Human immunodeficiency virus type 1 envelope-specific cytotoxic T lymphocytes response dynamics after prime-boost vaccine regimens with human immunodeficiency virus type 1 canarypox and pseudovirions

Virus-specific cytotoxic T lymphocytes (CTLs) may represent significant imm une mechanisms in the control of human immunodeficiency virus (HIV) infecti on and, therefore, CTL induction may be a fundamental goal in the developme nt of an efficacious acquired immunodeficiency syndrome (AIDS) vaccine. In the current study, prime-boost protocols were used to investigate the poten tial of noninfectious human immunodeficiency virus type 1 (HIV-1) pseudovir ions (HIV PSV) in enhancing HIV-specific CTL responses in Balb/c mice prime d with the recombinant canarypox vector, vCP205, encoding HIV-1 gp120 (MN s train) in addition to Gag/Protease (IIIB strain). The prime-boost immunizat ion regimens were administered intramuscularly and involved injections of v CP205 followed by boosts with HIV PSV. Previous vaccination strategies sole ly involving vCP205 had induced good cellular immune responses in uninfecte d human volunteers, despite some limitations. The use of genetically engine ered HIV PSV was a logical step in the evaluation of whole noninfectious vi rus or inactivated virus vaccine strategies, particularly as a potential bo osting agent for vCP205-primed recipients. Based on this current study, HIV PSV appeared to have the capability to effectively induce and boost cell-m ediated HIV-1-specific responses. In order to observe the immune effects of HIV PSV in a prime-boost immunization strategy, both HIV vaccine immunogen s required careful titration in vivo. This suggests that careful considerat ion should be given to the optimization of immunization protocols destined for human use.