Submitted to: Journal of Immunology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/1/2004
Publication Date: 8/15/2004
Citation: Endsley, J.J., Furrer, J.L., Endsley, M.A., Mcintosh, M.A., Maue, A., Waters, W.R., Lee, D.R., Estes, M. 2004. Characterization of bovine homologue of granulysin and nk-lysin with broad spectrum antimicrobial activity. Journal of Immunology. 173(4):2607-14. Interpretive Summary: Despite highly successful eradication efforts in several countries, tuberculosis of cattle remains a serious health concern worldwide. In addition, recent outbreaks of tuberculosis in Michigan, California, Texas, and New Mexico demonstrate that the disease is far from eliminated from the United States. Improved techniques are needed for detection of infected cattle. To develop improved tests, it is beneficial to first understand the immune response to infection. In this study, a new method to evaluate a specific subset of the host response generated by cattle to infectious agents was developed. This method was then used to characterize the response by cattle to tuberculosis infection. Knowledge obtained from this study will assist in the development of new reagents and methods for the detection of tuberculosis of cattle.
Technical Abstract: Granulysin and NK-lysin are cationic proteins found in granules of human and swine cytotoxic lymphocytes cabaple of disrupting microbial membrane integrity. A murine counterpart to granulysin has not been identified to date, indicating the importance of additional models to fully characterize the role of granulysin-like molecules in the immune response to infectious disease. Two partial nucleotide sequences corresponding to the complete functional domain of granulysin and NK-lysin were amplified from bovine peripheral blood mononuclear cell (PBMC) mRNA. Nucleotide identity is significant to granulysin and NK-lysin and predicted amino acid sequence indicates structural and lytic motifs in the core region of the granulysin-like molecules are likely conserved among species. Following stimulation with phorbol ester and calcium ionophore, expression of the bovine gene was detected in CD3+ T cells, CD4+ T cells, CD8+T cells, WC1+ gd T cells, and PBMC depleted of CD3+ T cells, but was absent in CD21+ cells and CD14+ cells. Synthetic human, bovine, and swine peptides corresponding to the carboxy terminus of helix 2 through helix 3 region of granulysin displayed potent antimicrobial activity against Escherichia coli, Salmonella enteritidis, Staphylococcus aureus, and Mycobacterium bovis BCG. Human and bovine peptides corresponding to helix 2 displayed antimycobacterial activity against Mycobacterium bovis BCG only, while the corresponding swine peptide was not active. Expression of the bovine gene was detected in laser microscopy dissected lymph node lesions from Mycobacterium bovis infected animals. The identification of a biologically active bovine homologue to granulysin demonstrates the application of the bovine model in characterizing the role of granulysin in the immune response to a variety of infectious agents.