The response of protein-deficient mice to tetanus toxoid. Effects of antigen dose, adjuvants, period of deprivation and age on antibody production.

The effects of a 4% albumin diet initiated at weaning on primary and secondary responses to AIPO4-adsorbed and soluble tetanus toxoid (TT) were studied in C57BL mice. Responses of both groups were directly proportional to the dose of antigen over most of the range tested, but at very low doses protein-deficient mice produced higher primary titres than normal mice. In the primary response AIPO4-adsorption of the antigen essentially increased the effective dose irrespective of the diet, but after secondary challenge responses to soluble TT were more severely affected by the diet. Normal secondary titres to AIPO4-adsorbed TT were achieved when deficient mice were given high doses of antigen. Diet also affected the relative proportions of IgG and IgM produced in most responses. Gram-negative bacterial vaccines and lipopolysaccharide increased antibody production in both groups of mice. The low protein diet produced less dramatic effects when initiated at the time of inoculation or later, and mice maintained for longer on the diet produced more nearly normal titres. Mechanisms which may explain these findings are discussed.