CD4 and Abnormal intestine morphology: These results suggest that the delayed onset of inflammation in PP– OVA23-3 mice reflects the lack of an immediate response of PP CD4+ T-cells against OVA; aggravation of the enteropathy likely developed only after antigen and antigen-presenting cells reached the MLNs to initiate the activation of and IL-4 production by MLN CD4+ T-cells and their migration into the lamina propria.