PT  - JOURNAL ARTICLE
AU  - Jackson S. Turner
AU  - Fang Ke
AU  - Irina L. Grigorova
TI  - B cell receptor crosslinking can augment T cell help-mediated germinal center B cell selection
AID  - 10.1101/300939
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 300939
4099  - http://biorxiv.org/content/early/2018/04/14/300939.short
4100  - http://biorxiv.org/content/early/2018/04/14/300939.full
AB  - Selection of germinal center (GC) B cells with B cell receptors (BCR) possessing high affinity to foreign antigen (Ag) and their differentiation into antibody-secreting long-lived plasma cells is critical for potent long-term humoral immunity. Ag-dependent engagement of GC B cell BCR triggers Ag internalization and loading of antigenic peptides on MHCII molecules for presentation to follicular helper T cells (Tfh) and acquisition of T cell help. However, whether it also provides signals that are critical or synergistic with T cell help for GC B cell selection and differentiation in vivo is not known. Here we show that T cell help is sufficient to induce GC B cell expansion and plasmablast (PB) formation in the absence of recurrent BCR engagement with Ag. Ag-mediated BCR crosslinking on the other hand is not sufficient to promote GC B cell selection, but can synergize with T cell help to enhance the GC B cell and PB responses when T cell help is limiting.