Publications by authors named "Miguel López-Botet"

73 Publications

Reduced expansion of CD94/NKG2C NK cells in chronic lymphocytic leukemia and CLL-like monoclonal B-cell lymphocytosis is not related to increased human cytomegalovirus seronegativity or NKG2C deletions.

Int J Lab Hematol 2021 Feb 22. Epub 2021 Feb 22.

Molecular Cytogenetics Laboratory, Hematological Cytology Laboratory, Pathology Department, Hospital del Mar, Barcelona, Spain.

Introduction: Dysregulated NK cell-mediated immune responses contribute to tumor evasion in chronic lymphocytic leukemia (CLL), although the NK cell compartment in CLL-like monoclonal B-cell lymphocytosis (MBL) is poorly understood. In healthy individuals, human cytomegalovirus (HCMV) induces the expansion of NK cells expressing high levels of CD94/NKG2C NK cell receptor (NKR) specific for HLA-E.

Methods: We analyzed the expression of NKG2A, NKG2C, ILT2, KIR, CD161, and CD57 in 24 MBL and 37 CLL. NKG2C was genotyped in these patients and in 81 additional MBL/CLL, while NKG2C gene expression was assessed in 26 cases. In 8 CLL patients with increased lymphocytosis (≥20 × 10 /L), tumor HLA-E and HLA-G expression was evaluated.

Results: NKR distribution did not significantly differ between MBL and CLL patients, although they exhibited reduced NKG2C NK cells compared with a non-CLL group (4.6% vs 12.2%, P = .012). HCMV patients showed increased percentages of NKG2C NK cells compared with HCMV (7.3% vs 2.9%, P = .176). Frequencies of NKG2C deletions in MBL/CLL were similar to those of the general population. Low/undetectable NKG2C expression was found among NKG2C (45%) and NKG2C (12%) patients. CLL cases with increased lymphocytosis displayed especially reduced NKG2C expression (1.8% vs 8.1%, P = .029) and tumor cells with high HLA-E (>98%) and variable HLA-G expression (12.4%, range: 0.5-56.4). CLL patients with low NKG2C expression (<7%) showed shorter time to first treatment (P = .037).

Conclusion: Reduced percentages of CD94/NKG2C NK cells were observed in CLL and MBL patients independently of HCMV serostatus and NKG2C zygosity, particularly in CLL patients with increased lymphocytosis, which could potentially be related to the exposure to tumor cells.
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http://dx.doi.org/10.1111/ijlh.13494DOI Listing
February 2021

Complete genomic characterization of a new KLRC2 allele, NKG2C*03.

HLA 2021 Feb 20. Epub 2021 Feb 20.

Immunogenetics & Histocompatibility Lab, Instituto de Investigación Sanitaria Puerta de Hierro-Segovia de Arana, Madrid, Spain.

The novel NKG2C*03 allele encodes a hybrid of the NKG2C*01 and NKG2C*02 primary structures.
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http://dx.doi.org/10.1111/tan.14231DOI Listing
February 2021

Impact of cytomegalovirus infection on B cell differentiation and cytokine production in multiple sclerosis.

J Neuroinflammation 2020 May 20;17(1):161. Epub 2020 May 20.

Neurology Department, Hospital del Mar Medical Research Institute (IMIM), Passeig Marítim, 25-29, 08003, Barcelona, Spain.

Background: Human cytomegalovirus (HCMV) infection has been recently associated with a low risk of multiple sclerosis (MS), yet the basis behind this observation remains uncertain. In this study, we aimed to determine in MS patients whether HCMV induces modifications in the peripheral B cell compartment.

Methods: HCMV serostatus was determined in 73 MS patients (55 relapsing-remitting MS (RRMS); 18 progressive MS (PMS)) and 30 healthy controls, assessing their B cell immunophenotype and cytokine production (GM-CSF, IL-6, IL-10, and TNFα) by flow cytometry.

Results: HCMV seropositivity in untreated MS patients (n = 45) was associated with reduced switched memory B cells, contrasting with an opposite effect in PMS. Expansions of transitional B cells were observed in HCMV(+) IFNβ-treated RRMS patients but not in HCMV(-) cases (p < 0.01), suggesting that HCMV may influence the distribution of B cell subsets modulating the effects of IFNβ. Considering the B cell functional profile, HCMV(-) PMS displayed an increased secretion of proinflammatory cytokines (IL-6, TNFα) as compared to HCMV(+) PMS and RRMS cases (p < 0.001).

