Expression of a functional p75 interleukin-2 receptor on lung lymphocytes from patients with human immunodeficiency virus type 1 (HIV-1) infection

• Published in: Journal of clinical immunology 1992-09, Vol.12 (5), p.371-380
• Main Authors: ZAMBELLO, R, TRENTIN, L, BENETTI, R, CIPRIANI, A, CRIVELLARO, C, CADROBBI, P, AGOSTINI, C, SEMENZATO, G
• Format: Article
• Language: English
• Subjects: Adult; AIDS/HIV; Antibodies, Monoclonal; Biological and medical sciences; Bronchoalveolar Lavage Fluid - cytology; Bronchoalveolar Lavage Fluid - immunology; Female; Gene Expression; HIV Infections - immunology; HIV Seropositivity - immunology; HIV-1 - immunology; human immunodeficiency virus 1; Humans; Immunodeficiencies; Immunodeficiencies. Immunoglobulinopathies; Immunopathology; Immunophenotyping; Interleukin-2 - immunology; Interleukin-4 - immunology; Lymphocyte Activation - immunology; Male; Medical sciences; Receptors, Interleukin-2 - biosynthesis; Receptors, Interleukin-2 - genetics; RNA, Messenger - metabolism; T-Lymphocytes - immunology; T-Lymphocytes, Regulatory - immunology
• ISSN: 0271-9142; 1573-2592
• DOI: 10.1007/BF00920795

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.