HIV-2-specific cytotoxic T-lymphocyte activity is inversely related to proviral load.
OBJECTIVE
To characterize HIV-specific cytotoxic T-lymphocyte (CTL) activities in HIV-2-infected individuals and to relate these to HIV-2 proviral load.


METHODS
Peripheral blood mononuclear cells were collected from 16 HIV-2-seropositive and four HIV-1/2 dually seropositive subjects. CTL were restimulated with autologous phytohaemagglutinin-stimulated blasts and CTL activities in 'bulk' cultures were evaluated 7 and 14 days later by a standard 51Cr-release assay using autologous B-cell lines infected with recombinant vaccinia expressing HIV-2 Gag, Pol or Nef protein. Proviral load was quantified by polymerase chain reaction (PCR) which used HIV-2 long terminal repeat primers and an external standard control made by an HIV-2CBL-22 chronically infected C8166 cell line. A biotinylated primer was used to capture the 35S dATP-incorporated secondary PCR product in a quantitative radiometric assay.


RESULTS
After 14 days of culture CTL responses against Gag or Pol protein were seen in 18 (90.0%) and 14 (70.0%) out of 20 subjects, respectively, whereas a CTL response was noted against Nef protein in five (25.0%) out of 20 subjects. In 14 (70.0%) out of 20 subjects multiple HIV proteins were simultaneously recognized. The sum of specific lysis (%) against HIV-2 Gag, Pol and Nef at 30:1 effector-to-target ratio, or specific lysis of the dominant CTL response, correlated strongly with HIV-2 proviral load expressed as copies per 10(5) CD4+ cells (r = -0.625, P = 0.003 and r = -0.674, P = 0.001, respectively).


CONCLUSIONS
HIV-2-specific CTL to multiple gene products was demonstrated in most HIV-2-infected individuals. An inverse correlation between the level of CTL activity and proviral load was found, which supports the hypothesis that CTL are important in the control of HIV-2 replication.
Ariyoshi
K
K
Medical Research Council Laboratories, Fajara, The Gambia, West Africa.
Cham
F
F
Berry
N
N
Jaffar
S
S
Sabally
S
S
Corrah
T
T
Whittle
H
H
D000163:Acquired Immunodeficiency Syndrome / Q000276:immunology* / Q000821:virology; D002478:Cells, Cultured; D015488:HIV Antigens / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology; D015498:HIV-2 / Q000276:immunology*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology* / Q000821:virology; D011533:Proviruses / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D015488:HIV Antigens