Generation of CD8(+) T cell-generated suppressor factor and beta-chemokines by targeted iliac lymph node immunization in rhesus monkeys challenged with SHIV-89.6P by the rectal route

The targeted lymph node (TLN) immunization strategy was investigated in mac aques, in order to determine the efficacy in generating secretory, systemic , and cellular immune responses, CD8(+) T cell-generated suppressor factors , and beta-chemokines, TLN immunization of the rectal and genital mucosa-as sociated iliac lymph nodes (TILNs) was compared with axillary TLN immunizat ion (TAxLN) using HIV-1 MN/LAI gp140(env) and SIV p27(gag) in alum. Signifi cantly higher immune responses, as well as CD8(+) T cell-generated anti-SIV factors and the beta-chemokines RANTES, MIP-1 alpha, and MIP-1 beta, were elicited by iliac as compared with axillary TLN immunization. The immune re sponses induced by TLN immunization were examined for their capacity to pre vent rectal mucosal infection by the pathogenic dual-tropic SHIV-89.6P, Des pite significant secretory, serum, cellular, and beta-chemokine responses, the macaques were infected by SHIV-89.6P. Whether the lack of protection wa s associated with the antigenic unrelatedness of SHIV-89.6P to the immunizi ng HIV-1 MN/LAI gp140 or to the virus utilizing CXCR4 to a much greater ext ent than CCR5, remains to be determined.