The inhibitory effects by combined doses of DDS and several immunostimulants on the growth of leprosy bacilli inoculated into footpads of hybrid nude mice, Jcl:AF-nu.

The inhibitory effects by the combined doses of bacteriostatic DDS and several immunostimulants on the growth of leprosy bacilli (LB) inoculated into the footpads of nude mice were examined, using a strain of hybrid nude mice named Jcl:AF-nu, which is resistible to infections more than strain BALB/c-nu. The results found were: 1. LB could proliferate up to 10(9) level in the footpads of this strain of hybrid nude mice. 2. The combined dose of muramyl dipeptide (MDP) or a water-soluble lipoidal amine, CP-46665 and DDS mixed with chow in the content ratio of 0.005% completely inhibited the growth of LB. Whereas, the growth inhibition by DDS alone was only partial. 3. A derivative of MDP, muroctasin could partially inhibit the growth of LB without combined dose of DDS. 4. The combined dose of an antitumor beta-1, 3-glucan named ATSO could not enhance the partial growth inhibition due to the dose of DDS through 0.005%-DDS chow. Based on these results, the possibility of Jcl:AF-nu mice as a favorable animal model for examining the synergic inhibitory effect on the growth of LB due to the combined dose of an antileprous chemotherapeutic and an immunostimulant was discussed.