Identification of Inflammatory and Regulatory Cytokines IL-1α-, IL-4-, IL-6-, IL-12-, IL-13-, IL-17A-, TNF-α-, and IFN-γ-Producing Cells in the Milk of Dairy Cows with Subclinical and Clinical Mastitis

Abstract

Funding Information: The project is implemented under ERA-NET ICRAD (International Coordination of Research on Infectious Diseases) and co-financing of Spanish State Research Agency, Hungarian National Food Chain Safety Office, Polish National Centre for Research and Development, and Latvian State Education Development Agency. This project has received funding from the European Union?s Horizon 2020 research and innovation program under grant agreement no. 862605. Funding Information: Funding: The project is implemented under ERA-NET ICRAD (International Coordination of Research on Infectious Diseases) and co-financing of Spanish State Research Agency, Hungarian National Food Chain Safety Office, Polish National Centre for Research and Development, and Latvian State Education Development Agency. This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement no. 862605. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.In naturally occurring bovine mastitis, effects of infection depend on the host inflammatory response, including the effects of secreted cytokines. Knowledge about the inflammatory and regulatory cytokines in milk cells of free-stall barn dairy cows and in naturally occurring mastitis is lacking as most studies focus on induced mastitis. Hereby, the aim of the study was to determine inflammatory and regulatory cytokines in the milk of dairy cows with subclinical and clinical mastitis. The following examinations of milk samples were performed: differential counting of somatic cells (SCC), bacteriological examination, and immunocytochemical analysis. Mean SCC increased in subclinical and clinical mastitis cases. The number of pathogenic mastitis-causing bacteria on plates increased in subclinical mastitis cases but decreased in clinical mastitis. The inflammatory and regulatory markers in the milk cells of healthy cows showed the highest mean cell numbers (%). In mastitis cases, immunoreactivity was more pronounced for IL-4, IL-6, IL-12, IL-13, IL-17A, TNF-, and IFN-y. Data about subclinical and clinical mastitis demonstrate inflammatory responses to intramammary infection driven by IL-1, IL-4, and IL-17A. Moreover, the host defense response in mastitis is characterized by continuation or resolution of initial inflammation. IL-12 and INF-immunoreactivity was recognized to differ mastitis cases from the relative health status.publishersversionPeer reviewe