Fcgr2b基因及H-2复合体对SLE模型小鼠IgG抗体产生的调节作用

目的:分析Fcgr2b基因对SLE小鼠血清总IgG抗体产生的影响;Fcgr2b基因单独及Fcgr2b基因与H-2复合体共同作用对SLE小鼠血清IgG抗DNA抗体产生的调控。方法:建立(NZB×NZW)F1×NZW回交小鼠模型,用特异性荧光抗体染色,流式细胞术检测及PCR技术进行基因分型,以ELISA法测定血清总IgG及抗DNA抗体水平进行分析比较。采用扩增片段长度多态性(AmpFLP)分析NZB,NZW小鼠Fcgr2b基因启动子区是否有多态性。结果:(NZB×NZW)F1×NZW回交小鼠Fc-gr2b基因B/W型组血清总IgG水平明显高于W/W型组(P<0.0001)。Fcgr2b基因独作用时,回交小鼠Fcgr2b基因B/W型组与W/W型组间血清IgG抗DNA抗体水平差异不显著(P>0.05)。Fcgr2b基因与H-2复合体共同作用时,H-2复合体为d/z型时,无论Fcgr2b基因是B/W型或W/W型,其血清IgG抗DNA抗体水平明显高于含H-2复合体Z/Z型组(P<0.01);H-2复合体为d/z型时,含Fcgr2b基因B/W型组血清IgG抗DNA抗体水平明显高于W/W型组(P<0.01)。NZB小鼠Fcgr2b基因启动子区扩增片段长度短于非自身免疫病小鼠NZW,C57BL/6及BALB/c小鼠,提示可能存在碱基缺失。结论:血清总IgG水平由Fcgr2b基因调控;IgG抗DNA抗体产生主要由H-2复合体调控,Fcgr2b基因单独作用对该抗体产生的影响不明显,但与H-2复合体具有协同作用。     

IL-10RA基因多态性及其与系统性红斑狼疮关系的研究

目的:确定SLE模型小鼠IL-10RA基因变异及其与SLE表现型是否存在关联。方法:用微卫星遗传标记及数量性状位点(QTL)分析方法确定SLE模型小鼠B/W F1的SLE易感基因精确染色体定位并选取候选易感基因,对候选易感基因进行测序分析,选取有基因序列异常的候选易感基因进行PCR-SSCP分析,确定候选易感基因碱基序列变异位点与抗染色质抗体、抗DNA抗体,抗组蛋白抗体及蛋白尿等SLE表现型的相关关系。结果:QTL分析结果表明B/W F1×NZB小鼠抗染色质抗体易感基因与NZW型IL-10RA基因紧密连锁;测序分析发现IL-10RA基因编码区有18处碱基变异,其中7处碱基变异将导致编码氨基酸的变异;抗染色质抗体、抗DNA抗体,抗组蛋白抗体及蛋白尿等SLE表现型与NZW型IL-10RA基因密切相关。另一种SLE模型小鼠MRL的IL-10RA基因存在相同变异。结论:NZW小鼠IL-10RA基因编码区碱基序列存在变异,B/W F1×NZB小鼠SLE表现型与NZW小鼠第9染色体IL-10RA编码区碱基变异相关,提示IL-10RA可能是SLE模型小鼠的一个SLE易感基因。     

新西兰小鼠CD8+T细胞数量异常的易感基因定位

目的 :定位自发性SLE模型 (NZB×NZW)F1小鼠CD8 T细胞数量异常的遗传易感基因。方法 :建立 (NZB×NZW )F1×NZW回交小鼠模型 ,采用覆盖小鼠 1 9条常染色体的多态性微卫星遗传标记及数量性状位点分析进行基因定位。结果 :CD8 T细胞数量异常的易感基因与小鼠第 1条染色体尾端 92 3cM处的微卫星遗传标记D1Mit36肯定连锁 (Lods值 >3) ,且回交小鼠该遗传标记B W型组的外周血淋巴细胞中CD8 T细胞百分比明显低于W W型组 (P <0 0 0 1 )。结论 :(NZB×NZW )F1小鼠外周血CD8 T细胞数量异常的候选易感基因位于第 1条染色体尾端 92 3cM附近 ,来源于NZB小鼠。     

