National debt management as a presondition of macroeconomic stability

Стаття присвячена оцінці процесу управління державним боргом з точки зору відомих макроекономічних теорій представників різних наукових шкіл. Здійснено аналіз макроекономічних тенденцій і залежностей, які породжені дисбалансами, викликаними недосконалим менеджментом у сфері здійснення управління боргом в Україні. Основна взаємозалежність, що досліджується, — це залежність між методами здійснення процесу управління борговими зобов’язаннями та забезпеченням економічного зростання економіки, подолання основних макроекономічних дисбалансів розвитку та пропозиції щодо оптимізації процесу управління боргом задля досягнення макроекономічної стабільності.The article is devoted to evaluation of national debt management from points of view of popular macroeconomic theories by representatives of different scientific schools. We analyzed macroeconomic tendencies and dependences evoked by disbalances from imperfect debt management in Ukraine. The main interdependence, which is being investigated, is between methods of acting upon the process of debt obligation management and providing economy’s growth, overcoming main macroeconomic growth disbalances and suggestions as for debt management process optimization in order to achieve macroeconomic stability

Interaction of natural killer cells with MHC class II: reversal of HLA-DR1-mediated protection of K562 transfectant from natural killer cell-mediated cytolysis by brefeldin-A.

Major histocompatibility complex (MHC) class I antigens on tumour cell surfaces have been shown to modulate target susceptibility to natural killer (NK) cell-mediated lysis in some, although not all, systems investigated. MHC class II expression may also affect NK cell function, but the mechanism by which MHC class II antigen regulates NK cell activity has not been fully examined. In this study we induced HLA-DR1 expression by gene transfection into the classic NK-sensitive K562 cell line to study the interaction of NK cells with MHC class II molecules and the effect of brefeldin-A (BFA), an endogenous antigen-processing pathway blocker, on NK-target cell interaction. We demonstrated that the expression of HLA-DR1 on the cell surface reduced K562 cell susceptibility to NK lysis by peripheral blood monuclear cells and a NK cell line. The effect was demonstrable in prolonged (8 hr) cytotoxicity assays and was blocked by pretreatment of target cells with anti-HLA-DR antibody. Treatment of K562 DR transfectant with BFA abrogated the resistance of K562 transfectant to NK-mediated cytolysis. These findings indicate that HLA class II molecules regulate NK cell function and target recognition, and suggest that endogenous peptides presented through MHC molecules are responsible for regulating NK cytolysis

The Vγ2/Vδ2 T-cell repertoire in Macaca fascicularis: functional responses to phosphoantigen stimulation by the Vγ2/Jγ1.2 subset

Circulating Vγ2/Vδ2 T cells in human and non-human primates respond to small molecular weight non-peptidic phosphoantigens in a major histocompatibility complex (MHC)-unrestricted manner. These responses are encoded by the Vγ2/Jγ1.2 chain of the T-cell receptor and are positively selected during early development to create a biased repertoire in adults. We characterized the Vγ2 chain in cynomolgus macaques (Macaca fascicularis) to develop a non-human primate model for studying the effects of infection and therapy on the circulating Vγ2/Vδ2 T-cell subset. The cynomolgus macaque Vγ2 chain was highly homologous to the Vγ2 chain from human beings and rhesus macaques (Macaca mulatta), though we noted conserved substitutions in critical residues within the CDR3 for both macaque species. Despite these substitutions, Vγ2/Vδ2(+) T cells from cynomolgus monkeys exhibited polyclonal responses to two different phosphoantigens. Proliferative responses were observed with both isopentenylpyrophosphate and alendronate, but stronger interferon-γ secretory responses were observed with isopentenylpyrophosphate. In vitro stimulation and expansion led to selective outgrowth of the Vγ2/Jγ1.2 subset, with a marked shift in the Vγ2 spectratype. As a result of the less biased starting repertoire for Vγ2, the cynomolgus macaque constitutes a sensitive model for examining the effects of in vitro or in vivo treatments on the Vγ2/Vδ2 T-cell population. Our studies establish the value of cynomolgus macaques as a model for Vγ2/Vδ2 T-cell responses to non-peptidic antigens, and further evidence the remarkable evolutionary conservation of this unusual, phosphoantigen-responsive T-cell subset that is found only in primate species

Antigen-specific B and T cells in human/mouse radiation chimera following immunization in vivo

Adoptive transfer of human peripheral blood mononuclear cells (PBMC) into mice with severe combined immunodeficiency (SCID) or into lethally irradiated BALB/c mice radioprotected with SCID bone marrow, leads to marked engraftment of human T and B cells. In such chimeras, human serum antibody responses can be stimulated readily by vaccination with recall antigens, but the detection of antigen-specific functional T or B cells has been extremely difficult. In the present study, we were able to detect by Elispot analysis high frequencies of immunoglobulin G (IgG)-secreting B cells and mitogen-responsive interferon-γ (IFN-γ) or interleukin-4 (IL-4)-secreting T cells in peritoneum and spleen of human/BALB/c chimeric mice during the first 3 weeks after PBMC transfer. Moreover, specific memory responses were elicited by vaccination with tetanus toxoid (TT) or hepatitis B virus (HBV) surface (HBs) antigen of chimeric mice transplanted with PBMC derived from TT- or HBV-immune donors. Substantially higher TT-specific B-cell frequencies were found during the first 3 weeks after vaccination in mice challenged with the specific antigen compared to the levels found in control animals. High numbers of TT-specific IFN-γ-secreting T cells persisted in the peritoneum of vaccinated, but not of unvaccinated, animals during the entire observation period, but only low numbers of specific IL-4-secreting T cells were found in vaccinated mice. Similar results were achieved following vaccination with HBs antigen of chimeric mice, transplanted with PBMC of HBV immunized donors. Thus, TT or HBsAg-specific antibody responses in our model correlate closely with the existence of specific IFN-γ-secreting T helper 1/0 cells. Furthermore, these results show that adoptive transfer of human PBMC into lethally irradiated mice provides an efficient approach to generate specific B-cell fusion partners for the production of human monoclonal antibodies and specific T-cell lines for adoptive cell therapy of malignant or infectious diseases