Characterization of T cell subsets involved in the production of IFN-gamma in asymptomatic HIV-infected patients.
Cells capable of interferon (IFN)-gamma synthesis following mitogenic stimulation can be detected and quantified by a recently developed immunofluorescence assay and flow cytometric analysis. The production of IFN-gamma was investigated in a cohort of 20 asymptomatic human immunodeficiency virus (HIV)-seropositive patients with normal numbers of CD4+ lymphocytes, and in 10 healthy subjects. About 60% of asymptomatic stage A1 patients had increased percentages of blood lymphocytes capable of IFN-gamma synthesis, as compared to healthy subjects. The difference reflected the relatively higher numbers of CD8+ cells, in particular the CD8+ T cell subset lacking CD28 antigen expression. The strong correlation between the CD4+/CD8+ ratio and the CD8+CD28+/CD8+CD28- ratio suggests either a role for CD4+ cells in controlling the CD28+ phenotype or a role for CD8+CD28- cells in the decline of CD4+ lymphocytes. The peculiar ability of CD8+CD28- cells to produce high amounts of IFN-gamma, as compared to CD8+CD28+ cells, supports the hypothesis that the CD8+CD28- lymphocytes constitute a population that is functionally distinct from their double-positive counterparts.
Caruso
A
A
Institute of Microbiology, University of Brescia, Italy.
Licenziati
S
S
Canaris
A D
AD
Cantalamessa
A
A
Corulli
M
M
Benzoni
B
B
Peroni
L
L
Balsari
A
A
Turano
A
A
D018106:CD28 Antigens; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D005434:Flow Cytometry; D006679:HIV Seropositivity / Q000097:blood / Q000276:immunology* / Q000378:metabolism; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology*; D010641:Phenotype; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013997:Time Factors
D018106:CD28 Antigens; D007371:Interferon-gamma