Enhanced culture method for detection of replication-competent virus in peripheral blood mononuclear cells of HIV type 1-infected individuals

The detection of replication-competent human immunodeficiency virus type 1 (HIV-1) in infected individuals is integral for studies of viral latency and reservoirs of continuing replication during treatment. We describe a modified coculture method to detect/isolate virus from HIV-1-infected individuals with low or undetectable plasma viral loads. We observed a wide range in CD4 and chemokine receptor concentrations on CD4(+) T cells of HIV-1-uninfected donors. We selected cells from donors who expressed high levels of CCR5 after mitogen stimulation to combine in culture with peripheral blood mononuclear cells of HIV-1-infected individuals. Using this donor-enhanced culture method, viruses were isolated from asymptomatic adults with long-term nonprogressive infection, and children receiving effective highly active antiretroviral therapy, whereas parallel cultures with cells expressing lower levels of CCR5 yielded none. Virus was isolated from an individual for whom all previous attempts using reported methods were unsuccessful. Virus growth from cryopreserved cells from this same individual was detected at multiple sampling time points, including a time point at which a sensitive assay to measure 2-LTR (long terminal repeat) circular forms of the viral genome was negative. This will be a useful technique by which to study viral latency and HIV-1 pathogenesis in adult and pediatric populations.