Differences in mouse strain influence leukocyte and immunoglobulin phenotype response to Porphyromonas gingivalis

This study examined the nature of the infiltrating cells in Porphyromonas gingivalis-induced lesions and immunoglobulins in the serum samples of BALB/c (H-2d), C57BL6 (H-2b), DBA/2J (H-2d) and CBA/CaH (H-2k) mice. Mice were immunized intraperitoneally with P. gingivalis outer membrane antigens or sham-immunized with phosphate-buffered saline followed by subcutaneous challenge with live organisms 1 week after the final immunization. The resulting skin abscesses were excised 7 days later, cryostat sections cut and an immunoperoxidase method used to detect the presence of CD4+ and CD8+ T-cell subsets, CD14+ macrophages and CD19+ B cells. Peroxidase positive neutrophils and IgG1- and IgG2a-producing plasma cells were also identified. Anti P. gingivalis IgG1 and IgG2a subclass antibodies were determined in serum obtained by cardiac puncture. Very few CD8+ T cells and CD19+ B cells were found in any of the lesions. The percentages of CD4+ cells, CD14+ cells and neutrophils were similar in lesions of immunized BALB/c and C57BL6 mice, with a trend towards a higher percentage of CD14+ cells in sham-immunized mice. The percentage of CD14+ cells was higher than that of CD4+ cells in immunized compared with sham-immunized DBA/2J mice. The percentages of CD4+ and CD14+ cells predominated in immunized CBA/CaH mice and CD4+ cells in sham-immunized CBA/CaH mice. The percentage of neutrophils in immunized CBA/CaH mice was significantly lower than that of CD14+ cells and CD4+ cells in sham-immunized mice. IgG1+ plasma cells were more dominant than IgG2a+ cells in immunized BALB/c, C57BL6 and DBA/2J mice, whereas IgG2a+ plasma cells were more obvious in sham-immunized mice. IgG2a+ plasma cells were predominant in immunized and sham-immunized CBA/CaH mice. In the serum, specific anti-P. gingivalis IgG2a antibody levels (Th1 response) were higher than IgG1 levels (Th2 response) in sham-immunized CBA/CaH and DBA/2J mice. In immunized BALB/c mice, IgG2a levels were lower than IgG1 levels, while IgG2a levels were higher in immunized C57BL6 mice. In conclusion, this study has shown differences in the proportion of infiltrating leukocytes and in the subclasses of immunoglobulin produced locally and systemically in response to P. gingivalis in different strains of mice, suggesting a degree of genetic control over the response to P. gingivalis.     

Role of helper T cells in the humoral immune responses against 53-kDa outer membrane protein from Porphyromonas gingivalis

Outer membrane protein with a 53-kDa molecular weight (Ag53) isolated from Porphyromonas gingivalis evokes strong humoral immune responses in many periodontitis patients. To examine the effects of cytokines produced by Ag53-specific Th cells on the IgG production against Ag53, we established Ag53-specific Th-cell lines from patients with early onset periodontitis and from healthy volunteers. We then developed a mixed lymphocyte culture system between Ag53-specific Th cells and auto- or allo-derived T-cell-depleted leukocytes produced from the subjects whose HLA class II haplotypes were completely matched. Interferon-gamma production was observed in all Th cell lines from patients and healthy subjects. As for Th2 type cytokines, interleukin (IL)-4, IL-5, IL-6 and IL-10 production varied greatly in Th cells regardless of the periodontal condition of the donor. Only Th cell lines with a high Th2/Th1 ratio induced Ag53-specific IgG production when cocultured with T-cell-depleted leukocytes. Thus, the difference in Th2/Th1 balance may regulate the Ag53-specific IgG production.     

伴免疫球蛋白G 沉积原发性膜性肾病病人疾病缓解影响因素及与肾小球免疫球蛋白G4 表达强度的关系研究

目的 探讨伴免疫球蛋白(Ig)G沉积原发性膜性肾病(PMN)病人疾病缓解影响因素及与肾小球IgG4表达强度的关系。方法 回顾性纳入山西省运城市中心医院2014年1月至2020年1月收治伴IgG沉积PMN病人共500例,根据有无IgG4表达和表达强度分组,分析临床病理及随访预后资料,采用单因素和多因素Cox回归模型评价伴IgG沉积PMN病人疾病缓解独立影响因素。结果 阳性组24 h尿蛋白量和M型磷脂酶A2受体(PLA2R)表达强度比例显著高于阴性组(P<0.05);弱阳性组、中阳性组及强阳性组血浆白蛋白、IgG1强度比例及IgA强度比例比较差异有统计学意义(P<0.05);阴性组、弱阳性组、中阳性组及强阳性组随访3个月( 30.0%比17.3%比15.9%比9.5%)和6个月(38.4%比30.6%比26.5%比13.0%)累积缓解率比较差异有统计学意义(P<0.05);Cox回归模型单因素和多因素分析结果显示,IgG4阳性高强度、男性、基线高24 h尿蛋白量均是伴IgG沉积PMN病人疾病未缓解独立危险因素［RR=1.33,95%CI:(1.05,1.61);RR=1.80,95%CI:(1.17,3.04);RR=1.51,95%CI:(1.09,2.80)。P<0.05］。结论 伴IgG沉积PMN病人疾病缓解效果与IgG4表达强度、性别及基线24 h尿蛋白量密切相关;而肾小球IgG4表达强度可作为PMN治疗反应性潜在评估指标加以应用。     

