β-chemokine production in macaques vaccinated with live attenuated virus correlates with protection against simian immunodeficiency virus (SIVsm) challenge

Simian immunodeficiency virus (SIV) uses the CCR5 chemokine receptor as the main co-receptor to enter CD4(+) cells. RANTES, MIP-1 alpha and MIP-1 beta have been suggested as the major human immunodeficiency virus-suppressor factors produced by CD8(+) T-cells. The aim of this study was to investigate the CD8+ T-cell production of anti-viral factors and of beta-chemokines in six cynomolgus macaques vaccinated with live attenuated SIVmacC8 in relation to protection against infectious intrarectal SIVsm challenge. Three of the vaccinated animals were completely protected and one was partially protected against the challenge virus. Interestingly, these monkeys showed higher in vitro anti-viral CD8(+) cell suppressor activity and beta-chemokine production both before and after vaccination as compared to the infected monkeys. The results indicate that beta-chemokines may play a role in protective immunity but also that genetic and/or environmental factors may influence their production.