Mucosal HIV-1 Pox Virus Prime-Boost Immunization Induces High-Avidity CD8+ T Cells with Regime-Dependent Cytokine/Granzyme B Profiles

Abstract

The quality of virus-specific CD8+ CTL immune responses generated by mucosal and systemic poxvirus prime-boost vaccines were evaluated in terms of T cell avidity and single-cell analysis of effector gene expression. Intranasal (I.N.) immunization regimes generated higher avidity CTL responses specific for HIV KdGag197–205 (amino acid sequence AMQMLKETI; H-2Kd binding) compared with i.m. immunization regime. Single-cell RT-PCR of KdGag197–205-specific mucosal and systemic CTL revealed that the cytokine and granzyme B expression profiles were dependent on both the route and time after immunization. The I.N./i.m.-immunized group elicited elevated number of CTL-expressing granzyme B mRNA from the genitomucosal sites compared with the i.m./i.m. regime. Interestingly, CTL generated after both I.N. or i.m. immunization demonstrated expression of Th2 cytokine IL-4 mRNA that was constitutively expressed over time, although lower numbers were observed after I.N./I.N. immunization. Results suggest that after immunization, Ag-specific CTL expression of IL-4 may be an inherent property of the highly evolved poxvirus vectors. Current observations indicate that the quality of CTL immunity generated after immunization can be influenced by the inherent property of vaccine vectors and route of vaccine delivery. A greater understanding of these factors will be crucial for the development of effective vaccines in the future.

Functional CD8+ CTLs in mucosal sites and HIV infection: moving forward toward a mucosal AIDS vaccine

“…Similar findings have been reported when mucosal and systemic poxvirus prime-boost routes of immunization were evaluated [102]. Mucosal (intranasal) immunization regimens induced higher avidity CD8 + T cells compared with intramuscular vaccination.…”

“…Mucosal (intranasal) immunization regimens induced higher avidity CD8 + T cells compared with intramuscular vaccination. CD8 + CTLs expressing high levels of granzyme B were observed in the genital tract after mucosal HIV-1 recombinant homologous primeboost immunization [102]. Intranasal (mucosal) primewith intramuscular (systemic) boost immunization elicited a higher number of granzyme B-positive CD8 + CTLs in genital mucosa compared with an intramuscular primeboost protocol.…”

Simultaneous Approach Using Systemic, Mucosal and Transcutaneous Routes of Immunization For Development of Protective HIV-1 Vaccines

“…The route of immunization and vaccine delivery regimen are important variables in the in generation of functionally active and effective HIV-1-specific CD8 + CTL and antibody responses in mucosal and systemic sites [5,6,8,13,14,29,38,39,42,65,[109][110][111][112][113]. Our recent study demonstrates that mucosal prime and boost immunizations are essential to the induction of high avidity CD8 + CTL responses in inductive and effector sites of gastrointestinal mucosa, while IR vaccination with rMVA alone was not effective in generation of high avidity CD8 + CTL in the gut mucosa [38].…”

Anti-SIV Cytolytic Molecules in Pigtail Macaques

“…We chose to design a nested PCR reaction for each molecule to provide a highly sensitive means to detect these molecules in low cell sample numbers as used in murine experiments. 5,6 The multiplex primers were designed to result in bands with differing sizes readily detected on the final gel. With this assay we were able to readily detect all four cytolytic molecules from M. nemestrina bulk PBMCs together with CD8 and LAMP-1 (Fig.…”

“…Granzymes and perforin molecules are differentially expressed in single CD8 T cells in murine influenza infection models, highlighting the complexity of mammalian cytotoxic molecules. 5,6 Several simian models of HIV-1 infection exist, with the most commonly studied models being SIV infection of rhesus (Macaca mulatta), and, increasingly, cynomolgus (M. fascicularis) and pigtail macaques (M. nemestrina). Most studies of cytotoxic molecules in nonhuman primates have employed only rhesus macaques.…”