P19-50 LB. Role of vaccine-induced innate and adaptive immunity in controlling mucosal transmission of SIV in macaques (original) (raw)
Related papers
Proceedings of the National Academy of Sciences, 2010
Adjuvant effects on innate as well as adaptive immunity may be critical for inducing protection against mucosal HIV and simian immunodeficiency virus (SIV) exposure. We therefore studied effects of Toll-like receptor agonists and IL-15 as mucosal adjuvants on both innate and adaptive immunity in a peptide/poxvirus HIV/SIV mucosal vaccine in macaques, and made three critical observations regarding both innate and adaptive correlates of protection: (i) adjuvant-alone without vaccine antigen impacted the intrarectal SIVmac251 challenge outcome, correlating with surprisingly long-lived APOBEC3G (A3G)-mediated innate immunity; in addition, even among animals receiving vaccine with adjuvants, viral load correlated inversely with A3G levels; (ii) a surprising threshold-like effect existed for vaccine-induced adaptive immunity control of viral load, and only antigen-specific polyfunctional CD8 + T cells correlated with protection, not tetramer + T cells, demonstrating the importance of T-cell quality; (iii) synergy was observed between Toll-like receptor agonists and IL-15 for driving adaptive responses through the up-regulation of IL-15Rα, which can present IL-15 in trans, as well as for driving the innate A3G response. Thus, strategic use of molecular adjuvants can provide better mucosal protection through induction of both innate and adaptive immunity. APOBEC3G | HIV vaccine | Toll-like receptor agonist | IL-15 | Polyfunctional T cells
Vaccine, 2011
Adjuvant plays an important role in increasing and directing vaccine-induced immune responses. In a previous study, we found that a mucosal SIV vaccine using a combination of IL-15 and TLR agonists as adjuvant mediated partial protection against SIVmac251 rectal challenge, whereas neither IL-15 nor TLR agonists alone as an adjuvant impacted the plasma viral loads. In this study, dissociation of CD4 + T cell preservation with viral loads was observed in the animals vaccinated with adjuvants. Significantly higher levels of memory CD4 + T cell numbers were preserved after SIVmac251 infection in the colons of the animals vaccinated with vaccine containing any of these adjuvants compared to no adjuvant. When we measured the viral-specific CD8 + tetramer responses in the colon lamina propria, we found significantly higher levels of gag, tat, and pol epitope tetramer + T cell responses in these animals compared to ones without adjuvant, even if some of the animals had similarly high viral loads. Furthermore, this CD4 + T preservation was positively correlated with increased levels of gag and Tat, but not pol tetramer + T cell responses, and inversely correlated with beta-chemokine expression. The pre-challenged APOBEC3G expression level, which has previously been shown inversely associated with viral loads, was further found positively correlated with CD4 + T cell number preservation. Overall, these data highlight one unrecognized role of adjuvant in HIV vaccine development, and show that vaccines can produce a surprising discordance between CD4 + T cell levels and SIV viral load.
Utilizing IL12, IL15 and IL7 as Mucosal Vaccine Adjuvants
Letters in Drug Design & Discovery, 2006
In this paper we review and discuss three of the most exciting and promising cytokines for therapeutic intervention and immunomodulation of immune responses including those on mucosal surfaces. The main properties of IL-12, IL-15 and IL-7 are described and the studies utilizing these cytokines as immunomodulators and vaccine adjuvants discussed.
PLoS ONE, 2012
Immunotherapies that induce durable immune control of chronic HIV infection may eliminate the need for life-long dependence on drugs. We investigated a DNA vaccine formulated with a novel genetic adjuvant that stimulates immune responses in the blood and gut for the ability to improve therapy in rhesus macaques chronically infected with SIV. Using the SIV-macaque model for AIDS, we show that epidermal co-delivery of plasmids expressing SIV Gag, RT, Nef and Env, and the mucosal adjuvant, heat-labile E. coli enterotoxin (LT), during antiretroviral therapy (ART) induced a substantial 2-4-log fold reduction in mean virus burden in both the gut and blood when compared to unvaccinated controls and provided durable protection from viral rebound and disease progression after the drug was discontinued. This effect was associated with significant increases in IFN-c T cell responses in both the blood and gut and SIV-specific CD8+ T cells with dual TNF-a and cytolytic effector functions in the blood. Importantly, a broader specificity in the T cell response seen in the gut, but not the blood, significantly correlated with a reduction in virus production in mucosal tissues and a lower virus burden in plasma. We conclude that immunizing with vaccines that induce immune responses in mucosal gut tissue could reduce residual viral reservoirs during drug therapy and improve long-term treatment of HIV infection in humans.
Journal of Clinical Investigation, 1998
Although crucial to mucosal vaccine development, the mechanisms of defense against mucosal viral infection are still poorly understood. Protection, cytotoxic T lymphocytes (CTL), and neutralizing antibodies have all been observed, but cause and effect have been difficult to determine. The ability of CTL in the mucosa to mediate protection against mucosal viral transmission has never been proven. Here, we use an HIV peptide immunogen and an HIV-1 gp160expressing recombinant vaccinia viral intrarectal murine challenge system, in which neutralizing antibodies do not play a role, to demonstrate for the first time that long-lasting immune resistance to mucosal viral transmission can be accomplished by CD8 ϩ CTL that must be present in the mucosal site of exposure. The resistance is ablated by depleting CD8 ϩ cells in vivo and requires CTL in the mucosa, whereas systemic (splenic) CTL are shown to be unable to protect against mucosal challenge. Furthermore, the resistance as well as the CTL response can be increased by local mucosal delivery of IL-12 with the vaccine. These results imply that induction of local mucosal CTL may be critical for success of a vaccine against viruses transmitted through a mucosal route, such as HIV.
