PSIX-20 - Galectins expression and secretion in cow milk.

The objective of this study was to assess the expression and secretion of Galectins (Gal) in cow milk. Cow milk contains a range of proteins of moderate or low abundance that contribute to host defense. However, host defense proteins in milk were not fully discovered. Galectins belong to the lectin family that recognizes specific carbohydrates on cells and involved in innate immune responses. Holstein Friesian cows (n = 16) from North Carolina A&T diary unit were used for this study. Based on the Dairy Heard farm index, eight cows each were assigned to the high or low SCC group. Total RNA was isolated from somatic cells converted to cDNA, for real-time PCR. Cow-specific Gal primers were designed using the NCBI Primer 3 tool. Housekeeping genes RPLP0, UCHL5, and beta-actin were served as internal controls. Total whey protein concentration was determined using a BCA kit. Secretion of Gal was assessed using a specific ELISA kit. Data were analyzed using the Proc ANOVA procedure in SAS 9.4. Galectin was transcribed and secreted in milk. Transcription of Galectin was different in both HSCC and LSCC groups. Total protein concentration remained the same in both groups. Secretion of galectins was different between the HSCC and LSCC group but not significantly. The observed difference in HSCC and LSCC cows warrants further study using more animals; this will aid in a better definition of the role of Gal in the milk host defense. These may also aid as the diagnostic biomarkers for certain infections.