Mouse Anti-Rabbit IL-8 Hybridoma [7H5.3.6]

Individuals carrying the ATC/TTC haplotype (Hap-1) in the interleukin 8 (IL8) gene were reported as more susceptible to chronic periodontitis (CP), an infectious disease associated with Gram-negative bacteria, in comparison to patients with the ATT/TTC haplotype (Hap-2). This study investigated the functionality of the IL8 haplotypes in lymphocytes and monocytes of individuals carrying the Hap-1 or Hap-2 IL8 haplotypes in the response to CP-associated Gram-negative bacteria (periodontopathogens). Peripheral blood was collected from 6 subjects carrying each haplotype, and their immune cells were challenged with periodontopathogens or phorbol 12-myristate 13-acetate (PMA) plus Ionomycin. Depending on the immune cell type (lymphocytes or monocytederived macrophages) the assessed outcomes were: phenotypical polarization, gene expression, phagocytic activity, chemotaxis and production of reactive oxygen species (ROS). Subjects carrying the Hap-1 haplotype showed increased expression of IL8 and TNFA and significantly skewing towards pro-inflammatory Th1/M1/Th17 phenotypes. There was increased percentage of ROS-producing monocyte-derived macrophages from individuals carrying the Hap-1 haplotype. Cells from individuals presenting the Hap-2 haplotype had an overall attenuated response to periodontopathogens, with a significant shift towards the Treg phenotype. In conclusion, the IL8 haplotypes showed to be functional both in monocyte-derived macrophages and lymphocytes. The Hap-1 haplotype previously associated with increased susceptibility to CP demonstrated greater skewing to pro-inflammatory Th1/M1/Th17 phenotypes and production of ROS.

Sphingosine 1-phosphate (S1P) is a bioactive lipid mediator generated when a cell membrane or its components are damaged by various factors. S1P regulates diverse cell activities via S1P receptors (S1PRs). Keratinocytes express S1PR1-5. Although it is known that S1PRs control keratinocyte differentiation, apoptosis, and wound healing, S1PR functions in keratinocyte infections have not been fully elucidated. We propose that the S1P-S1PR axis in keratinocytes works as a biosensor for bacterial invasion. Indeed, in human impetigo infection, we found high epidermal expression of S1PR1 and S1PR2 in the skin. Furthermore, in normal human epidermal keratinocytes in vitro, treatment with Staphylococcus aureus bacterial supernatant not only induced S1P production but also increased the transcription of S1PR2, confirming our in vivo observation, as well as increased the levels of TNFA, IL36G, IL6, and IL8 mRNAs. However, direct treatment of normal human epidermal keratinocytes with S1P increased the expressions of IL36G, TNFA, and IL8, but not IL6. In both S1P- and S. aureus bacterial supernatant-treated normal human epidermal keratinocytes, S1PR1 knockdown reduced IL36G, TNFA, and IL8 transcription, and the S1PR2 antagonist JTE013 blocked the secretion of these cytokines. Overall, we have proven that during infections, keratinocytes communicate damage by using S1P release and tight control of S1PR1 and 2.