The TAM receptor tyrosine kinases Axl and Mer drive the maintenance of highly phagocytic macrophages

• DOI: 10.3389/fimmu.2022.960401
• Publication Date: 2022-07-29T12:52:40Z
• Authors: Lidia Jiménez-García; Christopher Mayer; Patrick G. Burrola; Youtong Huang; Maxim N. Shokhirev; Greg Lemke
• Keywords: GAS6

Many apoptotic thymocytes are generated during the course of T cell selection in thymus, yet machinery through which these dead cells recognized and phagocytically cleared is incompletely understood. We found that TAM receptor tyrosine kinases Axl Mer, co-expressed by a specialized set phagocytic thymic macrophages, essential components this machinery. Mutant mice lacking Mer exhibited marked accumulation time autoreactive nonreactive normally die. Unexpectedly, double mutants also displayed profound deficit total number highly macrophages concomitantly diminished expression TIM-4, CD163, other non-TAM engulfment systems remained. Importantly, previously unrecognized deficits were not confined to as they evident spleen bone marrow. They had pleiotropic consequences for mutants, unrecognized, included dysregulation hemoglobin turnover iron metabolism leading anemia.