Rickettsia heilongjiangensis is an obligate intracellular bacterium that causes Far-Eastern tick-borne spotted fever. Outer membrane protein B(Omp B) is an important surface protein antigen of rickettsiae. In the pres...Rickettsia heilongjiangensis is an obligate intracellular bacterium that causes Far-Eastern tick-borne spotted fever. Outer membrane protein B(Omp B) is an important surface protein antigen of rickettsiae. In the present study, the omp B gene of R. heilongjiangensis was divided into four fragments, resulting in four recombinant proteins(OmpB-p1, Omp B-p2, Omp B-p3, and Omp B-p4). Each Omp B was used in vitro to stimulate murine bone marrow-derived dendritic cells(BMDCs) of C3H/He N mice, and the Omp B-pulsed BMDCs were transferred to naive C3H/He N mice. On day 14 post-transfer of BMDCs, the mice were challenged with R. heilongjiangensis and the rickettsial loads in the mice were quantitatively determined on day 7 post-challenge. Mice receiving BMDCs pulsed with Omp B-p2, Omp B-p3, or Omp B-p4 exhibited significantly lower bacterial load compared with mice receiving Omp B-p1-pulsed BMDCs. CD4+ and CD8+ T cells isolated from the spleen of C3H/He N mice receiving BMDCs pulsed with each OmpB were co-cultured with BMDCs pulsed with the respective cognate protein. In flow cytometric analysis, the expression level of CD69 on CD4+ or CD8+ T cells from mice receiving BMDCs pulsed with Omp B-p2, OmpB-p3, or Omp B-p4 was higher than that on cells from mice receiving Omp B-p1-pulsed BMDCs, while the expression level of tumor necrosis factor(TNF)-α on CD8+ T cells and interferon(IFN)-γ on the CD4+ and CD8+ T cells from mice receiving Omp B-p2,-p3, or-p4 was significantly higher than on cells from mice receiving Omp B-p1-pulsed BMDCs. Our results suggest that the protective Omp Bs could activate CD4+ and CD8+ T cells and drive their differentiation toward CD4+ Th1 and CD8+ Tcl cells, respectively, which produce greater amounts of TNF-α and, in particular, IFN-γ, to enhance rickettsicidal activity of host cells.展开更多
文摘目的:筛选预测初发高危急性早幼粒细胞白血病(acute promyelocytic leukemia,APL)发生分化综合征的因素,比较翻倍白细胞(WBC_(Double))与峰值白细胞(WBC_(Peak))的预测价值。方法:回顾性分析我院血液科收治的78例经亚砷酸诱导治疗的初诊高危APL患者的临床特征,比较WBC_(Double)和WBC_(Peak)分化综合征的分化程度。结果:分化综合征的发生率为57.69%(45/78),分化综合征最常见的临床症状为发热,重度分化综合征组发热、肺部浸润、心包积液发生率明显高于轻度分化综合征组,差异有统计学意义(P<0.05)。高危APL患者分化综合征的发生与化疗后WBC_(Peak)(45.21×10^(9)/L vs 25.24×10^(9)/L,P<0.001)和化疗后WBC_(Double)(37.59×10^(9)/L vs 17.46×10^(9)/L,P=0.007)有关。与WBC_(Peak)组比较,WBC_(Double)组早于分化事件的发生率高(68.57%vs 40.00%,P=0.016),2组间重度分化、轻度分化和未分化差异均有统计学意义(P=0.002);WBC_(Peak)组出现4个以上分化综合征症状的患者比例更多(28.57%vs 5.71%,P=0.012)。与WBCNO-_(Double)组比较,WBC_(Double)组患者诊断时白细胞计数(P=0.003)、谷丙转氨酶(P=0.040)、外周血早幼粒细胞数(P=0.047)差异有统计学意义。结论:化疗后WBC_(Double)和化疗后WBC_(Peak)是分化综合征的危险因素,化疗后WBC_(Double)较WBC_(Peak)提示分化综合征的发生更有优势。
基金supported by the National Basic Research Program of China(2010CB530200,2010CB530205)the National Natural Science Foundation of China(81371767,31170161)the National Science and Technology Major Project(2013ZX10004803)
文摘Rickettsia heilongjiangensis is an obligate intracellular bacterium that causes Far-Eastern tick-borne spotted fever. Outer membrane protein B(Omp B) is an important surface protein antigen of rickettsiae. In the present study, the omp B gene of R. heilongjiangensis was divided into four fragments, resulting in four recombinant proteins(OmpB-p1, Omp B-p2, Omp B-p3, and Omp B-p4). Each Omp B was used in vitro to stimulate murine bone marrow-derived dendritic cells(BMDCs) of C3H/He N mice, and the Omp B-pulsed BMDCs were transferred to naive C3H/He N mice. On day 14 post-transfer of BMDCs, the mice were challenged with R. heilongjiangensis and the rickettsial loads in the mice were quantitatively determined on day 7 post-challenge. Mice receiving BMDCs pulsed with Omp B-p2, Omp B-p3, or Omp B-p4 exhibited significantly lower bacterial load compared with mice receiving Omp B-p1-pulsed BMDCs. CD4+ and CD8+ T cells isolated from the spleen of C3H/He N mice receiving BMDCs pulsed with each OmpB were co-cultured with BMDCs pulsed with the respective cognate protein. In flow cytometric analysis, the expression level of CD69 on CD4+ or CD8+ T cells from mice receiving BMDCs pulsed with Omp B-p2, OmpB-p3, or Omp B-p4 was higher than that on cells from mice receiving Omp B-p1-pulsed BMDCs, while the expression level of tumor necrosis factor(TNF)-α on CD8+ T cells and interferon(IFN)-γ on the CD4+ and CD8+ T cells from mice receiving Omp B-p2,-p3, or-p4 was significantly higher than on cells from mice receiving Omp B-p1-pulsed BMDCs. Our results suggest that the protective Omp Bs could activate CD4+ and CD8+ T cells and drive their differentiation toward CD4+ Th1 and CD8+ Tcl cells, respectively, which produce greater amounts of TNF-α and, in particular, IFN-γ, to enhance rickettsicidal activity of host cells.
