T cells in renal cell carcinoma (RCC) patients display multiple features of impairment and exhaustion. Here, we hypothesize that Astragalus membranaceus, a herbal medicine commonly used to accompany chemotherapy, might have adjuvating effects on T cells from RCC patients. To investigate this, circulating T cells from healthy individuals and RCC patients were cocultured ex vivo with aqueous extract from Astragalus. Functional characteristics of T cells in the absence and presence of Astragalus extract were then compared. We first identified a downregulation of IL-21 expression in RCC patients in association with a functional dysregulation of CXCR5 Tfh-like cells. Astragalus extract could significantly increase IL-21 expression in a dose-dependent manner. This Astragalus-mediated effect depended on the presence of antigen-presenting cells (APCs), as purified CXCR5 Tfh-like cells presented little IL-21 upregulation following Astragalus stimulation. APCs primed by Astragalus extract also promoted IL-21 expression from Tfh-like cells. Interestingly, Astragalus-stimulated Tfh-like cells presented enhanced helper function and resulted in higher humoral responses and better CD8 T cell survival. This effect was dependent on the presence of IL-21. Overall, these data indicated that Astragalus could enhance IL-21 production and effector function from CXCR5 Tfh-like cells in a manner that depended on the presence of APCs.Copyright © 2021 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.
About The Expert
Qin Dong
Jin Pu
Tingting Du
Shenqian Xu
Wuxia Liu
Ling Liu
Zhenlong Wang
Chen Cai
References
PubMed