ABSTRACT
When compared with normal milk, bovine colostrum contains a large amount of uridine 5'-monophosphate (UMP) and its derivatives. In the present study, we carried out 2 experiments to determine the effects of dietary UMP (2 g/d) on the immune status of newborn calves. In Exp. 1, newborn Holstein bull calves were fed milk replacer alone (control group) or milk replacer supplemented with UMP (UMP group) from d 4 to 10 after birth. The increase in interferon-gamma concentration by peripheral blood mononuclear cells (PBMC) on d 24 tended to be greater in the UMP group than in the control group (P = 0.06). The IgA concentration of the ileal mucosa was greater in the UMP group than in the control group (P < 0.05), although there was no difference between groups in the jejunal mucosa. In Exp. 2, newborn Holstein bull calves were fed milk replacer alone (control group) or milk replacer supplemented with UMP (UMP group) from d 4 to 56 after birth. The proliferation of PBMC was greater in the UMP group than in the control group on d 14, 28, and 42 (P < 0.01). The increase in interferon-gamma concentration by PBMC was greater in the UMP group than in the control group on d 28 and 42 (P < 0.05). From these results, we concluded that dietary UMP affected the immune responses of newborn calves.
Subject(s)
Animals, Newborn/immunology , Cattle/immunology , Diet/veterinary , Dietary Supplements , Uridine Monophosphate/administration & dosage , Animals , Body Weight , Cell Proliferation , Genitalia , Immunoglobulin A/immunology , Interferon-gamma/immunology , Intestinal Mucosa/immunology , Leukocytes, Mononuclear/cytology , Leukocytes, Mononuclear/immunology , Liver/physiology , Male , Spleen/physiologyABSTRACT
We have investigated the effects of dietary nucleotides on intraepithelial lymphocytes (IEL) and intestinal epithelial cells (IEC) in weanling mice. The proportion of T-cell receptor (TCR) gammadelta+ IEL in BALB/c mice fed a diet supplemented with nucleotides (NT(+) diet) was significantly higher than that in mice fed the nucleotide-free diet, while the proportion of TCR alphabeta+ IEL in NT(+) diet-fed mice was significantly decreased. The change of the TCR alphabeta+/TCR gammadelta+ ratio was mainly observed in a CD8 alphaalpha+ subset of IEL. IEC from NT(+) diet-fed mice produced a higher level of IL-7, which is important in the development of TCR gammadelta+ IEL, than those from control diet-fed mice. The expression levels of IL-7 and IL-2 receptors on IEL were not different between the two dietary groups. Our findings suggest that the increased population of a TCR gammadelta+ IEL subset by feeding nucleotides may be caused by the increased production of IL-7 by IEC.