Human alveolar macrophages express Ia-like antigens.

Monoclonal antibody to la-like antigens was used to demonstrate the presence of these antigens on human alveolar macrophages. Immunoprecipitation demonstrated the 27,000 and 34,000 molecular weight peaks that correspond to the la-like antigen subunits. Immunofluorescence confirmed the presence of la-like antigens on alveolar macrophages but not on other bronchoalveolar cells. The presence of alveolar macrophage la-like antigens may be important in cellular interactions.