Functional skewing of the global CD8 T cell population in chronic hepatitis B virus infection

The inflamed liver in chronic hepatitis B virus (HBV) infection (CHB) is characterized by a large influx of non–virus-specific CD8 T cells. Little is known about the functional capacity of these lymphocytes, which could provide insights into mechanisms of failure of viral control and liver damage in this setting. We compared the effector function of total circulating and intrahepatic CD8 T cells in CHB patients and healthy donors. We demonstrated that CD8 T cells from CHB patients, regardless of their antigen specificity, were impaired in their ability to produce interleukin-2 and proliferate upon TCR-dependent stimulation. In contrast, these CD8 T cells had preserved production of the proinflammatory cytokines interferon-γ and tumor necrosis factor-α. This aberrant functional profile was partially attributable to down-regulation of the proximal T cell receptor signaling molecule CD3ζ, and could be corrected in vitro by transfection of CD3ζ or replenishment of the amino acid arginine required for its expression. We provide evidence for depletion of arginine in the inflamed hepatic microenvironment as a potential mechanism for these defects in global CD8 T cell signaling and function. These data imply that polarized CD8 T cells within the HBV-infected liver may impede proliferative antiviral effector function, while contributing to the proinflammatory cytokine environment

Good Publication Practice (GPP) Guidelines for Company-Sponsored Biomedical Research: 2022 Update

These updated Good Publication Practice (GPP) guidelines include recommendations for publishing company-sponsored biomedical research. The GPP guidelines apply to peer-reviewed or peer-oriented biomedical publications, such as manuscripts, meeting presentations, posters, and abstracts, as well as enhanced content, such as plain-language summaries. The current GPP guidelines incorporate guidance on ethics and transparency as well as the planning, development, review, and approval of biomedical publications and policies and procedures that describe these practices. Supplemental materials lay out processes for steering committees, publication plans, publication working groups, determining authorship, and documentation. Information about new topics, such as alliances and working with patients, has been included where appropriate within these supplemental materials. Incorporating the principles and best practices presented in these GPP guidelines will result in increased transparency and a firm ethical footing. This guidance is also intended to enable the compliant incorporation of new and emerging publication tools for the ethical publication of company-sponsored research

Analogical effects in regular past tense production in Dutch

Contains fulltext : 60833.pdf (publisher's version ) (Open Access)31 p

KLRG1 signaling induces defective Akt (ser(473)) phosphorylation and proliferative dysfunction of highly differentiated CD8(+) T cells

Highly differentiated CD8(+)CD28(-)CD27(-) T cells have short telomeres, defective telomerase activity, and reduced capacity for proliferation, indicating that they are close to replicative senescence. In addition, these cells express increased levels of the senescence-associated inhibitory receptor KLRG1 and have poor capacity for IL-2 synthesis and defective Akt (ser(473)) phosphorylation after activation. It is not known whether signaling via KLRG1 contributes to any of the attenuated differentiation-related functional changes in CD8(+) T cells. To address this, we blocked KLRG1 signaling during T-cell receptor activation using antibodies against its major ligand, E-cadherin. This resulted in a significant enhancement of Akt (ser473) phosphorylation and T-cell receptor-induced proliferative activity of CD8(+)CD28(-)CD27(-) T cells. Furthermore, the increase of proliferation was directly linked to the Akt-mediated induction of cyclin D and E and reduction in the cyclin inhibitor p27 expression. In contrast, the reduced telomerase activity in highly differentiated CD8(+)CD28(-)CD27(-) T cells was not altered by KLRG1 blockade, indicating the involvement of other mechanisms. This is the first demonstration of a functional role for KLRG1 in primary human CD8(+) T cells and highlights that certain functional defects that arise during progressive T-cell differentiation toward replicative senescence are maintained actively by inhibitory receptor signaling. (Blood. 2009; 113: 6619-6628