A Combination of Muramylpeptides from Gram-Negative Bacteria Corrects Hematological and Immunological Disorders Induced by Cyclophosphamide.

We have studied the effect of a combination of three natural muramylpeptides containing a meso-diaminopimelic acid residue (polyramyl) on the subpopulations of circulating T cells, spleen morphology, and leukocyte level in the blood of C57Bl/6 mice with cyclophosphamideinduced immunosuppression. Intraperitoneal injections of cyclophosphamide in a dose of 100 mg/kg on days 1, 3, 5, and 7 of the experiment reduced leukocyte count and the relative number of CD4+ T cells in the blood, and also depleted the cellular composition of splenic white pulp on day 10. Subcutaneous injections of polyramyl in a dose of 200 μg/mouse on days 8 and 9 practically completely restored blood leukocytes count and morphology of the splenic white pulp. Moreover, administration of polyramyl induced marked tendency to increase in the relative number of CD4+ T cells and CD4/CD8 ratio in mice with cyclophosphamideinduced immunosuppression.