狼瘡小鼠以鼻腔給予胜肽治療來調節免疫的機制探討

Abstract

紅斑性狼瘡是一種系統性的自體免疫疾病，通常在體內可發現多種的抗核抗體。在先前的研究中，以皮內注射之方式將組織蛋白3 (Histone 3)的第111 至130之胜肽片段 (H3111-130)打入紅斑性狼瘡小鼠模式中(NZB × NZW F1),發現這樣的處理對於疾病小鼠具有療效。因此，我實驗的主要目的是研究有關此胜肽片段(H3111-130)之特性及生理之作用。在T 細胞增生實驗，我們發現胜肽片段(H3111-130)無法刺激T 細胞分裂增殖，但是卻可引發介白質素-4 (IL-4)的增加，代表此胜肽片段 (H3111-130)具有T細胞接受體之部份擬化劑 (partial agonist)的特性。此外，將此胜肽片段 (H3111-130)以鼻腔方式投藥至疾病小鼠，在周邊血液中發現可增加調節性T細胞的比例，這個現象與當時老鼠出現較少的自體抗體及蛋白尿情形似乎有關聯性存在，故推論此調節性T細胞在此扮演著重要的角色。在停止投藥後，保護效果無法繼續維持。為了增加調節性T細胞的數目，在TCR基因轉殖小鼠中，我們額外使用了一種免疫抑制藥物rapamycin來測試誘發調節性T細胞產生的能力。由結果發現，rapamycin 可協同卵白蛋白片段(OVA323-339)鼻腔投藥來增加卵白蛋白專一性之調節性T細胞，並且可抑制卵白蛋白專一性抗體產生。由上述結果可得知，狼瘡小鼠以鼻腔給予胜肽可以造成調節性T細胞產生，這屬於造成黏膜耐受性其中機制之一。而我們也由TCR基因轉殖小鼠中驗證rapamycin可增加專一性調節性T細胞。未來我們可以結合鼻腔給予胜肽及rapamycin來增加專一性調節性T細胞，作為將來治療狼瘡之應用。

Systemic lupus erythematosus is a multiple-organic autoimmune disease characterized by the presence of autoantibodies against various nuclear antigens.Previous studies have suggested that intradermal injection of peptide of histone 3,H3111-130, could induce tolerance and alleviate disease in NZB × NZW F1 (BWF1)mice, which spontaneously develop SLE.In the study, we aimed to examine the role of TCR partial agonist of H3111-130 in vitro, and investigate the effects of delivery of this peptide in the nasal route, which was considered to induce tolerance more efficiently. Using proliferation assay and ELISA, we found that H3111-130 could not stimulate proliferation of CD4+ T cells but IL-4 production. Therefore, H3111-130,as the partial agonist, would be applied in therapy. Next, nasal H3111-130 inhalation could increase Foxp3+CD4+CD25+ cells, correlated with lower titer of autoantibody and nephritis,suggesting that regulatory T cells play an important role in controlling autoimmunity.However, the therapeutic effects could not sustain after 30 weeks of mice age. In order to induce regulatory T cells, rapamycin was taken to enrich T cells with regulatory function. By intracellular staining, we found that rapamycin could synergistically augment KJ1.26+Foxp3+CD4+ cells after nasal OVA323-339 administration in OVA-TCR transgenic mice. Comparing the level of OVA-specificIgG, combination rapamycin and OVA323-339 could enhance tolerance to immunization with OVA protein. Mucosal tolerance was induced by Treg cells in BWF1 mice after intranasal delivery of peptides. In addition, we had confirmed that rapamycin could induce antigen-specific Treg cells in TCR transgenic mice. In conclusion, combination rapamycin and H3111-130 could be the better therapy in murine lupus.