Conclusions: Our study reveals an influence of HCMV infection on the phenotype and function of B cells, promoting early differentiation stages in RRMS and reducing the proinflammatory cytokine profile in advanced MS forms, which might be related with the putative protective role of this virus in MS.
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http://dx.doi.org/10.1186/s12974-020-01840-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7238600PMC
May 2020

Long-Term Redistribution of Peripheral Lymphocyte Subpopulations after Switching from Calcineurin to mTOR Inhibitors in Kidney Transplant Recipients.

J Clin Med 2020 Apr 11;9(4). Epub 2020 Apr 11.

Department of Nephrology; Hospital del Mar, 08003 Barcelona, Spain.

Classical immunosuppression based on steroids, calcineurin inhibitors, and mycophenolate results in several unwanted effects and unsatisfactory long-term outcomes in kidney transplantation (KT). New immunosuppressors search for fewer adverse events and increased graft survival but may have a distinct impact on graft function and immunological biomarkers according to their mechanism of action. This prospective study evaluates the immunological effect of tacrolimus to serine/threonine protein kinase mechanistic target of rapamycin inhibitors (mTORi) conversion in 29 KT recipients compared with 16 controls maintained on tacrolimus. We evaluated renal function, human leukocyte antigen (HLA) antibodies and peripheral blood lymphocyte subsets at inclusion and at 3, 12, and 24 months later. Twenty immunophenotyped healthy subjects served as reference. Renal function remained stable in both groups with no significant change in proteinuria. Two patients in the mTORi group developed HLA donor-specific antibodies and none in the control group (7% vs. 0%, = 0.53). Both groups showed a progressive increase in regulatory T cells, more prominent in patients converted to mTORi within the first 18 months post-KT ( < 0.001). All patients showed a decrease in naïve B cells ( < 0.001), excepting those converted to mTORi without receiving steroids ( = 0.31). Transitional B cells significantly decreased in mTORi patients ( < 0.001), independently of concomitant steroid treatment. Finally, CD56 and CD94/NK group 2 member A receptor positive (NKG2A) Natural Killer (NK) cell subsets increased in mTORi- compared to tacrolimus-treated patients (both < 0.001). Patients switched to mTORi displayed a significant redistribution of peripheral blood lymphocyte subpopulations proposed to be associated with graft outcomes. The administration of steroids modified some of these changes.
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http://dx.doi.org/10.3390/jcm9041088DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7230655PMC
April 2020

Haplotype-Based Analysis of -Gene Profiles in a South European Population-Distribution of Standard and Variant Haplotypes, and Identification of Novel Recombinant Structures.

Front Immunol 2020 17;11:440. Epub 2020 Mar 17.

Immunogenetics and Histocompatibility, Instituto de Investigación Sanitaria Puerta de Hierro Segovia de Arana, Madrid, Spain.

Inhibitory Killer-cell Immunoglobulin-like Receptors (KIR) specific for HLA class I molecules enable human natural killer cells to monitor altered antigen presentation in pathogen-infected and tumor cells. genes display extensive copy-number variation and allelic polymorphism. They organize in a series of variable arrangements, designated haplotypes, which derive from duplications of ancestral genes and sequence diversification through point mutation and unequal crossing-over events. Genomic studies have established the organization of multiple haplotypes-many of them are fixed in most human populations, whereas variants of those have less certain distributions. Whilst -gene diversity of many populations and ethnicities has been explored superficially (frequencies of individual genes and presence/absence profiles), less abundant are in-depth analyses of how such diversity emerges from -haplotype structures. We characterize here the genetic diversity of KIR in a sample of 414 Spanish individuals. Using a parsimonious approach, we manage to explain all 38 observed -gene profiles by homo- or heterozygous combinations of six fixed centromeric and telomeric motifs; of six variant gene arrangements characterized previously by us and others; and of two novel haplotypes never detected before in Caucasoids. Associated to the latter haplotypes, we also identified the novel transcribed allele, and a chimeric / gene (designated ) that challenges current criteria for classification and nomenclature of genes and haplotypes.
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http://dx.doi.org/10.3389/fimmu.2020.00440DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7089957PMC
March 2021

Adaptive NKG2C+ natural killer cells are related to exacerbations and nutritional abnormalities in COPD patients.

