The differentiation of distinct leukocyte subsets is governed by lineage-specific growth factors that elicit disparate expression of transcription factors and markers by the developing cell populations. For example, macrophages (Mφs) and granulocytes (Grns) arise from common granulocyte-macrophage progenitors in response to distinct myeloid growth factors. In turn, myelopoiesis of the Xenopus laevis anuran amphibian appears to be unique to other studied vertebrates in several respects while the functional differentiation of amphibian Mφs and Grns from their progenitor cells remains poorly understood. Notably, the expression of colony stimulating factor-1 receptor (CSF-1R) or CSF-3R on granulocyte-macrophage progenitors marks their commitment to Mφ- or Grn-lineages, respectively. CSF-1R is activated by the colony stimulating factor-1 (CSF-1) and interleukin (IL-34) cytokines, resulting in morphologically and functionally distinct Mφ cell types. Conversely, CSF-3R is ligated by CSF-3 in a process indispensable for granulopoiesis. Presently, we explore the relationships between X. laevis CSF-1-Mφs, IL-34-Mφs and CSF-3-Grns by examining their expression of key lineage-specific transcription factor and myeloid marker genes as well as their enzymology. Our findings suggest that while the CSF-1- and IL-34-Mφs share some commonalities, the IL-34-Mφs possess transcriptional patterns more akin to the CSF-3-Grns. IL-34-Mφs also possess robust expression of dendritic cell-associated transcription factors and surface marker genes, further underlining the difference between this cell type and the CSF-1-derived frog Mφ subset. Moreover, the three myeloid populations differ in their respective tartrate-resistant acid phosphatase, specific- and non-specific esterase activity. Together, this work grants new insights into the developmental relatedness of these three frog myeloid subsets.

不同白细胞亚群的分化受谱系特异性生长因子的控制，这些生长因子通过发育中的细胞群引起转录因子和标记物的不同表达。例如，巨噬细胞 (Mφs) 和粒细胞 (Grns) 来自常见的粒细胞-巨噬细胞祖细胞，以响应不同的骨髓生长因子。反过来，爪蟾的骨髓生成anuran 两栖动物在几个方面似乎是其他研究的脊椎动物所独有的，而两栖动物 Mφs 和 Grns 从其祖细胞的功能分化仍然知之甚少。值得注意的是，集落刺激因子-1 受体 (CSF-1R) 或 CSF-3R 在粒细胞-巨噬细胞祖细胞上的表达标志着它们分别对 Mφ-或 Grn-谱系的承诺。CSF-1R 被集落刺激因子-1 (CSF-1) 和白介素 (IL-34) 细胞因子激活，导致形态和功能不同的 Mφ 细胞类型。相反，CSF-3R 在粒细胞生成必不可少的过程中被 CSF-3 连接。目前，我们探索X. laevis之间的关系CSF-1-Mφs、IL-34-Mφs 和 CSF-3-Grns 通过检查它们的关键谱系特异性转录因子和骨髓标记基因的表达以及它们的酶学。我们的研究结果表明，虽然 CSF-1- 和 IL-34-Mφs 有一些共同点，但 IL-34-Mφs 具有更类似于 CSF-3-Grns 的转录模式。IL-34-Mφ 还具有强大的树突细胞相关转录因子和表面标记基因的表达，进一步强调了这种细胞类型与 CSF-1 衍生的青蛙 Mφ 子集之间的差异。此外，这三个髓系群体在各自的抗酒石酸酸性磷酸酶、特异性和非特异性酯酶活性方面存在差异。总之，这项工作为这三个青蛙骨髓亚群的发育相关性提供了新的见解。