系统性红斑狼疮抗核抗体易感基因染色体定位

目的 :确定新西兰小鼠自身抗染色质抗体、抗DNA抗体、抗组蛋白抗体的遗传易感基因染色体定位。方法 :建立新西兰黑色品系 (NZB)和新西兰白色品系 (NZW)子代F1的回交小鼠模型 (NZB×NZW)×NZB和 (NZB×NZW)×NZW ,采用覆盖小鼠 19条染色体的微卫星遗传标记及数量性状位点 (QTL)分析进行基因定位。结果 :确定了自身抗染色质抗体产生的易感基因 ,位于NZW小鼠第 9染色体中段 30厘摩临近 (Lods=3 0 1) ;另外自身抗染色质抗体、抗DNA抗体、抗组蛋白抗体产生的共同易感基因 ,位于NZB及NZW小鼠第 17染色体 ,即H 2复合体及TNF α的基因区域 (Lods值 >4 )。结论 :(NZB×NZW)F1小鼠自身抗核抗体的产生受多基因调控 ,候选易感基因不仅来自于NZB ,也来自于NZW。     

NZB/W狼疮鼠体外IFN-α信号调控网络研究

通过IFN-α刺激基因(ISG)表达谱勾画SLE发病机制中可能的IFN-α异常调控通路。采用基因芯片技术,比较分析发病前新西兰黑/白(NZB/W)F1代狼疮鼠和年龄性别相匹配的对照组BALB/c小鼠脾脏单个核细胞3 h干扰素刺激基因表达谱,并运用信号通路分析软件(CRSD)解析IFN-α信号调控网络。结果:IFN-α体外刺激诱导上调了BALB/c小鼠而非NZB/W狼疮鼠脾脏单个核细胞p53通路相关基因转录产物的表达;IFN-α共同诱导了NZB/W狼疮鼠和BALB/c小鼠Th1型细胞因子和趋化因子网络,相对于BALB/c鼠,IFN-α刺激后IL15、IP10、XCL1、CCL3、CCL7及CCL12的转录产物在NZB/W狼疮鼠中高表达(P值均<0.01)。NZB/W狼疮鼠对IFN-α抑制细胞增殖作用和促炎作用的异常反应,参与并加重了NZB/W狼疮鼠自身免疫性疾病的进展。     

初步探讨(NZB×NZW)F1×NZW回交鼠和狼疮性肾炎相关的易感基因

目的:探讨与狼疮性肾炎相关的新西兰黑鼠(NZB)易感基因染色体位点.方法:通过建立(NZB×NZW)F1×NZW回交小鼠模型,以尿蛋白为狼疮性肾炎表现型,利用微卫星遗传标记进行基于数量性状位点(QTL)分析的全基因组扫描方法,寻找源于NZB的遗传易感基因位点并确定染色体位置.结果:根据QTL分析发现两个与狼疮鼠蛋白尿发生有关的易感基因位点,分别位于NZB小鼠第4号染色体的D4Mit71区域及第17号染色体D17Mit22区域(LOD＞3.3).同时携有两个NZB位点的小鼠尿蛋白阳性率最高,而只有一个位点的小鼠其尿蛋白阳性率较NZW纯合鼠也明显增高(P＜0.005).结论:NZB第4号染色体的D4Mit71区域及第17号染色体的D17Mit22区域可能为(NZB×NZW)F1×NZW回交鼠狼疮性肾炎蛋白尿易感位点.两个位点之间具有协同增效作用.     

