Assessment of human immunodeficiency virus expression in cocultures of peripheral blood mononuclear cells from healthy seropositive subjects

Abstract

We have evaluated a number of methodological variables effecting the expression of human immunodeficiency virus (HIV) in cultured peripheral blood mononuclear cells (PBMCs) of 93 healthy anti‐HIV‐positive and 72 healthy seronegative subjects. For optimal HIV recovery, PBMCs had to be freshly separated from whole blood. Short‐term freezing of purified PBMCs was practically advantageous and actually resulted in more rapid virus recovery. The minimal number of PBMCs necessary for virus expression was determined by dilutional cultures and varied from 10² to 10⁶ cells. HIV expression was demonstrated initially at the cellular level by immunocytochemical detection of HIV core and envelope proteins using a mixture of monoclonal antibodies, subsequently confirmed by detection of viral antigens and reverse transcriptase (RT) in the culture supernatants. HIV recovery was not improved following induction with 5‐iodo‐2′‐deoxyuridine (IUDR) and only marginally improved following depletion of the CD8⁺‐suppressor cell population in the PBMC specimens. The overall frequency of HIV detection in cultures was 84% in healthy seropositive subjects, whereas none of the PBMCs from 72 seronegative persons yielded HIV expression.