immune and inflammatory responses"http://www.biomedcentral.com/1471-2164/9/369BMC Genomics 2008;9():369-369.Published online 1 Aug 2008PMCID:PMC2529314.

Abstract : The Mustard Consortium (MC) consists of Amaox, Ltd., University of Michigan, and Cente... more Abstract : The Mustard Consortium (MC) consists of Amaox, Ltd., University of Michigan, and Center for Blood Research, East Tennessee State University, Meharry Medical College and Institute for Chemical Defense. It was developed in order to take advantage of the core competencies of each investigator and institution; as well as creating a learning organization. The creation of this type of organization has allowed us to have an unparallel insight into the pathophysiology of mustards; as well as redox regulated mediated pathways that have much larger implication in the pathogenesis of disease. The MC has used a systemic approach for the elucidation of the pathophysiology of the mustard analogue CEES (2-chloroethyl ethyl sulfur); and the development of methods of intervention (potential treatments). Both in vitro and in vivo models were used by the various investigators. One investigator used human primary myeloid cells for his investigation. The success of this approach will be evident to the reader in examination of the methods of interventions that have been developed, and will continue to evolve. It is anticipated that of these several methods of experimental intervention a few will be developed into treatment regimen.

An Overview of the Continuation of the Work of the Mustard Gass Consortium for the Use of the Fre... more An Overview of the Continuation of the Work of the Mustard Gass Consortium for the Use of the Free and Liposome Encapsulated Antioxidants as a Counter Measure to Mustard.

Journal of Virology, 2003

Small interfering RNAs (siRNAs) can induce potent gene silencing by degradation of cognate mRNA. ... more Small interfering RNAs (siRNAs) can induce potent gene silencing by degradation of cognate mRNA. However, in dividing cells, the silencing lasts only 3 to 7 days, presumably because of siRNA dilution with cell division. Here, we investigated if sustained siRNA-mediated silencing of human immunodeficiency virus type 1 (HIV-1) is possible in terminally differentiated macrophages, which constitute an important reservoir of HIV in vivo. CCR5, the major HIV-1 coreceptor in macrophages, and the viral structural gene for p24 were targeted either singly or in combination. When transfected 2 days prior to infection, both CCR5 and p24 siRNAs effectively reduced HIV-1 infection for the entire 15-day period of observation, and combined targeting of both genes abolished infection. To investigate whether exogenously introduced siRNA is maintained stably in macrophages, we tested the kinetics of siRNA-mediated viral inhibition by initiating infections at various times (2 to 15 days) after transfec...

The Journal of Infectious Diseases, 2002

Macrophages, microglia, and other mononuclear phagocytes serve as cellular reservoirs for viral p... more Macrophages, microglia, and other mononuclear phagocytes serve as cellular reservoirs for viral persistence in patients with acquired immunodeficiency syndrome. To understand host mechanisms that affect human immunodeficiency virus type 1 (HIV-1) pathogenesis by modulating expression of coreceptors, cytokine regulation of CC chemokine receptor 5 (CCR5) and CD4 expression on monocytes, monocyte-derived macrophages (MDMs), and microglia was investigated. Interleukin (IL)-4 and IL-10 enhanced the entry and replication of HIV-1 in microglia through up-regulation of CD4 and CCR5 expression, respectively. IL-4 stimulated HIV-1 replication in MDMs but down-regulated CD4 and CCR5 expression and inhibited virus entry, whereas IL-10 had the opposite effects. Thus, mechanisms independent of CCR5 and CD4 expression levels are involved in pathways that regulate HIV-1 replication in MDMs. CCR5 up-regulation by IL-10 was associated with increased migration of microglia in response to macrophage inflammatory protein-1b. These findings suggest that increased production of T helper type 2 cytokines in the later stages of disease can enhance virus entry and replication in mononuclear phagocytes and facilitate chemotactic migration.

Journal of Immunotherapy, 2012

The fowl pox vector expressing the tumor associated antigens MUC1 and CEA in the context of costi... more The fowl pox vector expressing the tumor associated antigens MUC1 and CEA in the context of costimulatory molecules (rF-PANVAC) has shown promise as a tumor vaccine. However, vaccine mediated expansion of suppressor T cell populations may blunt clinical efficacy. We characterized the cellular immune response induced by ex-vivo dendritic cells (DCs) transduced with (rF)-PANVAC. Consistent with the functional characteristics of potent antigen presenting cells, rF-PANVAC-DCs demonstrated strong expression of MUC1 and CEA and costimulatory molecules, CD80, CD86, and CD83; decreased levels of phosphorylated STAT3, and increased levels of Tyk2, JAK2 and STAT1. rF-PANVAC-DCs stimulated expansion of tumor antigen specific T cells with potent cytolytic capacity. However, rF-PANVAC transduced DCs also induced the concurrent expansion of FOXP3 expressing CD4 + CD25 +high regulatory T cells (Tregs) that inhibited T cell activation. Moreover, Tregs expressed high levels of Th2 cytokines (IL-10, IL-4, IL-5, and IL-13) together with phosphorylated STAT3 and STAT6. In contrast, the vaccine expanded Treg population expressed high levels of Th1 cytokines IL-2 and IFNγ and the proinflammatory RORγt and IL-17A suggesting that these cells may share effector functions with conventional T H 17 T cells. These data suggest that Tregs expanded by rF-PANVAC-DCs, exhibit immunosuppressive properties potentially mediated by Th2 cytokines, but simultaneous expression of Th1 and Th17 associated factors suggests a high degree of plasticity.

