Change in interleukin 2 production by lymphocytes during maturation of young cats

Lymphocytes from four specific-pathogen free cats were tested for their interleukin 2 activity every week beginning when the cats were 12 weeks old and ending when they were 26 weeks old. Lymphocytes from cats > or = 20 weeks old released significantly more interleukin 2 than those obtained from these cats at earlier ages when stimulated with calcium ionophore A23187 and phorbol myristate acetate. The change of interleukin 2 levels with maturation of young cats may represent an important difference in their level of defense to infections with various pathogens.