Inhibitory killer cell immunoglobulin-like receptor (iKIR) mismatches improve survival after T-cell-repleted haploidentical transplantation

2015 ◽  
Vol 96 (5) ◽  
pp. 483-491 ◽  
Author(s):  
Mariana Bastos-Oreiro ◽  
Javier Anguita ◽  
Carolina Martínez-Laperche ◽  
Lucía Fernández ◽  
Elena Buces ◽  
...  
Keyword(s):  
T Cell ◽  
Killer Cell ◽  
Haploidentical Transplantation

scholarly journals Haploidentical hematopoietic transplantation for the cure of leukemia: from its biology to clinical translation

Blood ◽  
2016 ◽  
Vol 128 (23) ◽  
pp. 2616-2623 ◽  
Author(s):  
Antonella Mancusi ◽  
Loredana Ruggeri ◽  
Andrea Velardi
Keyword(s):  
T Cell ◽  
Ex Vivo ◽  
Killer Cell ◽  
Human Leukocyte ◽  
Leukocyte Antigen ◽  
Graft Versus Host ◽  
Haploidentical Transplantation ◽  
Hematopoietic Transplantation ◽  
Human Leukocyte Antigen Haplotype ◽  
Mother To Child

Abstract The present review describes the biology of human leukocyte antigen haplotype mismatched (“haploidentical”) transplantation, its translation to clinical practice to cure leukemia, and the results of current transplantation protocols. The 1990s saw what had been major drawbacks of haploidentical transplantation, ie, very strong host-versus-graft and graft-versus-host alloresponses, which led respectively to rejection and graft-versus-host disease (GVHD), being overcome through transplantation of a “mega-dose” of T cell–depleted peripheral blood hematopoietic progenitor cells and no posttransplant pharmacologic immunosuppression. The absence of posttransplant immunosuppression was an opportunity to discover natural killer cell alloreactions that eradicated acute myeloid leukemia and improved survival. Furthermore, it also unveiled the benefits of transplantation from mother donors, a likely consequence of the mother-to-child interaction during pregnancy. More recent transplantation protocols use unmanipulated (without ex vivo T-cell depletion) haploidentical grafts combined with enhanced posttransplant immunosuppression to help prevent GVHD. Unmanipulated grafts substantially extended the use of haploidentical transplantation with results than even rival those of matched hematopoietic transplantation. In T cell–depleted haploidentical transplantation, recent advances were made by the adoptive transfer of regulatory and conventional T cells.

scholarly journals PD-L1 targeting and subclonal immune escape mediated by PD-L1 mutations in metastatic colorectal cancer

2021 ◽  
Vol 9 (7) ◽  
pp. e002844
Author(s):  
Alexander Stein ◽  
Donjete Simnica ◽  
Christoph Schultheiß ◽  
Rebekka Scholz ◽  
Joseph Tintelnot ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
T Cell ◽  
Metastatic Colorectal Cancer ◽  
Multispectral Imaging ◽  
Standard Treatment ◽  
Immune Escape ◽  
Killer Cell ◽  
Cell Killing ◽  
Antitumor Effects ◽  
High Affinity

BackgroundIn patients with microsatellite stable (MSS) metastatic colorectal cancer (mCRC), immune checkpoint blockade is ineffective, and combinatorial approaches enhancing immunogenicity need exploration.MethodsWe treated 43 patients with predominantly microsatellite stable RAS/BRAF wild-type mCRC on a phase II trial combining chemotherapy with the epidermal growth factor receptor antibody cetuximab and the programmed cell death ligand 1 (PD-L1) antibody avelumab. We performed next-generation gene panel sequencing for mutational typing of tumors and liquid biopsy monitoring as well as digital droplet PCR to confirm individual mutations. Translational analyses included tissue immunohistochemistry, multispectral imaging and repertoire sequencing of tumor-infiltrating T cells. Detected PD-L1 mutations were mechanistically validated in CRISPR/Cas9-generated cell models using qRT-PCR, immunoblotting, flow cytometry, complement-dependent cytotoxicity assay, antibody-dependent cytotoxicity by natural killer cell degranulation assay and LDH release assay as well as live cell imaging of T cell mediated tumor cell killing.ResultsCirculating tumor DNA showed rapid clearance in the majority of patients mirroring a high rate of early tumor shrinkage. In 3 of 13 patients expressing the high-affinity Fcγ receptor 3a (FcγR3a), tumor subclones with PD-L1 mutations were selected that led to loss of tumor PD-L1 by nonsense-mediated RNA decay in PD-L1 K162fs and protein degradation in PD-L1 L88S. As a consequence, avelumab binding and antibody-dependent cytotoxicity were impaired, while T cell killing of these variant clones was increased. Interestingly, PD-L1 mutant subclones showed slow selection dynamics reversing on avelumab withdrawal and patients with such subclones had above-average treatment benefit. This suggested that the PD-L1 mutations mediated resistance to direct antitumor effects of avelumab, while at the same time loss of PD-L1 reduced biological fitness by enhanced T cell killing limiting subclonal expansion.ConclusionThe addition of avelumab to standard treatment appeared feasible and safe. PD-L1 mutations mediate subclonal immune escape to avelumab in some patients with mCRC expressing high-affinity FcγR3a, which may be a subset experiencing most selective pressure. Future trials evaluating the addition of avelumab to standard treatment in MSS mCRC are warranted especially in this patient subpopulation.Trial registration numberNCT03174405.

