Dr. Gina M. Pighetti
Associate Professor

Education

PhD in Pathobiology, The Pennsylvania State University
MS in Pathobiology, The Pennsylvania State University
BS in Dairy Production, Minor in Business, The Pennsylvania State University

Professional Interest: Immunology, mammary gland biology, mastitis

Immunology plays a critical role our daily lives – preventing & eliminating infections, minimizing reactions to our own body, and monitoring for cancer.  As a whole, immunology is a complex system which is intertwined with most, if not all, basic physiological processes.  Disruption of the immune system can lead to a wide variety of problems – increased susceptibility to infectious diseases, inflammation, obesity, diabetes, and atherosclerosis to name a few.  Most of my research centers on mastitis, an inflammation of the mammary gland commonly caused by bacteria.  Mastitis occurs in both animals and humans – occurring in nearly 1 of 3 individuals.  In dairy cows, this disease affects every herd across the world, negatively impacting animal health, productivity, and milk safety.  Therefore, identifying a means of reducing the incidence and severity of mastitis are critical for improving dairy cow health and milk quality. 

Early studies focused on identifying genetic markers for mastitis resistance/susceptibility in order to increase the speed and accuracy of selecting for healthier dairy cow populations.  We were able to identify a genetic marker associated with mastitis susceptibility.  Now, the big question is why?  By understanding why these animals are more susceptible or resistant to infection, we can develop targets to prevent or decrease mastitis severity.  We have focused our attention on two cell types – mammary epithelial cells and neutrophils.  Mammary epithelial cells are the first cells to interact with invading organisms – producing cytokines and other immune regulatory proteins.  Mammary cells also call in neutrophils, white blood cell ‘first-responders’ that are programmed to seek and destroy.  Through a combination of cellular, genomic, and proteomic approaches, we seek to understand the mechanistic differences in mammary epithelial cells and neutrophils that contribute to mastitis resistance or susceptibility.

Stress can also greatly increase disease susceptibility by modulating the immune response and perhaps the invading organism – causing a potential ‘double-whammy’ which limits the immune response and activates growth/pathogenic genes in the invading organism.  This interaction may explain the greater number and severity of infections which occur during summer months when cows experience chronic heat stress.  Current studies in the lab also are testing this hypothesis by investigating the interaction of mammary epithelial cells, Escherichia coli, and norepinephrine.  With greater understanding of these interactions, we expect to be able to develop potential targets for preventive or therapeutic intervention. 

Overall, through our research, we aim to improve dairy cow health, productivity, and milk safety by providing solutions for controlling mastitis and possibly other inflammatory diseases.

Selected Publications:

• Youngerman SM, AM Saxton, and GM Pighetti.  2004.  Identification of single nucleotide polymorphisms, haplotypes and their frequencies within the bovine il-8 receptor locus in Jersey and Holstein cattle.  Immunogenetics.  56: 355-359.
• Youngerman SM, AM Saxton, SP Oliver, and GM Pighetti.  2004.  Analysis of bovine CXCR2 polymorphisms with subclinical and clinical mastitis incidence in Holstein and Jersey cattle.  J Dairy Sci.  87: 2442-2448.
• Rambeaud M and GM Pighetti.  2005.  Impaired neutrophil migration associated with specific bovine CXCR2 genotypes. Infect Immun.  73:4955-4959.
• Rambeaud M, R Clift, and GM Pighetti.  2006.  Association of a bovine CXCR2 gene polymorphism with neutrophil survival and killing ability.  Vet. Immunol. Immunopathol. 11:231-238.
• Pighetti GM and M Rambeaud. 2006. Genome conservation between the bovine and human interleukin-8 receptor complex: Improper annotation of bovine interleukin-8 receptor b identified. Vet. Immunol. Immunopathol. 114:335-340.
• Rambeaud M and GM Pighetti. 2007. Differential interleukin-8 receptor expression and calcium signaling in dairy cows with different CXCR1 genotypes. Immunogenetics. 59:53-58.