CD4+Th细胞亚群
- Th1
- 分泌IL-12和IFN-γ
- 促炎，增加TLR（Toll样受体）、诱导细胞因子分泌或巨噬细胞激活
- 促进T细胞细胞免疫，促进T细胞和NK细胞的细胞毒作用
- Th-2
- 分泌IL-4，IL-2和TGF-β
- 促进体液免疫：促进antigen-primed的B细胞分化为浆细胞并产生抗体
- Treg
- 分泌IL-10
- immunosuppresive
-Th17
- 分泌IL-13
- 促炎，募集中性粒细胞
CD4 T 细胞的分化
Teff的CD127是阴性
CD4+细胞从原始细胞向效应记忆细胞和中央记忆细胞的分化。抗原呈递细胞递呈致病性抗原，原始T细胞就会被激活，细胞数量增加，并分化为效应细胞，这些效应细胞迁移到感染部位并消除病原体。效应细胞是短命细胞，而记忆细胞的一个子集是具有长期生存潜力的记忆细胞。记忆细胞可以位于次级淋巴器官（中央记忆细胞，TCM）或最近感染的组织-效应记忆细胞（TEM细胞）。在第二次免疫反应期间再次暴露于抗原，记忆T细胞经历快速扩增，产生更有效和更快的免疫反应。
记忆细胞通常有几个特点：1.先前扩展和激活的存在；2.在没有抗原的情况下持续存在；3.再次暴露于抗原后活性增加。
CD8 T细胞
CD8 T细胞分化
-
Central memory T cells (TCM): TCM lymphocytes have several attributes in common with stem cells, the most important being the ability of self-renewal, mainly because of high level of phosphorylation on key transcription factor STAT5. In mice, TCM proved to confer more powerful immunity against viruses, bacteria and cancer cells, compared to TEM lymphocytes in several experimental models.
-
Effector memory T cells (TEM): TEM and TEMRA lymphocytes are primarily active as the CD8 variants, thus being mainly responsible for cytotoxic action against pathogens.
-
Tissue-resident memory T cell(TRM): Because TRM lymphocytes are present over long periods of time in tissues, or more importantly, barrier tissues (epithelium for example), they are crucial for quick response to barrier breach and response to any relevant pathogen present. One mechanism used by TRM to restrict pathogens is the secretion of granzyme B.
-
Stem cell memory T cells (TSCM): Those lymphocytes are capable of self-renewal as are the TCM lymphocytes and are also capable of generating both the TCM and TEM subpopulations. Presence of this population in humans is currently under investigation.
-
Virtual memory T cell (TVM): As of now, the only function apparent in TVM cells is production of various cytokines,[7][8] but there are speculations about their influence in subduing unwanted immunological states and their usage in treating autoimmune disorders.[9]
网友评论