The Preliminary Study On The Effect Mechanism Of Schistosomiasis Japonicum Infection And Associated Antigen Against The TypeⅠ Diabetesin Mice Model

Objectives： To establish a model of diabetes experimental type Ⅰ in mice,preliminary study on the effect mechanism of schistosomiasis japonicum infectionand schistosoma associated antigen against typeⅠdiabetes in mice model, and try todevelop a new method in prevention and treatment of the typeⅠdiabetes.Methods: The experiment were divided into two parts, the first part used32male BALB/c mice (18-22g), and fed in conventional adaptive method in one week,randomly divided into four groups: A group was schistosomiasis japonicum andDiabetes model, and B group was, diabetes model,C group was negative group, Dgroup was normal group.Every group was eight mice. After8weeks of the infectedwith schistosome japonicum cercariae, the group A mice were injected streptozotocininto abdominal cavity for inducing the type1diabetes model, then the group B micewere only induced to type1diabetes model. the group C mice were injected citricacid buffer into abdominal.Blood glucose and urine sugar level of the every groupmice were detected once a week. After4weeks, all mice was killed, and collectedserum specimens and the pancreatic tissue.The interferon-γ and interleukin-4(IL-4)levels in serum were test by the enzyme-linked immunosorbent assay (ELISA) andthe pathological changes of the pancreatic tissue was observed by HE stain. Thesecond part used the same method with the first part to build the1type diabetes micemodel. And then prepare soluble worm antigen(SWA) and soluble egg antigen(SEA).After the success of modeling24mice were randomly divided into3groups, erveygroup was8mice. The soluble worm antigens of Schistosoma japonicumimmunization diabetes model group(A group),Soluble egg antigen immunizationdiabetes model group(B group), PBS injection diabetes model group (C group).group A and group B mice were injected SWA or SEA separately into multi-point immunization of abdominal subcutaneous, each mouse was injected50μg antigens,once a week, total four times. After7days of the last time immunization, all micewere tested the blood glucose once a week, continuous observation1month. Afterthe last time, the blood glucos was detected, then the mice were sacrificed, collectedserum specimens, using double-antibody sandwich ELISA method for thedetermination of serum levels of IL-4and IFN-γ expression, and took the pancreastissue to observe the pathological changes.Results: The experimental results of the first part showed compared with negativecontrol group(C group) and normal control group D, the STZ-induced Schistosomajaponicum infection and diabetes modeling group (A group) and Simple STZ-induceddiabetes modeling group(B group) appeared the diabetes symptom of clearlypolydipsia, polyphagia, polyuria and weight loss. in4w about, the urine glucose of Bgroup mice were all positive,75%was++++,25%was+++, the pancreatic tissue haddifferent degrees of islet atrophy and the reduce of the cell numbers, the pancreaticislet β cells degeneration and the empty state of islet, and the different degrees oflymphocyte infiltration and insulitis changes.were observed. After modeling about4win group A,75%of urine glucose was+,25%was++, the body weight21.62±1.88gwas increased compared with B group16.32±0.38g, And statistics has a significantdifference (P<0.01). The blood glucose of the group A9.40±1.01mmol/L wasreduced compared with the group B13.05±0.83mmol/L, and the statistics has asignificant difference(P<0.01). and the islet structure remained intact in the most miceof group A, the lymphocyte only infiltrated into the islets surrounding area, or catheterdistrict, did not found a large numbers of lymphocyte to infiltrate into the islet. TheLevel of the IL-463.21±10.92pg/ml in in the group A mice serum was significantlyhigher than B group4.42±0.48pg/ml, and the statistics is a significantdifference(P<0.01);and then the level of IFN-γ287.33±34.85pg/ml was significantlylower than B group341.11±39.88pg/ml, and the statistics is a significantdifference(P<0.01).The experimental results of the second part showed: the blood glucose of Schistosoma japonicum SEA immunization diabetes model mice (group B) wasslightly lower than group C in about3w and4w, the level of the blood glucose of thegroup B was9.85±1.17mmol/L, and it was significantly lower than the diabetesmodel group C12.14±1.25mmol/L, and the statistics is a significantdifference(P<0.01). But compared with SWA immunization diabetes modeling groupA and group C, the level of the blood glucose did not have significant difference （P﹥0.05）. Although the islet structure of the group B mice was destroyed partial,butlymphocyte invasion extent in the tissue to compare with group C was less. The groupA mice compared with group C, the pathological change of the pancreas tissue wasnot significant difference, the large numbers of lymphocytes infiltration, the islet cellsdecrease and structure destruction was observed in the islet The level of IL-423.87±4.85pg/ml of group B mice in serum was higher than group C4.39±0.56pg/ml at the4w end, and the statestics hda a significant difference(P<0.01). and thenin the level of IFN-γ, the group B （271.85±26.04pg/ml）was lower than group C362.79±32.50pg/ml（P<0.01）. The level of IL-4and IFN-γ in srum, between thegroup A miceIL-45.09±0.37pg/ml, IFN-γ379.56±34.47pg/ml and the group C werenot significant difference（P﹥0.05）.Conclusions：The schistosomiasis japonicum infection and the SEA of Schistosomaimmunization can resist the type Ⅰ diabetes in mice model, the mechanism may beSchistosoam antigen stimulated the immune response, produce IL-4and IFN-γ andadjust Th1/Th2immune shifting.