Kawanishi H, Ajitsu S, Mirabella S
Gut Mucosal Immunity Laboratory, State University of New York, Stony Brook.
Mech Ageing Dev. 1990 May 30;54(2):143-61. doi: 10.1016/0047-6374(90)90062-k.
Senescence-related alterations of local gut mucosal immune responses to enteric mycobacterial antigen (Ag) were examined. Both aged (greater than 24 months old) and young adult (4-5 months old) BALB/c mice were enterically immunized with crude Mycobacterium paratuberculosis (M. paratbc) protoplasmic Ag, and in vitro Ag- and class-specific immunoglobulin (g) production by lymphocytes from gut-associated lymphoid tissues (GALT) (Peyer's patches, PP; mesenteric lymph nodes, MLN) and non-GALT (spleen, SPN) were determined against semipurified M. paratbc Ag. Ag-specific spontaneous immunoglobulin production by aged B cells from both GALT and non-GALT was enhanced only to a minor extent. Similarly, the functional activity of the Ag-specific T (Th) (CD3+, CD4+) cell in both GALT and non-GALT was not profoundly affected by senescence (qualitative preservation). However, that of the suppressor T (Ts) (CD3+, CD8+) cell was considerably diminished (qualtative defect). Thus, oral tolerance (systemic immunologic hyporesponsiveness) to M. paratbc Ag in aged mice is impaired. These age-related changes, manifested as hyperreactive humoral responses to the enteric microbial Ag, are due, at least in part, to hyporeactivity of the Ts cell, resulting in relative hyperfunction of the Ag-specific Th cell, despite the quantitative defect of the latter cell.
研究了肠道局部黏膜对肠道分枝杆菌抗原（Ag）的衰老相关免疫反应改变。分别用副结核分枝杆菌（M. paratbc）原生质粗抗原对老年（大于24月龄）和年轻成年（4 - 5月龄）BALB/c小鼠进行肠道免疫，并测定来自肠道相关淋巴组织（GALT）（派尔集合淋巴结，PP；肠系膜淋巴结，MLN）和非GALT（脾脏，SPN）的淋巴细胞针对半纯化M. paratbc抗原的体外抗原特异性和类别特异性免疫球蛋白（g）产生情况。来自GALT和非GALT的老年B细胞的抗原特异性自发免疫球蛋白产生仅略有增强。同样，GALT和非GALT中抗原特异性T（Th）（CD3 +，CD4 +）细胞的功能活性并未受到衰老的显著影响（质量保留）。然而，抑制性T（Ts）（CD3 +，CD8 +）细胞的功能活性则显著降低（质量缺陷）。因此，老年小鼠对M. paratbc抗原的口服耐受性（全身免疫低反应性）受损。这些与年龄相关的变化表现为对肠道微生物抗原的体液反应亢进，至少部分是由于Ts细胞反应低下，导致抗原特异性Th细胞相对功能亢进，尽管后者细胞存在数量缺陷。