Respir Res 2020 Mar 4;21(1):63. Epub 2020 Mar 4.

Respiratory Department, Hospital del Mar, Pg. Marítim 27, 08003, Barcelona, Spain.

Chronic obstructive pulmonary disease (COPD) is a chronic and often progressive disorder with a heterogeneous presentation and frequent systemic manifestations. Several aspects like persistence in smoking habit, continuous exacerbations, alpha-1-antitrypsin deficiency and inflammatory-immune response, are involved in the pathophysiology and progression of the disease. However, the role of natural killer (NK) cells remains controversial. Otherwise, human cytomegalovirus (HCMV) infection has been reported to induce an adaptive differentiation and expansion of an NK cell subset which carries the CD94/NKG2C receptor, which may contribute to an upset immune defense. For these reasons, our objective is to assess the distribution of NK cells and their subset in COPD patients and some of its phenotypes.

Methods: Peripheral blood samples were obtained from 66 COPD patients. HCMV serology and the proportions of total NK cells and the NKG2C+ and NKG2A+ subsets were evaluated by flow cytometry. The NKG2C genotype was also assessed.

Results: Eighty-eight per cent of COPD patients were HCMV(+), and the proportions of total NK cells were higher in patients with severe-very severe airway obstruction than in those with only mild-moderate involvement. There were no differences in the proportions of NKG2C+ cells between controls and COPD, either among COPD patients classified by severity of the disease. However, the percentage of NKG2C+ cells were higher in COPD patients with frequent exacerbations than in occasional exacerbators, and higher in cases with reduced lean mass (Fat free mass index) than in those with normal nutritional status.

Conclusion: These results suggest a relationship between levels of NKG2C+ cells in COPD patients and clinical variables closely linked to a poor/worse prognosis.
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http://dx.doi.org/10.1186/s12931-020-1323-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7057582PMC
March 2020

Adaptive Features of Natural Killer Cells in Multiple Sclerosis.

Front Immunol 2019 15;10:2403. Epub 2019 Oct 15.

Neurology Department, Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain.

Human cytomegalovirus (HCMV) has been recently related with a lower susceptibility to multiple sclerosis (MS). HCMV promotes an adaptive development of NK cells bearing the CD94/NKG2C receptor with a characteristic phenotypic and functional profile. NK cells are proposed to play an immunoregulatory role in MS, and expansion of the NKG2C(+) subset was recently associated with reduced disability progression. To further explore this issue, additional adaptive NK cell markers, i.e., downregulation of FcεRIγ chain (FcRγ) and PLZF transcription factor, as well as antibody-dependent NK cell activation were assessed in controls and MS patients considering HCMV serology and clinical features. In line with previous reports, increased proportions of NKG2C(+), FcRγ(-), and PLZF(-) CD56 NK cells were found in HCMV(+) cases. However, PLZF(-) NK cells were detected uncoupled from other adaptive markers within the CD56 subset from HCMV(+) cases and among CD56 NK cells from HCMV(-) MS patients, suggesting an additional effect of HCMV-independent factors in PLZF downregulation. Interferon-β therapy was associated with lower proportions of FcRγ(-) CD56 NK cells in HCMV(+) and increased PLZF(-) CD56 NK cells in HCMV(-) patients, pointing out to an influence of the cytokine on the expression of adaptive NK cell-associated markers. In addition, proportions of NKG2C(+) and FcRγ(-) NK cells differed in progressive MS patients as compared to controls and other clinical forms. Remarkably, an adaptive NK cell phenotype did not directly correlate with enhanced antibody-triggered degranulation and TNFα production in MS in contrast to controls. Altogether, our results provide novel insights into the putative influence of HCMV and adaptive NK cells in MS.
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http://dx.doi.org/10.3389/fimmu.2019.02403DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6803486PMC
October 2020

Guidelines for the use of flow cytometry and cell sorting in immunological studies (second edition).

