Search

The severity of COVID 19 symptoms has a direct correlation with lymphopenia, affecting natural killer (NK) cells. SARS-CoV-2 specific "memory" NK cells obtained from convalescent donors can be used as cell immunotherapy. In 2022 a phase I, dose-escalation, single center clinical trial was conducted to evaluate the safety and feasibility of the infusion of CD3 - /CD56 + NK cells against moderate/severe cases of COVID-19 (NCT04578210). Six participants with pneumonia and/or lymphopenia were infused. Four patients received a single-dose infusion of NK cells of 1×10 6 /kg, and the following two patients a dose of 2×10 6 /kg of NK cells. All participants' clinical status and inflammation markers were monitored. No serious adverse events were reported after infusion. Exploratory outcomes included the donor chimerism, NK-cell immunophenotype evolution, and immune lymphocyte reconstitution. This study provides preliminary evidence supporting the idea that treatment of COVID-19 patients with moderate/severe symptoms using NK from COVID-19 convalescent donors is feasible and safe., Competing Interests: The authors have no conflicts of interest to declare., (© 2024 Published by Elsevier Inc.)

Memory T selected cells (CD45RA - /RO + ) as donor lymphocyte infusion are less capable of producing alloreactivity and graft versus host disease (GvHD) compared with naïve T cells. The objective of this study was to evaluate the safety and efficacy of high-dose memory (CD45RA - /RO + ) donor lymphocyte infusion (mDLI) after allogeneic hematopoietic cell transplantation (HCT). Indications for mDLI were "as needed" and "as prophylactic regimen." Sixty-one children diagnosed with malignant (82%) and non-malignant diseases (18%) received 241 mDLIs. Patients received a median of three infusions (range 1‒13) of mDLI with a median infused dose of 1.35 × 10 7 /kg CD45RO + containing 8.96 × 10 6 /kg CD3 + CD45RO + and 3.81 × 10 3 /kg CD3 + CD45RA + . De novo GvHD developed in 7 patients following 4% of the mDLI infusions. Among patients with GvHD before mDLI, this condition worsened following 6 infusions (11%) in the 3 patients with grade II-IV acute GvHD. A decrease in cytomegalovirus viral load followed 65% of mDLI infusions. Two-year overall survival (OS) for the total cohort was 64% (95% CI 57%‒72%). For patients receiving prophylactic mDLI, the two-year non-relapse mortality was 10% (95% CI 9%‒11%). In summary, high-dose mDLI is feasible and safe, with a relatively low risk of severe GvHD even in patients with active GvHD. Importantly, mDLI was associated with positive effects, including enhanced control of CMV viremia., Competing Interests: Declaration of competing interest The authors declare that the study was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 International Society for Cell & Gene Therapy. Published by Elsevier Inc. All rights reserved.)

A subpopulation of NK cells with distinctive phenotype and function differentiates and expands specifically in response to infection by human cytomegalovirus (HCMV). A hallmark of these adaptive NK cells is their increased expression levels of the activating CD94/NKG2C receptor for HLA-E, and lack of expression of its inhibitory homologue CD94/NKG2A. Their frequency is highly variable in HCMV + individuals, and the basis for such differences is only partially understood. Here, we explore the possible influence of sequence polymorphism of the NKG2C (or KLRC2) gene on the expansion of NKG2C + NKG2A - NK cells in healthy HCMV-seropositive donors. Our results show a significant association of greater proportions of adaptive NK cells with allele NKG2C*02. This is defined by two amino acid substitutions in comparison with the most prevalent allele, NKG2C*01, and associates with additional sequence polymorphisms in noncoding regions. Furthermore, we demonstrate consistently higher mRNA levels of NKG2C*02 in heterozygous individuals co-expressing this allele in combination with NKG2C*01 or *03. This predominance is independent of polymorphisms in the promoter and 3' UTRs and is appreciated also in HCMV-seronegative donors. In summary, although additional factors are most likely implicated in the variable expansion of NKG2C + NKG2A - NK cells in response to HCMV, our results demonstrate that host immunogenetics, in particular NKG2C diversity, influences the magnitude of such response., (© 2024 The Author(s). HLA: Immune Response Genetics published by John Wiley & Sons Ltd.)

