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

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-α, and IFN-γ. Data about subclinical and clinical mastitis demonstrate inflammatory responses to intramammary infection driven by IL-1α, 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-γ immunoreactivity was recognized to differ mastitis cases from the relative health status.

Escherichia coli Mastitis in Dairy Cattle: Etiology, Diagnosis, and Treatment Challenges

“…In ruminants, lactoferrin has been shown to inhibit the multiplication of E. coli by binding to iron ions, making them unavailable for bacterial growth ( Rybarczyk et al, 2017 ; Kieckens et al, 2018 ). Additionally, cytokines including interleukins (IL), colony-stimulating factor (CSF), interferon (IFN), and tumor necrosis factor (TNF) are crucial in the mammary gland innate defense ( Bhattarai et al, 2018 ; Vitenberga-verza et al, 2022 ). Cytokines are responsible for local signs of inflammation such as swelling, redness, pain, and systemic symptoms such as fever, tachycardia, increased respiratory rate, anorexia, and depression ( Sordillo et al, 1997 ; Thompson-Crispi et al, 2014 ).…”

“…(Zhang et al, 2017), MPEC have undergone evolutionary adaptations (e.g., acquisition of VFs) that improve its colonization of the unique environmental niches found within the mammary gland (Shpigel et al, 2008). These niches include competing microbes, soluble and cellular antimicrobials in milk, e.g., lactoferrin and lactoperoxidase (Kawai et al, 2015;Koshiishi et al, 2017), and the innate response elicited by immune cells (Wellnitz and Bruckmaier, 2012). Consequently, E. coli with specific VFs selected within the mammary gland are better suited to cause bovine mastitis (Blum et al, 2015;Richards et al, 2015;Goldstone et al, 2016;Roussel et al, 2017;Sun et al, 2021;Zhou et al, 2021).…”

Whole genome sequencing of Red Chittagong Cattle (RCC) cattle and insight into genetic variants in candidate genes for disease resistance

“…Seven non-synonymous SNVs were detected in four mastitis associated genes (Table 6). Vitenberga-Verza et al (46) showed that immunoreactivity was more pronounced for IL-4 in mastitis cases. We identified a non-synonymous mutation in the IL4 gene that coding for IL4.…”

Synthetic Cationic Lipopeptide Can Effectively Treat Mouse Mastitis Caused by Staphylococcus aureus

“…Among them, TNF-α and IL-1 are essential for mediating the recruitment of leukocytes to the site of the inflammation [ 34 ]. TNF-α and IL-6 are immunoreactive in cases of mastitis, while IL-1α of the IL-1 family is more capable of driving the corresponding inflammatory response [ 35 ]. These pro-inflammatory cytokines can promote the proliferation of S. aureus within the bovine mammary epithelium [ 36 ].…”