Kaji Tomohiro, Hijikata Atsushi, Ishige Akiko, Kitami Toshimori, Watanabe Takashi, Ohara Osamu, Yanaka Noriyuki, Okada Mariko, Shimoda Michiko, Taniguchi Masaru, Takemori Toshitada
Laboratory for Immunological Memory, RIKEN Research Center for Allergy and Immunology, 1-7-22, Suehirocho, Tsurumi, Yokohama, Kanagawa 230-0045, Japan.
Immunogenomics, RIKEN Research Center for Allergy and Immunology, 1-7-22, Suehirocho, Tsurumi, Yokohama, Kanagawa 230-0045, Japan.
Int Immunol. 2016 Jun;28(6):267-82. doi: 10.1093/intimm/dxv071. Epub 2015 Dec 29.
Memory CD4(+) T cells promote protective humoral immunity; however, how memory T cells acquire this activity remains unclear. This study demonstrates that CD4(+) T cells develop into antigen-specific memory T cells that can promote the terminal differentiation of memory B cells far more effectively than their naive T-cell counterparts. Memory T cell development requires the transcription factor B-cell lymphoma 6 (Bcl6), which is known to direct T-follicular helper (Tfh) cell differentiation. However, unlike Tfh cells, memory T cell development did not require germinal center B cells. Curiously, memory T cells that develop in the absence of cognate B cells cannot promote memory B-cell recall responses and this defect was accompanied by down-regulation of genes associated with homeostasis and activation and up-regulation of genes inhibitory for T-cell responses. Although memory T cells display phenotypic and genetic signatures distinct from Tfh cells, both had in common the expression of a group of genes associated with metabolic pathways. This gene expression profile was not shared to any great extent with naive T cells and was not influenced by the absence of cognate B cells during memory T cell development. These results suggest that memory T cell development is programmed by stepwise expression of gatekeeper genes through serial interactions with different types of antigen-presenting cells, first licensing the memory lineage pathway and subsequently facilitating the functional development of memory T cells. Finally, we identified Gdpd3 as a candidate genetic marker for memory T cells.
记忆性CD4(+) T细胞促进保护性体液免疫;然而,记忆性T细胞如何获得这种活性仍不清楚。本研究表明,CD4(+) T细胞发育成为抗原特异性记忆性T细胞,与初始T细胞相比,其促进记忆性B细胞终末分化的效率要高得多。记忆性T细胞的发育需要转录因子B细胞淋巴瘤6(Bcl6),已知该因子可指导滤泡辅助性T(Tfh)细胞分化。然而,与Tfh细胞不同,记忆性T细胞的发育不需要生发中心B细胞。奇怪的是,在没有同源B细胞的情况下发育的记忆性T细胞不能促进记忆性B细胞的回忆反应,并且这种缺陷伴随着与稳态和激活相关基因的下调以及对T细胞反应具有抑制作用基因的上调。尽管记忆性T细胞表现出与Tfh细胞不同的表型和基因特征,但两者都共同表达了一组与代谢途径相关的基因。这种基因表达谱在很大程度上与初始T细胞不共享,并且在记忆性T细胞发育过程中不受同源B细胞缺失的影响。这些结果表明,记忆性T细胞的发育是通过与不同类型抗原呈递细胞的系列相互作用,由守门基因的逐步表达来编程的,首先许可记忆细胞谱系途径,随后促进记忆性T细胞的功能发育。最后,我们将Gdpd3鉴定为记忆性T细胞的候选遗传标志物。