CD5阳性B1细胞增殖易感基因的定位

目的 :定位NZB、NZW及NZB WF1小鼠外周血B1细胞增殖的易感基因。方法 :建立 (NZB×NZW )F1×NZB回交小鼠模型 ,用覆盖小鼠全部常染色体的多态性微卫星遗传标记数量性状位点 (QTL)分析进行基因定位。结果 :B1细胞增殖的易感基因与小鼠的第 2、4、17号染色体上的微卫星遗传标记D2Mit 10 1、D4Mit 11及D17Mit 6 1肯定连锁 (Lods值 >3) ,其中D2Mit10 1、D4Mit11位点来源于NZB ,D17Mit 6 1位点来源于NZW。在D2Mit10 1位点附近存在Ltk、Rag1、2基因 ,在D4Mit 11位点附近存在Lck基因 ,在D17Mit6 1位点附近存在H 2及TNF α基因。结论 :NZB、NZW及NZB WF1小鼠外周血B1细胞增殖受多基因调控 ,易感基因分别位于NZB的Ltk、Rag1、2及Lck基因编码区和位于NZW的H 2、TNF α基因编码区 ,这些易感基因之间有相互促进的叠加效应。     

NZB/W F1狼疮模型小鼠泪腺病变的特征

目的:观察狼疮易感NZB/W F1小鼠泪腺随周龄变化特点以及明确是否存在相应眼部体征改变。方法:应用BALB/c小鼠作对照,采用泪液分泌试验进行泪液分泌量测定,ELISA法行血清抗dsDNA抗体检测,采用H-E染色观察小鼠泪腺结构的病理改变及炎症程度并进行炎症评分。结果:NZB/W F1小鼠泪液分泌量低于BALB/c小鼠,29周龄开始其差值逐渐增大,到35周龄NZB/W F1小鼠泪液分泌量(4.6 mm±0.7 mm)显著低于同周龄BALB/c小鼠(8.7mm±0.7mm);NZB/WF1小鼠泪腺显著的灶性炎症细胞浸润出现在35周龄,密集成片浸润的炎症细胞甚至部分取代原有的腺泡结构,其炎症评分(3.3分±0.5分)明显高于同周龄BALB/c小鼠(1.1分±0.6分),小叶内及小叶间导管结构仍保存。结论:随周龄增加,NZB/W F1小鼠自发出现加重类似继发性干燥综合征的泪腺炎症变化,其眼部体征异常出现在35周龄。     

NZB和NZW小鼠脾淋巴细胞CD48和CD244分子表达及其基因多态性研究

目的：了解NZB小鼠中是否存在与其CD8^＋T细胞增殖相关的CD48和CD244分子表达异常及其机制。方法：利用流式细胞分析技术检测NZB和NZW小鼠脾淋巴细胞表面CD48和CD244分子的表达。利用DNA序列测定进行CD48和CD244基因多态性分析。结果：NZB小鼠活化的CD8^＋T细胞表面CD48和CD244分子表达水平均高于NZW小鼠。DNA序列分析显示CD48和CD244 eDNA序列在NZB和NZW小鼠问不存在多态性，但是NZB小鼠的CD48基因转录起始点上游-119bp处存在5个碱基缺失。结论：NZB小鼠活化的脾淋巴细胞高水平表达CD48和CD244分子可能是其CD8^＋T细胞增生的原因之一。NZB CD48基因转录调控区域异常可能与其高水平表达CD48分子有关。     

系统性红斑狼疮(SLE)自然发病模型动物MRL/1、BXSB小鼠的免疫反应

目的疾病动物模型的研究强有力地推动了各种疾病的基础及临床研究的进展。自发现作为全身性SLE实验动物模型的两种NZB、(NZB×NZW)F_1小鼠以来,SLE的研究有了迅速进展。 1978年Murpby等更进一步报告新的SLE动物模型MRL/l、MRL/n、BXSB等三种小鼠。这些小鼠的病变与前两种小鼠不     

Genetic regulation of hypergammaglobulinaemia and the correlation to autoimmune traits in (NZB X NZW) F1 hybrid

