Generation of functionally active HIV-1 specific CD8+ CTL in intestinal mucosa following mucosal, systemic or mixed prime-boost immunization

Molecular Immunogenetics and Vaccine Research Section, Vaccine Branch, CCR, NCI, NIH, Bethesda, MD 20892, USA
Virology (Impact Factor: 3.32). 10/2008; 381(1):106-15. DOI: 10.1016/j.virol.2008.08.019
Source: PubMed

ABSTRACT Gastrointestinal and vaginal mucosa are major sites of entry in natural HIV infection and therefore the preferred sites to elicit high-avidity CD8+ CTL by vaccination. We directly compare systemic and mucosal immunization in mice after DNA priming and boosting with rgp160 env expressed either in MVA or Ad for their ability to induce mucosal as well as systemic HIV-specific CTL. The optimal CTL response in the gut mucosa was observed after priming with the HIV-1 gp160 env DNA vaccine and boosting with rMVA or rAd encoding the same envelope gene all administered intrarectally (IR). Maximum levels of high-avidity CD8+ T cells were seen in intestinal lamina propria following this regimen. When the prime and boost routes were distinct, the delivery site of the boost had a greater impact than the DNA priming. IM DNA prime and IR rMVA boost were more effective than IR DNA prime and IM rMVA boost for eliciting mucosal CD8+ T-cell avidity. A systemic DNA-prime-followed by systemic rMVA boost induced high levels of high-avidity CD8+ T cells systemically, but responses were undetectable in mucosal sites. A single systemic immunization with rMVA was sufficient to induce high-avidity IFN-gamma secreting CD8+ T cells in systemic organs, whereas a single mucosal immunization with rMVA was not sufficient to elicit high-avidity CD8+ T cells in mucosa. Thus, a heterologous mucosal DNA prime-viral vectored boost strategy was needed. The requirement for a heterologous DNA prime-recombinant viral boost strategy for generation of high-avidity CD8+ T cells in mucosal sites in mice may be more stringent than for the induction of high-avidity CD8+ T cells in systemic compartments.

