A correct antibody response requires the participation of both B and T lymphocytes and antigen presenting cells. In this review we address the role of follicular helper T lymphocytes(T FH) in this reaction. We shall f...A correct antibody response requires the participation of both B and T lymphocytes and antigen presenting cells. In this review we address the role of follicular helper T lymphocytes(T FH) in this reaction. We shall focus on the regulation of their development and function in health and disease. T FH can be characterized on the basis of their phenotype and the pattern of secretion of cytokines. This fact is useful to study their participation in the generation of antibody deficiency in primary immunodeficiency diseases such as common variable immunodeficiency, X-linked hyper Ig M syndrome orX-linked lymphoproliferative disease. Increased numbers of T FH have been demonstrated in several autoimmune diseases and are thought to play a role in the development of autoantibodies. In chronic viral infections caused by the human immunodeficiency virus, hepatitis B or C virus, increased circulating T FH have been observed, but their role in the protective immune response to these agents is under discussion. Likewise, an important role of T FH in the control of some experimental protozoan infections has been proposed, and it will be important to assess their relevance in order to design effective vaccination strategies.展开更多
Circulating monocytes （Mos） may continuously repopulate macrophage （MAC） or dendritic cell （DC） populations to maintain homeostasis. MACs and DCs are specialized cells that play different and complementary immun...Circulating monocytes （Mos） may continuously repopulate macrophage （MAC） or dendritic cell （DC） populations to maintain homeostasis. MACs and DCs are specialized cells that play different and complementary immunological functions. Accordingly, they present distinct migratory properties. Specifically, whereas MACs largely remain in tissues, DCs are capable of migrating from peripheral tissues to lymphoid organs. The aim of this work was to analyze the expression of the fractalkine receptor （CX3CR1） during the monocytic differentiation process. Freshly isolated Mos express high levels of both CX3CR1 mRNA and protein. During the Mo differentiation process, CX3CR1 is downregulated in both DCs and MACs. However, MACs showed significantly higher CX3CR1 expression levels than did DC. We also observed an antagonistic CX3CR1 regulation by interferon （IFN）-γ and interleukin （IL）-4 during MAC activation through the classical and alternative MAC pathways, respectively. IFN-γinhibited the loss of CX3CR1, but IL-4 induced it. Additionally, we demonstrated an association between CX3CR1 expression and apoptosis prevention by soluble fractalkine （sCX3CL1） in Mos, DCs and MACs. This is the first report demonstrating sequential and differential CX3CR1 modulation during Mo differentiation. Most importantly, we demonstrated a functional link between CX3CR1 expression and cell survival in the presence of sCX3CL1.展开更多
We apply to the concrete setup of a bank engaged into bilateral trade portfolios the XVA theoretical framework of Albanese and Crepey(2017),whereby´so-called contra-liabilities and cost of capital are charged by ...We apply to the concrete setup of a bank engaged into bilateral trade portfolios the XVA theoretical framework of Albanese and Crepey(2017),whereby´so-called contra-liabilities and cost of capital are charged by the bank to its clients,on top of the fair valuation of counterparty risk,in order to account for the incompleteness of this risk.The transfer of the residual reserve credit capital from shareholders to creditors at bank default results in a unilateral CVA,consistent with the regulatory requirement that capital should not diminish as an effect of the sole deterioration of the bank credit spread.Our funding cost for variation margin(FVA)is defined asymmetrically since there is no benefit in holding excess capital in the future.Capital is fungible as a source of funding for variation margin,causing a material FVA reduction.We introduce a specialist initial margin lending scheme that drastically reduces the funding cost for initial margin(MVA).Our capital valuation adjustment(KVA)is defined as a risk premium,i.e.the cost of remunerating shareholder capital at risk at some hurdle rate.展开更多
基金Supported by Consejo Nacional de Investigaciones Científicas y Técnicas,CONICET,PIP Nos.0032 and 11220120100619CO
文摘A correct antibody response requires the participation of both B and T lymphocytes and antigen presenting cells. In this review we address the role of follicular helper T lymphocytes(T FH) in this reaction. We shall focus on the regulation of their development and function in health and disease. T FH can be characterized on the basis of their phenotype and the pattern of secretion of cytokines. This fact is useful to study their participation in the generation of antibody deficiency in primary immunodeficiency diseases such as common variable immunodeficiency, X-linked hyper Ig M syndrome orX-linked lymphoproliferative disease. Increased numbers of T FH have been demonstrated in several autoimmune diseases and are thought to play a role in the development of autoantibodies. In chronic viral infections caused by the human immunodeficiency virus, hepatitis B or C virus, increased circulating T FH have been observed, but their role in the protective immune response to these agents is under discussion. Likewise, an important role of T FH in the control of some experimental protozoan infections has been proposed, and it will be important to assess their relevance in order to design effective vaccination strategies.
文摘Circulating monocytes （Mos） may continuously repopulate macrophage （MAC） or dendritic cell （DC） populations to maintain homeostasis. MACs and DCs are specialized cells that play different and complementary immunological functions. Accordingly, they present distinct migratory properties. Specifically, whereas MACs largely remain in tissues, DCs are capable of migrating from peripheral tissues to lymphoid organs. The aim of this work was to analyze the expression of the fractalkine receptor （CX3CR1） during the monocytic differentiation process. Freshly isolated Mos express high levels of both CX3CR1 mRNA and protein. During the Mo differentiation process, CX3CR1 is downregulated in both DCs and MACs. However, MACs showed significantly higher CX3CR1 expression levels than did DC. We also observed an antagonistic CX3CR1 regulation by interferon （IFN）-γ and interleukin （IL）-4 during MAC activation through the classical and alternative MAC pathways, respectively. IFN-γinhibited the loss of CX3CR1, but IL-4 induced it. Additionally, we demonstrated an association between CX3CR1 expression and apoptosis prevention by soluble fractalkine （sCX3CL1） in Mos, DCs and MACs. This is the first report demonstrating sequential and differential CX3CR1 modulation during Mo differentiation. Most importantly, we demonstrated a functional link between CX3CR1 expression and cell survival in the presence of sCX3CL1.
基金The research of Stephane Cr´epey benefited from the support of the“Chair Markets´in Transition,”Fed´eration Bancaire Franc´¸aise,of the ANR project 11-LABX-0019 and from the EIF grant“Collateral management in centrally cleared trading.”。
文摘We apply to the concrete setup of a bank engaged into bilateral trade portfolios the XVA theoretical framework of Albanese and Crepey(2017),whereby´so-called contra-liabilities and cost of capital are charged by the bank to its clients,on top of the fair valuation of counterparty risk,in order to account for the incompleteness of this risk.The transfer of the residual reserve credit capital from shareholders to creditors at bank default results in a unilateral CVA,consistent with the regulatory requirement that capital should not diminish as an effect of the sole deterioration of the bank credit spread.Our funding cost for variation margin(FVA)is defined asymmetrically since there is no benefit in holding excess capital in the future.Capital is fungible as a source of funding for variation margin,causing a material FVA reduction.We introduce a specialist initial margin lending scheme that drastically reduces the funding cost for initial margin(MVA).Our capital valuation adjustment(KVA)is defined as a risk premium,i.e.the cost of remunerating shareholder capital at risk at some hurdle rate.
