AUTHOR=Horn Sacha , Ritter Manuel , Arndts Kathrin , Borrero-Wolff Dennis , Wiszniewsky Anna , Debrah Linda Batsa , Debrah Alexander Y. , Osei-Mensah Jubin , Chachage Mkunde , Hoerauf Achim , Kroidl Inge , Layland Laura E. TITLE=Filarial Lymphedema Patients Are Characterized by Exhausted CD4+ T Cells JOURNAL=Frontiers in Cellular and Infection Microbiology VOLUME=11 YEAR=2022 URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2021.767306 DOI=10.3389/fcimb.2021.767306 ISSN=2235-2988 ABSTRACT=

Worldwide, more than 200 million people are infected with filariae which can cause severe symptoms leading to reduced quality of life and contribute to disability-adjusted life years (DALYs). In particular, lymphatic filariasis (LF) caused by Wuchereria bancrofti can lead to lymphedema (LE) and consequently presents a serious health problem. To understand why only a fraction of the infected individuals develop pathology, it is essential to understand how filariae regulate host immunity. The central role of T cells for immunity against filariae has been shown in several studies. However, there is little knowledge about T cell exhaustion, which causes T cell dysfunction and impaired immune responses, in this group of individuals. Recently, we showed that LE patients from Ghana harbor distinct patterns of exhausted effector and memory CD8+ T cell subsets. Based on these findings, we now characterized CD4+ T cell subsets from the same Ghanaian patient cohort by analyzing distinct markers within a 13-colour flow cytometry panel. We revealed that LE patients had increased frequencies of CD4+ T cells expressing exhaustion-associated receptors such as KLRG-1, TIM-3 and PD-1 compared to healthy endemic normal and W. bancrofti-infected individuals. Moreover, CD4+ T cells in LE patients were characterized by distinct co-expression patterns of inhibitory receptors. Collectively with the previous findings on CD8+ T cell exhaustion patterns, the data shown here demonstrates that filarial LE patients harbor distinct subsets of exhausted T cells. Thus, T cell exhaustion patterns in LE patients need attention especially in regards to susceptibility of concomitant infections and should be taken into consideration for LE management measures.