Negative energy balance does not decrease expression of leukocyte adhesion or antigen-presenting molecules in cattle

Abstract

Sixteen yearling Holstein steers were fed for 210 or 60% of maintenance requirements to impose positive or negative energy balance, respectively. Blood was collected and analyzed for serum concentration of non-esterified fatty acids (NEFA), and leukocytes were isolated and counted. Isolated leukocytes were then analyzed for expression of the adhesion molecules L-selectin (CD62L), Mac-1 (CD11b and CD18), and major histocompatability complex (MHC) class I and class II molecules with immunostaining and flow cytometric analysis. Negative energy balance increased the concentration of NEFA in serum (P < 0.0001). Expression of CD62L on neutrophils was increased 14% during negative energy balance (P = 0.03). Energy balance did not affect expression of CD62L on any other cell types or expression of CD11b or CD18. Negative energy balance did not affect MHC class I expression but resulted in a small but significant increase in the expression of MHC class II (P = 0.03). The results of this study provide little evidence that nutritionally created negative energy balance impairs expression of CD62L, CD11b, and CD18 or expression of MHC class I or MHC class II molecules by resting bovine blood leukocytes.