Immune complexes from HIV-1+ patients contain infectious virus able to infect normal lymphocytes

It has been suggested that circulating immune complexes containing HIV-1 could be involved in enhancement of the infection through Fc receptors. To test this hypothesis, immune complexes precipitated from the sera of 25 HIV-1–seropositive individuals, at different stages of the disease, were assayed for the presence of infectious virus. When added to phytohemagglutinin-activated peripheral blood lymphocytes, seven of 25 complexes were able to sustain a productive infection. This was demonstrated by release of HIV-p24 antigens in the supernatant of activated but not resting peripheral blood lymphocytes after several days of culture. Moreover, peripheral blood lymphocytes cultured with complexes from HIV-1+ patients but not from control subject, contained integrated HIV-1 provirus in their DNA. These results demonstrated the presence of infectious virus in immune complexes from HIV-1+ patients. (J A LLERGY C LIN I MMUNOL 1996;98:827-30.)