Decreased expression of the memory marker CD26 on both CD4+ and CD8+ T lymphocytes of HIV-infected subjects.
Using a novel anti-CD26 (or anti-dipeptidyl peptidase IV) monoclonal antibody, we showed that the absolute numbers and the proportions of T4 and T8 cells expressing CD26 were significantly lower in HIV-infected persons than in controls. The absolute number of CD26+ T4 cells decreased according to disease progression, whereas the number of CD26+ T8 cells was low throughout all clinical stages. These trends were similar in CD26 dim and bright positive T-cell subsets. In both controls and HIV-positive subjects, the CD26 bright positive T cells were restricted to the CD45RO+ subset and preferentially co-expressed CD25 but largely lacked HLA-DR and CD38. Recall antigen-responsive cells from seronegative individuals were shown to co-express CD26 and CD45RO. The deficient CD26 expression on T8 cells from HIV-infected subjects could be normally upregulated after in vitro stimulation. In contrast to decreased T-cell-bound CD26, the enzymatic activity of plasma CD26/dipeptidyl peptidase IV was unchanged in HIV-infected patients compared with controls. We conclude that HIV infection leads to a deficient in vivo co-expression of CD26 bright and CD45RO on T cells. We speculate that this deficiency might play a part in the decrease of immunological memory during HIV infection.
Vanham
G
G
Laboratory of Pathology and Immunology, Institute of Tropical Medicine, Antwerp, Belgium.
Kestens
L
L
De Meester
I
I
Vingerhoets
J
J
Penne
G
G
Vanhoof
G
G
Scharpé
S
S
Heyligen
H
H
Bosmans
E
E
Ceuppens
J L
JL
D036541:ADP-ribosyl Cyclase; D051997:ADP-ribosyl Cyclase 1; D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD / Q000096:biosynthesis; D000943:Antigens, Differentiation / Q000096:biosynthesis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D018819:Dipeptidyl Peptidase 4; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000097:blood; D015658:HIV Infections / Q000276:immunology*; D006684:HLA-DR Antigens / Q000096:biosynthesis; D006801:Humans; D007156:Immunologic Memory; D016130:Immunophenotyping; D017493:Leukocyte Common Antigens / Q000096:biosynthesis; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D015854:Up-Regulation
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; D000945:Antigens, Differentiation, T-Lymphocyte; D006684:HLA-DR Antigens; D008562:Membrane Glycoproteins; D015375:Receptors, Interleukin-2; D017493:Leukocyte Common Antigens; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; D018819:Dipeptidyl Peptidase 4