ABSTRACT
Aging is a major health issue due to the increased susceptibility of elderly people to infectious, autoimmune, and cardiovascular diseases. Innate immunity is an important mechanism to avoid primary infections; therefore, decreasing of its activity may lead to development of infections. Antimicrobial peptides (AMPs) are effector molecules of innate immunity that can eliminate microbial invaders. The role that cytokines play in the regulation of these innate immune mechanisms needs to be explored. Serum determinations of Th1, Th2, and Th17 cytokines were performed in order to evaluate their association with AMPs human beta-defensin (HBD)-2 and LL-37 in young adults, elder adults, and elder adults with recurrent infections. Our results showed differences in interleukin (IL)-10 and IL-6 among the different groups. Inverse correlations in serum cytokine levels and HBD-2 production were identified for IL-10, IL-2, IL-4, tumor necrosis factor-α, and IL-6. Also inverse correlations were identified for IL-10, IL-4, and cathelicidin (LL-37). Such results could impact the development of immunomodulators that promote AMP production to prevent and/or contain infectious diseases in this population.
Subject(s)
Aging/immunology , Antimicrobial Cationic Peptides/metabolism , Infections/immunology , Th1 Cells/immunology , Th17 Cells/immunology , Th2 Cells/immunology , beta-Defensins/blood , Adult , Aged , Aged, 80 and over , Antimicrobial Cationic Peptides/blood , Cells, Cultured , Cytokines/metabolism , Humans , Immunity, Innate , Middle Aged , Recurrence , Young Adult , CathelicidinsABSTRACT
Antimicrobial peptide innate immunity plays a central role in the susceptibility to infectious diseases, as has been described extensively in different settings. However, the role that these molecules play in the immunity mediated by polymorphonuclear phagocytes as part of the innate immunity of ageing individuals has not been described. In the present study, we addressed the question whether antimicrobial activity in polymorphonuclear cells from elderly individuals was altered in comparison with young adults. We compared phagocytosis index, bacterial killing efficiency, myeloperoxidase activity and cathelicidin expression. Results showed that there were no statistical differences among groups. However, human neutrophil peptide-1 (HNP-1) was decreased in the elderly individuals group. Results suggest that the decreased HNP-1 production in the polymorphonuclear phagocytes form elderly individuals might have an important participation in the increased susceptibility to infectious diseases.
Subject(s)
Aging/metabolism , Neutrophils/immunology , Neutrophils/metabolism , alpha-Defensins/metabolism , Adult , Aged , Aged, 80 and over , Aging/genetics , Female , Gene Expression , Humans , Immunity, Innate , Interleukin-1/genetics , Interleukin-1/metabolism , Intracellular Space , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/metabolism , Male , Peroxidase/genetics , Peroxidase/metabolism , Phagocytosis , alpha-Defensins/geneticsABSTRACT
It has been reported that patients with progressive tuberculosis (TB) express abundant amounts of the antimicrobial peptides (AMPs) cathelicidin (LL-37) and human neutrophil peptide-1 (HNP-1) in circulating cells, whereas latent TB infected donors showed no differences when compared with purified protein derivative (PPD) and QuantiFERON®-TB Gold (QFT)-healthy individuals. The aim of this study was to determine whether LL-37 and HNP-1 production correlates with higher tuberculin skin test (TST) and QFT values in TB household contacts. Twenty-six TB household contact individuals between 26-58 years old TST and QFT positive with at last two years of latent TB infection were recruited. AMPs production by polymorphonuclear cells was determined by flow cytometry and correlation between TST and QFT values was analysed. Our results showed that there is a positive correlation between levels of HNP-1 and LL-37 production with reactivity to TST and/or QFT levels. This preliminary study suggests the potential use of the expression levels of these peptides as biomarkers for progression in latent infected individuals.
Subject(s)
Blood Cells/chemistry , Cathelicidins/blood , Latent Tuberculosis/diagnosis , Mycobacterium tuberculosis/immunology , alpha-Defensins/blood , Adult , Antimicrobial Cationic Peptides , Biomarkers/blood , Cathelicidins/metabolism , Contact Tracing , Disease Progression , Female , Gene Expression , Humans , Interferon-gamma Release Tests/methods , Latent Tuberculosis/metabolism , Male , Middle Aged , Neutrophils/metabolism , Tuberculin Test/methodsABSTRACT
It has been reported that patients with progressive tuberculosis (TB) express abundant amounts of the antimicrobial peptides (AMPs) cathelicidin (LL-37) and human neutrophil peptide-1 (HNP-1) in circulating cells, whereas latent TB infected donors showed no differences when compared with purified protein derivative (PPD) and QuantiFERON®-TB Gold (QFT)-healthy individuals. The aim of this study was to determine whether LL-37 and HNP-1 production correlates with higher tuberculin skin test (TST) and QFT values in TB household contacts. Twenty-six TB household contact individuals between 26-58 years old TST and QFT positive with at last two years of latent TB infection were recruited. AMPs production by polymorphonuclear cells was determined by flow cytometry and correlation between TST and QFT values was analysed. Our results showed that there is a positive correlation between levels of HNP-1 and LL-37 production with reactivity to TST and/or QFT levels. This preliminary study suggests the potential use of the expression levels of these peptides as biomarkers for progression in latent infected individuals.
