Expression of TNF receptors by T cells and membrane TNF-alpha by alveolar macrophages suggests a role for TNF-alpha in the regulation of the local immune responses in the lung of HIV-1-infected patients.
J Immunol
; 154(6): 2928-38, 1995 Mar 15.
Article
em En
| MEDLINE
| ID: mdl-7876559
ABSTRACT
High amounts of TNF-alpha are released by alveolar macrophages (AMs) in the lungs of patients with HIV-1 infection. To investigate the role of this cytokine in the local immune response, we studied the expression of surface receptors for TNF-alpha (TNF-Rs) and the presence of the transmembrane form of TNF-alpha (mTNF-alpha) on bronchoalveolar lavage (BAL) cells recovered from 14 patients with HIV-1 infection. The role of TNF-alpha both in the events leading to the T cell alveolitis and as a mediator of cytotoxicity was also evaluated. TNF-R expression was determined by flow cytometry on BAL CD8 lymphocytes and AMs (i.e., the cells that account for the alveolitis in HIV-1 infection). We found that CD8 cells express the 75-kDa (CD120a) but not the 55-kDa (CD120a) TNF-Rs, whereas AMs were devoid of TNF-R expression. More than 90% of BAL T cells efficiently bound TNF-alpha; when T cells were tested for their proliferative capacity, an up-regulation of the IL-2-mediated proliferation by TNF-alpha was observed, suggesting that this cytokine may drive the in situ proliferation of CD120b+ T cells. As shown by flow cytometry analysis and immunoprecipitation with anti-TNF-alpha Ab, mTNF-alpha expression was observed on AMs but not on alveolar T cells. Fixed AMs showed high levels of killing against TNF-sensitive targets. Taken together, our data demonstrate the selective expression of TNF-Rs and mTNF-alpha on cells accumulating within the alveolar spaces of patients with HIV-1 infection, pointing to the compound role of TNF-alpha in the local immune responses.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Linfócitos T
/
Infecções por HIV
/
Fator de Necrose Tumoral alfa
/
Macrófagos Alveolares
/
Receptores do Fator de Necrose Tumoral
Limite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
J Immunol
Ano de publicação:
1995
Tipo de documento:
Article
País de afiliação:
Itália