Vanadium stimulates immunological responses of chicks

In a continuation of studies on the interaction of dietary phosphorus (P) and vanadium (V) levels, studies have directed toward an examination of this interaction on the immune system of chicks. Antibody titers to sheep red blood cells (SRBC) were increased at 7 days post-inoculation (PI) by as little as 10 mg V/kg diet in the P-deficient group, while 50 mg V/kg was required in the P-supplemented group. At 14 days PI, only the 50 mg V/kg was significantly higher in both P-deficient and P-supplemented groups. At 21 days PI, vanadium had no significant effect. P-deficiency resulted in a decrease in the percentage of phagocytic macrophages obtained from the abdominal cavity and a decrease in the number of intracytoplasmic SRBC per phagocytic macrophage. These two criteria were increased by vanadium in both the P-deficient and P-supplemented animals. In P-supplemented animals, the CD4/CD8 ratios of lymphocytes obtained from the blood and spleen were increased by the inclusion of 50 mg V/kg diet. The IL-l-like activity of macrophage supernatants was not significantly affected by dietary V, but IL-6 activity was increased. Densitometric analysis of lysates of macrophages isolated from control and V-fed chicks for anti-protein-tyrosinephosphate (PTP) bands indicate that dietary V increased PTP. While the evidence is not clear that there is a P × V interaction in the immune system studies, it is clear that dietary V at the levels used results in a positive immune response of chicks, possibly mediated through increased PTP.