Anti-S100A9 (full length) polyclonal antibody

Background: The receptor for advanced glycation end products (RAGE), a multiligand receptor, has been proved to be implicated in inflammatory responses in chronic obstructive pulmonary disease (COPD). In this study, we investigated the role of RAGE in cigarette smoke (CS)-induced airway inflammation in COPD. Methods: Wild-type (WT) and RAGE gene knockout (KO) mice were exposed to mainstream CS or room air for 2 h twice daily, 6 days per week for consecutive 4 weeks. Cell counts and proinflammatory cytokines were measured in bronchoalveolar lavage fluid (BALF). Lung tissues were collected for histological examination and gene expression profiling by cDNA microarray. Results: CS exposure induced significant airway inflammation in WT mice evidenced by histological inflammatory changes in HE stain with increased neutrophils and proinflammatory cytokines in the BALF, which were all attenuated by RAGE KO. cDNA microarray indicated a total of 179 upregulated genes and 351 downregulated genes in mouse lungs. Among these genes, 5100 proteins (S100A8 and S100A9), the RAGE common ligands, were significantly downregulated, which were validated by real-time qPCR. Further analyses by Gene Ontology, KEGG and Disease Ontology suggested these differentiated expressed genes significantly related to the immune-inflammatory responses in lungs via crosstalking with a complicated network of signaling pathways. Conclusions: Knockout of RAGE significantly ameliorates mainstream CS-induced airway inflammation in mice possibly via downregulating S100A8/A9 expression and its related immune-inflammatory responses.

Persistent genus beta-HPV (human papillomavirus) infection is a major co-factor for non-melanoma skin cancer in patients suffering from the inherited skin disease epidermodysplasia verruciformis (EV). Malignant EV lesions are particularly associated with HPV type 5 or 8. There is clinical and molecular evidence that HPV8 actively suppresses epithelial immunosurveillance by interfering with the recruitment of Langerhans cells, which may favor viral persistence. Mechanisms how persistent HPV8 infection promotes the carcinogenic process are, however, less well understood. In various tumor types chronic inflammation has a central role in tumor progression. The calprotectin complex consisting of S100A8 and S100A9 proteins has recently been identified as key driver of chronic and tumor promoting inflammation in skin carcinogenesis. It induces chemotaxis of neutrophil granulocytes and modulates inflammatory as well as immune responses. In this study, we demonstrate that skin lesions of EV-patients are massively infiltrated by inflammatory cells, including CD15 C granulocytes. At the same time we observed a very strong expression of S100A8 and S100A9 proteins in lesional keratinocytes, which was mostly confined to the suprabasal layers of the epidermis. Both proteins were hardly detected in nonlesional skin. Further experiments revealed that the HPV8 oncoproteins E6 and E7 were not involved in S100A8/A9 up-regulation. They rather suppressed differentiationinduced S100A8/A9 expression. In contrast, the viral transcription factor E2 strongly enhanced PMA-mediated S100A8/A9 up-regulation in primary human keratinocytes. Similarly, a tremendous up-regulation of both S100 proteins was observed, when minute amounts of the PMA-inducible CCAAT/enhancer binding protein b (C/EBP b), which is expressed at low levels in the suprabasal layers of the epidermis, were co-expressed together with HPV8 E2. This confirmed our previous observation that C/EBP b interacts and functionally synergizes with the HPV8 E2 protein in differentiationdependent gene expression. Potent synergistic up-regulation of S100A8/A9 was seen at transcriptional and protein levels. S100A8/A9 containing supernatants from keratinocytes co-expressing HPV8 E2 and C/EBP b significantly induced chemotaxis of granulocytes in migration assays supporting the relevance of our finding. In conclusion, our data suggest that the HPV8 E2 protein actively contributes to the recruitment of myeloid cells into EV skin lesions, which may support chronic inflammation and progression to skin cancer.