MONOCLONAL-ANTIBODIES SPECIFIC FOR PORCINE MONOCYTES MACROPHAGES - MACROPHAGE HETEROGENEITY IN THE PIG EVIDENCED BY THE EXPRESSION OF SURFACE-ANTIGENS/

Macrophages are widely distributed in most tissues of the body, where they play important roles in host defense and repair of tissue damage. In this report we describe the production and characterization of a p anel of six monoclonal antibodies (mAb) against porcine macrophages an d their use for phenotyping tissue macrophages. All mAbs were produced by immunizing mice with porcine alveolar macrophages. Three of them ( 2A10/11, 3B1l/11 and 3F7/11) react mainly with macrophages and, at a l ower extent, blood monocytes, whereas the others (1E12/11, 2C12/10 and 4E9/11) also recognize granulocytes. Antigens recognized by these ant ibodies could be characterized by Western blot and/or immunoprecipitat ion, with the exception of that one recognized by 2C12/10. By their be havior in SDS-PAGE under reducing and nonreducing conditions, all seem to be single polypeptides, whose apparent molecular weight under redu cing conditions are:1E12/11 and 3B11/11 larger than 204 kDa; 2A10/11, 150 kDa; 4E9/11, 125-170 kDa; and 3F7/11, 135 kDa. Immunohistochemical analyses of both lymphoid and non-lymphoid organs using these mAbs re veal important antigenic heterogeneity among tissue macrophages. These mAbs are, therefore, useful tools for the study of porcine macrophage maturation and differentiation and for determining their heterogeneit y both in normal and pathological conditions.