PROTECTION OF MICE FROM GROUP-A STREPTOCOCCAL SKIN INFECTION BY INTERLEUKIN-12

It has been shown that interleukin (IL)-12 induces cell-mediated immun ity and provides significant protection against intracellular organism s, The ability of this cytokine to enhance immunity in a mouse model o f group A streptococcal skin infection was studied. Outbred CD1 mice w ere injected for 3 consecutive days with 0.1 mu g of recombinant murin e IL-12 before or after challenge with strain 64/14 group A streptococ ci. In both cases, in vivo IL-12 treatment significantly decreased the rate of death after infection and increased survival over the period of experimental observation, Thus, IL-12 may be useful for treatment o f gram-positive bacterial infections. The time course of the experimen ts suggests that IL-12 is acting in this model system to enhance natur al, rather than acquired, immunity.