Van Buskirk A M, Braley-Mullen H
J Immunol. 1987 Sep 1;139(5):1400-5.
Although type 2 antigens, such as PVP, generally do not activate specific TH, previous studies have established that low doses of PVP (0.0025 microgram) can activate TH in vivo which provide help in primed B cells for PVP-specific IgG responses. Doses of PVP that are optimally immunogenic for IgM antibody production (0.25 to 25 micrograms) preferentially activate PVP-specific TS, which suppress IgG antibody production. In the studies reported here, TH and TS that regulate PVP-specific IgG antibody responses were activated in vitro by culturing normal spleen cells for 4 days with PVP. Induction of the TH and TS is dependent upon the amount of PVP in culture: 10(-4) micrograms PVP activates TH, whereas 10(-2) micrograms PVP preferentially activates TS. TH induced in vitro express Thy-1, L3T4, and I-A determinants and help provided by these TH is similar in magnitude to that provided by TH from mice primed with 0.0025 microgram PVP in vivo. TH can also be activated in vitro if donor mice are treated with Cy before culture of their spleen cells with 10(-2) micrograms PVP. Cy pretreatment prevents TS activation, and TH are then induced in these cultures. The presence of TS does not prevent activation of TH by 10(-2) micrograms PVP, because removal of TS by treatment of T cells with anti-Lyt-2 + complement at the end of culture uncovers TH activity. This TH activity is comparable with that of TH obtained after culture with 10(-4) micrograms PVP. The ability to activate PVP-specific TH and TS in vitro should allow determination of the mechanisms involved in activation of T cells by type 2 antigens and the mechanisms by which TS and TH interact with one another.
虽然2型抗原，如聚乙烯吡咯烷酮（PVP），一般不会激活特异性辅助性T细胞（TH），但先前的研究已证实，低剂量的PVP（0.0025微克）可在体内激活TH，这为引发的B细胞针对PVP特异性IgG反应提供帮助。对IgM抗体产生具有最佳免疫原性的PVP剂量（0.25至25微克）优先激活PVP特异性抑制性T细胞（TS），后者抑制IgG抗体的产生。在本文报道的研究中，通过将正常脾细胞与PVP培养4天，在体外激活了调节PVP特异性IgG抗体反应的TH和TS。TH和TS的诱导取决于培养物中PVP的量：10^(-4)微克PVP激活TH，而10^(-2)微克PVP优先激活TS。体外诱导的TH表达Thy-1、L3T4和I-A决定簇，这些TH提供的帮助在程度上与体内用0.0025微克PVP致敏的小鼠的TH提供的帮助相似。如果在用10^(-2)微克PVP培养供体小鼠的脾细胞之前用环磷酰胺（Cy）处理供体小鼠，TH也可在体外被激活。Cy预处理可防止TS激活，然后在这些培养物中诱导出TH。TS的存在并不妨碍10^(-2)微克PVP对TH的激活，因为在培养结束时用抗Lyt-2加补体处理T细胞以去除TS会揭示TH活性。这种TH活性与用10^(-4)微克PVP培养后获得的TH活性相当。体外激活PVP特异性TH和TS的能力应有助于确定2型抗原激活T细胞所涉及的机制以及TS和TH相互作用的机制。
