Wege H, Schliephake A, Körner H, Flory E, Wege H
Institute of Virology and Immunobiology, University of Würzburg, Germany.
J Gen Virol. 1993 Jul;74 ( Pt 7):1287-94. doi: 10.1099/0022-1317-74-7-1287.
The murine coronavirus neurotropic strain JHM (MHV-JHM) nucleocapsid (N) protein induces a strong T-helper cell response in Lewis rats. It has been shown previously that N-specific CD4+ T cells can confer protection against acute disease upon transfer to otherwise lethally infected rats. To define the major antigenic regions that elicit this T cell response, truncated fragments of N protein were expressed from a bacterial expression vector and employed as T cell antigens. Lymphocytes from either MHV-JHM-infected or immunized rats were stimulated in culture with virus antigen, grown and tested for their specificity to the N protein fragments. The carboxy-terminally located C4-N fragment (95 amino acids) induced the most pronounced proliferative response irrespective of whether the lymphocyte culture was derived from immunized or MHV-JHM-infected rats. We established T cell lines specific for the truncated N protein fragments and tested their potential to mediate protection by transfer experiments. Only the T cell line C4-N and the T cell line specific for the full-length N protein were protective. By contrast, all truncated N protein fragments elicited a humoral immune response and contained antigenic sites recognized by antibodies from diseased rats.
鼠冠状病毒嗜神经毒株JHM（MHV-JHM）的核衣壳（N）蛋白可在Lewis大鼠中诱导强烈的辅助性T细胞应答。先前已表明，N特异性CD4⁺ T细胞转移至原本会受到致死性感染的大鼠后，可使其免受急性疾病侵害。为确定引发这种T细胞应答的主要抗原区域，从细菌表达载体中表达了N蛋白的截短片段，并将其用作T细胞抗原。用病毒抗原在培养物中刺激来自MHV-JHM感染或免疫大鼠的淋巴细胞，使其生长并检测它们对N蛋白片段的特异性。无论淋巴细胞培养物来源于免疫大鼠还是MHV-JHM感染的大鼠，位于羧基末端的C4-N片段（95个氨基酸）都能诱导最明显的增殖反应。我们建立了对截短的N蛋白片段具有特异性的T细胞系，并通过转移实验测试它们介导保护作用的潜力。只有C4-N T细胞系和对全长N蛋白具有特异性的T细胞系具有保护作用。相比之下，所有截短的N蛋白片段都能引发体液免疫应答，并含有患病大鼠抗体识别的抗原位点。
