A subset of leukocyte immune-type receptors (LITRs) regulates phagocytosis in channel catfish (Ictalurus punctatus) leukocytes
A subset of leukocyte immune-type receptors (LITRs) regulates phagocytosis in channel catfish (Ictalurus punctatus) leukocytes
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DOI：
10.1016/j.molimm.2022.12.009
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发表时间：
2022-12-29
影响因子：
3.6
通讯作者：
Bengten，Eva
中科院分区：
文献类型：
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作者：
Crider，Jonathan;Wilson，Melanie;Bengten，Eva
斑点叉尾鱼白细胞免疫型受体（LITRs）是硬骨鱼类特有的一个免疫调节受体大家族。基于在哺乳动物细胞系中的研究，已经提出了LITR在吞噬作用中的作用;然而，尚未在鲶鱼模型中检查LITR介导的吞噬作用。在这项研究中，我们使用两种抗LITR单克隆抗体，CC 41和125.2，来对比抑制性和激活性LITR的交联亚群的作用。简言之，使用mAb缀合的荧光微珠使鲶鱼γδ T细胞、αβ T细胞和巨噬细胞系表达的LITR交联，并通过流式细胞术评价珠摄取，并通过共聚焦显微镜证实。观察到125.2-和CC 41-缀合珠的摄取的明显差异。LITR与mAb 125.2的交联导致有效的珠子内化，而mAb CC 41与抑制性LITR的交联主要导致捕获表型。用mAb CC 41预处理鲶鱼巨噬细胞导致LITR介导的125.2缀合珠的吞噬作用显著降低。总的来说，这些发现提供了对鱼类免疫生物学的深入了解，并验证了LITR作为鲶鱼巨噬细胞和γδ T细胞中吞噬作用的调节剂。
Channel catfish,Ictalurus punctatus,leukocyte immune-type receptors (LITRs) constitute a large family of paired, immunoregulatory receptors unique to teleosts. A role for LITRs in phagocytosis has been proposed based on studies in mammalian cell lines; however, LITR-mediated phagocytosis has not been examined in the catfish model. In this study, we use two anti-LITR monoclonal antibodies, CC41 and 125.2, to contrast the effects of crosslinking subsets of inhibitory and activating LITRs. Briefly, LITRs expressed by catfish γδ T cells, αβ T cells, and macrophage cell lines were crosslinked using mAb-conjugated fluorescent microbeads, and bead uptake was evaluated by flow cytometry and confirmed by confocal microscopy. A clear difference in the uptake of 125.2- and CC41-conjugated beads was observed. Crosslinking LITRs with mAb 125.2 resulted in efficient bead internalization, while mAb CC41 crosslinking of inhibitory LITRs resulted predominantly in a capturing phenotype. Pretreating catfish macrophages with mAb CC41 resulted in a marked decrease in LITR-mediated phagocytosis of 125.2-conjugated beads. Overall, these findings provide insight into fish immunobiology and validate LITRs as regulators of phagocytosis in catfish macrophages and γδ T cells.