ABSTRACT
AIM: The selective recognition of the sense peptides which are located in special regions of thyrotropin receptor (TSHR) by their corresponding antisense peptides has been investigated. Three pairs of sense and antisense peptides were named TR1 (aa37-45) and RT1 (aa45-37), TR2 (aa353-366) and RT2 (aa366-353), TR3 (aa648-655) and RT3 (aa655-648). METHODS: To prepare three affinity chromatography columns, antisense peptides were immobilized, called RT1-sepharose 4B, RT2-sepharose 4B and RT3-sepharose 4B, respectively and investigate the retardative behavior for each of native peptide TR1, TR2 or TR3 on above columns with stepwise elution. RESULTS: Each of the three immobilized antisense peptides recognized and retarded its corresponding sense peptide-TR1, TR2 or TR3 instead of those non-complementary peptides. Immobilized RT1 recognized free TSHR protein molecule as well. In additional, bovine thyrotropin was recognized by immobilized TR1. CONCLUSION: The results indicate that molecular recognition theory exsits in thyrotropin receptor system. It may be useful to isolate biological molecules and to locate epitopes of TSH on TSHR molecule. Otherwise, antisense peptide may be used for treatment of experimental autoimmunolized thyroid disease (AITD) in the rat. [
ABSTRACT
Objective To study the immune regulation of antisense peptide in rats by observing immune function of activity fragments of thyrotropin receptor (TSHR) and their corresponding antisense peptides. Methods TSHR peptides TR1, TR2, TR3 and their antisense peptides RT1, RT2, RT3, and three pairs of complementary peptides were injected into rats of different groups respectively, and the serum levels of TT_3, TT_4, TSHR antibody (TRAb), thyroid stimmulating antibody, thyroid blocking antibody and TSH antibody (TSHAb) and pathological changes in thyroid tissue were investigated. Results Serum TRAb could be induced when each of three fragments of TSHR was injected into rats; TRAb and TSHAb were induced by RT1 or RT2; epithelial hyperplasia and lymphocytic infiltration observed in thyroid tissue of rats injected with TR2 could be abated by injecting RT2 subsequently. Conclusion The results suggest that all 3 TSHR fragments are shown to be immunogenic and are capable to induce TRAb; both RT1 and RT2 show their effect on immune regulation and are idiotypic of TSHR peptides; On the other hand, the humoural and cell immunities are ameliarated by injection of antisense peptides. Therefore, it is possible that antisense peptides may be involved in immune regulation via immune network.
ABSTRACT
AIM: To study the characterization of thyrotropin receptor (TSHR) and its active fragment TSHR aa352-366 as immunogens in BALB/c mice. METHODS: BALB/c mice were injected peritoneally with TSHR aa352-366-KLH (hemocyanin from keyhole limpets) and the mixture of TSHR aa352-366-KLH and guinea pig TSHR every 15 days, respectively. The levels of thyroid hormones and TSHR antibodies and TSHR mRNA were measured, and the pathological changes of thyroid tissue were observed. RESULTS: In the group injected with TSHR aa352-366-KLH, the serum levels of TT_3 and TT_4 decreased (P