Therapeutic effects of PADRE-BAFF autovaccine on rat adjuvant arthritis.

B cell activating factor (BAFF) is a cytokine of tumor necrosis factor family mainly produced by monocytes and dendritic cells. BAFF can regulate the proliferation, differentiation, and survival of B lymphocytes by binding with BAFF-R on B cell membrane. Accumulating evidences showed that BAFF played crucial roles and was overexpressed in various autoimmune diseases such as systemic lupus erythematous (SLE) and rheumatoid arthritis (RA). This suggests that BAFF may be a therapeutic target for these diseases. In the present study, we developed a BAFF therapeutic vaccine by coupling a T helper cell epitope AKFVAAWTLKAA (PADRE) to the N terminus of BAFF extracellular domains (PADRE-BAFF) and expressed this fusion protein in Escherichia coli. The purified vaccine can induce high titer of neutralizing BAFF antibodies and ameliorate the syndrome of complete Freund's adjuvant (CFA) induced rheumatoid arthritis in rats. Our data indicated that the BAFF autovaccine may be a useful candidate for the treatment of some autoimmune diseases associated with high level of BAFF.

Construction, expression, and characterization of thymosin alpha 1 tandem repeats in Escherichia coli.

Thymosin alpha 1 (T α 1), which is composed of 28 amino acids, has been commercialized worldwide for its immune-modulatory and antitumor effects. T α 1 can stimulate T cell proliferation and differentiation from bone marrow stem cells, augment cell-mediated immune responses, and regulate homeostasis of immune system. In this study, we developed a novel strategy to produce T α 1 concatemer (T α 1③) in Escherichia coli and compared its activity with chemically synthesized T α 1. Results showed that T α 1③ can more effectively stimulate T cell proliferation and significantly upregulate IL-2 receptor expression. We concluded that the expression system for T α 1 concatemer was constructed successfully, which could serve as an efficient tool for the production of large quantities of the active protein.

[An optimized method for extracting corosolic acid from loquat leaves].

OBJECTIVE: To extract corosolic acid from loquat leaves for medical use. METHODS: Loquat leaves were boiled in water to remove the water-soluble substances followed by 3 cycles of extraction with 25% aqueous methanol for 30 min and then by 95% aqueous methanol for 1 h at 80 degrees celsius;. After cooling at room temperature and filtration, the extract was treated with activated carbon to remove chlorophyll, and the liquid was filtered and concentrated to allow precipitation. The sediment was washed to obtain the total crude triterpene acid, which was further dissolved with methanol and purified by high-performance liquid chromatography (HPLC). The fractions including corosolic acid were collected, concentrated with vacuum distillation, and dried to obtain corosolic acid product, which was analyzed with HPLC. RESULTS: HPLC analysis of the extracts showed that the percentages of corosolic acid were 4.66%, 2.42%, and 24.18% in crude corosolic acid extracted with methanol, boiling water, and 95% aqueous methanol, respectively. After purification with HPLC, the purity of corosolic acid in the product exceeded over 80%. CONCLUSION: The optimal extraction method, which is convenient and cost-effective, is established for extracting corosolic acid from loquat leaves for medical use.

Protective effects of pentadecapeptide BPC 157 on gastric ulcer in rats.

AIM: To investigate the protective effects of gastric pentadecapeptide BPC 157 on acute and chronic gastric ulcers in rats and to compare the results in therapy of human gastric ulcers by different administration methods. METHODS: Gastric pentadecapeptide BPC 157 was administered (initial single or continuous administration) into rats either intragastrically or intramuscularly before (induced acute gastric ulcer) or after (induced chronic gastric ulcer) the applications of inducing agents, and each animal was sacrificed to observe the protective effects of BPC 157 on gastric ulcers. RESULTS: Both intramuscular (im) and intragastric (ig) administration of BPC 157 could apparently reduce the ulcer area and accelerate the healing of induced ulcer in different models and the effect of im administered BPC 157 was better than that of ig. The rats treated with higher dosages (400 ng/kg, 800 ng/kg) of BPC 157 (im and ig) showed significantly less lesion (P<0.01 vs excipient or saline control), the inhibition ratio of ulcer formation varied between 45.7% and 65.6%, from all measurements except 400 ng/kg BPC 157 in pylorus ligation induced model (P<0.05), in which the inhibition rate was 54.2%. When im administered (800 ng/kg BPC 157) in three models, the inhibition ratio of ulcer formation was 65.5%, 65.6% and 59.9%, respectively, which was better than that of famotidine (its inhibition rate was 60.8%, 57.2% and 34.3%, respectively). Continuous application of BPC 157 (in chronic acetate induced gastric ulcer) could accelerate rebuilding of glandular epithelium and formation of granulation tissue (P<0.05 at 200 ng/kg and P<0.01 at 400 ng/kg and 800 ng/kg vs excipient or saline control). CONCLUSION: Both im and ig administered gastric pentadecapeptide BPC 157 can apparently ameliorate acute gastric ulcer in rats and antagonize the protracted effect of acetate challenge on chronic ulcer. The effect of im administration of BPC 157 is better than that of ig, and the effective dosage of the former is lower than that of the latter.