Anti-ICK monoclonal antibody Made to order

Somatic cell hybrids were obtained by cell fusions between Lck-positive EL4 mouse T lymphoma cells and Lck-negative B82 mouse fibroblasts or S194 mouse plasmacytoma cells to examine negative control of lck gene expression in the resulting hybrids. Western blot analysis using a monoclonal antibody against the Lck protein showed a marked decrease in p56(lck) expression in B82 x EL4 (EEL) hybrids. In contrast to EEL hybrids, the level of p56(lck) was not changed significantly in S194 x EL4 (SEL) hybrids and was approximately one-half of that seen in EL4 cells. Diminished expression of the Lck protein in EEL hybrids paralleled downregulation of Ick mRNA, which was exclusively transcribed from the distal promoter in EL4 cells. It is unlikely that the suppression was simply a consequence of chromosome segregation critical for lck gene expression, since EEL hybrids retained the EL4-derived lck gene and most of the chromosomes from both parental cells. The results from treatment of EEL hybrids with actinomycin D or cycloheximide suggested that suppression of Ick gene expression in the hybrids might not be due to posttranscriptional control. DNA methylation status in the lck distal promoter and the coding regions did not appear to correlate with the expression of the gene. Our results suggest that negative control of Ick gene expression differs between fibroblasts and B cells, in that Ick gene expression in T cells can be shut down by transfer of a putative repressor factor or factors in fibroblasts but not in B cells.

Diabetic patients are at an increased risk of developing severe and progressive periodontitis. Periodontal disease also increases the severity of diabetes by enhancing insulin resistance. Therefore, the regulation of periodontal inflammation in diabetic patients may contribute to the control of both diseases. Glycyrrhizic acid exerts anti-inflammatory effects by inhibiting high mobility group box 1 (HMGB1). HMGB1, one of the ligands of the receptor for advanced glycation end products (RAGE), is a damage-associated molecular pattern and induces inflammatory cytokine production. In the present study, we examined the effects of glycyrrhizic acid on ligature-and Porphyromonas gulae infection-induced periodontitis as well as the involvement of the HMGB1-RAGE axis in diabetic model mice. The molars of diabetic model mice, established by feeding HFD32 to ICK/TaJcl mice, were subjected to silk thread ligation and P. gulae was then intraorally applied in the presence or absence of glycyrrhizic acid given topically. The topical application of glycyrrhizic acid suppressed ligature/P. gulae-induced increases in interleukin (IL)-6 and tumor necrosis factor (TNE)-alpha at the mRNA level in the gingiva and at the protein level in serum. Furthermore, glycyrrhizic acid suppressed ligature/P. gulae-induced increases in serum amyloid A (SAA) in serum and fasting blood glucose levels. It also suppressed ligature/P. gulae-induced increases of HMGB1 and RAGE at the mRNA level in the gingiva and at the protein level in serum. A mouse anti-HMGB1-neutralizing antibody inhibited increases in serum glucose levels. In conclusion, topical treatments with glycyrrhizic acid may suppress periodontal and systemic inflammation and reduce blood glucose levels through the HMGB1-RAGE axis in diabetic mice.