The number of central and peripheral B cells and their responsiveness are decreased in aged
mice. The diversity of mouse central and peripheral B cell repertoires with increasing age has not
been elucidated. In this study, we demonstrated that there were significant differences in the
usage of some V, D, and J genes in the BCR H-CDR3 repertoire of bone marrow B cells, spleen B
cells and spleen memory B cells in 3-, 12-, and 20-month-old mice. In the productive, pseudogene,
and out-of-frame sequences, bone marrow B cells had significant differences in 5′J trimming
with age; peripheral spleen B cells and memory B cells had significant differences in N1 insertion,
N2 insertion, P5'D insertion, and 5'D trimming with age. The BCR H-CDR3 repertoire diversity
of mouse bone marrow B cells, spleen B cells and spleen memory B cells decreased with
increasing age. The proportion of overlap in bone marrow and spleen B cells, but not spleen
memory B cells, of mice at different ages was lower at 3 months than at 12 and 20 months.This
study is the first to report the homogeneity and heterogeneity of the CDR3 repertoire of central
and peripheral B cells change as mice age , to further investigation of the decline and response of
B cell immunity in young/middle/old-aged mice.