Deletion of immune regulatory factor Fgl2 affects the mouse spleen immune profile

Transcription profiles identified 18 cell types, including 9 B cell subsets, 5 T cell subsets, pc cells, monocytes, natural killer (NK) cells, and dc cells. Compared with WT group, the proportion of naive B cells, transitional B cells, marginal B cells, follicular B cells, CD4-T naive, CD8-T naive, CD4-T regulatory subsets, NKT, NK and DC subsets in Fgl2 KO group decreased. The proportion of PCs, CD4-Tem and monocyte subsets increased. Notably, we identified four new B cell subpopulations in the Fgl2 KO group that cannot be classified as classical B cell subpopulations and are therefore named B cell_sp1, B cell_sp2, B cell_sp3, and B cell_sp4.B cell_sp1 subgroup showed dominant clones of IGHA, IGHM and IGHD in the constant region, while the other 3 different subgroups and pc only showed dominant clones of IGHA in the constant region. This suggests that IGHA clones are most abundant and dominant in Fgl2 KO B cells. In addition, we analyzed in detail the number of different BCR heavy chain genes and related VH gene fragments in the Fgl2 KO-specific B cell subpopulation. At the same time, they also highly express Ccl5, Ccl4, Cxcl2, Cxcl10, Slpi, S100a8, S100a9, Fcer1g and IL-1b genes, which are involved in the regulation of immune process and molecular function. In addition, these specific B cells also highly express genes. Such as PDCD1, HAVCR2, CTLA4 and ICOS, suggesting that these B cells are more likely to fail and may not survive for long.