Vingsbo C, Larsson P, Andersson M, Holmdahl R
Department of Medical and Physiological Chemistry, Uppsala University, Sweden.
Scand J Immunol. 1993 Mar;37(3):337-42. doi: 10.1111/j.1365-3083.1993.tb02562.x.
Lewis rats develop arthritis after immunization with heterologous but not homologous rat type II collagen (CII). We have observed that if the rat CII is prepared by pepsin digestion without subsequent extensive purification, it is arthritogenic in Lewis rats. To address whether pepsin in the CII preparations contributed to the development of arthritis and whether this was associated with the induction of an immune response to CII, Lewis rats were immunized with rat CII of various degrees of purity and with various pepsin contents. After immunization with a crude preparation of CII, containing relatively large amounts of pepsin, Lewis rats developed arthritis with an incidence of 80% together with a strong anti-CII autoantibody production. Further purification of the CII on DEAE-Sepharose, which removes pepsin, eliminated the arthritogenic properties and the capacity to activate CII-specific B cells. Likewise, lathyritic CII, prepared without pepsin, induced neither a CII-specific immune response nor arthritis. If, however, pepsin was added to non-arthritogenic batches of rat CII, arthritis appeared at an incidence of 40%. By using an ELISPOT technique to detect antigen-specific interferon-gamma-producing T cells and antibody-producing B cells, the immune response to CII and pepsin can be evaluated. Eleven days after immunization with lathyritic CII and pepsin, a B-cell response towards both CII and pepsin was seen. Pepsin-specific T cells were also seen at day 11, but CII-specific T cells did not appear until day 14 after immunization. In addition, a weak CII-specific proliferative response of the T cells could be demonstrated at day 14 but not at day 11 or 12. These data show that pepsin plays an important role in the triggering of a CII-specific immune response. We suggest a carrier-hapten mechanism where pepsin acts as a carrier and CII as a 'hapten' which will activate CII-specific B cells. Subsequently these CII-specific B cells will break the T-cell tolerance and evoke a T-cell-mediated immune response towards CII.
用异源而非同源的大鼠II型胶原蛋白（CII）免疫后，Lewis大鼠会患上关节炎。我们观察到，如果大鼠CII是通过胃蛋白酶消化制备且随后没有进行广泛纯化，那么它在Lewis大鼠中具有致关节炎性。为了探究CII制剂中的胃蛋白酶是否导致关节炎的发生，以及这是否与诱导针对CII的免疫反应相关，用不同纯度和不同胃蛋白酶含量的大鼠CII免疫Lewis大鼠。用含有相对大量胃蛋白酶的CII粗制剂免疫后，Lewis大鼠患关节炎的发生率为80%，同时产生强烈的抗CII自身抗体。在DEAE - 琼脂糖上对CII进一步纯化，可去除胃蛋白酶，消除了其致关节炎特性以及激活CII特异性B细胞的能力。同样，未用胃蛋白酶制备的致跛行CII既不诱导CII特异性免疫反应，也不引发关节炎。然而，如果将胃蛋白酶添加到无致关节炎性的大鼠CII批次中，关节炎的发生率为40%。通过使用ELISPOT技术检测抗原特异性产生干扰素 - γ的T细胞和产生抗体的B细胞，可以评估对CII和胃蛋白酶的免疫反应。用致跛行CII和胃蛋白酶免疫11天后，观察到针对CII和胃蛋白酶的B细胞反应。在第11天也观察到了胃蛋白酶特异性T细胞，但CII特异性T细胞直到免疫后第14天才出现。此外，在第14天可证明T细胞有微弱的CII特异性增殖反应，但在第11天或第12天未出现。这些数据表明胃蛋白酶在触发CII特异性免疫反应中起重要作用。我们提出一种载体 - 半抗原机制，其中胃蛋白酶作为载体，CII作为“半抗原”，它将激活CII特异性B细胞。随后，这些CII特异性B细胞将打破T细胞耐受性，并引发针对CII的T细胞介导的免疫反应。