scholarly journals Immunomodulating nano-adaptors potentiate antibody-based cancer immunotherapy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Cheng-Tao Jiang ◽  
Kai-Ge Chen ◽  
An Liu ◽  
Hua Huang ◽  
Ya-Nan Fan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Cancer Immunotherapy ◽  
Tumor Cells ◽  
Noncovalent Interactions ◽  
Killer Cell ◽  
Antibody Immobilization ◽  
Effector Cells ◽  
Nanoparticle Surface

AbstractModulating effector immune cells via monoclonal antibodies (mAbs) and facilitating the co-engagement of T cells and tumor cells via chimeric antigen receptor- T cells or bispecific T cell-engaging antibodies are two typical cancer immunotherapy approaches. We speculated that immobilizing two types of mAbs against effector cells and tumor cells on a single nanoparticle could integrate the functions of these two approaches, as the engineered formulation (immunomodulating nano-adaptor, imNA) could potentially associate with both cells and bridge them together like an ‘adaptor’ while maintaining the immunomodulatory properties of the parental mAbs. However, existing mAbs-immobilization strategies mainly rely on a chemical reaction, a process that is rough and difficult to control. Here, we build up a versatile antibody immobilization platform by conjugating anti-IgG (Fc specific) antibody (αFc) onto the nanoparticle surface (αFc-NP), and confirm that αFc-NP could conveniently and efficiently immobilize two types of mAbs through Fc-specific noncovalent interactions to form imNAs. Finally, we validate the superiority of imNAs over the mixture of parental mAbs in T cell-, natural killer cell- and macrophage-mediated antitumor immune responses in multiple murine tumor models.

scholarly journals Characterization of T cell, B cell and Natural Killer Cell Subsets in COVID-19 Patients

2021 ◽  
Vol 147 (2) ◽  
pp. AB79
Author(s):  
Alena Rynda ◽  
Andrei Hancharou ◽  
Natalia Antonevich ◽  
Oxana Timohina ◽  
Yana Minich ◽  
...  
Keyword(s):  
T Cell ◽  
Natural Killer Cell ◽  
B Cell ◽  
Natural Killer ◽  
Killer Cell

Modulation of T-Cell Functions in KIR2DL3 (CD158b) Transgenic Mice

Blood ◽  
1999 ◽  
Vol 94 (7) ◽  
pp. 2396-2402 ◽  
Author(s):  
Anna Cambiaggi ◽  
Sylvie Darche ◽  
Sophie Guia ◽  
Philippe Kourilsky ◽  
Jean-Pierre Abastado ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Transgenic Mice ◽  
T Cell Activation ◽  
Cell Activation ◽  
Killer Cell ◽  
In Vitro Proliferation ◽  
Cell Functions ◽  
Double Transgenic Mice

In humans, a minor subset of T cells express killer cell Ig-like receptors (KIRs) at their surface. In vitro data obtained with KIR+ β and γδ T-cell clones showed that engagement of KIR molecules can extinguish T-cell activation signals induced via the CD3/T-cell receptor (TCR) complex. We analyzed the T-cell compartment in mice transgenic for KIR2DL3 (Tg-KIR2DL3), an inhibitory receptor for HLA-Cw3. As expected, mixed lymphocyte reaction and anti-CD3 monoclonal antibody (MoAb)-redirected cytotoxicity exerted by freshly isolated splenocytes can be inhibited by engagement of transgenic KIR2DL3 molecules. In contrast, antigen and anti-CD3 MoAb-induced cytotoxicity exerted by alloreactive cytotoxic T lymphocytes cannot be inhibited by KIR2DL3 engagement. In double transgenic mice, Tg-KIR2DL3 × Tg-HLA-Cw3, no alteration of thymic differentiation could be documented. Immunization of double transgenic mice with Hen egg white lysozime (HEL) or Pigeon Cytochrome-C (PCC) was indistinguishable from immunization of control mice, as judged by recall antigen-induced in vitro proliferation and TCR repertoire analysis. These results indicate that KIR effect on T cells varies upon cell activation stage and show unexpected complexity in the biological function of KIRs in vivo.

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