Vaccine, 2009
APOBEC3G is an innate intracellular anti-viral factor which deaminates retroviral cytidine to uridine. In vivo studies of APOBEC3G (A3G) were carried out in rhesus macaques, following mucosal immunization with SIV antigens and CCR5 peptides, linked to the 70kD heat shock protein. A progressive increase in A3G mRNA was elicited in PBMC after each immunization (p<0.0002 to p≤0.02), which was maintained for at least 17 weeks. Analysis of memory T cells showed a significant increase in A3G mRNA and protein in CD4 + CCR5 + memory T cells in circulating (p=0.0001), splenic (p=0.0001), iliac lymph nodes (p=0.002) and rectal (p=0.01) cells of the immunized compared with unimmunized macaques. Mucosal challenge with SIVmac 251 showed a significant increase in A3G mRNA in the CD4 + CCR5 + circulating cells (p<0.01) and the draining iliac lymph node cells (p<0.05) in the immunized uninfected macaques, consistent with a protective effect exerted by A3G. The results suggest that mucosal immunization in a non-human primate can induce features of a memory response to an innate anti-viral factor in CCR5 + CD4 + memory and CD4 + CD95 + CCR7 − effector memory T cells.
Adjuvants modulating mucosal immune responses or directing systemic responses towards the mucosa
Veterinary Research, 2006
In developing veterinary mucosal vaccines and vaccination strategies, mucosal adjuvants are one of the key players for inducing protective immune responses. Most of the mucosal adjuvants seem to exert their effect via binding to a receptor/or target cells and these properties were used to classify the mucosal adjuvants reviewed in the present paper: (1) ganglioside receptor-binding toxins (cholera toxin, LT enterotoxin, their B subunits and mutants); (2) surface immunoglobulin binding complex CTA1-DD; (3) TLR4 binding lipopolysaccharide; (4) TLR2-binding muramyl dipeptide; (5) Mannose receptor-binding mannan; (6) Dectin-1-binding ß 1,3/1,6 glucans; (7) TLR9-binding CpG-oligodeoxynucleotides; (8) Cytokines and chemokines; (9) Antigen-presenting cell targeting ISCOMATRIX and ISCOM. In addition, attention is given to two adjuvants able to prime the mucosal immune system following a systemic immunization, namely 1α, 25(OH) 2 D 3 and cholera toxin.
Journal of Virology, 2002
Here we designed a study in macaques carrying the major histocompatibility complex class I Mamu-A10ء molecule to assess the capacity of the highly attenuated poxvirus NYVAC/simian immunodeficiency virus (SIV) SIV gpe vaccine candidate administered by the intranasal, intramuscular, or intrarectal route to induce mucosal immunity. All macaques, including one naive macaque, were exposed to SIV mac251 by the intrarectal route and sacrificed 48 h after infection. The kinetics of immune response at various time points following immunization with NYVAC/SIV gpe and the anamnestic response to SIV mac251 at 48 h after challenge were assessed in blood, in serial rectal and vaginal biopsy samples, and in tissues at euthanasia with an SIV mac Gag-specific tetramer. In addition, at euthanasia, antigen-specific cells producing gamma interferon or tumor necrosis factor alpha from the jejunum lamina propria were quantified in all macaques. Surprisingly, antigenspecific CD8 ؉ T cells were found in the mucosal tissues of all immunized macaques regardless of whether the vaccine was administered by a mucosal route (intranasal or intrarectal) or systemically. In addition, following mucosal SIV mac251 challenge, antigen-specific responses were mainly confined to mucosal tissues, again regardless of the route of immunization. We conclude that immunization with a live vector vaccine results in the appearance of CD8 ؉ T-cell responses at mucosal sites even when the vaccine is delivered by nonmucosal routes.
Clinical immunology (Orlando, Fla.), 2014
High-level T cell expression of PD-1 during SIV infection is correlated with impaired proliferation and function. We evaluated the phenotype and distribution of T cells and Tregs during antiretroviral therapy plus PD-1 modulation (using a B7-DC-Ig fusion protein) and post-ART. Chronically SIV-infected rhesus macaques received: 11 weeks of ART (Group A); 11 weeks of ART plus B7-DC-Ig (Group B); 11 weeks of ART plus B7-DC-Ig, then 12 weeks of B7-DC-Ig alone (Group C). Continuous B7-DC-Ig treatment (Group C) decreased rebound viremia post-ART compared to pre-ART levels, associated with decreased PD-1 hi expressing T cells and Tregs in PBMCs, and PD-1 hi Tregs in lymph nodes. It transiently decreased expression of Ki67 and α 4 β 7 in PBMC CD4 þ and CD8 þ Tregs for up to 8 weeks post-ART and maintained Ag-specific T-cell responses at low levels. Continued immune modulation targeting PD-1 hi cells during and post-ART helps maintain lower viremia, keeps a favorable T cell/Treg repertoire and modulates antigen-specific responses.