Background Aims: There are currently no effective anti-viral treatments for coronavirus disease 2019 (COVID-19)-hospitalized patients with hypoxemia. Lymphopenia is a biomarker of disease severity usually present in patients who are hospitalized. Approaches to increasing lymphocytes exerting an anti-viral effect must be considered to treat these patients. Following our phase 1 study, we performed a phase 2 randomized multicenter clinical trial in which we evaluated the efficacy of the infusion of allogeneic off-the-shelf CD45RA - memory T cells containing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T cells from convalescent donors plus the standard of care (SoC) versus just the SoC treatment., Methods: Eighty-four patients were enrolled in three Spanish centers. The patients were randomized into the infusion of 1 × 10 6 /kg CD45RA - memory T cells or the SoC. We selected four unvaccinated donors based on the expression of interferon gamma SARS-CoV-2-specific response within the CD45RA - memory T cells and the most frequent human leukocyte antigen typing in the Spanish population., Results: We analyzed data from 81 patients. The primary outcome for recovery, defined as the proportion of participants in each group with normalization of fever, oxygen saturation sustained for at least 24 hours and lymphopenia recovery through day 14 or at discharge, was met for the experimental arm. We also observed faster lymphocyte recovery in the experimental group. We did not observe any treatment-related adverse events., Conclusions: Adoptive cell therapy with off-the-shelf CD45RA - memory T cells containing SAR-CoV-2-specific T cells is safe, effective and accelerates lymphocyte recovery of patients with COVID-19 pneumonia and/or lymphopenia., Trial Registration: NCT04578210., Competing Interests: Declaration of Competing Interest CF, AP-M and BS filed patent PCT/EP2021/076516 on Memory T cells as adoptive cell therapy for viral diseases. All other authors have no commercial, proprietary or financial interest in the products or companies described in this article., (Copyright © 2023 International Society for Cell & Gene Therapy. Published by Elsevier Inc. All rights reserved.)

An unprecedented global social and economic impact as well as a significant number of fatalities have been brought on by the coronavirus disease 2019 (COVID-19), produced by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Acute SARS-CoV-2 infection can, in certain situations, cause immunological abnormalities, leading to an anomalous innate and adaptive immune response. While most patients only experience mild symptoms and recover without the need for mechanical ventilation, a substantial percentage of those who are affected develop severe respiratory illness, which can be fatal. The absence of effective therapies when disease progresses to a very severe condition coupled with the incomplete understanding of COVID-19's pathogenesis triggers the need to develop innovative therapeutic approaches for patients at high risk of mortality. As a result, we investigate the potential contribution of promising combinatorial cell therapy to prevent death in critical patients., Competing Interests: AP-M, CF and BS filed patents on this topic. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Gonzaga, Andreu, Hernández-Blasco, Meseguer, Al-Akioui-Sanz, Soria-Juan, Sanjuan-Gimenez, Ferreras, Tejedo, Lopez-Lluch, Goterris, Maciá, Sempere-Ortells, Hmadcha, Borobia, Vicario, Bonora, Aguilar-Gallardo, Poveda, Arbona, Alenda, Tarín, Marco, Merino, Jaime, Ferreres, Figueira, Cañada-Illana, Querol, Guerreiro, Eguizabal, Martín-Quirós, Robles-Marhuenda, Pérez-Martínez, Solano and Soria.)

Background Aims: We have previously demonstrated the safety and feasibility of adoptive cell therapy with CD45RA - memory T cells containing severe acute respiratory syndrome coronavirus 2-specific T cells for patients with coronavirus disease 2019 from an unvaccinated donor who was chosen based on human leukocyte antigen compatibility and cellular response. In this study, we examined the durability of cellular and humoral immunity within CD45RA - memory T cells and the effect of dexamethasone, the current standard of care treatment, and interleukin-15, a cytokine critically involved in T-cell maintenance and survival., Methods: We performed a longitudinal analysis from previously severe acute respiratory syndrome coronavirus 2-infected and infection-naïve individuals covering 21 months from infection and 10 months after full vaccination with the BNT162b2 Pfizer/BioNTech vaccine., Results: We observed that cellular responses are maintained over time. Humoral responses increased after vaccination but were gradually lost. In addition, dexamethasone did not alter cell functionality or proliferation of CD45RA -  T cells, and interleukin-15 increased the memory T-cell activation state, regulatory T cell expression, and interferon gamma release., Conclusions: Our results suggest that the best donors for adoptive cell therapy would be recovered individuals and 2 months after vaccination, although further studies with larger cohorts would be needed to confirm this finding. Dexamethasone did not affect the characteristics of the memory T cells at a concentration used in the clinical practice and IL-15 showed a positive effect on SARS-CoV-2-specific CD45RA -  T cells., Competing Interests: Declaration of Competing Interest AP-M and CF filed patent EP20382850 on Memory T cells as adoptive cell therapy for viral diseases. All other authors declare no competing interest., (Copyright © 2022 International Society for Cell & Gene Therapy. Published by Elsevier Inc. All rights reserved.)

