The defect in delayed‐type hypersensitivity of young adult SJL mice is due to a lack of functional antigen‐presenting cells

SJL mice exhibit a strain‐specific age‐dependent delay in the maturation of delayed‐type hypersensitivity (DTH) responsiveness. They do not attain “adult” levels of DTH responsiveness until the 10th week of age, which is 4 to 6 weeks later than the other strains of mice tested. In this report we demonstrate that spleen cells, resident peritoneal cells and thioglycollate‐elicited peritoneal exudate cells are all able to transfer DTH responsiveness from naive 12‐week‐old DTH responders to 6‐week‐old nonresponders. Transfer prior to immunization was more efficient at eliciting a response than transfer after immunization. As few as 5 ± 10⁴ cells from 12‐week‐old SJL mice can adoptively transfer responsiveness to unresponsive 6‐week‐old animals. The active cell was found to be adherent, radiation (2000 rds) resistant, I‐A⁺, Thy‐1⁻ and Mac‐l⁺. I‐A compatibility between the adoptively transferred population and the nonresponder mice is required. These data suggest that young adult SJL mice lack a functional population of antigen‐presenting cells specific for DTH and that the appearance of these cells is under maturational control.