Negative Feedback by NUR77/ <i>Nr4a1</i> Restrains B Cell Clonal Dominance During Early T-Dependent Immune Responses

B cell clones compete for entry into and dominance within germinal centers (GC), where the highest affinity BCRs are selected. However, diverse low cells can enter reside in GCs extended periods. To reconcile these observations, we hypothesized that a negative feedback loop may operate to preferentially restrain high from monopolizing early GC niche. Here report role nuclear receptor NUR77/Nr4a1 this process. We previously showed NUR77 expression scales with antigen stimulation restrains expansion when T help is limiting. show that, although dispensable regulating size elicited largely clonal manner, it serves curb immunodominance under conditions populations must constrained Moreover, independent of precursor frequency reflects, at least part, cell-intrinsic NUR77. propose important preserve diversity order limit holes post-immune repertoire optimize selection.