Lung macrophages and dendritic cells express HLA-G molecules in pulmonary diseases

Hum Immunol. 2002 Feb;63(2):83-90. doi: 10.1016/s0198-8859(01)00373-1.

Abstract

HLA-G is selectively expressed in extravillous trophoblast of human placenta, which does not express classical HLA-A and -B molecules. Several studies report the role of HLA-G as a molecule involved in immune tolerance. By interacting with NK and T cells inhibitory receptors, HLA-G may downregulate their cytotoxicity functions. To appreciate the biologic and clinical relevance of HLA-G expression in lung diseases, HLA class I and HLA-G expression were analyzed in a panel of 36 ex vivo neoplastic tissues and 8 non-neoplastic lung tissues. Immunohistochemical analysis was performed using a pan-HLA class I antibody (W6/32) and three different specific anti-HLA-G antibodies (87G, MEMG/9 and 4H84). These findings demonstrated that HLA-G products were not expressed in pulmonary structural cells. However, HLA-G molecules were detected in activated macrophages and dendritic cells infiltrating lung carcinomas (33%) and nontumoral pulmonary diseases (25%). HLA-G expression was not correlated with classical HLA alterations. No statistical correlation was found between HLA-G expression and clinical or biologic parameters except high tumor size. The expression of HLA-G in myelo-monocytic cells infiltrating lung pathologic tissues could alter antigenic presentation and contribute to decrease immune response efficiency, subsequently favoring the progression of tumoral or inflammatory processes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Dendritic Cells / metabolism*
  • Female
  • HLA Antigens / metabolism
  • HLA-G Antigens
  • Histocompatibility Antigens Class I / metabolism
  • Humans
  • Lung / cytology
  • Lung / metabolism*
  • Lung Diseases / metabolism*
  • Lung Neoplasms / metabolism
  • Macrophages / metabolism*
  • Male

Substances

  • HLA Antigens
  • HLA-G Antigens
  • Histocompatibility Antigens Class I