Recognition of major histocompatibility complex class I molecules by natural killer (NR) cells leads to inhibition of target cell lysis. Based on the capacity of different human histocompatibility leukocyte antigen (HLA)-C and HLA-B molecules to inhibit target cell lysis by NK lines and clones, three NK allospecificities have been defined: NK1 and NK2 cells are inhibited by different HLA-C allotypes and NK3 cells by some HLA-B allotypes. The NK1 and NK2 inhibitory ligands on target cells correspond to a dimorphism of HLA-C at residues 77 and 80 in the alpha 1 helix: Asn77-Lys80 in NK1 and Ser77-Asn80 in NK2 inhibitory ligands. It has been reported that protection from NK1 killers depended on the presence of the Lys residue at position 80, an upward pointing residue near the end of the alpha 1 helix (and not on Asn77), whereas inhibition of NK2 effector cells required Ser77, a residue deep in the F pocket and interacting with the peptide (and not Asn80). As part of ongoing experiments to investigate the structural requirements for NK cell inhibition by HLA-C locus alleles, we also examined the effects of mutations at residues 77 and 80 on the ability of HLA-C alleles to confer protection from NK lysis. We present data confirming that the NK1 specificity depended on Lys80 (and not on Asn77); however recognition of NK2 ligands by NK cells was also controlled by the amino acid at position 80 (Asn), and mutation of Ser77 had no effect. Furthermore, bound peptide was shown to be unnecessary for the inhibition of NK cell-mediated lysis since HLA-C molecules assembled in the absence of peptide in RMA-S cells at 26 degrees C were fully competent to inhibit NK cells specifically. The implications of these data for peptide-independent recognition of HLA-C by NK receptors are discussed.
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http://dx.doi.org/10.1084/jem.184.3.913 | DOI Listing |
Mol Ther
January 2025
Brown Center for Immunotherapy. Indiana University School of Medicine. 975 W. Walnut St., IB554A, Indianapolis, IN 46202. Electronic address:
Chimeric Antigen Receptor (CAR) T cell therapy has revolutionized cancer treatment and is now being explored for other diseases, such as autoimmune disorders. While the tumor microenvironment (TME) in cancer is often immunosuppressive, in autoimmune diseases, the environment is typically inflammatory. Both environments can negatively impact CAR T cell survival: the former through direct suppression, hypoxia, and nutrient deprivation, and the latter through chronic T cell receptor (TCR) engagement, risking exhaustion.
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January 2025
Department of Surgery, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15219, United States; Department of Surgery, Indiana Center for Regenerative Medicine and Engineering, Indiana University School of Medicine, Indianapolis, IN 46202, United States. Electronic address:
Diabetic wounds are complicated by underlying peripheral vasculopathy. Reliance on vascular endothelial growth factor (VEGF) therapy to improve perfusion makes logical sense, yet clinical study outcomes on rescuing diabetic wound vascularization have yielded disappointing results. Our previous work has identified that low endothelial phospholipase Cγ2 (PLCγ2) expression hinders the therapeutic effect of VEGF on the diabetic ischemic limb.
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January 2025
Department of Molecular Medicine, University of Southern Denmark; Odense, 5230, Denmark. Electronic address:
Neovascular age-related macular degeneration and diabetic macular edema are leading causes of vision-loss evoked by retinal neovascularization and vascular leakage. The glycoprotein microfibrillar-associated protein 4 (MFAP4) is an integrin αβ ligand present in the extracellular matrix. Single-cell transcriptomics reveal MFAP4 expression in cell-types in close proximity to vascular endothelial cells including choroidal vascular mural cells and retinal astrocytes and Müller cells.
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January 2025
Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA. Electronic address:
Gene therapy with Adeno-Associated Virus (AAV) vectors requires knowledge of their tropism within the body. Here we analyze the tropism of ten naturally occurring AAV serotypes (AAV3B, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAVrh8, AAVrh10 and AAVrh74) following systemic delivery into male and female mice. A transgene expressing ZsGreen and Cre recombinase was used to identify transduction in a cell-dependent manner based on fluorescence.
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January 2025
Shanghai Frontiers Science Center of Genome Editing and Cell Therapy, Shanghai Key Laboratory of Regulatory Biology and School of Life Sciences, East China Normal University, Shanghai, China, 200241. Electronic address:
CAR T-cell therapy has achieved remarkable clinical success in treating hematological malignancies. However, its clinical efficacy in solid tumors is less satisfactory, partially due to poor in vivo expansion and limited persistence of CAR-T cells. Here, we demonstrated that the overexpression of glucocorticoid-induced tumor necrosis factor receptor-related protein ligand (GITRL) enhances the anti-tumor activity of CAR-T cells.
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