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Available from: Igor M Belyakov, Sep 29, 2015
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    • "Unfortunately, due to the complexities associated with delivery, safety and evaluation of vaccines efficacy in the mucosae, no mucosal HIV vaccine strategy has yet entered clinical development. Belyakov and co-workers have demonstrated that the intra-rectal immunisation induces local mucosal compartmentalisation of CTL of high " functional avidity " and protection of gastrointestinal CD4+ T cells from SHIV viral depletion in rhesus macaques compared to systemic delivery [17] [18]. Consistent to their finding we have also found that i.m. rDNA/i.n. "
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    ABSTRACT: We have established that the efficacy of a heterologous poxvirus vectored HIV vaccine, fowlpox virus (FPV)-HIV gag/pol prime followed by attenuated vaccinia virus (VV)-HIV gag/pol booster immunisation, is strongly influenced by the cytokine milieu at the priming vaccination site, with endogenous IL-13 detrimental to the quality of the HIV specific CD8+ T cell response induced. We have now developed a novel HIV vaccine that co-expresses a C-terminal deletion mutant of the mouse IL-4, deleted for the essential tyrosine (Y119) required for signalling. In our vaccine system, the mutant IL-4C118 can bind to IL-4 type I and II receptors with high affinity, and transiently prevent the signalling of both IL-4 and IL-13 at the vaccination site. When this IL-4C118 adjuvanted vaccine was used in an intranasal rFPV/intramuscular rVV prime-boost immunisation strategy, greatly enhanced mucosal/systemic HIV specific CD8+ T cells with higher functional avidity, expressing IFN-γ, TNF-α and IL-2 and greater protective efficacy were detected. Surprisingly, the IL-4C118 adjuvanted vaccines also induced robust long-lived HIV gag-specific serum antibody responses, specifically IgG1 and IgG2a. The p55-gag IgG2a responses induced were of a higher magnitude relative to the IL-13Rα2 adjuvant vaccine. More interestingly, our recently tested IL-13Rα2 adjuvanted vaccine which only inhibited IL-13 activity, even though induced excellent high avidity HIV-specific CD8+ T cells, had a detrimental impact on the induction of gag-specific IgG2a antibody immunity. Our observations suggest that (i) IL-4 cell-signalling in the absence of IL-13 retarded gag-specific antibody isotype class switching, or (ii) IL-13Rα2 signalling was involved in inducing good gag-specific B cell immunity. Thus, we believe our novel IL-4R antagonist adjuvant strategy offers great promise not only for HIV-1 vaccines, but also against a range of chronic infections where sustained high quality mucosal and systemic T and B cell immunity are required for protection.
    Vaccine 08/2014; 32(43). DOI:10.1016/j.vaccine.2014.08.023 · 3.62 Impact Factor
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    • "Several studies suggest that the abatement of HIV replication at mucosal surfaces is likely to be essential for the success of a prophylactic vaccine and that the local induction of high levels of high-avidity mucosal CD8+ T cells with antigen protective specificities may be able to prevent, at early times of infection, the steady and massive spread of virus from the mucosa into the systemic circulation [1] [2] [3] [4]. Antienvelope responses can play an important protective role, and antibodies to early HIV regulatory gene products, including Tat, Rev, and Nef, are expected to impact HIV acute infection. "
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    ABSTRACT: Recombinant influenza viruses hold promise as vectors for vaccines to prevent transmission of mucosal pathogens. In this study, we generated a recombinant WSN/TatΔ51-59 virus in which Tat protein lacking residues 51 to 59 of the basic domain was inserted into the N-terminus of the hemagglutinin (HA) of A/WSN/33 virus. The TatΔ51-59 insertion into the viral HA caused a 2-log reduction in viral titers in cell culture, compared with the parental A/WSN/33 virus, and severely affected virus replication in vivo. Nevertheless, Tat-specific antibodies and T cell responses were elicited upon a single intranasal immunization of BALB/c mice with WSN/TatΔ51-59 virus. Moreover, Tat-specific immune responses were also detected following vaccine administration via the vaginal route. These data provide further evidence that moderately large HIV antigens can be delivered by chimeric HA constructs and elicit specific immune responses, thus increasing the options for the potential use of recombinant influenza viruses, and their derivatives, for prophylactic and therapeutic vaccines.
    BioMed Research International 05/2014; 2014:904038. DOI:10.1155/2014/904038 · 3.17 Impact Factor
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    • "Surprisingly, high influenza-specific sIgA levels were also detected in the nasal washes of animals that received CYT-IVAC~mIL23 and CYT-IVAC~mIL12 strictly by the I.M. route (Figure 3B). This is not without precedence, as the transcutaneous or epicutaneous route of immunization coupled with mucosal adjuvants including bacterial toxins, chemical enhancers of cyclic AMP and the active form of Vitamin D3 have been reported to induce peripheral DC migration to Peyers patches (mucosal tissues) and subsequent priming of T and B cells for mucosal homing [27-29]. Hence, our membrane-anchored IL-12 and IL-23 adjuvants may be activating dendritic cells in muscle tissue and targeting them to migration in draining lymph nodes, in a state that is conducive for priming T and B cells for homing to mucosal tissues. "
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    ABSTRACT: Background Potent and safe adjuvants are needed to improve the efficacy of parenteral and mucosal vaccines. Cytokines, chemokines and growth factors have all proven to be effective immunomodulatory adjuvants when administered with a variety of antigens. We have previously evaluated the efficacy of membrane-anchored interleukins (IL) such as IL-2 and IL-4 co-presented as Cytokine-bearing Influenza Vaccines (CYT-IVACs) using a mouse model of influenza challenge. Findings Here, we describe studies evaluating the parenteral and mucosal adjuvanticity of membrane-bound IL-12 and IL-23 CYT-IVACs in young adult mice. Mucosal immunization using IL-12 and IL-23 bearing whole influenza virus vaccine (WIV) was more effective at eliciting virus-specific nasal IgA and reducing viral lung burden following challenge compared to control WIV vaccinated animals. Both IL-12 and IL-23 bearing WIV elicited the highest anti-viral IgA levels in serum and nasal washes. Conclusions This study highlights for the first time the mucosal adjuvant potential of IL-12 and IL-23 CYT-IVAC formulations in eliciting mucosal immune responses and reducing viral lung burden. The co-presentation of immunomodulators in direct context with viral antigen in whole inactivated viral vaccines may provide a means to significantly lower the dose of vaccine required for protection.
    Virology Journal 05/2014; 11(1):78. DOI:10.1186/1743-422X-11-78 · 2.18 Impact Factor
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