To determine the inheritance patterns of both IgM class and IgG class hypergammaglobulinaemias, the locations of genes and the relations of these genes to other autoimmune traits in NZB X NZW (B/W) F1 hybrid, we measured serum levels of both IgM and IgG in NZB, NZW, B/W F1 hybrid, B/W F1 X NZW back-cross and B/W F1 X NZB back-cross mice. The highest serum IgM levels were observed in NZB mice, however the serum IgG levels were normal. In contrast, a large amount of IgG was produced in B/W F1 hybrids, in which the serum IgM levels were lower than those observed in NZB mice. The NZW mice had fairly normal values for both measures. Progeny studies suggested that a single dominant locus (Imh-1) of NZB strain, which is loosely linked to brown-black coat colour locus b and Mup-1 locus on chromosome 4, determines the IgM class hypergammaglobulinaemia. The estimated gene order was Mup-1:b:Imh-1. This IgM class hypergammaglobulinaemia in NZB mice was suppressed to a considerable extent in B/W F1 hybrid mice by either a gene dosage effect or more likely, a regulatory gene locus of NZW strain, being also loosely linked to Mup-1 locus on chromosome 4. As for the IgG class hypergammaglobulinaemia, a complementary effect of two or three genes, either one or two dominant genes derived from NZB and a single dominant gene from NZW strains, determines this trait in B/W F1 hybrid mice. There appeared to be no relationships between the genes responsible for the IgM class and IgG class hypergammaglobulinaemias. When looking at the correlations between the hypergammaglobulinaemias and the traits, anti-double stranded DNA (dsDNA) antibodies and renal disease in both back-cross mice, we found a significant quantitative correlation only between the IgG class hypergammaglobulinaemia and the IgG class anti-dsDNA antibodies in B/W F1 X NZB back-cross mice.     

Molecular and Idiotypic Analyses of the Antibody Response to Cryptococcus neoformans Glucuronoxylomannan-Protein Conjugate Vaccine in Autoimmune and Nonautoimmune Mice

The antibody response to Cryptococcus neoformans capsular glucuronoxylomannan (GXM) in BALB/c mice frequently expresses the 2H1 idiotype (Id) and is restricted in variable gene usage. This study examined the immunogenicity of GXM-protein conjugates, V (variable)-region usage, and 2H1 Id expression in seven mouse strains: BALB/c, C57BL/6, A/J, C3H, NZB, NZW, and (NZB x NZW)F(1) (NZB/W). All mouse strains responded to vaccination with GXM conjugated to tetanus toxoid (TT), the relative magnitude of the antibody response being BALB/c approximately C3H > C57BL/6 approximately NZB approximately NZW approximately NZB/W > A/J. Analysis of serum antibody responses to GXM with polyclonal and monoclonal antibodies to the 2H1 Id revealed significant inter- and intrastrain differences in idiotype expression. Thirteen monoclonal antibodies (MAbs) (two immunoglobulin M [IgM], three IgG3, one IgG1, three IgG2a, two IgG2b, and two IgA) to GXM were generated from one NZB/W mouse and one C3H/He mouse. The MAbs from the NZB/W mouse were all 2H1 Id positive (Id(+)) and structurally similar to those previously generated in BALB/c mice, including the usage of a V(H) from the 7183 family and Vkappa5.1. Administration of both 2H1 Id(+) and Id(-) MAbs from NZB/W and C3H/H3 mice prolonged survival in a mouse model of cryptococcosis. Our results demonstrate (i) that V-region restriction as indicated by the 2H1 Id is a feature of both primary and secondary responses of several mouse strains; and (ii) that there is conservation of V-region usage and length of the third complementarity-determining region in antibodies from three mouse strains. The results suggest that V-region restriction is a result of antibody structural requirements necessary for binding an immunodominant antigen in GXM.     

