118 Granzyme B producing B cells in systemic lupus erythematosus patients and lupus-like mouse models

Abstract

Background Systemic lupus erythematosus (SLE) is a chronic and systemic autoimmune disease, which is accompanied by abnormal activation of T/B lymphocytes, multiple autoantibodies and immune complex deposition. Granzyme B producing (GrB+) B cells are a group of new regulatory B cell subsets, which can participate in the pathogenesis of autoimmune disease, but its role in SLE is not clear. In this study, we investigate the expression level of Granzyme B producing B cells in SLE patients and lupus-like mouse models. Methods 1. Patients with SLE (n=7) meeting 1997 American College of Rheumatology revised criteria were enrolled from the Department of Rheumatology and Immunology. 15 healthy individual samples were obtained from physical examination center in our hospital. We collected 4 mL peripheral anticoagulant blood from both groups and peripheral blood mononuclear cells were isolated. The proportion of GrB +B cells in PBMC was identified by flow cytometry. 2. A lupus-like mouse model induced by transfer of spleen cells from bm12 mice was constructed. Two wildtype C57BL/c mice and two lupus-like mouse models (both 68 weeks old mice) were sacrificed by CO2anesthesia. The spleens of the mice were aseptically isolated, and the spleen single cells were obtained after grinding the tissues. The ratio of GrB +Breg cells in the spleen cells of the two groups was detected by flow cytometry (FACS). 3. SPSS24.0 software was used for statistical analysis, and p Results 1. Using flow cytometry 7AAD label excludes dead cells, CD3 marker excludes T lymphocytes and CD56 markers exclude NK cells. After CD14 labeling excludes monocytes/macrophages, the proportion of GrB +Breg cells in peripheral blood of healthy controls was 7.52%; Compared with healthy controls, the proportion of GrB +Breg cells in peripheral blood of SLE patients (4.45%) showed a significant downward trend. 2. Compared with the wild type control mice, the proportion of GrB +Breg cells in the spleen cells of lupus mouse model (2.14%) showed a significant downward trend. Conclusions The proportion of GrB +Breg cells in the peripheral blood of SLE patients and the spleen cells of lupus-like mouse models showed a downward trend, which may be related to the pathogenesis of SLE, but the exact role remains to be further verified. Funding Source(s): This study was supported by grants from the National Natural Science Foundation of China.