title: Defensin γ-thionin from Capsicum chinense has immunomodulatory effects on bovine mammary epithelial cells during Staphylococcus aureus internalization.
abstract: β-Defensins are members of the antimicrobial peptide superfamily that are produced in various species from different kingdoms, including plants. Plant defensins exhibit primarily antifungal activities, unlike those from animals that exhibit a broad-spectrum antimicrobial action. Recently, immunomodulatory roles of mammal β-defensins have been observed to regulate inflammation and activate the immune system. Similar roles for plant β-defensins remain unknown. In addition, the regulation of the immune system by mammalian β-defensins has been studied in humans and mice models, particularly in immune cells, but few studies have investigated these peptides in epithelial cells, which are in intimate contact with pathogens. The aim of this work was to evaluate the effect of the chemically synthesized β-defensin γ-thionin from Capsicum chinense on the innate immune response of bovine mammary epithelial cells (bMECs) infected with Staphylococcus aureus, the primary pathogen responsible for bovine mastitis, which is capable of living within bMECs. Our results indicate that γ-thionin at 0.1 μg/ml was able to reduce the internalization of S. aureus into bMECs (∼50%), and it also modulates the innate immune response of these cells by inducing the mRNA expression (∼5-fold) and membrane abundance (∼3-fold) of Toll-like receptor 2 (TLR2), as well as by inducing genes coding for the pro-inflammatory cytokines TNF-α and IL-1β (∼14 and 8-fold, respectively) before and after the bacterial infection. γ-Thionin also induces the expression of the mRNA of anti-inflammatory cytokine IL-10 (∼12-fold). Interestingly, the reduction in bacterial internalization coincides with the production of other antimicrobial products by bMECs, such as NO before infection, and the secretion into the medium of the endogenous antimicrobial peptide DEFB1 after infection. The results from this work support the potential use of β-defensins from plants as immunomodulators of the mammalian innate immune response.
authors.affiliation: Centro Multidisciplinario de Estudios en Biotecnología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Km 9.5 Carr. Morelia-Zinapécuaro, Posta Veterinaria, C.P. 58893, Morelia, Michoacán, Mexico, Mexico.
authors.forename: Violeta
authors.initials: V
authors.lastname: Díaz-Murillo
authors.affiliation: Centro Multidisciplinario de Estudios en Biotecnología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Km 9.5 Carr. Morelia-Zinapécuaro, Posta Veterinaria, C.P. 58893, Morelia, Michoacán, Mexico, Mexico.
authors.forename: Ivan
authors.initials: I
authors.lastname: Medina-Estrada
authors.affiliation: Centro Multidisciplinario de Estudios en Biotecnología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Km 9.5 Carr. Morelia-Zinapécuaro, Posta Veterinaria, C.P. 58893, Morelia, Michoacán, Mexico, Mexico.
authors.forename: Joel E
authors.initials: JE
authors.lastname: López-Meza
authors.affiliation: Centro Multidisciplinario de Estudios en Biotecnología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Km 9.5 Carr. Morelia-Zinapécuaro, Posta Veterinaria, C.P. 58893, Morelia, Michoacán, Mexico, Mexico. Electronic address: ochoaz@umich.mx.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Ochoa-Zarzosa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002212:Capsicum / Q000737:chemistry*; D002417:Cattle; D002470:Cell Survival / Q000187:drug effects; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects* / Q000276:immunology / Q000382:microbiology; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000276:immunology; D007113:Immunity, Innate; D007155:Immunologic Factors / Q000302:isolation & purification / Q000494:pharmacology*; D016753:Interleukin-10 / Q000235:genetics / Q000276:immunology; D053583:Interleukin-1beta / Q000235:genetics / Q000276:immunology; D008321:Mammary Glands, Animal / Q000166:cytology / Q000187:drug effects / Q000276:immunology / Q000382:microbiology; D010936:Plant Extracts / Q000737:chemistry; D061251:Primary Cell Culture; D012333:RNA, Messenger / Q000235:genetics / Q000276:immunology; D015398:Signal Transduction; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000502:physiology; D054809:Thionins / Q000302:isolation & purification / Q000494:pharmacology*; D051195:Toll-Like Receptor 2 / Q000235:genetics / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000276:immunology; D023083:beta-Defensins / Q000096:biosynthesis / Q000276:immunology / Q000378:metabolism
chemical_list: D007155:Immunologic Factors; D053583:Interleukin-1beta; D010936:Plant Extracts; D012333:RNA, Messenger; D054809:Thionins; D051195:Toll-Like Receptor 2; D014409:Tumor Necrosis Factor-alpha; D023083:beta-Defensins; D016753:Interleukin-10
keywords: Antimicrobial peptides; Bovine mammary epithelium; Defensins; Immunomodulation; Innate immune response; Staphylococcus aureus