tretinoin and lipoteichoic-acid

Pattern recognition receptors are involved in innate and adaptive immunity by detecting microbial components. Bacteria have been accused to play a role in inflammatory acne. We investigated the potential involvement of Toll-like receptor (TLR)2, TLR4, TLR6, and CD14 in the direct influence of bacterial components and standard antiacne compounds on human sebocytes.. mRNA and protein expression of TLR2, TLR4, TLR6, and CD14 in SZ95 sebocytes was evaluated by real-time qRT-PCR and immunocytochemistry. The effects of lipopolysaccharides (LPS) and lipoteichoic acid on TLR2, TLR4, and CD14 expression and of cytokine/chemokine secretion by 13-cis-retinoic acid, all-trans-retinoic acid, retinol, and hydrocortisone at the mRNA and protein levels were assessed by real-time qRT-PCR and ELISA and verified by cocultivation with neutralizing antibodies.. The constitutive expression of TLR2, TLR4, and CD14 in SZ95 sebocytes was augmented by exposure to LPS. Hydrocortisone induced TLR2, but markedly reduced TLR4 expression. 13-cis-retinoic acid and all-trans-retinoic acid regulated IL-6 release. LPS enhanced and hydrocortisone reduced cytokine and chemokine release. Anti-TLR4 and anti-CD14 mAb blocked LPS-induced IL-8 and IL-6 release.. Microbial components use pattern recognition receptors to directly activate sebocytes to express a wide range of proinflammatory molecules and especially IL-8 and IL-6 in a TLR4- and CD14-specific manner. Retinoids, but mostly corticosteroids, also use this pathway to exhibit anti-inflammatory effects.

Topics: Acne Vulgaris; Cell Culture Techniques; Humans; Hydrocortisone; Inflammation Mediators; Isotretinoin; Lipopolysaccharide Receptors; Lipopolysaccharides; Real-Time Polymerase Chain Reaction; Retinoids; RNA, Messenger; Sebaceous Glands; Teichoic Acids; Toll-Like Receptors; Tretinoin; Vitamin A

In this paper we describe a new pyrogen assay using the human leukemia cell line HL-60. The cell line is differentiated using all-trans retinoic acid (ATRA) to generate a cell population that resembles mature granulocytes. The differentiated HL-60 cell is capable of generating reactive oxygen species (ROS) when challenged with pyrogenic substances. In a luminol enhanced chemilumimetric assay the responsiveness of differentiated HL-60 cells is tested towards Salmonella typhimurium, Bacillus subtilis, Saccharomyces cerevisiae, Candida albicans, lipopolysaccharide (LPS) and lipoteichoic acid (LTA). The results show a poor sensitivity to S. typhimurium but displays good sensitivity towards B. subtilis, LTA and LPS. Furthermore, the sensitivity towards the yeasts C. albicans and S. cerevisiae is considerably better than obtained in other in vitro cell systems. Overall these results indicate that the HL-60 cell assay possibly could be evolved to a supplementary assay for the known pyrogenic detection assays. Furthermore, the utilization of the assay for pyrogenic examination of recombinant drugs derived from yeast expression systems would be relevant to examine.

Topics: Bacillus subtilis; Biological Assay; Candida albicans; Cell Differentiation; Drug Contamination; HL-60 Cells; Humans; Indicators and Reagents; Lipopolysaccharides; Luminescence; Luminol; Pyrogens; Reactive Oxygen Species; Reproducibility of Results; Teichoic Acids; Time Factors; Tretinoin