Kakiuchi T, Watanabe M, Hozumi N, Nariuchi H
Department of Allergology, University of Tokyo, Japan.
J Immunol. 1990 Sep 15;145(6):1653-8.
Specific and nonspecific Ag-presentation by B cells was examined for the sensitivity to the treatment with emetin, an irreversible protein synthesis inhibitor. For this aim, A20-HL B lymphoma cells expressing surface IgM receptors specific for TNP were used as APC. OVA and TNP-OVA were used as nonspecific and specific Ag, respectively. The treatment with emetin greatly impaired the ability of A20-HL cells to present specific Ag, but not nonspecific Ag, to 42-6A cloned T cells specific for OVA. The ability of the emetin-treated A20-HL cells to present nonspecific Ag indicates that the treated cells are able to process nonspecific Ag and to present processed Ag. Ag binding and the internalization by A20-HL cells through surface receptors were not affected by the emetin treatment. A20-HL cells took up specific Ag for stimulation of 42-6A cells in the presence of cycloheximide, a reversible protein synthesis inhibitor. These results suggest that the action of emetin is localized to the intracellular processing of specific Ag, not of nonspecific Ag. Thus, the processing pathway for specific Ag seems to be different from that for nonspecific Ag.
研究了B细胞特异性和非特异性抗原呈递对不可逆蛋白质合成抑制剂依米丁处理的敏感性。为此，将表达对TNP特异的表面IgM受体的A20-HL B淋巴瘤细胞用作抗原呈递细胞。OVA和TNP-OVA分别用作非特异性和特异性抗原。依米丁处理极大地损害了A20-HL细胞向对OVA特异的42-6A克隆T细胞呈递特异性抗原的能力，但不影响呈递非特异性抗原的能力。依米丁处理的A20-HL细胞呈递非特异性抗原的能力表明，处理后的细胞能够处理非特异性抗原并呈递处理后的抗原。依米丁处理不影响A20-HL细胞通过表面受体进行的抗原结合和内化。在可逆蛋白质合成抑制剂放线菌酮存在的情况下，A20-HL细胞摄取特异性抗原以刺激42-6A细胞。这些结果表明，依米丁的作用局限于特异性抗原的细胞内加工，而非非特异性抗原的细胞内加工。因此，特异性抗原的加工途径似乎与非特异性抗原的加工途径不同。
