Neutrophil cathepsin G is specifically decreased under vitamin A deficiency

Vitamin A deficiency leads to an increased susceptibility to infections, increased severity of infections and increased mortality. Because the neutrophil is the first cell to respond to infection, this study explores the effect of vitamin A deficiency on neutrophil proteinases. We found that neutrophils from vitamin A-deficient rats had lower levels of two cathepsin G-like enzymes (28 and 24 kDa) when compared to neutrophils from weight-matched pair-fed rats, vitamin A-deficient rats which were repleted with retinyl palmitate and nonrestricted vitamin A complete diet rats. The 28 kDa cathepsin G-like enzyme, which migrated with the same mobility as elastase on SDS-polyacrylamide gels, was quantified using Western blots. The 24 kDa cathepsin G-like enzyme was quantified using zymogram gels. This activity was inhibited by chymostatin. Other neutrophil proteinases, elastase, plasminogen activators and gelatinase, were not altered significantly by vitamin A deficiency. The low levels of cathepsin G may contribute to differences in the inflammatory process observed under vitamin A deficiency.