Aim: To assess effect of continued immunization of mice from CBA line with inactivated group A streptococcal vaccine on levels of serum cytokines and number of stromal bone marrow progenitor cells in immunized mice and in heterotopic transplants after different variants of transplantation.
Materials and methods: CBA mice were immunized during 3 weeks with heat-killed vaccine prepared from group A streptococci type 5. Levels of pro- and antiinflammatory cytokines were measured with BioPlex device. Number of stromal progenitor cells was determined on quantity of colonies formed by cells explanted to monolayer cultures.
Results: Significant 2.3-fold increase of number of stromal progenitor cells in femoral bone marrow of immune mice was demonstrated. Experiments with heterotopic transplants showed that bone marrow in transplants of mice immunized with streptococci--variant Normal-->Immune (N-->1)-- is defective both on efficacy of cloning and number of stromal progenitor cells. Even short-term presence of stromal tissue in immune organism (variant I -->N) significantly changed these parameters, especially at late time after transplantation. In serum of immune mice changes of cytokines levels, especially TNFalpha, were observed. The level of the latter was decreased (mean--2.5-fold) in all immune serum samples compared to normal serum.
Conclusion: Immunization of mice with group A streptococci leads to changes in stromal tissue and, possibly, to damage of microenvironment functions including hemo- and lymphopoiesis.