Eur J Immunol 2019 Oct;49(10):1457-1973

Flow Cytometry Laboratory, Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, München, Germany.

These guidelines are a consensus work of a considerable number of members of the immunology and flow cytometry community. They provide the theory and key practical aspects of flow cytometry enabling immunologists to avoid the common errors that often undermine immunological data. Notably, there are comprehensive sections of all major immune cell types with helpful Tables detailing phenotypes in murine and human cells. The latest flow cytometry techniques and applications are also described, featuring examples of the data that can be generated and, importantly, how the data can be analysed. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid, all written and peer-reviewed by leading experts in the field, making this an essential research companion.
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http://dx.doi.org/10.1002/eji.201970107DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7350392PMC
October 2019

Pretransplant adaptive NKG2C+ NK cells protect against cytomegalovirus infection in kidney transplant recipients.

Am J Transplant 2020 03 19;20(3):663-676. Epub 2019 Nov 19.

Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain.

Cytomegalovirus (CMV) infection constitutes a complication for kidney transplant recipients (KTR) and CMV-specific T cells reduce the risk of viral replication in seropositive patients. CMV promotes the adaptive differentiation and expansion of an NK cell subset, hallmarked by expression of the CD94/NKG2C receptor with additional characteristic features. We previously reported an association of pretransplant NKG2C+ NK cells with a reduced incidence of CMV infection. We have strengthened the analysis in cryopreserved peripheral blood mononuclear cells from an enlarged KTR cohort (n = 145) with homogeneous immunosuppression, excluding cases at low risk of infection (ie, CMV D-R-) or receiving antiviral prophylaxis. Moreover, adaptive NKG2C+ NK cell-associated markers (ie, NKG2A, CD57, Immunoglobulin-like transcript 2 [LIR1 or LILRB1], FcεRI γ chain, and Prolymphocytic Leukemia Zinc Finger transcription factor) as well as T lymphocyte subsets were assessed by multicolor flow cytometry. The relation of NKG2C+ NK cells with T cells specific for CMV antigens was analyzed in pretransplant patients (n = 29) and healthy controls (n = 28). Multivariate Cox regression and Kaplan-Meier analyses supported that NKG2C+ NK cells bearing adaptive markers were specifically associated with a reduced incidence of posttransplant symptomatic CMV infection; no correlation between NKG2C+ NK cells and CMV-specific T cells was observed. These results support that adaptive NKG2C+ NK cells contribute to control CMV infection in KTR.
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http://dx.doi.org/10.1111/ajt.15658DOI Listing
March 2020

High Numbers of Circulating CD57 NK Cells Associate with Resistance to HER2-Specific Therapeutic Antibodies in HER2 Primary Breast Cancer.

Cancer Immunol Res 2019 08 12;7(8):1280-1292. Epub 2019 Jun 12.

Immunity and Infection, IMIM (Institut Hospital del Mar d'Investigacions Mèdiques), Barcelona, Spain.

Natural killer (NK) cells can orchestrate effective antitumor immunity. The presence of tumor-infiltrating NK cells in diagnostic biopsies predicts pathologic complete response (pCR) to HER2-specific therapeutic antibodies in patients with primary breast cancer. Here, we analyzed whether diversity in circulating NK cells might influence tumor infiltration and HER2-specific therapeutic antibody efficacy. We found that numbers of circulating CD57 NK cells inversely correlated with pCR to HER2-specific antibody treatment in patients with primary breast cancer independently of age, traditional clinicopathologic factors, and CD16A 158F/V genotype. This association was uncoupled from the expression of other NK-cell receptors, the presence of adaptive NK cells, or changes in major T-cell subsets, reminiscent of cytomegalovirus-induced immunomodulation. NK-cell activation against trastuzumab-coated HER2 breast cancer cells was comparable in patients with high and low proportions of CD57 NK cells. However, circulating CD57 NK cells displayed decreased CXCR3 expression and CD16A-induced IL2-dependent proliferation Presence of CD57 NK cells was reduced in breast tumor-associated infiltrates as compared with paired peripheral blood samples, suggesting deficient homing, proliferation, and/or survival of NK cells in the tumor niche. Indeed, numbers of circulating CD57 were inversely related to tumor-infiltrating NK-cell numbers. Our data reveal that NK-cell differentiation influences their antitumor potential and that CD57 NK cells may be a biomarker useful for tailoring HER2 antibody-based therapeutic strategies in breast cancer.
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http://dx.doi.org/10.1158/2326-6066.CIR-18-0896DOI Listing
August 2019

Daratumumab in combination with urelumab to potentiate anti-myeloma activity in lymphocyte-deficient mice reconstituted with human NK cells.

