Studies of blood monocytes from patients infected with the human immunodeficiency virus-1 (HIV-1).

Abstract

To determine if blood monocytes from HIV-1 seropositive patients contain HIV-1 antigen and genome, we separated monocytes and T cell subsets using monoclonal antibodies (mAbs) conjugated to magnetic beads and by monocyte adherence to glass. We found: (1) Monocytes cultured without depletion of CD4$\sp+$ T cells (11 of 11 patients) were HIV-1 antigen positive and showed dramatically increased spontaneous formation of MGCs. (2) Monocytes cultured after depletion of CD4$\sp+$ T cells (3 experiments) were HIV-1 antigen negative and MGC formation was markedly decreased. (3) In 14 subsequent patients analyzed by PCR, all patients were positive for HIV-1 proviral DNA in cells enriched for CD4$\sp+$ T cells. In 11 of 14 patients (79%), the monocyte fractions were HIV-1 proviral DNA negative, while in the remaining 3 patients, the monocytes were positive for HIV-1 proviral DNA. In conclusion, the major reservoir for HIV-1 infection in human peripheral blood is CD4$\sp+$ T cells (14 of 14 cases). Fresh blood monocytes from HIV-1 seropositive patients were HIV-1 proviral DNA negative in 11 of 14 cases (79%). Blood monocyte-derived macrophages from HIV-1 seropositive patients may acquire HIV-1 infection in vitro from contaminating infected CD4$\sp+$ T cells. The pathogenic and clinical significance of HIV-1 infected monocytes (21% of patients) remains to be determined. (Abstract shortened by UMI.)