Department of Life Science, Fu-Jen Catholic University, New Taipei, Taiwan; Institute of Applied Science & Engineering, Fu-Jen Catholic University, New Taipei, Taiwan.
Department of Life Science, Fu-Jen Catholic University, New Taipei, Taiwan.
Biomed J. 2024 Apr;47(2):100628. doi: 10.1016/j.bj.2023.100628. Epub 2023 Jul 23.
DnaJ homolog subfamily A member 3 (DNAJA3), also known as the tumorous imaginal disc (Tid1), is shown to be crucial in T cell development. DNAJA3 functions as a tumor suppressor implicated in lymphocyte development and survival. However, the role of DNAJA3 in B cell development and immune function remains unknown. In this study, we utilized a mouse model of B cell-specific DNAJA3 knockout (CD19-Cre/; DNAJA3) to investigate the physiological function of DNAJA3 in B cell development and immune function.
We characterized B cell populations in various developmental stages and examined mitochondrial content and function between control and DNAJA3 KO using flow cytometry analysis. DNAJA3 and OXPHOS protein complexes in sorted B cells between mice groups were compared using immunoblot techniques. The activity of B cell blastogenesis in splenocytes was measured by performing CFSE and MTT assays. Furthermore, immunoglobulin production was detected using the ELISA method.
DNAJA3 deficiency decreases from pro B cells to immature B cells. The overall B220 population in the bone marrow and secondary immune organs also decreased. B cell subpopulations B1 (B1b) and B2 significantly decrease. The B cell blastogenesis activity and immunoglobulin production decreased in DNAJA3 KO mice. Mechanistically, DNAJA3 deficiency significantly increases dysfunctional mitochondria activity and decreases mitochondrial mass, membrane potential, and mitochondria respiratory complex proteins. These factors could have influenced B cell differentiation during development, differentiation to antibody-secreting cells, and immune activation.
Overall, our study provides supportive evidence for the role of DNAJA3 in B cell development and function.
DNAJ 同源物亚家族 A 成员 3（DNAJA3），也称为肿瘤性 imaginal 盘（Tid1），在 T 细胞发育中被证明是至关重要的。DNAJA3 作为一种肿瘤抑制因子，参与淋巴细胞的发育和存活。然而，DNAJA3 在 B 细胞发育和免疫功能中的作用尚不清楚。在这项研究中，我们利用 B 细胞特异性 DNAJA3 敲除（CD19-Cre/；DNAJA3）的小鼠模型，研究了 DNAJA3 在 B 细胞发育和免疫功能中的生理功能。
我们在各种发育阶段对 B 细胞群体进行了特征描述，并使用流式细胞术分析比较了对照组和 DNAJA3 KO 组之间的线粒体含量和功能。使用免疫印迹技术比较了两组小鼠分选 B 细胞中的 DNAJA3 和 OXPHOS 蛋白复合物。通过 CFSE 和 MTT 测定法测量脾细胞中 B 细胞母细胞的活性。此外，使用 ELISA 法检测免疫球蛋白的产生。
DNAJA3 缺乏导致从前 B 细胞到未成熟 B 细胞的减少。骨髓和次级免疫器官中的总体 B220 群体也减少。B 细胞亚群 B1（B1b）和 B2 明显减少。DNAJA3 KO 小鼠的 B 细胞母细胞的活性和免疫球蛋白的产生减少。在机制上，DNAJA3 缺乏会显著增加功能失调的线粒体活性，并降低线粒体质量、膜电位和线粒体呼吸复合物蛋白。这些因素可能影响了 B 细胞在发育过程中的分化、分化为抗体分泌细胞以及免疫激活。
总的来说，我们的研究为 DNAJA3 在 B 细胞发育和功能中的作用提供了支持性证据。
