Gammadelta T cells increase with Mycobacterium avium complex infection but not with tuberculosis in AIDS patients.
The aim of the present study was to better characterize the expansion of double-negative (DN) T cells in vivo in AIDS patients and to ascertain the discrepant response of an immunodepressed immune system towards two distinct mycobacterial infections. In a large cohort of HIV-1 seropositive patients with low CD4(+) T cell counts (<100/mm(3)), we have recently reported on an expansion of DN T cells which was observed only in patients with disseminated Mycobacterium avium infection, toxoplasmosis and Kaposi sarcoma, but not in patients with tuberculosis. The potential differential gammadelta T cells response observed in vivo in AIDS patients with tuberculosis or disseminated M. avium complex infection was investigated by collecting the concomitant or the closest T lymphocyte counts performed within 2 weeks of bacterial diagnosis of 112 disseminated M. avium infection and 41 tuberculosis patients. The DN and gammadelta T cell percentages were different between the two groups (P < 10(-4)) and the expansion of this compartment was found only with disseminated M. avium infections. An analysis of the variable delta2 segment versus pan-delta bearing T cells ratio disclosed a predominance of non-V(delta)2 T cells in these patients whose average values were identical in both groups. It is therefore concluded that the difference seen between these two types of mycobacterial infections concerning the DN T cells only involved the gammadelta T cells although the mechanism of their preferential expansion in disseminated M. avium infections remains a matter of speculation.
Pellegrin
J L
JL
Services de Médecine Interne et Maladies Infectieuses, Laboratoire d'Immunologie, Centre Hospitalier Régional et Universitaire de Bordeaux, 33076 Bordeaux Cedex, France.
Taupin
J L
JL
Dupon
M
M
Ragnaud
J M
JM
Maugein
J
J
Bonneville
M
M
Moreau
J F
JF
D017088:AIDS-Related Opportunistic Infections / Q000276:immunology* / Q000382:microbiology; D017252:CD3 Complex / Q000276:immunology; D018791:CD4 Lymphocyte Count; D016827:CD8 Antigens / Q000276:immunology; D015331:Cohort Studies; D005500:Follow-Up Studies; D006679:HIV Seropositivity / Q000276:immunology; D015497:HIV-1; D006801:Humans; D007111:Immunity, Cellular; D016867:Immunocompromised Host / Q000276:immunology; D017493:Leukocyte Common Antigens / Q000276:immunology; D018655:Lymphocyte Count; D015269:Mycobacterium avium Complex; D015270:Mycobacterium avium-intracellulare Infection / Q000276:immunology* / Q000382:microbiology; D009169:Mycobacterium tuberculosis; D016692:Receptors, Antigen, T-Cell, gamma-delta; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D014376:Tuberculosis / Q000276:immunology* / Q000382:microbiology
D017252:CD3 Complex; D016827:CD8 Antigens; D016692:Receptors, Antigen, T-Cell, gamma-delta; D017493:Leukocyte Common Antigens