Konnai Satoru, Takeshima Shin-nosuke, Tajima Shigeru, Yin Shan Ai, Okada Kosuke, Onuma Misao, Aida Yoko
Retrovirus Research Unit, RIKEN, Wako, Saitama 351-0198, Japan.
Microbiol Immunol. 2003;47(3):223-32. doi: 10.1111/j.1348-0421.2003.tb03391.x.
We have reported previously that the alleles of the ovine leukocyte antigen (OLA)-DRB1 gene that encode the Arg-Lys (RK) motif and the Ser-Arg (SR) motif at positions beta70/71 of the OLA-DRbeta1 domain are associated with resistance and susceptibility, respectively, to development of bovine leukemia virus (BLV)-induced ovine lymphoma. Here, to investigate the different immune response in sheep that carried alleles associated with resistance and susceptible for 30 weeks after infection with BLV, we selected sheep that had the RK/RK or SR/SR genotype among the 52 sheep analyzed by polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing of PCR product for the OLA-DRB1 exon 2 and infected them with BLV. Although the number of BLV-infected cells and virus titer had been maintaining low levels throughout the experimental period, the sheep with the RK/RK genotype could induce expansion of CD5- B-cells and rapid production of neutralizing antibody in the early phase of infection. The level of incorporation of [3H]thymidine by peripheral blood mononuclear cells from the sheep with RK/RK genotype gave a strong response to BLV virion antigen and synthetic antigenic peptides that corresponded to T-helper epitope of the BLV envelope glycoprotein gp51. In contrast, the sheep with SR/SR genotype showed a strong response to BLV virion antigen and synthetic antigenic peptides that corresponded to T-cytotoxic and B-cell epitopes. In such cases, the animals with the RK/RK strongly expressed IFN-gamma, the animals with SR/SR genotype strongly expressed IL-2. To determine the proliferating cells, we tried a blocking assay with monoclonal antibodies such as anti-CD4, -CD8 and -DR molecule. We found that these proliferating cells were MHC-restricted CD4+ T-cells.
我们之前报道过，绵羊白细胞抗原（OLA）-DRB1基因的等位基因，在OLA-DRβ1结构域的β70/71位编码精氨酸-赖氨酸（RK）基序和丝氨酸-精氨酸（SR）基序，分别与对牛白血病病毒（BLV）诱导的绵羊淋巴瘤的抗性和易感性相关。在此，为了研究感染BLV 30周后携带抗性和易感等位基因的绵羊的不同免疫反应，我们在通过聚合酶链反应-限制性片段长度多态性和OLA-DRB1外显子2的PCR产物DNA测序分析的52只绵羊中，选择具有RK/RK或SR/SR基因型的绵羊，并使其感染BLV。尽管在整个实验期间，BLV感染细胞的数量和病毒滴度一直维持在低水平，但具有RK/RK基因型的绵羊在感染早期可诱导CD5 - B细胞扩增和快速产生中和抗体。具有RK/RK基因型的绵羊外周血单核细胞对[3H]胸腺嘧啶核苷的掺入水平，对BLV病毒粒子抗原和与BLV包膜糖蛋白gp51的T辅助表位相对应的合成抗原肽有强烈反应。相比之下，具有SR/SR基因型的绵羊对BLV病毒粒子抗原和与T细胞毒性和B细胞表位相对应的合成抗原肽有强烈反应。在这种情况下，具有RK/RK的动物强烈表达IFN-γ，具有SR/SR基因型的动物强烈表达IL-2。为了确定增殖细胞，我们尝试用抗CD4、-CD8和-DR分子等单克隆抗体进行阻断试验。我们发现这些增殖细胞是MHC限制的CD4 + T细胞。
