Alveolar macrophage stimulation of T-cell proliferation in autologous mixed lymphocyte reactions. Role of HLA-DR antigens

G. A. Rossi, E. Zocchi, O. Sacco, B. Balbi, C. Ravazzoni, G. Damiani

Research output: Contribution to journalArticle

Abstract

Alveolar macrophages act as accessory cells in lymphocyte response to mitogens or alloantigens. Because the autologous mixed lymphocyte reaction (MLP), in which HLA-DR-positive non-T cells stimulate the proliferation of autologous T lymphocytes, represents a good model to study macrophage-T cell interaction, we examined and compared the ability of human alveolar macrophages and peripheral blood-derived monocytes to induce T-cell proliferation in autologous MLR. Maximal T lymphocyte proliferation was observed in both alveolar-macrophage- and blood-monocyte-stimulated autologous MLR at a T cell to alveolar macrophage or blood monocyte ratio of 4:1, but the ability to stimulate T-cell proliferation was lower for alveolar macrophages than for blood monocytes (p <0.01). Because HLA-DR antigens modulate monocyte-T cell interaction, we quantified the proportions of HLA-DR-positive cells in alveolar macrophage and blood monocyte suspensions and determined the inhibitory effects on T-cell proliferation of masking HLA-DR antigens on stimulator cells with monoclonal antibodies. The proportions of HLA-DR-positive cells were higher in alveolar macrophage than in blood suspensions (p <0.01); interestingly, however, the preincubation of the stimulator cells with anti-HLA-DR monoclonal antibodies inhibited to a similar extent both alveolar-macrophage- and blood-monocyte-stimulated autologous MLR (p > 0.2). These studies indicate that alveolar macrophages are less effective than blood monocytes are as stimulator cells in autologous MLR and that, although the masking of HLA-DR molecules results in inhibition of autologous MLR, T-cell proliferation is not dependent on the numbers of stimulator cells bearing HLA-DR antigens. The autologous MLR may represent a good model to study the functions of alveolar macrophages during their interaction with autologous T cells in health and disease.

Original languageEnglish
Pages (from-to)78-82
Number of pages5
JournalAmerican Review of Respiratory Disease
Volume133
Issue number1
Publication statusPublished - 1986

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine

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