The world population is undergoing a rapid expansion of older adults. Aging is associated with numerous changes that affect all organs and systems, including every component of the immune system. Immunosenescence is a multifaceted process characterized by poor response to vaccine and higher incidence of bacterial and viral infections, cancer, cardiovascular and autoimmune diseases. Immunosenescence has been associated with chronic low-grade inflammation referred to as inflammaging, whose underlying mechanisms remain incompletely elucidated, including age-related changes affecting components of the innate and adaptive immune system. T follicular helper (T_FH) cells, present in lymphoid organs and in peripheral blood, are specialized in providing cognate help to B cells and are required for the production of immunoglobulins. Several subsets of T_FH cells have been identified in humans and mice and modifications in T_FH cell phenotype and function progressively occur with age. Dysfunctional T_FH cells play a role in cancer, autoimmune and cardiovascular diseases, all conditions particularly prevalent in elderly subjects. A specialized population of Treg cells, named T follicular regulatory (T_FR) cells, present in lymphoid organs and in peripheral blood, exerts opposing roles to T_FH cells in regulating immunity. Indeed, changes in T_FH/T_FR cell ratio constitute a relevant feature of aging. Herein we discuss the cellular and molecular changes in both T_FH cells and T_FR cells that occur in aging and recent findings suggesting that T_FH cells and/or their subsets could be involved in atherosclerosis, cancer, and autoimmunity.

世界人口正在迅速增长的老年人。衰老与影响所有器官和系统（包括免疫系统的每个组成部分）的众多变化相关。免疫衰老是一个多方面的过程，其特征在于对疫苗的反应较差，细菌和病毒感染，癌症，心血管疾病和自身免疫性疾病的发生率较高。免疫衰老与慢性低度炎症（称为发炎）有关，其潜在机制仍未完全阐明，包括与年龄相关的变化会影响先天性和适应性免疫系统的组成部分。卵泡辅助糖（T _FH存在于淋巴器官和外周血中的细胞专门为B细胞提供同源帮助，是产生免疫球蛋白所必需的。已经在人和小鼠中鉴定出_TFH细胞的几个子集，并且随着年龄的增长，_TFH细胞表型和功能的修饰逐渐发生。功能失调的T _FH细胞在癌症，自身免疫性疾病和心血管疾病中起作用，所有情况在老年人中尤为普遍。存在于淋巴器官和外周血中的称为T卵泡调节（T _FR）细胞的Treg细胞专门化群体在调节免疫力方面与T _FH细胞起相反的作用。确实，T _FH / T的变化_FR细胞比例构成衰老的相关特征。在本文中，我们讨论了在衰老中发生的T _FH细胞和T _FR细胞中的细胞和分子变化，最近的发现表明T _FH细胞和/或其子集可能与动脉粥样硬化，癌症和自身免疫有关。