Infection of CD8+ T lymphocytes with HIV. Requirement for interaction with infected CD4+ cells and induction of infectious virus from chronically infected CD8+ cells.
In this study, we have investigated the basic requirements for HIV-1 infection of CD8+ lymphocytes in vitro. Unfractionated PBL obtained from healthy HIV-1 seronegative donors were activated with PHA and infected in vitro with HIV-1LAV. Based on immunofluorescent labeling, the vast majority of cells (85 to 97%) surviving peak virus replication belonged to the CD8+ subset and only a small percentage (0.5 to 1.5%) were CD4+. Amplification of HIV-1 proviral sequences by polymerase chain reaction performed on the sorted surviving CD8+ cells demonstrated that CD8+ cells harbored HIV-1 proviral DNA. In addition, stimulation of these HIV-1-infected, CD8(+)-sorted cells either with PHA or anti-CD2 mAb resulted in induction of virus replication, as measured by reverse transcriptase activity. Electron microscopic analysis of CD8+ cells chronically infected with HIV-1 and stimulated with PHA showed typical virions budding from, and associated with, the surface of cells immunolabeled with gold beads directed toward the CD8 molecule. Infection of CD8+ cells with HIV-1 occurred only when CD4+ cells were present in the PHA-activated lymphocyte population exposed to HIV-1 at the beginning of the culture or when sorted CD8+CD4- lymphocytes were cocultured with autologous sorted CD8-CD4+ cells that had been previously infected with HIV-1. Coculture of these cells with PHA-blasts and incubation of their supernatants with a CD4+ cell line showed that these chronically infected CD8+ cells could spread HIV-1 infection to uninfected CD4+ cells after stimulation with PHA or anti-CD2 mAb. Therefore, these results suggest that the minimal requirement for in vitro infection of CD3+CD8+CD4- lymphocytes is the presence of infected CD4+ cells and that infected CD8+ T lymphocytes can further spread the infection to CD4+ cells.
De Maria
A
A
Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892.
Pantaleo
G
G
Schnittman
S M
SM
Greenhouse
J J
JJ
Baseler
M
M
Orenstein
J M
JM
Fauci
A S
AS
D015703:Antigens, CD / Q000032:analysis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis*; D017252:CD3 Complex; D015496:CD4-Positive T-Lymphocytes / Q000382:microbiology*; D016827:CD8 Antigens; D002478:Cells, Cultured; D004279:DNA, Viral / Q000032:analysis; D005434:Flow Cytometry; D015658:HIV Infections / Q000382:microbiology*; D015497:HIV-1 / Q000254:growth & development*; D006801:Humans; D066298:In Vitro Techniques; D008854:Microscopy, Electron; D016133:Polymerase Chain Reaction; D012194:RNA-Directed DNA Polymerase / Q000032:analysis; D011948:Receptors, Antigen, T-Cell / Q000032:analysis; D016176:T-Lymphocyte Subsets / Q000382:microbiology*; D014779:Virus Replication
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D016827:CD8 Antigens; D004279:DNA, Viral; D011948:Receptors, Antigen, T-Cell; D012194:RNA-Directed DNA Polymerase