Background: Immunocompromised patients are susceptible to high-risk opportunistic infections and malignant diseases. Most antiviral and antifungal drugs are quite toxic, relatively ineffective, and induce resistance in the long term. The transfer of pathogen-specific Cytotoxic T-Lymphocytes has shown a minimal toxicity profile and effectiveness in treating Cytomegalovirus, Adenovirus, Epstein - Barr virus, BK Virus and Aspergillus infections, but this therapy have the main limitations of regulatory issues, high cost, and absence of public cell banks. However, CD45RA - cells containing pathogen-specific memory T-cells involve a less complex manufacturing and regulatory process and are cheaper, feasible, safe, and potentially effective., Methods: We present preliminary data from six immunocompromised patients: four who had severe infectious diseases and two who had EBV lymphoproliferative disease. All of them underwent multiple safe familial CD45RA - T-cell infusions as adoptive passive cell therapy, containing Cytomegalovirus, Epstein - Barr virus, BK virus, and Aspergillus -specific memory T-cells. We also present the method for selecting the best donors for CD45RA - cells in each case and the procedure to isolate and store these cells., Results: The infusions were safe, there was no case of graft-versus host disease, and they showed a clear clinical benefit. The patients treated for BK virus nephritis, Cytomegalovirus encephalitis, Cytomegalovirus reactivation, and disseminated invasive aspergillosis experienced pathogen clearance, complete resolution of symptoms in 4-6 weeks and a lymphocyte increase in 3 of 4 cases after 3-4 months. Donor T cell transient microchimerism was detected in one patient. The two patients treated for EBV lymphoproliferative disease underwent chemotherapy and several infusions of CD45RA - memory T-cells containing EBV cytotoxic lymphocytes. Donor T-cell microchimerism was observed in both patients. The viremia cleared in one of the patients, and in the other, despite the viremia not clearing, hepatic lymphoproliferative disease remained stable and was ultimately cured with EBV-specific Cytotoxic T-Lymphocytes., Conclusion: The use of familial CD45RA - T-cells containing specific Cytotoxic T-lymphocytes is a feasible, safe and potential effective approach for treating severe pathogen infections in immunocompromised patients through a third party donor. Furthermore, this approach might be of universal use with fewer institutional and regulatory barriers., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Al-Akioui Sanz, Echecopar Parente, Ferreras, Menéndez Ribes, Navarro, Mestre, Clares, Vicario, Balas, De Paz, López Granados, Sánchez Zapardiel, Jiménez, López-Oliva, Ramos, Hernández-Oliveros and Pérez-Martínez.)

NK cells monitor altered molecular patterns in tumors and infected cells through an ample array of receptors. Two families of evolutionarily distant receptors have converged to enable human NK cells to sense levels of HLA class I ligands, frequently abnormal in altered cells. Whilst different forms of polymorphism are a hallmark of killer-cell immunoglobulin-like receptors and their classic HLA-A, B, and C ligands, genetic diversity of killer-cell lectin-like receptors for the non-classical HLA-E (CD94/NKG2 heterodimers) is less conspicuous and has attracted less attention. A common pattern of diversification in both receptor families is evolution of pairs of inhibitory and activating homologs for a common ligand, the genes encoding activating receptors being more frequently affected by copy number variation (CNV). This is exemplified by the gene encoding the activating NKG2C subunit (KLRC2 or NKG2C), which marks an NK-cell subpopulation that differentiates or expands in response to cytomegalovirus. We have studied NKG2C diversity in 240 South European individuals, using polymerase chain reaction and sequencing methods to assess both gene CNV and single-nucleotide polymorphisms (SNPs) affecting its promoter, coding and 3'-untranslated (3'UT) regions. Sequence analysis revealed eight common SNPs-one in the promoter, two in the coding sequence, and five in the 3'UT region. These SNPs associate strongly with each other, forming three conserved extended haplotypes (frequencies: 0.456, 0.221, and 0.117). Homo- and heterozygous combination of these, together with complete gene deletion (0.175) and additional haplotypes with frequencies lower than 0.015, generate a diversity of NKG2C genotypes of potential immunological importance., (© 2022 The Authors. HLA: Immune Response Genetics published by John Wiley & Sons Ltd.)

