Proceeding of Veterinary and Animal Science Days 2015, 15th- 17th July, Milan, Italy 

riviste.unimi.it/index.php/haf 

   

 

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CORRESPONDING AUTHOR 

Giada Magro,  

giada.magro@unimi.it 

 

 

ABSTRACT  

Mastitis represents the most important disease of dairy cattle. Stabilized or primary epithelial cell lines have been 
extensively used to study the molecular mechanisms of the immune response in the udder. Both models are 
considered reliable, but are constituted by a single cell population, i.e. epithelial cells, and changes in cell 
morphology and metabolism may occur, as a result of subculture, or even genetic instability. The aim of this study 
was to evaluate the immune response of an ex vivo model of the mammary gland, where the three-dimensional 
structure is maintained, assuming that the results were more comparable to the in vivo response. Ex vivo 2 mm3 -
sections of a heifer udder were cultured under standardized conditions and treated for 3, 6, and 18 h with either 
E. coli lipopolysaccharide (LPS) or with S. aureus lipoteichoic acid (LTA). These molecules are constituent of the 
cell walls of Gram-negative or -positive bacteria, respectively and are applied as an inflammatory stimulus in the 
research of mastitis pathogenesis. Samples were analyzed for cell proliferation and apoptosis by 
immunofluorescence, in order to validate the model. Thereafter, we analyzed the mRNA expression of key 
molecules of the innate immune response (TNFα, IL-1β, IL-6, IL-8 and LAP) by quantitative real-time PCR. We used 
three reference genes validated by geNorm application, as the better internal standard for mammary gland 
tissue. The model did not show proliferation and apoptosis increased during the culture period. The preliminary 
results showed diverse patterns for the different cytokines and LAP: mRNA expression was overall increased, but 
peaked at different time points. These data suggest that such ex vivo model could be a valid approach to study 
the mammary immune response to bacteria. 

 

 

 
REFERENCES  
Bonnet, M., L. Bernard, S. Bes and C. Leroux. 2013. Animal 7(8):1344–1353; Günther, J., S.Liu, K. Esch, H. J. Schuberth 
and H. M. Seyfert. 2010.Veterinary Immunology and Immunopathology 135: 152–157; Griesbeck-Zilch, B., H. H. D. 
Meyer, Ch. Kuhn, M. Schwerin, and O. Wellnitz. 2008. Journal of Dairy Science  91:2215–2224. 

 

An ex vivo model of the bovine mammary 

gland to study the pathogenesis of 

bacterial infections.  

Magro G.
1
 , Brevini T.A.L.

2
 , Pasello L.

2
 , Piccinini R.

1
  

1 
Department of Veterinary Science and Public Health, Università degli Studi 

di Milano, Via Celoria 10, 20133 Milan, Italy 

2
 Department of Health, Animal Science and FoodSafety, Università degli 

Studi di Milano, Via Celoria 10, 20133 Milan, Italy