Osteopontin-enriched formula feeding improves the T-cell-dependent humoral immune responses in infant rats.

Previous studies have shown that osteopontin (OPN) can enhance infant resistance to infection. However, the underlying mechanisms remain to be explored. Here, we studied the effects of OPN on the development and functions of immune cells in infant rats fed with OPN-enriched formula (OF) compared with regular formula (RF). After 21 days feeding, the proportion of infant rats' CD3+ T cells of lymph nodes in the OF group is significantly increased compared with the RF group. The proportion of CD4+ and CD8+ T cells of lymph nodes in the OF group is closer to the breast feeding (BF) group than to the RF group. Upon immunisation with the thymus-dependent antigen ovalbumin (OVA), the concentration of OVA-specific IgG in the OF group was significantly higher than that in the RF group. Altogether OPN-enriched infant formula feeding can promote the differentiation of CD3+ T cells and improve the T-cell-dependent humoral immune responses in infant rats.