Susceptibility loci for the defective foreign protein-induced tolerance in New Zealand Black mice: implication of epistatic effects of Fcgr2b and Slam family genes

In contrast to normal mice, autoimmune-prone New Zealand Black (NZB) mice are defective in susceptibility to tolerance induced by deaggregated bovine γ globulin (DBGG). To examine whether this defect is related to the loss of self-tolerance in autoimmunity, susceptibility loci for this defect were examined by genome-wide analysis using the F(2) intercross of nonautoimmune C57BL/6 (B6) and NZB mice. One NZB locus on the telomeric chromosome 1, designated Dit (Defective immune tolerance)-1, showed a highly significant linkage. This locus overlapped with a locus containing susceptibility genes for autoimmune disease, namely Fcgr2b and Slam family genes. To investigate the involvement of these genes in the defective tolerance to DBGG, we took advantage of two lines of Fcgr2b-deficient B6 congenic mice: one carries autoimmune-type, and the other carries B6-type, Slam family genes. Defective tolerance was observed only in Fcgr2b-deficient mice with autoimmune-type Slam family genes, indicating that epistatic effects of both genes are involved. Thus, common genetic mechanisms may underlie the defect in foreign protein antigen-induced tolerance and the loss of self-tolerance in NZB mouse-related autoimmune diseases.     

Does the deletion within T cell receptor β-chain gene of NZW mice contribute to autoimmunity in (NZB × NZW)F1mice?

To determine the transacting genetic factors of NZW contributing to the development of autoimmune disease in (NZB X NZW)F1 (B/W F1) mice, we examined the relationship between the T cell receptor beta chain gene deletion and the severity of autoimmune manifestations in 76 B/W F1 X NZB backcross mice. Very high association between the T cell receptor beta chain gene deletion and the development of autoimmune manifestations including the production of IgG anti-DNA antibodies and circulating retroviral gp70 immune complexes was observed, indicating that a defect in the NZW T cell receptor beta chain gene or a locus closely linked to it contributes to the autoantibody formation in B/W F1.     

Effects of major histocompatibility complex on autoimmune disease of H-2-congenic New Zealand mice

Autoimmune-prone NZB mice mainly produce IgM-class anti-DNA antibodies and mild SLE develops later in life. The F1 hybrid of NZB and non-autoimmune NZW mice (NZB/W F1 mice) develop a more fulminant SLE, associated with decreases in IgM class, and, in turn, increases in IgG class anti-DNA antibodies. To elucidate the role of the H-2 complex in this mode of anti-DNA antibody production, we established and studied H-2-congenic New Zealand mice, i.e. NZB, NZW, and NZB/W F1 mice with either the homozygous H-2z/H-2z or H-2d/H-2d haplotype or the heterozygous H-2d/H-2z haplotype. The data showed that: (i) although the non-H-2-linked NZB gene(s) seems to determine the IgM anti-DNA antibody production in NZB mice, the effect of this gene is fully expressed only in the case of the H-2d/H-2d homozygous state. (ii) The production of IgG anti-DNA antibodies observed in NZB/W F1 hybrid mice is restricted to the H-2d/H-2z heterozygosity. (iii) Because both NZB and NZW mice with the H-2d/H-2z haplotype produce a lower titer of IgG anti-DNA antibodies than do the NZB/W F1 mice, other complementary non-H-2-linked genetic elements from both NZB and NZW parents are required. The development of lupus nephritis correlated well with that of anti-DNA antibodies. Thus, H-2d/H-2z heterozygosity is a necessary but not sufficient condition for the development of autoimmunity in NZB/W F1 mice.(ABSTRACT TRUNCATED AT 250 WORDS)     

The contribution of I-Abm12 to the production of autoantibodies to dsDNA.