CD247 (or CD3-ζ chain) is an essential adaptor and signal-transducing molecule of the T-cell antigen receptor (TCR) complex, and it also couples to NK-cell activating receptors such as NKp46, NKp30 and CD16A (FcγRIII). Noncoding sequence polymorphisms and variations in CD247 expression, a tightly regulated process, have been related with an altered immune response in multiple health conditions. A single nucleotide polymorphism (T > A) at nucleotide 844 of the CD247 3'-untranslated region, rs1052231, has been related with lower CD247 gene expression and it has been investigated as a potential biomarker of autoimmune disease. We present here a simple, accurate, reliable, time-efficient, and cost-effective method for CD247-rs1052231 genotyping. Using this method, based on polymerase chain reaction with confronting two-pair primers (PCR-CTPP), we have also characterized the CD247-rs1052231 genotypes in a panel of worldwide available cell lines, which should facilitate study of the role of this polymorphism in immunity and human health., (© 2021 The Authors. HLA: Immune Response Genetics published by John Wiley & Sons Ltd.)

Fcγ receptors (FcγR), cell-surface glycoproteins that bind antigen-IgG complexes, control both humoral and cellular immune responses. The FCGR locus on chromosome 1q23.3 comprises five homologous genes encoding low-affinity FcγRII and FcγRIII, and displays functionally relevant polymorphism that impacts on human health. Recurrent events of non-allelic homologous recombination across the FCGR locus result in copy-number variation of ~82.5 kbp-long fragments known as copy-number regions (CNR). Here, we characterize a recently described deletion that we name CNR5, which results in loss of FCGR3A , FCGR3B , and FCGR2C , and generation of a recombinant FCGR3B/A gene. We show that the CNR5 recombination spot lies at the beginning of the third FCGR3 intron. Although the FCGR3B/A- encoded hybrid protein CD16B/A reaches the plasma membrane in transfected cells, its possible natural expression, predictably restricted to neutrophils, could not be demonstrated in resting or interferon γ-stimulated cells. As the CNR5-deletion was originally described in an Ecuadorian family from Llano Grande (an indigenous community in North-Eastern Quito), we characterized the FCGR genetic variation in two populations from the highlands of Ecuador. Our results reveal that CNR5-deletion is relatively frequent in Llano Grande (5 carriers out of 36 donors). Furthermore, we found a high frequency of two strong-phagocytosis variants: the FCGR3B -NA1 haplotype and the CNR1 duplication, which translates into an increased FCGR3B and FCGR2C copy-number. CNR1 duplication was particularly increased in Llano Grande, 77.8% of the studied sample carrying at least one such duplication. In contrast, an extended haplotype CD16A-176V - CD32C-ORF+2B.2 - CD32B-2B.4 including strong activating and inhibitory FcγR variants was absent in Llano Grande and found at a low frequency (8.6%) in Ecuador highlands. This particular distribution of FCGR polymorphism, possibly a result of selective pressures, further confirms the importance of a comprehensive, joint analysis of all genetic variations in the locus and warrants additional studies on their putative clinical impact. In conclusion, our study confirms important ethnic variation at the FCGR locus; it shows a distinctive FCGR polymorphism distribution in Ecuador highlands; provides a molecular characterization of a novel CNR5-deletion associated with CD16A and CD16B deficiency; and confirms its presence in that population., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Moraru, Perez-Portilla, Al-Akioui Sanz, Blazquez-Moreno, Arnaiz-Villena, Reyburn and Vilches.)