title: Expression of a functional p75 interleukin-2 receptor on lung lymphocytes from patients with human immunodeficiency virus type 1 (HIV-1) infection.
abstract: Lung involvement in patients affected by HIV-1 infection is characterized by an alveolitis sustained by the accumulation of CD8+ T lymphocytes. To investigate whether in situ T cell growth plays a relevant role in the pooling of CD8+ lymphocytes, we have analyzed the activity of two lymphokines involved in the mechanisms of T cell proliferation, i.e., interleukin-2 (IL-2) and interleukin-4. To this aim, following appropriate triggering and blocking, the expression and the functional role of IL-2 receptors (IL-2R) (both p55 and p75 chains) and IL-4 receptors have been analyzed on T lymphocytes obtained from the bronchoalveolar lavage (BAL) of 16 HIV-1+ patients. Molecular and phenotypic studies we performed demonstrated that CD8+ lymphocytes from the BAL of HIV-1 + patients strongly expressed the p75 chain of IL-2 receptor, while neither p55 mRNA nor its surface membrane product (Tac antigen) was detectable; in addition, there was no expression of IL-4 receptors. IL-2 stimulation was able to induce T cell growth in a dose-dependent manner, whereas IL-4 did not. Finally, using mAbs which specifically block the p55 or p75 IL-2R, we showed that both subunits of IL-2R were involved in the proliferative activity of lung lymphocytes. The results obtained in the present study directly demonstrate that BAL T lymphocytes of HIV-1 + patients express a fully functional IL-2 receptor apparatus, pointing to the role for this lymphokine in maintaining the alveolitis taking place in the lungs of AIDS patients.
authors.affiliation: Padua University School of Medicine, Department of Clinical Medicine, Padua Hospital, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Zambello
authors.forename: L
authors.initials: L
authors.lastname: Trentin
authors.forename: R
authors.initials: R
authors.lastname: Benetti
authors.forename: A
authors.initials: A
authors.lastname: Cipriani
authors.forename: C
authors.initials: C
authors.lastname: Crivellaro
authors.forename: P
authors.initials: P
authors.lastname: Cadrobbi
authors.forename: C
authors.initials: C
authors.lastname: Agostini
authors.forename: G
authors.initials: G
authors.lastname: Semenzato
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000276:immunology*; D005260:Female; D015870:Gene Expression; D015658:HIV Infections / Q000276:immunology*; D006679:HIV Seropositivity / Q000276:immunology; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D016130:Immunophenotyping; D007376:Interleukin-2 / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis* / Q000235:genetics; D013601:T-Lymphocytes / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D007376:Interleukin-2; D012333:RNA, Messenger; D015375:Receptors, Interleukin-2; D015847:Interleukin-4