CD4 and periodontitis: Specifically, the plasma and naive B cells and neutrophils were all elevated in the periodontitis group, when compared to those for healthy controls (Fig. 1), while memory B cells, resting dendritic, mast and CD4 memory cells, as well as activated mast cells, M1 and M2 macrophages, and follicular helper T cells, were higher in healthy periodontal tissues versus periodontitis tissues (Fig. 1c and e).