抗核抗体独特型多肽在慢性移植物抗宿主病狼疮样肾炎小鼠模型中的作用及其作用机制探讨

The Protective Effects and its Machenism of Autoantybody ldiotypic Peptide on the Murine Model of GVHD Lupus Nephritis.

目的 以往的研究显示具有SNFI小鼠抗核抗体独特型的多肽对SNFl，B／W，MRL／＋小鼠的肾脏组织具有保护作用。本文旨在初步探讨独特型多肽这种保护作用的机制。方法 雌性慢性移植物抗宿主病（GVHD）狼疮样肾炎小鼠（C57BL／10×DBA／2）FI27只，其中15只为多肽实验组小鼠，12只为对照组小鼠。两组小鼠均于24周龄左右处死，观察两组小鼠体重，尿蛋白，肾脏组织学变化，及血清IL-6水平的变化。结果 皮下注射多肽4周时，实验组小鼠尿蛋白明显少于对照组。在皮下注射多肽12周时，实验组小鼠体重明显高于对照组小鼠；肾脏损害较对照组明显减轻，血清IL-6水平明显低于对照组。结论 皮下注射独特型多肽对血清IL-6水平的影响可能是其对GVHD狼疮样肾炎小鼠肾脏起保护作用的机制之一。

Objective The previous study shows that the autoantibody idiotypic peptide has the protective effects on SNFI, B/W, MRL/＋ mice. But the mechanisms of this protection are not clear. Recently, some studies found that the idiotypic peptide immunization can induce the decreasent of specific T cell proliferation and autoantibodies production in animal models. And this may lead us to find a new method to manage the lupus nephritis. In order to further understand these effects, we did some work, and hope to find the effects of idiotypic peptide treated on the other type of mice and on the alterations in the cytokines. Here are some of our observations. Methods In order to get the lupus nephritic animal model, we invite the GVHD（C57BL/ 10×DBA/2）F1 mice. For the induction of chronic graft-versus-host disease （GVHD）,8-10-week-old （C57 BI/10×DBA/2） FI hybrids were used as recipients, and the donor lymphocytes were from DBA/2 mice. Single-cell suspensions containing a mixture of donor＇s thymus, spleen, and lymphnode cells were injected intravenously 4 times at 3 to 4 day intervals.The recipient mice develop a variety of pathologic alterations associated with the formation of autoantibodies. A SLE-like disease was evoked, as in human systemic lupus erythematosis, autoantibodies were directly against nuclear antigens （such as antidouble-stranded DNA） and erythrocytes. Corresponding to human lupus nephritis, antinuclear antibodies are thought to play a pathogenetic role in animal renal involvement. For this study, twentyseven female of （C57BL/10 × DBA/2） F I mice were used. Fifteen of them were put in the treated group, and others were in control group. In treated mice, we immunized them with 0.5μg idiotypic peptide at the second day of lymphocytes injection. And they were immunized with 0.25μg idiotypic peptide monthly thereafter, till they were killed at 24 weeks of age. For control ones, we immunized them with Freund＇s Adjuvant, the same dosage as the treated one. And their body weight, urinary protein, renal histology, and serum IL-6 level were observed. Results After 12 weeks of subcutaneous idiotypic peptide injection, the increasent of body weight in treated mice was significantly greater,（4.78 ± 1.78）g and （4.30± 1.61）g respectively, P〈0.05. Four weeks after subcutaneous idiotypic peptide injection, the increasent of urinary protein in treated group was significantly lower, （18.67 ± 11.25）mg/dl and （45.83 ± 41.22）mg/dl, respectively, P〈0,05. And the immunized mice had a slower increasent of urinary protein in the later 8 to 10 weeks. 12 weeks after subcutaneous idiotypic peptide injection, the serum IL-6 level was significant lower in treated group, （13.85 ± 2.48）pg/ml and （32.39±15.05）pg/ml, respectively, P〈0.05. For histology, the amount of cells in the glomerular cross area for treated and contral ones were （32.80 ± 3.76）and （44.42±5.7）, respectively, P〈 0.05. And there were no significant tubulointerstitial damage in two experiment groups. Conclusion Subcutaneous idiotypic peptide injection shows the protective effects on lupus nephritis in （C57BL/10×DBA/2）F1 mice. The mechanism of this protection maybe though the decreasing of serum IL-6 level.