Lack of Restimulation by Non-HLA Antigens in Primed Lymphocyte Typing

We have studied the role of non-HLA antigens in restimulation of PLT cells by the following protocols. Responder cells were sensitized to cells from family members differing by one HLA haplotype. The PLT cells were restimulated by family members HLA- or HLA-D-identical to the responder. In none of these cases did we find significant restimulation, indicating that it is unlikely that there is a restimulatory non-HLA locus with even two alleles (p less than 0.05) of equal frequency. Other protocols we have used are consistent with this interpretation. This indicates that antigens determined by genes segregating independently of HLA do not play a major role in the PLT restimulation.     

Antibody Formation in Mouse Bone Marrow During Secondary Type Responses to Various Thymus-Independent Antigens

The data presented in this paper show that different thymus-independent (TI) antigens have a differential capacity of inducing antibody formation in mouse bone marrow, both after primary and secondary intravenous immunization. Primary immunization with certain TI antigens (e.g., lipopolysaccharide [LPS], TNP-LPS, DNP-Ficoll) induces the appearance of antibody-forming cells not only in the spleen, but also in the bone marrow. A single injection of certain other TI antigens (e.g., pneumococci [Pn], TNP-conjugated detoxified LPS [TNP-dLPS], TNP-conjugated Brucella abortus bacteria [TNP-BA]), on the other hand, induces antibody formation in the spleen only. After secondary immunization with these TI antigens only TNP-BA induces a PFC response in the bone marrow. Pn, TNP-dLPS and TNP-BA, but also DNP-Ficoll, are unable to induce bone marrow antibody formation after secondary injection of the antigen, in spite of the clear-cut secondary type character of the splenic response. Thus, the absence of a bone marrow PFC response after secondary immunization with these antigens is not due to a failure to induce memory B cells. This data implies that either two subpopulations of memory B cells exist, one giving rise to antibody formation in the spleen and the other accounting for the bone marrow response, or that antibody can selectively inhibit the secondary bone marrow antibody response to certain TI antigens.     

Counts of Stromal Precursor Cells in the Bone Marrow and Heterotopic Bone Marrow Transplants from Mice Immunized with Group A Streptococcus Antigens during Different Periods after Immunization

The counts of stromal precursor cells in bone marrow transplants obtained from animals 2 months after their immunization with killed type 5 group A streptococcus vaccine drop almost 3-fold in comparison with transplants from normal donors. Six months after donor immunization, the count of stromal precursor cells in the transplants reaches the normal level. The count of stromal precursor cells in bone marrow transplants from normal mice transplanted to recipients 6 months after their immunization with killed streptococcus vaccine also virtually did not change in comparison with the counts in bone marrow transplants from normal donors transplanted to normal recipients. The weight and size of bone capsules of 6.5-month bone marrow transplants in intact recipients after transplantation from donors immunized 2 months before with killed type 5 group A streptococcus vaccine was 3-fold lower than in bone marrow transplants collected from intact donors. The content of stromal precursor cells in the femoral bone marrow of animals immunized with killed streptococcus vaccine was 2.5 time higher in comparison with the parameter in the femoral bone marrow of normal mice even 8 months after immunization. The results indicate a significant long-acting effect of streptococcal antigens on the bone marrow stromal tissue, specifically, on its osteogenesis potential. Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 147, No. 1, pp. 78-81, January, 2009     

Y Chromatin as Indicator of Chimaerism Following Bone Marrow Transplantation in Severe Combined Immunodeficiency

Determination of the Y chromatin body should rank among the battery of techniques used to assess the presence of grafted bone marrow cells in cases of male donor and female recipient. The method permits early determination of a take, and probably some measurement of its magnitude. This might provide correlation between level of grafted cells and occurrence of various parameters indicating an immune reconstitution and/or an eventual GVH reaction. The technique may be a highly sensitive marker for chimaerism in cases of histocompatibility between donor and recipient of different sexes.     

Effect of Endocrine Manipulation on Graft Rejection

Immune competence (as determined by xenograft rejection) was measured following classical endocrine ablation and replacement procedures in the adult rat. Graft rejection, expressed as initial rejection time, was not changed by thyroidectomy, adrenalectomy, or hypophysectomy, either with or without appropriate hormone replacement. In contrast, gonadectomy in 3 rat types (female Sprague-Dawley, male and female Long Evans) decreased initial rejection time; administration of physiological doses of 17β-estradiol plus progesterone returned the initial rejection time of ovariectomized rats to that observed in un-operated controls. Since initial rejection time was neither decreased by secondary ovariectomy (hypophysectomy) nor increased by sex steroid administration to hypophysectomized rats, it was suggested that the increased immune response after ovariectomy may be due to the presence of an immunopotentiating pituitary factor(s). Although commercial preparations of follicle-stimulating hormone, luteinizing hormone, and luteotropic hormone were found to mimic the effect of ovariectomy, the impurity of these preparations (as judged by isoelectric focusing gels) precluded any conclusion as to the nature of the postulated immunopotentiating factor.     

Effect of Endocrine Manipulation on Graft Rejection

Immune competence (as determined by xenograft rejection) was measured following classical endocrine ablation and replacement procedures in the adult rat. Graft rejection, expressed as initial rejection time, was not changed by thyroidectomy, adrenalectomy, or hypophysectomy, either with or without appropriate hormone replacement. In contrast, gonadectomy in 3 rat types (female Sprague-Dawley, male and female Long Evans) decreased initial rejection time; administration of physiological doses of 17β-estradiol plus progesterone returned the initial rejection time of ovariectomized rats to that observed in un-operated controls. Since initial rejection time was neither decreased by secondary ovariectomy (hypophysectomy) nor increased by sex steroid administration to hypophysectomized rats, it was suggested that the increased immune response after ovariectomy may be due to the presence of an immunopotentiating pituitary factor(s). Although commercial preparations of follicle-stimulating hormone, luteinizing hormone, and luteotropic hormone were found to mimic the effect of ovariectomy, the impurity of these preparations (as judged by isoelectric focusing gels) precluded any conclusion as to the nature of the postulated immunopotentiating factor.