Effect of Immunization with Type 5 Group A Streptococcal Antigens and Liposaccharide (LPS) In Vivo and In Vitro on Splenic and Bone Marrow Multipotent Stromal Cells in Mice.

The number of multipotent stromal cells (MSC) in the splenic transplants of normal CBA mice in recipients immunized with inactivated type 5 group A streptococcal vaccine decreased by 3.5-1.8 times depending on the age of the recipients in comparison with that in the transplants grafted to the control recipients. Such immunization suppressed MSC transplantability, i.e., their potency to construct and maintain specific microenvironment of initial organs. In 24 h after administration of LPS to normal mice in vivo, the MSC content in the spleen and bone marrow increased by 1.8 and 1.6 times, respectively; in immunized mice, these parameters did not increase after LPS injection. The concentration of TNFα in the culture medium of bone marrow from normal mice increased pronouncedly after treatment with LPS both in vivo and in vitro (from 0 to 16.1±2.0 and to 14.2±0.1 pg/ml, respectively), while in the culture medium of bone marrow cells from of immunized mice, this cytokine was not detected after LPS treatment. Probably, immunization of mice with antigens of type 5 group A streptococci and resulting autoimmunity diminish animal sensitivity to LPS, which is reflected by examined parameters of the stromal tissue.