Two-site enzyme immunoassay of CD4 and CD8 molecules on the surface of T lymphocytes from healthy subjects and HIV-1-infected patients.
A highly sensitive two-site enzyme immunoassay (Capcellia) was developed to determine the concentration of CD4 and CD8 molecules expressed on the surface of human T lymphocytes. This assay, performed in one step (20 min), involves the specific immunocapture of T lymphocytes and reaction of the CD4 or CD8 molecules with an enzyme-labeled monoclonal antibody (mAb). The results were expressed as molar concentrations of the T-cell markers on the basis of results obtained with calibrated CD4 and CD8 standards. The assay was sensitive enough to detect 0.4 pmol/L CD4 or 0.8 pmol/L CD8, which corresponded to approximately 20 x 10(6) CD4+ or CD8+ T cells per liter of blood. Mean concentrations in healthy adults were 17.2 pmol/L for CD4 and 22.1 pmol/L for CD8. The CD4 concentration was < 8 pmol/L in 50% of HIV-1-infected patients and in 95% of AIDS patients. Given the epitopic specificity of the mAb to CD4 we used, these values correspond to the concentration of CD4 molecules free of envelope glycoprotein (gp)120.
Carriere
D
D
Sanofi Recherche, Montpellier, France.
Fontaine
C
C
Berthier
A M
AM
Rouquette
A M
AM
Carayon
P
P
Laprode
M
M
Juillard
R
R
Jansen
A
A
Paoli
P
P
Paolucci
F
F
D000386:AIDS-Related Complex / Q000276:immunology*; D000163:Acquired Immunodeficiency Syndrome / Q000276:immunology*; D000328:Adult; D015704:CD4 Antigens / Q000097:blood*; D016827:CD8 Antigens / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D015699:HIV Envelope Protein gp120 / Q000276:immunology; D015497:HIV-1; D006801:Humans; D007124:Immunoenzyme Techniques / Q000706:statistics & numerical data; D011994:Recombinant Proteins / Q000276:immunology; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013601:T-Lymphocytes / Q000276:immunology*
D015704:CD4 Antigens; D016827:CD8 Antigens; D015699:HIV Envelope Protein gp120; D011994:Recombinant Proteins