Wipasa Jiraprapa, Hirunpetcharat Chakrit, Mahakunkijcharoen Yuvadee, Xu Huji, Elliott Salenna, Good Michael F
Cooperative Research Center for Vaccine Technology, Queensland Institute of Medical Research, Royal Brisbane Hospital, Queensland, Australia.
J Immunol. 2002 Jul 15;169(2):944-51. doi: 10.4049/jimmunol.169.2.944.
Merozoite surface protein 1 (MSP1) of malaria parasites undergoes proteolytic processing at least twice before invasion into a new RBC. The 42-kDa fragment, a product of primary processing, is cleaved by proteolytic enzymes giving rise to MSP1(33), which is shed from the merozoite surface, and MSP1(19), which is the only fragment carried into a new RBC. In this study, we have identified T cell epitopes on MSP1(33) of Plasmodium yoelii and have examined their function in immunity to blood stage malaria. Peptides 20 aa in length, spanning the length of MSP1(33) and overlapping each other by 10 aa, were analyzed for their ability to induce T cell proliferation in immunized BALB/c and C57BL/6 mice. Multiple epitopes were recognized by these two strains of mice. Effector functions of the dominant epitopes were then investigated. Peptides Cm15 and Cm21 were of particular interest as they were able to induce effector T cells capable of delaying growth of lethal P. yoelii YM following adoptive transfer into immunodeficient mice without inducing detectable Ab responses. Homologs of these epitopes could be candidates for inclusion in a subunit vaccine.
疟原虫的裂殖子表面蛋白1（MSP1）在侵入新的红细胞之前至少经历两次蛋白水解加工。42 kDa片段是初次加工的产物，被蛋白水解酶切割后产生MSP1(33)和MSP1(19)，其中MSP1(33)从裂殖子表面脱落，而MSP1(19)是唯一进入新红细胞的片段。在本研究中，我们鉴定了约氏疟原虫MSP1(33)上的T细胞表位，并研究了它们在抗血期疟疾免疫中的功能。分析了长度为20个氨基酸、覆盖MSP1(33)全长且彼此重叠10个氨基酸的肽段在免疫的BALB/c和C57BL/6小鼠中诱导T细胞增殖的能力。这两种品系的小鼠识别出多个表位。随后研究了优势表位的效应功能。肽段Cm15和Cm21特别受关注，因为它们能够诱导效应T细胞，在过继转移到免疫缺陷小鼠后能够延缓致死性约氏疟原虫YM的生长，且不诱导可检测到的抗体反应。这些表位的同源物可能是亚单位疫苗的候选成分。
