RESUMEN
BACKGROUND: Severe asthma is characterized by neutrophilic inflammation and high levels of interleukin (IL)-8. Airway epithelial cells play a pivotal role in the pathogenesis and chronicity of asthma. The objective of this work was to determine whether CXC receptors were involved in human small airway epithelial cell (SAEC) activity by incubating them with IL-8; the investigation also included a proteomic approach. METHODS: IL-6 and intercellular adhesion molecule-1 (ICAM-1) were assessed by ELISA and flow cytometry, respectively. CXCR-1 and CXCR-2 receptor mRNA and protein expressions were analyzed by RT-PCR, immunocytochemistry and flow cytometry. Cells were incubated with different concentrations (0-100 ng/ml) of IL-8. The involvement of both receptors was assessed using specific antibodies. RESULTS: Only the CXCR-1 receptor was expressed in SAECs. IL-8 (50 ng/ml, 12 h) induced the release of IL-6 and had no effect on ICAM-1. Supernatants analyzed by surface enhanced laser desorption ionization time of flight mass spectrometry (SELDI-TOF MS) showed very weak differences in peptide profiles. Interestingly, 4,820-m/z peptide release was detected in the presence of IL-8 and abolished by CXCR-1 antibody. DISCUSSION: The present study illustrated the fact that IL-8 mediated by CXCR-1 increased IL-6. We also highlight the usefulness of SELDI ProteinChip technology to confirm the potential variation of peptide profile. Moreover, we were able to detect the 4,820-m/z peptide secreted in vitro by human airway epithelial cells induced by IL-8 via CXCR-1 receptor. Determination of the protein secretion profile in response to inflammatory stimuli could be an important therapeutic strategy in severe asthma.
Asunto(s)
Células Epiteliales/metabolismo , Interleucina-8/metabolismo , Pulmón/citología , Receptores CXCR/metabolismo , Anticuerpos/inmunología , Anticuerpos/farmacología , Bronquios/citología , Bronquios/metabolismo , Células Epiteliales/citología , Células Epiteliales/efectos de los fármacos , Expresión Génica/genética , Humanos , Molécula 1 de Adhesión Intercelular/metabolismo , Interleucina-6/metabolismo , Interleucina-8/farmacología , Péptidos/análisis , Péptidos/metabolismo , Proteínas/análisis , Proteínas/metabolismo , Receptores CXCR/genética , Receptores CXCR/inmunología , Receptores de Interleucina-8A/genética , Receptores de Interleucina-8A/inmunología , Receptores de Interleucina-8A/metabolismo , Receptores de Interleucina-8B/genética , Receptores de Interleucina-8B/inmunología , Receptores de Interleucina-8B/metabolismo , Mucosa Respiratoria/citología , Mucosa Respiratoria/metabolismo , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
Previous studies of the HIV-1 disease have shown that HLA and Chemokine receptor genetic variants influence disease progression and early viral load. We performed a Genome Wide Association study in a cohort of 605 HIV-1-infected seroconverters for detection of novel genetic factors that influence plasma HIV-RNA and cellular HIV-DNA levels. Most of the SNPs strongly associated with HIV-RNA levels were localised in the 6p21 major histocompatibility complex (MHC) region and were in the vicinity of class I and III genes. Moreover, protective alleles for four disease-associated SNPs in the MHC locus (rs2395029, rs13199524, rs12198173 and rs3093662) were strikingly over-represented among forty-five Long Term HIV controllers. Furthermore, we show that the HIV-DNA levels (reflecting the HIV reservoir) are associated with the same four SNPs, but also with two additional SNPs on chromosome 17 (rs6503919; intergenic region flanked by the DDX40 and YPEL2 genes) and chromosome 8 (rs2575735; within the Syndecan 2 gene). Our data provide evidence that the MHC controls both HIV replication and HIV reservoir. They also indicate that two additional genomic loci may influence the HIV reservoir.