The development of IgG autoantibodies to dsDNA in NZBxNZW F1 (NZB/W) and NZBxSWR F1 (SNF1) mice have been linked to specific alleles of MHC class II genes contributed by the NZW and SWR parents respectively. Recently, our laboratory has shown that the introduction of the bm12 mutation into NZB mice (NZB.H-2bm12) results in mice which are phenotypically similar to NZB/W F1 mice and, in particular, develop IgG anti-dsDNA antibodies. A variety of immune abnormalities have been described in autoimmune NZB (H-2d) mice. It is, however, unclear at present, whether all these abnormalities are due to the influence or effect of a single set of linked genes or due to multiple genes. It was reasoned that NZB.H-2bm12 mice provide a unique opportunity to examine this issue. Specifically, we bred a series of five different F1 colonies of mice: (a) NZB.H-2bm12/b F1; (b) NZB.H-2bm12/d F1; (c) NZB-H-2b/d F1; (d) NZB-H-2bm12 x B6.C-2bm12 F1 (NZB/B6.H-2bm12 F1); and (e) NZB x B6.C-H-2bm12 F1 (NZB/B6.H-2d/bm12 F1) mice. All groups of mice were serially followed for the appearance of IgM and IgG anti-ssDNA and anti-dsDNA antibodies, splenic CFU-B, spontaneous secretion of IgM, FMF analysis, proteinuria and survival. We report herein that H-2bm12 genes have a dominant influence on the appearance of IgG anti-dsDNA antibodies. In contrast, antibodies to ssDNA, IgM secreting cells, CFU-B and Ly-1 B cells are linked to genes from the NZB background. Finally, we particularly note an absence of IgG antibodies to dsDNA in NZB-H-2b/d F1 mice.     

Perforin mRNA expression in the inflamed tissues of NZB/W F1 lupus mice decreases with methylprednisolone treatment.

Perforin is one of the important cytolytic factors in cytotoxic T lymphocytes (CTL) and natural killer (NK) cells. In this study, the authors examined perforin mRNA levels in the kidney, spleen, liver, lung, heart, and brain of NZB/W F1 lupus mice and NZW mice. Perforin mRNA levels in the kidney, spleen, liver, and lung of NZB/W F1 mice increased significantly with age, whereas those in the heart and brain of NZB/W F1 mice showed little change between 2 and 10 months of age. In all tissues examined in NZW, control mice perforin mRNA levels showed little change during the experimental period. In addition, the authors examined the effect of methylprednisolone (MPSL) on perforin gene expression in the tissues of NZB/W F1 mice. MPSL ameliorated the increase in perforin mRNA levels in the kidney, spleen, liver, and lung of NZB/W F1 mice. These findings suggest that perforin may contribute to tissue injuries in autoimmune lupus mice and that MPSL may be effective in lupus partly by decreasing perforin expression.     

Increased incidence of anti-GBM disease in Fcgamma receptor 2b deficient mice, but not mice with conditional deletion of Fcgr2b on either B cells or myeloid cells alone

Fcgamma receptor 2b (Fcgr2b) is the only inhibitory Fcgamma receptor in both humans and mice, and is implicated in both antibody production and effector responses to antibody complexes. Reduced function of Fcgr2b has previously been associated with anti-glomerular basement membrane antibody (anti-GBM) disease in mice. However, the mice used had 129 genetic elements flanking the deleted Fcgr2b gene, which are known to increase susceptibility to autoimmunity. In order to confirm a role for Fcgr2b in protection from anti-GBM disease, wild type (WT) mice, mice lacking Fcgr2b on a pure C57BL/6 background, or mice lacking Fcgr2b on a C57BL/6 background with 129 flanking sequences, were immunized with the recombinant NC1 domain of alpha 3 Type IV collagen. Twenty two weeks after immunization, there was a higher incidence of crescentic glomerulonephritis, macrophage infiltration and renal dysfunction in both groups of Fcgr2b-/- mice, indicating an important role of Fcgr2b in regulating the development of anti-GBM disease, on both genetic backgrounds. In order to determine the cellular origin of the Fcgr2b-associated effect, disease was induced in mice with deficiency of Fcgr2b on either B cells alone (CD19Cre), or a subset of myeloid cells (LysozymeMCre). Neither B cell nor myeloid specific knockout mice developed crescentic glomeruonephritis with higher incidence than WT mice indicating that Fcgr2b deficiency on either B cells or a subset of myeloid cells alone is not sufficient to increase susceptibility to anti-GBM disease, but that a combination of cell types, or deficiency of Fcgr2b in a different cell type, is also required.