elRefaei M, Blank K J, Murasko D M
Department of Microbiology and Immunology, MCP Hahnemann University School of Medicine, Philadelphia, Pennsylvania 19129, USA.
Virology. 2001 Nov 25;290(2):281-9. doi: 10.1006/viro.2001.1128.
E55+ murine leukemia retrovirus (E55+ MuLV) infection of young and aged C57BL/6 (B6) mice was used to investigate the relationship between increased incidences of infection and decreased immune responsiveness of elderly individuals. Young mice decreased E55+ MuLV burden to below detectable levels by 8 weeks postinfection (p.i.). In contrast, virus burden in aged mice did not reach undetectable levels until 20 weeks p.i. A significant T cell proliferative response to E55+ MuLV was detected from 2 to 12 weeks p.i. in young mice, but was never observed in aged mice. Both age groups demonstrated significant E55+ MuLV-specific T-cell-mediated cytotoxic responses at 3 and 4 weeks p.i. and virus neutralizing antibody titers at 2, 4, 8, and 12 weeks p.i. In both cases, responses were consistently higher in young mice (P < 0.04 and P < 0.02, respectively). These results demonstrate that the observed delay in E55+ MuLV clearance by aged mice is associated with an age-related decrease in the immune response to the virus.
利用E55 +鼠白血病逆转录病毒（E55 + MuLV）感染年轻和老年C57BL/6（B6）小鼠，以研究感染发生率增加与老年人免疫反应性降低之间的关系。年轻小鼠在感染后8周（p.i.）将E55 + MuLV负荷降至可检测水平以下。相比之下，老年小鼠的病毒负荷直到感染后20周才达到不可检测水平。在年轻小鼠感染后2至12周检测到对E55 + MuLV的显著T细胞增殖反应，但在老年小鼠中从未观察到。两个年龄组在感染后3周和4周均表现出显著的E55 + MuLV特异性T细胞介导的细胞毒性反应，以及在感染后2周、4周、8周和12周的病毒中和抗体滴度。在这两种情况下，年轻小鼠的反应始终更高（分别为P < 0.04和P < 0.02）。这些结果表明，老年小鼠中观察到的E55 + MuLV清除延迟与对该病毒的免疫反应随年龄相关的降低有关。
