Hanada K, Katoh H, Hosokawa T, Hosono M, Takeda T
Department of Senescence Biology, Kyoto University, Japan.
Immunology. 1991 Sep;74(1):160-4.
Short-lived SAMP-P/1 mice are low responders in in vitro antibody responses because of a selectively impaired helper T(Th)-cell activity. After crossing with high responders (B10.BR mice), about 12% of (B10.BR x SAM-P/1) (BRP)F2 mice showed low responsiveness, as did SAM-P/1 mice, against two T-dependent antigens, sheep and horse red blood cells (RBC), both of which were not cross-reactive to each other at helper T- and B-cell levels. The immune activities against the two antigens in individual BRPF2 mice showed a good correlation (r = 0.81), thereby suggesting that SAM-P/1 mice have an antigen non-specific Th cell dysfunction. Based on the incidence of the low responders in F2 generation and statistical analyses, the hypo-responsiveness was postulated to be controlled by two genes. To survey the location of these genes, linkage analyses were performed in the F2 mice using a large set of genetic markers. Low responders in the F2 generation showed a significantly higher incidence of SAM-P/1 genotype at the Gpi-1 as well as c locus on chromosome 7 (Chr.7). However, no linkage of low responsiveness to the Hbb locus was evident, an area present at a more distal site to the centromere on the same chromosome. These results suggest that one of the genes controlling the hypo-responsiveness of SAM-P/1 mice is linked to both Gpi-1 and c loci and that it locates at a more proximal site on Chr.7.
短命的SAMP-P/1小鼠在体外抗体反应中是低反应者，因为其辅助性T（Th）细胞活性存在选择性受损。与高反应者（B10.BR小鼠）杂交后，约12%的（B10.BR×SAM-P/1）（BRP）F2小鼠表现出与SAM-P/1小鼠一样的低反应性，针对两种T细胞依赖性抗原，即绵羊和马红细胞（RBC），这两种抗原在辅助性T细胞和B细胞水平上彼此无交叉反应。个体BRPF2小鼠针对这两种抗原的免疫活性显示出良好的相关性（r = 0.81），从而表明SAM-P/1小鼠存在抗原非特异性Th细胞功能障碍。基于F2代中低反应者的发生率及统计分析，推测这种低反应性受两个基因控制。为了探究这些基因的位置，在F2小鼠中使用大量遗传标记进行了连锁分析。F2代中的低反应者在7号染色体（Chr.7）上的Gpi-1以及c位点处显示出显著更高的SAM-P/1基因型发生率。然而，低反应性与Hbb位点无明显连锁关系，Hbb位点位于同一染色体上着丝粒更远端的区域。这些结果表明，控制SAM-P/1小鼠低反应性的其中一个基因与Gpi-1和c位点均连锁，且位于Chr.7上更靠近近端的位置。
