Calorie-Protein Deficiencies and the Immune Response of the Chicken. II. Cell-Mediated Immunity

Calorie-protein deficiency affects humoral immunity in the chicken. Secondary responses to sheep-red blood cells, a T-dependent antigen, were lower in birds fed diets two-thirds deficient in calories (C), amino acids (AA), or both (C/AA). These results led us to question what effects might be found in cell-mediated immunity after nutritional deficiency. Birds fed the same diets as in our previous study showed no reduction in total white blood cells, absolute lymphocytes, or absolute heterophils. Splenic lymphocytes from 3- or 7-week-old nutritionally deficient chickens with the exception of the AA group at 7 weeks, produced a nonsignificant increase in graft-versus-host (GvH) response of 12-day-old embryos. Thymic cells from 3-week-old nutritionally deficient birds were not deficient in the GvH potential. Thymic histology revealed reduced cellularity in AA-deficient birds. The reduced cellularity may not have been in response to stress since the mean corticosterone levels were not significantly different. Birds fed the deficient diets for 10 weeks had a significantly reduced delayed hypersensitivity response to human gamma globulin. The results indicate that the chickens' ability to produce a GvH response was not compromised and that T-cell subpopulations may have differential sensitivities to nutritional deficiencies.