Medical Research Center, The First Affiliated Hospital of Zhengzhou University, 450052 Zhengzhou, China.
Institute of Anatomy and Cell Biology, Unit of Reproductive Biology, Justus-Liebig University Giessen, 35392 Giessen, Germany.
Proc Natl Acad Sci U S A. 2021 Jan 5;118(1). doi: 10.1073/pnas.2013686117.
Macrophages are the principal immune cells of the epididymis and testis, but their origins, heterogeneity, development, and maintenance are not well understood. Here, we describe distinct populations of epididymal and testicular macrophages that display an organ-specific cellular identity. Combining in vivo fate-mapping, chimeric and parabiotic mouse models with in-depth cellular analyses, we found that CD64MHCII and CD64MHCII macrophage populations of epididymis and testis arise sequentially from yolk sac erythro-myeloid progenitors, embryonic hematopoiesis, and nascent neonatal monocytes. While monocytes were the major developmental source of both epididymal and testicular macrophages, both populations self-maintain in the steady-state independent of bone marrow hematopoietic precursors. However, after radiation-induced macrophage ablation or during infection, bone marrow-derived circulating monocytes are recruited to the epididymis and testis, giving rise to inflammatory macrophages that promote tissue damage. These results define the layered ontogeny, maintenance and inflammatory response of macrophage populations in the male reproductive organs.
巨噬细胞是附睾和睾丸的主要免疫细胞，但它们的起源、异质性、发育和维持尚不清楚。在这里，我们描述了附睾和睾丸中具有器官特异性细胞特征的不同巨噬细胞群体。通过体内示踪、嵌合和联体小鼠模型与深入的细胞分析相结合，我们发现附睾和睾丸的 CD64MHCII 和 CD64MHCII 巨噬细胞群是从卵黄囊红髓造血前体细胞、胚胎造血和新生新生儿单核细胞中依次出现的。虽然单核细胞是附睾和睾丸中两种巨噬细胞的主要发育来源，但在稳态下，它们都可以独立于骨髓造血前体自我维持。然而，在辐射诱导的巨噬细胞耗竭或感染后，骨髓来源的循环单核细胞被招募到附睾和睾丸中，产生促炎巨噬细胞，导致组织损伤。这些结果定义了男性生殖器官中巨噬细胞群体的分层发生、维持和炎症反应。