The Journal of Immunology, 2005

The MUC1 transmembrane mucin is expressed on the surface of activated human T cells; however, the... more The MUC1 transmembrane mucin is expressed on the surface of activated human T cells; however, the physiologic signals responsible for the regulation of MUC1 in T cells are not known. The present studies demonstrate that IL-7, but not IL-2 or IL-4, markedly induces MUC1 expression on CD3+ T cells. MUC1 was also up-regulated by IL-15, but to a lesser extent than that found with IL-7. The results show that IL-7 up-regulates MUC1 on CD4+, CD8+, CD25+, CD69+, naive CD45RA+, and memory CD45RO+ T cells. In concert with induction of MUC1 expression by IL-7, activated dendritic cells (DC) that produce IL-7 up-regulate MUC1 on allogeneic CD3+ T cells. DC also induce MUC1 expression on autologous CD3+ T cells in the presence of recall Ag. Moreover, DC-induced MUC1 expression on T cells is blocked by a neutralizing anti-IL-7 Ab. The results also demonstrate that DC induce polarization of MUC1 on T cells at sites opposing the DC-T cell synapse. These findings indicate that DC-mediated activation...

The Journal of Immunology, 2008

Vaccination of patients with dendritic cell (DC)/breast carcinoma fusions stimulated antitumor im... more Vaccination of patients with dendritic cell (DC)/breast carcinoma fusions stimulated antitumor immune responses in a majority of patients with metastatic disease but only a subset demonstrate evidence of tumor regression. To define the factors that limit vaccine efficacy, we examined the biological characteristics of DC/breast carcinoma fusions as APCs and the nature of the vaccine-mediated T cell response. We demonstrate that fusion of DCs with breast carcinoma cells up-regulates expression of costimulatory and maturation markers and results in high levels of expression of IL-12 consistent with their role as activated APCs. Fusion cells also express the chemokine receptor CCR7, consistent with their ability to migrate to the draining lymph node. However, DC/breast cancer fusions stimulate a mixed T cell response characterized by the expansion of both activated and regulatory T cell populations, the latter of which is characterized by expression of CTLA-4, FOXP3, IL-10, and the supp...

BMC Genomics, 2008

Background Peripheral arterial disease (PAD), a major manifestation of atherosclerosis, is associ... more Background Peripheral arterial disease (PAD), a major manifestation of atherosclerosis, is associated with significant cardiovascular morbidity, limb loss and death. However, mechanisms underlying the genesis and progression of the disease are far from clear. Genome-wide gene expression profiling of clinical samples may represent an effective approach to gain relevant information. Results After histological classification, a total of 30 femoral artery samples, including 11 intermediate lesions, 14 advanced lesions and 5 normal femoral arteries, were profiled using Affymetrix microarray platform. Following real-time RT-PCR validation, different algorithms of gene selection and clustering were applied to identify differentially expressed genes. Under a stringent cutoff, i.e., a false discovery rate (FDR) <0.5%, we found 366 genes were differentially regulated in intermediate lesions and 447 in advanced lesions. Of these, 116 genes were overlapped between intermediate and advanced l...

Blood, 2003

We have shown previously that primary dendritic cells and monocytes express equal levels of CD14 ... more We have shown previously that primary dendritic cells and monocytes express equal levels of CD14 but are distinguishable by the presence of CD2 on dendritic cells. CD2 is known to mediate the activation of T and natural killer (NK) cells through its interaction with CD58. CD2 epitopes recognized by anti-T111, -T112, and -T113 monoclonal antibodies (mAbs) are present on dendritic cells. Here we show that CD2 engagement significantly increases class II, costimulatory (CD40, CD80, CD86), adhesion (CD54, CD58), and CCR7 molecule expression on primary dendritic cells. Conversely, minimal or no change in the expression of the above antigens occurs on monocyte-derived dendritic cells, because these molecules are already maximally expressed. However, both kinds of dendritic cells release interleukin-1β (IL-1β) and IL-12 after CD2 engagement. Lastly, interference with dendritic cell CD2–T-cell CD58 engagement decreases naive CD4+CD45RA+ T-cell proliferation. Collectively, our results suggest...