1. Engagement of monocytes, NK cells, and CD4(+) Th1 cells by ALVAC-SIV vaccination results in a decreased risk of SIVmac251 vaginal acquisition
- Author
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Gorini, Giacomo, Fourati, Slim, Vaccari, Monica, Rahman, Mohammad Arif, Gordon, Shari N., Brown, Dallas R., Law, Lynn, Chang, Jean, Green, Richard, Barrenäs, Fredrik, Liyanage, Namal P. M., Doster, Melvin N., Schifanella, Luca, Bissa, Massimiliano, de Castro, Isabela Silva, Washington-Parks, Robyn, Galli, Veronica, Fuller, Deborah H., Santra, Sampa, Agy, Michael, Pal, Ranajit, Palermo, Robert E., Tomaras, Georgia D., Shen, Xiaoying, LaBranche, Celia C., Montefiori, David C., Venzon, David J., Trinh, Hung, V, Rao, Mangala, Gale, Michael, Jr., Sekaly, Rafick P., Franchini, Genoveffa, Gorini, Giacomo, Fourati, Slim, Vaccari, Monica, Rahman, Mohammad Arif, Gordon, Shari N., Brown, Dallas R., Law, Lynn, Chang, Jean, Green, Richard, Barrenäs, Fredrik, Liyanage, Namal P. M., Doster, Melvin N., Schifanella, Luca, Bissa, Massimiliano, de Castro, Isabela Silva, Washington-Parks, Robyn, Galli, Veronica, Fuller, Deborah H., Santra, Sampa, Agy, Michael, Pal, Ranajit, Palermo, Robert E., Tomaras, Georgia D., Shen, Xiaoying, LaBranche, Celia C., Montefiori, David C., Venzon, David J., Trinh, Hung, V, Rao, Mangala, Gale, Michael, Jr., Sekaly, Rafick P., and Franchini, Genoveffa
- Abstract
The ALVAC-HIV/gp120/alum regimen tested in 8,197 human volunteers (61.4% males, 38.6% females) in the RV144 trial decreased the risk of HIV infection similarly in both sexes. The ALVAC-SIV/gp120/alum vaccine also reduced the risk of intrarectal SIVmac251 acquisition in both female and male vaccinated macaques at an average of 44% per exposure. In the current work, we tested whether this vaccine modality could also reduce the risk of intravaginal SIVmac251 exposure. In order to detect correlates of risk, we administered the virus by the intravaginal route and tested another vaccine regimen based on the vaccinia derivative poxvirus NYVAC in parallel. We demonstrate here that the ALVAC-SIV/gp120/alum regimen decreases the risk of vaginal SIVmac251 acquisition (50% vaccine efficacy) and, importantly, we confirmed that subsets of monocytes and CD4(+) T cells are correlates of risk of acquisition. In addition, we uncovered cytotoxic vaginal NKG2A(+) cells and gut-homing alpha(4)beta(7) positive plasmablasts as novel correlates of risk of intravaginal virus acquisition. In contrast, NYVAC-SIV vaccination induced high levels of activated T cells and did not protect against SIVmac251 acquisition. We examined the contrasting immune responses to better understand the correlate of protection and found that the unique ability of ALVAC-SIV to activate early interferon responses and the inflammasome during priming differentiates the two poxvirus vectors. This work demonstrates the reproducibility of the efficacy observed in the ALVAC-based regimen and defines novel correlates of risk in the rigorous SIVmac251 macaque model, establishing a benchmark for future improvement of this vaccine approach. The recombinant Canarypox ALVAC-HIV/gp120/alum vaccine regimen was the first to significantly decrease the risk of HIV acquisition in humans, with equal effectiveness in both males and females. Similarly, an equivalent SIV-based ALVAC vaccine regimen decreased the risk of virus acquisitio
- Published
- 2020
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