Cathelicidins are well-characterized antimicrobial peptides (AMPs) that are present in significant amounts in mastitic milk. Neutrophils are believed to be the main producers of these AMPs, while the role of mammary epithelial cells (MECs) in their production and release is still unclear. In this work, cathelicidin production patterns were investigated in mammary tissues of ewes infected by Staphylococcus aureus, Streptococcus uberis, or Mycoplasma agalactiae, with a combined approach including immunohistochemistry, immune-colocalization, and fluorescent in situ hybridization. Our results confirm that MECs produce and release cathelicidins in response to different mastitis pathogens. As opposed to neutrophils, however, MECs do not seem to store the preformed protein precursor in their cytoplasm, but appear to synthesize and release it only upon exposure to the microorganisms. Cathelicidin production by MECs appears to occur before leukocyte influx in the milk, suggesting a role for these cells in the initial response of the mammary epithelium to microbial infection. Once in the milk, infiltrating neutrophils release massive amounts of cathelicidin by degranulation and production of neutrophil extracellular traps, acting as the main contributor for cathelicidin abundance in mastitic milk. Taken together, our results support the active contribution of MECs to cathelicidin production and release, and reinforce the value of cathelicidins as sensitive and pathogen-independent mastitis markers.
Cathelicidin production and release by mammary epithelial cells during infectious mastitis / Cubeddu, Tiziana; Cacciotto, Carla; Pisanu, Salvatore; Tedde, Vittorio; Alberti, Alberto; Pittau, Marco; Dore, Simone; Cannas, Agnese; Uzzau, Sergio; Rocca, Stefano; Addis, Maria Filippa. - In: VETERINARY IMMUNOLOGY AND IMMUNOPATHOLOGY. - ISSN 0165-2427. - 189:(2017), pp. 66-70. [10.1016/j.vetimm.2017.06.002]
Cathelicidin production and release by mammary epithelial cells during infectious mastitis
CUBEDDU, Tiziana;CACCIOTTO, Carla;PISANU, Salvatore;TEDDE, Vittorio;ALBERTI, Alberto;PITTAU, Marco;DORE, Simone;UZZAU, Sergio;ROCCA, Stefano;ADDIS, Maria Filippa
2017-01-01
Abstract
Cathelicidins are well-characterized antimicrobial peptides (AMPs) that are present in significant amounts in mastitic milk. Neutrophils are believed to be the main producers of these AMPs, while the role of mammary epithelial cells (MECs) in their production and release is still unclear. In this work, cathelicidin production patterns were investigated in mammary tissues of ewes infected by Staphylococcus aureus, Streptococcus uberis, or Mycoplasma agalactiae, with a combined approach including immunohistochemistry, immune-colocalization, and fluorescent in situ hybridization. Our results confirm that MECs produce and release cathelicidins in response to different mastitis pathogens. As opposed to neutrophils, however, MECs do not seem to store the preformed protein precursor in their cytoplasm, but appear to synthesize and release it only upon exposure to the microorganisms. Cathelicidin production by MECs appears to occur before leukocyte influx in the milk, suggesting a role for these cells in the initial response of the mammary epithelium to microbial infection. Once in the milk, infiltrating neutrophils release massive amounts of cathelicidin by degranulation and production of neutrophil extracellular traps, acting as the main contributor for cathelicidin abundance in mastitic milk. Taken together, our results support the active contribution of MECs to cathelicidin production and release, and reinforce the value of cathelicidins as sensitive and pathogen-independent mastitis markers.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.