The interactions of CD4⁺ T cells and B cells are fundamental for the generation of protective antibody responses, as well as for the development of harmful autoimmune diseases. Recent studies of human tissues and blood samples have established a new subset of CD4⁺ B helper T cells named peripheral helper T (Tph) cells. Unlike T follicular helper (Tfh) cells, which interact with B cells within lymphoid organs, Tph cells provide help to B cells within inflamed tissues. Tph cells share many B helper-associated functions with Tfh cells and induce B cell differentiation toward antibody-producing cells. The differentiation mechanism is also partly shared between Tph and Tfh cells in humans, and both Tfh and Tph cells can be found within the same tissues, including cancer tissues. However, Tph cells display features distinct from those of Tfh cells, such as the expression of chemokine receptors associated with Tph cell localization within inflamed tissues and a low Bcl-6/Blimp1 ratio. Unlike that of Tfh cells, current evidence shows that the target of Tph cells is limited to memory B cells. In this review, we first summarize recent findings on human Tph cells and discuss how Tph and Tfh cells play shared and distinct roles in human diseases.

CD4 ⁺ T 细胞和 B 细胞的相互作用对于保护性抗体反应的产生以及有害自身免疫疾病的发展至关重要。最近对人体组织和血液样本的研究建立了一个新的 CD4 ⁺B 辅助 T 细胞称为外周辅助 T (Tph) 细胞。与与淋巴器官内的 B 细胞相互作用的 T 滤泡辅助 (Tfh) 细胞不同，Tph 细胞为发炎组织内的 B 细胞提供帮助。Tph 细胞与 Tfh 细胞共享许多 B 辅助相关功能，并诱导 B 细胞向抗体产生细胞分化。人类的 Tph 和 Tfh 细胞也部分共享了分化机制，并且 Tfh 和 Tph 细胞都可以在相同的组织中找到，包括癌组织。然而，Tph 细胞显示出与 Tfh 细胞不同的特征，例如与 Tph 细胞在炎症组织中的定位相关的趋化因子受体的表达和低 Bcl-6/Blimp1 比率。与 Tfh 细胞不同，目前的证据表明 Tph 细胞的目标仅限于记忆 B 细胞。在这次审查中，