Nutritional Determinants of Resistance to Tuberculosis

The relationship between malnutrition and tuberculosis is probably as ancient as the disease itself. One approach to the identification of nutritional determinants of resistance to tuberculosis has been to utilize a guinea pig model of low-dose pulmonary infection with virulent Mycobacterium tuberculosis. Although many of the host immune functions have been shown to be sensitive to nutrient deprivation in infected animals, few have been examined in the context of infection with M. tuberculosis or other human pathogens. However, vitamin D-deprived guinea pigs responded to pulmonary infection with virulent M. tuberculosis by allowing exactly the same degree of bacterial accumulation in the lung and spleen as that seen in well-nourished counterparts. Recent experiments involving adoptive transfer of immune cells between normal and malnourished donor and recipient inbred guinea pigs point to defects in T cell trafficking, clonal expansion in vivo, and subset balance as possible explanations for the loss of vaccine-induced resistance to tuberculosis in protein deficiency.