Antigenic Differences between Rat Alveolar and Peritoneal Macrophages

Abstract

According to current views all macrophages are derived from circulating blood monocytes (4). During their maturation they seem to acquire new antigenic surface determinants since it has been shown that antisera against guinea pig peritoneal macrophages react only with a small proportion of blood monocytes and not at all with bone marrow cells (3), the source of promonocytes and their precursors. This expression of new antigens does not proceed equally at various anatomical sites of the organism. For example, differences have been reported between alveolar and peritoneal macrophages in their reactivity with antimacrophage sera (2,3,5,7). These previous studies did not definitely answer the question as to whether the differences are caused by a different distribution of several common macrophage-specific antigens or by determinants specific for each cell type. This distinction accomplished by exhaustive cross absorptions is the subject of the present study.