No abstract

The count of stromal precursor cells in bone marrow transplants from CBA mice, transplanted to animals immunized with killed type 5 group A streptococcus vaccine, decreased 4.5-6.5 times (depending on the transplant age) in comparison with the grafts transplanted to normal recipients. The counts of stromal precursor cells in 1.5-3-month bone marrow transplants from animals immunized with killed streptococcal vaccine transplanted to normal mice were virtually the same, while in 7-month transplants they decreased 2-fold in comparison with their counts in bone marrow transplants from normal CBA mice transplanted to normal animals. The content of stromal precursor cells in the femoral bone marrow of animals immunized with killed streptococcal vaccine was appreciably (3.5 times) higher than in the bone marrow of normal mice. The results attest to an appreciable effect of streptococcal antigens on the bone marrow stromal tissue and suggest that not all stromal precursor cells, whose count increases after injection of antigens, are responsible for transplantability of the stromal tissue in case of its heterotopic transplantation.

Osteoinductive activity of the transitional epithelium in the urinary bladder increased by more than 3 times in aging guinea pigs. The count of inducible osteogenic precursors and their sensitivity to urinary bladder osteoinductive factor decreased by several times with age. Our experiments show that proliferation of some stromal precursors in the spleen requires not only platelet-derived factors, but also growth factors produced by urinary bladder transitional epithelium.

Efficiency of colony formation of stromal precursor cells in cultured bone marrow transplants from old (24 month) CBA mice implanted to young (2-month-old) mice almost 3-fold surpassed that in cultured transplants implanted to old recipients. The content of nucleated cells in bone marrow transplants from senescence accelerated mice SAMP increased more than 2-fold, if SAMR mice with normal aging rate were used as the recipients instead of SAMP mice. Bone marrow taken from old and young CBA mice endured the same number of transplantations if the recipient mice were of the same age (5 month). It was concluded that stromal tissue considerably changes with age and is under strict control of the body.

No abstract

The content of multipotent stromal cells (MSC) in the bone marrow and efficiency of their cloning (ECF-MSC) increased by 3 times 1 day after administration of complex S. typhimurium antigens to CBA mice, while the relative content of alkaline phosphatase-positive MSC colonies (marker of osteogenesis; P(+) colonies) decreased from 14% (control) to 3%. After administration of the complex S. typhimurium antigens to CBA mice 3 h after (or 3 h before) curettage or treatment with morphogenetic protein (BMP-2), the content of MSC and ECF-MSC decreased on the next day by ~3 times in comparison with animals receiving antigens alone and approached the control level. The relative content of P(+) colonies increased to 20 and 35%, respectively, in comparison with animals receiving antigens (3%), but was significantly lower than after curettage (34%) or BMP-2 (42%) administration. Expression of IL-1β, IL-6, IL-12, TNF-α, and IFN-γ genes in the primary cultures of stromal bone marrow cells induced by antigen administration was suppressed, while the concentrations of IL-12 and TNF-α in the culture medium sharply decreased after antigen treatment in combination with curettage or BMP-2 administration. Administration of complex S. typhimurium antigens after pretreatment with BMP-2 (3 h before) was associated with a decrease in serum levels of IL-2, IFN-γ, IL-12, and TNF-α in mice receiving BMP-2+S. typhimurium group 4 h after treatment in comparison with the animals receiving only S. typhimurium antigens alone by 1.9, 4.4, 1.5, and 6 times, respectively, i.e. to normal level or below it, while the concentration of IL-10 increased by almost 2 times, which probably reflected anti-inflammatory properties of BMP-2. These data probably attest to competitive relations between osteogenesis and immune response at the level of MSC.

No abstract

Administration of bacterial antigens to CBA mice induced an increase in serum concentration of virtually all cytokines with a peak in 4 h after administration of S. typhimurium antigens and in 7 h after administration of streptococcus antigens. In 20 h, cytokine concentrations returned to the control level or were slightly below it. In 4 h after administration of S. typhimurium antigens preceded 3 h before by administration of streptococcus antigens, we observed a significant decrease in serum concentrations of IFN-γ, IL-10, GM-CSF, IL-12, and TNF-α, in comparison with injection S. typhimurium antigens alone and IL-5, IL-10, GM-CSF, and TNF-α in comparison with injection of streptococcus antigens alone; the concentrations of IL-2 and IFN-γ, in contrast, increased by 1.5 times in this case. In 20 h after administration of S. typhimurium antigens, the number of multipotential stromal cells (MSC) in the bone marrow and their cloning efficiency (ECF-MSC) increased by 4.8 and 4.4 times, respectively, in comparison with the control, while after administration of streptococcus antigens by 2.6 and 2.4 times, respectively. In 20 h after administration of S. typhimurium antigens preceded 3 h before by administration of streptococcus antigens, these parameters increased by 3.2 and 2.9 times, respectively, in comparison with the control, i.e. the observed increase in the level of MSC count and ECF-MSC is more consistent with the response of the stromal tissue to streptococcus antigens. Thus, successive administration of two bacterial antigens corrected both serum cytokine profiles and MSC response to administration of each antigen separately, which indicates changeability of the stromal tissue in response to changes in the immune response.