Effects Of WASp Deficiency On IL-10-Producing Regulatory B Cells And Clinical Research On Atypical Severe Combined Immunodeficiency

Part One EFFECTS OF WASp DEFICIENCY ON IL-10-PRODUCING REGULATORY B CELLSObjective:To test the hypothesis that WASp deficiency would perturb the homeostasis of B10 cells and further contribute to the autoimmunity in patients with Wiskott-Aldrich syndrome (WAS).Methods:We measured the percentage of B10 cells, regulatory T cells (Tregs) and Th1 cells in WASp KO mice, and the percentage of BIO cells in patients with WAS by flow cytometry. We also used the non-induced autoimmune WASp KO mouse model to investigate the association between B10 numbers and the Treg/Thl balance.Results:The percentage of B10 cells in WAS patients was reduced significantly (0.75±0.29, n=9 versus 2.01±0.60, n=14; P=0.0002). And so was the percentage of B10+B10pro cells (1.09±0.58, n=6 versus 2.65± 0.58, n=9; P=0.0004). In WASp KO mice, percentages of B10 cells from peripheral blood, peritoneal cavity, spleen and mesenteric lymph nodes were all reduced (1.20±0.65, n=7 versus 2.06±0.43, n=7; 10.72±5.05, n=6 versus 22.51±6.69, n=7; 0.71±0.17, n=7 versus 1.52±0.80, n=7; 0.74±0.16, n=6 versus 1.89±0.47, n=5; P<0.05). In old WASp KO mice with autoimmune colitis, percentages of B10 cells from peritoneal cavity, spleen and mesenteric lymph nodes were all reduced (8.30+3.90, n=6 versus 15.81±6.87, n=9; 0.90±0.16, n=6 versus 1.49±0.35, n=7; 0.57± 0.25, n=3 versus 1.41±0.40, n=7; P<0.05), but peripheral blood B10 cells (P=0.2284). What’s more, the old WASp KO mice with autoimmune colitis showed increased Thl cells in the peritoneal cavity (33.17+14.35, n=6 versus 14.38±6.42, n=7; P<0.05), but in mesenteric lymph nodes (P=0.2403), and decreased Treg cells in both peritoneal cavity (1.07±0.65, n=9 versus 1.83±0.51, n=7; P<0.05) and mesenteric lymph nodes (3.17± 0.62, n=6 versus 5.42±0.85, n=7; P<0.05).Conclusions:These findings suggest that WASp plays a crucial role in B10 cells development, and that WASp-deficient B10 cells may contribute to autoimmunity in WASp KO mice.Part Two CLINICAL RESEARCH ON ATYPICAL SEVERE COMBINED IMMUNODEFICIENCYObjective:To introduce the concept of atypical severe combined immunodeficiency to domestic physicians, especially pediatric immunologists; to collect all known reported cases and retract the information of clinical manifestations, especially the immunologic manifestations, thus helping to make early diagnosis of this disease.Methods:We here summarized the cases reported ever until 12 June, 2013 and analyzed the clinical manifestations, immunophenotype and molecular characteristics.Results:The onset age ranged from 3 mon to 17 y, and the median age was 9 mon. The age at diagnosis ranged from 10 mon to 41 y, and the median age was 5 y. The infection was less severe (with no complications nor sequelae) for those whose infection interval was shorter (one month or so), while the infection was more severe (with complications or sequelae) for those whose infection interval was longer (months even years). Many patients in this cohort showed only slightly affected proliferation response of T cells to PHA, with ADA (7/19), JAK3 (6/8), Artemis (3/3), RAG1/2 (11/11). The immunoglobulin level remained low to normal, with ADA (9/20), Artemis (3/3), RAG1/2 (11/11).Conclusions:We found that these patients, compared to typical SCID patients, were very different in terms of infection characteristics, lymphocyte count, anti-body response and lymphocyte proliferation and so on. The awareness of atypical severe combined immunodeficiency is lacking in domestic medical community. But with the clinical and molecular characteristics summarized in our research, we can make more rapid and accurate diagnosis for the atypical cases with SCID.