AUTHOR=Zhong Ziwen , Nan Ke , Weng Meilin , Yue Ying , Zhou Wenchang , Wang Zhiqiang , Chu Yiwei , Liu Ronghua , Miao Changhong 

TITLE=Pro- and Anti- Effects of Immunoglobulin A- Producing B Cell in Tumors and Its Triggers

JOURNAL=Frontiers in Immunology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2021.765044

DOI=10.3389/fimmu.2021.765044

ISSN=1664-3224

ABSTRACT=<p>B cells are well known as key mediators of humoral immune responses <italic>via</italic> the production of antibodies. Immunoglobulin A (IgA) is the most abundantly produced antibody isotype and provides the first line of immune protection at mucosal surfaces. However, IgA has long been a divisive molecule with respect to tumor progression. IgA exerts anti- or pro-tumor effect in different tumor types. In this review, we summarize emerging evidence regarding the production and effects of IgA and IgA<sup>+</sup> cells in the tumor microenvironment (TME). Moreover, we discuss that the TME cytokines, host diet, microbiome, and metabolites play a pivotal role in controlling the class-switch recombination (CSR) of IgA. The analysis of intratumoral Ig repertoires and determination of metabolites that influence CSR may help establish novel therapeutic targets for the treatment of cancers.</p>