Multiple changes at the mucosal surface are induced by protective SIV vaccination

Systemic vaccination with the attenuated virus SIVmac239-Nef provides sterilizing or partial protection to rhesus monkeys challenged with WT SIV strains, providing important opportunities to study key immunological components of a protective host response. Here we show that intravenous vaccination with SIVmac239-Nef provides two potentially crucial immunological barriers localized at mucosal surfaces that correlate with the vaccines protective effects against WT SIVmac251 vaginal challenge: 1) a conditioned and coordinated response from the mucosal epithelium that blunts the early inflammatory and chemotactic signalling cascade that aids virus propagation and expansion; 2) early on-site generation/diversification of SIV-specific Abs from ectopic germinal center-like lymphoid aggregates. This unique host response to WT SIVmac251 in the female reproductive tract of SIVmac239-Nef-vaccinated animals points to a multi-layered strategy for a protective host response during immunodeficiency virus exposurerapid induction of humroal immunity at mucosal surfaces without the deleterious inflammatory side effects tied to innate recognition of virus. This vaccine-induced host response highlights potential key protective mechanisms needed for an effective HIV vaccine

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Smith AJ, Wietgrefe SW, Shang L, Reilly CS, Southern PJ, Perkey KE, Duan L, Kohler H, Müller S, Robinson J, Carlis JV, Li Q, Johnson RP, Haase AT