Human Immunodeficiency Virus Type 1 (HIV-1) Antigen Secretion by Latently Infected Resting CD4 ⁺ T Lymphocytes from HIV-1-Infected Individuals

Abstract

In resting CD4+ T lymphocytes harboring human immunodeficiency virus type 1 (HIV-1), replication-competent virus persists in patients responding to highly active antiretroviral therapy (HAART). This small latent reservoir represents between 103 and 107 cells per patient. However, the efficiency of HIV-1 DNA-positive resting CD4+ T cells in converting to HIV-1-antigen-secreting cells (HIV-1-Ag-SCs) after in vitro CD4+-T-cell polyclonal stimulation has not been satisfactorily evaluated. By using an HIV-1-antigen enzyme-linked immunospot assay, 8 HIV-1-Ag-SCs per 106 CD4+ resting T cells were quantified in 25 patients with a plasma viral load of <20 copies/ml, whereas 379 were enumerated in 10 viremic patients. In parallel, 369 and 1,238 copies of HIV-1 DNA per 106 CD4+ T cells were enumerated in the two groups of patients, respectively. Only a minority of latently HIV-1 DNA-infected CD4+ T cells could be stimulated in vitro to become HIV-1-Ag-SCs, particularly in aviremic patients. The difference between the number of HIV-1 immunospots in viremic versus aviremic patients could be explained by HIV-1 unintegrated viral DNA that gave additional HIV-1-Ag-SCs after in vitro CD4+-T-cell polyclonal stimulation. The ELISPOT approach to targeting the HIV-1-Ag-SCs could be a useful method for identifying latently HIV-1-infected CD4+ T cells carrying replication-competent HIV-1 in patients responding to HAART

Provirus Activation Plus CD59 Blockage Triggers Antibody-Dependent Complement-Mediated Lysis of Latently HIV-1–Infected Cells

“…Therefore, a combination of provirus stimulants with RCA blockers represents a novel approach for purging HIV-1 latently infected cells. The remaining issues to be addressed include (1) whether ADCML efficacy is correlated to the titer, neutralization activity and affinity of anti-HIV-1 Abs naturally present in infected individuals, and (2) whether simultaneous abrogation of CD46, CD55 and CD59 can further enhance ADCML of latently HIV-1-infected cells upon provirus activation.…”

CD4+T cells spontaneously producing human immunodeficiency virus type I in breast milk from women with or without antiretroviral drugs

“…We also quantified HIV-1 RNA levels after a short period of culture of CD4 + T cells without the addition of polyclonal activators. We and others have previously shown that HIV-1 latently infected CD4 + T cells derived from blood and breast milk are able to sustain the viral cycle and produce viral antigens and virions, following their polyclonal activation in vitro [ 21 , 32 - 34 ]. In vivo , some of the HIV-1 latently infected breast milk-derived CD4 + T cells may revert to productively infected lymphoblasts if they are able to survive for an extended period of time in the gut or body of the infant.…”

“…Immediately after a feed, each woman provided 70 ml of breast milk, by bimanual expression directly into a sterile polypropylene tube, as well as 20 ml of blood. Plasma HIV-1 RNA levels were measured in the Centre Muraz, Bobo-Dioulasso using the Generic HIV Charge Viral kit, (Biocentric, Bandol, France) and ABI PRISM ® 7000 thermocycler (Applied Biosystems, Foster City, USA) [ 32 ]. The lower limit of quantification (LLQ) of the test was 300 HIV-1 RNA copies/ml.…”

“…Blood CD4 + T cells were purified using an immunorosetting method (Rosette SepTM CD4 + cell enrichment cocktail, Stemcell Technologies) [ 32 ]. Purified CD4 + T cells were suspended in complete culture medium at a final concentration of 1 × 10 6 cells/ml.…”

“…Immobilon-P membrane 96-well plates (MAIPN 4550, Millipore Corporation, Bedford, MA) were coated overnight at 4°C with 100 μl of a mixture of anti-HIV-1 polyclonal Abs prepared as previously described [ 32 ]. To enumerate p24 spontaneously secreting cells, enriched CD4 + T cells from breast milk and blood were seeded on the nitrocellulose plate for 18 h, at a concentration of 1 × 10 5 CD4 + T cells/100 μl per well.…”