AUTHOR=Benet Zachary L. , Marthi Matangi , Ke Fang , Wu Rita , Turner Jackson S. , Gabayre Jahan B. , Ivanitskiy Michael I. , Sethi Sahil S. , Grigorova Irina L. 

TITLE=CCL3 Promotes Germinal Center B Cells Sampling by Follicular Regulatory T Cells in Murine Lymph Nodes

JOURNAL=Frontiers in Immunology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2018.02044

DOI=10.3389/fimmu.2018.02044

ISSN=1664-3224

ABSTRACT=<p>Previous studies and our findings suggest upregulated expression of proinflammatory chemokines CCL3/4 in germinal center (GC) centrocytes. However, the role of CCL3/4 for centrocyte interactions with follicular T cells and regulation of humoral immunity is poorly understood. We found that CCL3 promotes chemotaxis of Tfr cells <italic>ex vivo</italic>. Two-photon imaging revealed that B cells-intrinsic production of CCL3 promotes their probing by follicular regulatory T cells (Tfr) within GCs of murine lymph nodes. Overall this study suggests that CCL3 facilitates direct interactions of foreign antigen-specific GC B cells and their negative regulation with Tfr cells <italic>in vivo</italic>.</p>