PLA2R、 THSD7A与IgG亚型在特发性膜性肾病中的诊断价值

目的探讨特发性膜性肾病(idiopathic membranous nephropathy,IMN)患者血清抗磷脂酶A2受体(phospholipase A2 receptor,PLA2R)抗体水平、肾小球PLA2R、1型血小板反应蛋白7A域(thrombospondin type I domain containing 7A,THSD7A)、免疫球蛋白G(immunoglobulin G,IgG)亚型的表达及其在IMN中的诊断价值。方法选取2016年1月至2019年6月在雅安市人民医院肾内科经肾活检并确诊的IMN患者72例,以同期72例非IMN肾小球疾病患者为对照。采用酶联免疫吸附法检测血清抗PLA2R抗体滴度,免疫荧光法检测肾小球PLA2R、THSD7A及IgG亚型表达。采用受试者工作特征(ROC)曲线分析血清抗PLA2R抗体、肾小球PLA2R、THSD7A、IgG4诊断IMN的价值。结果血清抗PLA2R抗体、肾小球PLA2R、IgG4、THSD7A诊断IMN的灵敏度分别为61.11%、80.56%、97.22%、8.33%,特异度分别为97.22%、100.00%、97.22%、100.00%。血清抗PLA2R抗体和肾小球PLA2R任一指标阳性即诊断IMN的敏感性为83.33%;肾小球PLA2R、THSD7A和IgG4中任一指标阳性即诊断IMN的敏感性为97.22%。结论血清抗PLA2R抗体、肾小球PLA2R、THSD7A及IgG4亚型对于IMN诊断具有较高的临床价值。血清抗PLA2R抗体及肾小球PLA2R抗原的联合检测,肾小球PLA2R、THSD7A与IgG4的联合检测可以增加IMN诊断的敏感性。     

Tissue-associated self-antigens containing exosomes: Role in allograft rejection

Exosomes are extracellular vesicles that express self-antigens (SAgs) and donor human leukocyte antigens. Tissue-specific exosomes can be detected in the circulation following lung, heart, kidney and islet cell transplantations. We collected serum samples from patients who had undergone lung (n?=?30), heart (n?=?8), or kidney (n?=?15) transplantations to isolate circulating exosomes. Exosome purity was analyzed by Western blot, using CD9 exosome-specific markers. Tissue-associated lung SAgs, collagen V (Col-V) and K-alpha 1 tubulin (Kα1T), heart SAgs, myosin and vimentin, and kidney SAgs, fibronectin and collagen IV (Col-IV), were identified using western blot. Lung transplant recipients diagnosed with bronchiolitis obliterans syndrome had exosomes with higher expression of Col-V (4.2-fold) and Kα1T (37.1-fold) than stable. Exosomes isolated from heart transplant recipients diagnosed with coronary artery vasculopathy had a 3.9-fold increase in myosin and a 4.7-fold increase in vimentin compared with stable. Further, Kidney transplant recipients diagnosed with transplant glomerulopathy had circulating exosomes with a 2-fold increased expression of fibronectin and 2.5-fold increase in Col-IV compared with stable. We conclude that circulating exosomes with tissue associated SAgs have the potential to be a noninvasive biomarker for allograft rejection.     

Antigen‐specific airway IL‐33 production depends on FcγR‐mediated incorporation of the antigen by alveolar macrophages in sensitized mice

Although interleukin (IL)‐33 is a candidate for the aggravation of asthma, the mechanisms underlying antigen‐specific IL‐33 production in the lung are unclear. Therefore, we analysed the mechanisms in mice. Intra‐tracheal administration of ovalbumin (OVA) evoked increases in IL‐33 and IL‐33 mRNA in the lungs of both non‐sensitized and OVA‐sensitized mice, and the increases in the sensitized mice were significantly higher than in the non‐sensitized mice. However, intra‐tracheal administration of bovine serum albumin did not increase the IL‐33 level in the OVA‐sensitized mice. Depletion of neither mast cells/basophils nor CD4⁺ cells abolished the OVA‐induced IL‐33 production in sensitized mice, suggesting that the antigen recognition leading to the IL‐33 production was not related with either antigen‐specific IgE‐bearing mast cells/basophils or memory CD4⁺ Th2 cells. When a fluorogenic substrate‐labelled OVA (DQ‐OVA) was intra‐tracheally administered, the lung cells of sensitized mice incorporated more DQ‐OVA than those of non‐sensitized mice. The lung cells incorporating DQ‐OVA included B‐cells and alveolar macrophages. The allergic IL‐33 production was significantly reduced by treatment with anti‐FcγRII/III mAb. Depletion of alveolar macrophages by clodronate liposomes significantly suppressed the allergic IL‐33 production, whereas depletion of B‐cells by anti‐CD20 mAb did not. These results suggest that the administered OVA in the lung bound antigen‐specific IgG Ab, and then alveolar macrophages incorporated the immune complex through FcγRII/III on the cell surface, resulting in IL‐33 production in sensitized mice. The mechanisms underlying the antigen‐specific IL‐33 production may aid in development of new pharmacotherapies.