Dynamic correlation between CTL response and viral load in primary human immunodeficiency virus-1 infected Koreans

Background: HIV-1 specific cytotoxic T lymphocytes (CTLs) have an important role as antiviral effector cells for controlling HIV-1 infection. Methods: To investigate CTL response during the early stage of HIV infection, we measured immunity-related factors including CD4(+) T cell counts, CD8(+) T cell counts, HIV-1 RNA viral loads and IFN-gamma secretion according to CTL response in 78 selected primary HIV-1-infected Koreans. Results: The CTL response was strongly induced by HIV-1 specific Gag and Nef peptides (p = 0.016) compared with induction by Tat or Env peptides. These results suggest that the major antiviral factors inducing strong HIV-specific CTL responses are associated with the Gag and Nef viral regions in primary HIV-1 infected Koreans. The relationship between viral load and CTL response showed varying correlations with time following HIV infection. CTL response was inversely correlated with viral loads at preseroconversion stage I (r = -0.224 to -0.33) and changed to a positive correlation at the preseroconversion stage II (r = 0.132 to 0.854). Finally, it changed to an inverse correlation again after seroconversion until a viral set point was established on serological profiling (r = -0.195 to -0.407). Conclusions: These findings demonstrate a dynamic correlation between viral load and subsequent CTL responses during early HIV infection.