Distribution of functional HIV specific CD8 T lymphocytes between blood and secondary lymphoid organs after 8-18 months of antiretroviral therapy in acutely infected patients

Objectives: To assess whether drug-induced suppression of the plasma viral load is associated with selective differential distribution of virus-specif ic CD8 T cells between the blood and secondary lymphoid organs. Methods: HIV-specific CD8 T lymphocyte responses were quantified in matched peripheral blood and lymph node samples from seven patients starting treat ment shortly after infection, who received antiretroviral theray (ART) for a median of 14 months. Cells recovered from samples were subjected to IFN-v ELISPOT analysis. A series of synthetic peptides corresponding to previous ly characterized cytotoxic T lymphocyte epitopes restricted by HLA 1 molecu les present in each patient were used as antigens, together with appropriat e positive and negative controls. Results: HIV-specific CD8 T lymphocyte responses were found in six of the s even patients. The observed frequencies of HIV-specific CD8 T lymphocytes a nd the pattern of epitope recognition was identical within the two compartm ents. These results also confirm the observation that functional HIV-specif ic CD8 T cells are preserved on ART in most patients initiating treatment a t the time of primary HIV-1 infection. Conclusion: This investigation demonstrated that patterns of antigenic immu nodominance as well as frequencies of HIV-specific CD8 T lymphocytes are si milar in blood and lymphoid tissue compartments in HIV-infected individuals . These findings support current approaches to the identification of HIV-sp ecific CD8 T lymphocyte reactivity based on leukocytes isolated from blood even in patients with ART-induced suppression of viral load. (C) 2001 Lippi ncott Williams & Wilkins.