Oncoimmunology 2019;8(7):1599636. Epub 2019 Apr 13.

Program of Immunology and Immunotherapy, Center for Applied Medical Research (CIMA), Pamplona, Spain.

Daratumumab is an anti-CD38 fully human IgG1 mAb approved for multiple myeloma treatment. One of the proposed mechanisms of action is the induction of antibody-dependent cellular cytotoxicity (ADCC) mediated by NK cells. NK cells acquire surface CD137 expression in the presence of solid-phase-attached daratumumab and when encountering a daratumumab-coated CD38 tumor cell line. In this setting, addition of the agonist anti-CD137 mAb urelumab enhances NK-cell activation increasing CD25 expression and IFNɣ production. However, ADCC is not increased by the addition of urelumab both in 4h or 24h lasting experiments. To study urelumab-increased daratumumab-mediated ADCC activity , we set up a mouse model based on the intravenous administration of a luciferase-transfected multiple myeloma cell line of human origin, human NK cells and daratumumab to immuno-deficient NSG mice. In this model, intravenous administration of urelumab 24h after daratumumab delayed tumor growth and prolonged mice survival.
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http://dx.doi.org/10.1080/2162402X.2019.1599636DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6527281PMC
April 2019

Peripheral blood lymphocyte subsets change after steroid withdrawal in renal allograft recipients: a prospective study.

Sci Rep 2019 05 15;9(1):7453. Epub 2019 May 15.

Department of Nephrology, Hospital del Mar, Barcelona, Spain.

Several studies have assessed clinical outcomes after steroid withdrawal (SW) in kidney transplant (KT) recipients, but little is known about its potential impact on lymphocyte subpopulations. We designed a prospective study to evaluate the long-term impact of SW in 19 KT recipients compared to 16 KT recipients without changes in immunosuppression (steroid maintenance, SM). We assessed renal function, presence of HLA antibodies and peripheral blood lymphocyte subsets at time of inclusion, and 3, 12 and 24 months later. The immunophenotype of 20 healthy subjects was also analyzed. Serum creatinine and proteinuria remained stable in SW and SM patients. SW did not associate with generation of de novo donor-specific antibodies. SW patients showed decreases in T-lymphocytes (p < 0.001), and in the CD4 T cell subpopulation (p = 0.046). The proportion of B-lymphocytes (p = 0.017), and both naïve and transitional B cells increased compared to SM patients (p < 0.001). Changes in B cell subsets were detected 3 months after SW and persisted for 24 months. No changes were observed in NK cells related to steroid withdrawal. SW patients displayed significant changes in peripheral T and B cell subsets, transitioning to the phenotype detected in healthy subjects. This may be considered as a maintained positive effect of SW previously unnoticed.
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http://dx.doi.org/10.1038/s41598-019-42913-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6520389PMC
May 2019

Serum cytokine levels as predictive biomarkers of benefit from ipilimumab in small cell lung cancer.

Oncoimmunology 2019;8(6):e1593810. Epub 2019 Mar 27.

Cancer Research Program, IMIM (Institut Hospital del Mar d'Investigacions Mèdiques), Barcelona, Spain.

. Immunotherapy has shown efficacy in small cell lung cancer (SCLC), but only a subset of patients benefits. Surrogate biomarkers are urgently needed. Our aim was to evaluate serum Th1, Th2, and proinflammatory cytokines in two cohorts of SCLC patients before and during treatment with chemotherapy with or without ipilimumab and to correlate them with survival. . Two cohorts of SCLC patients were studied: patients treated with chemotherapy (n = 47), and patients treated with chemotherapy plus ipilimumab (n = 37). Baseline, on-treatment and after-treatment serum samples were evaluated for the presence of IL-1beta, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IFN-gamma, TNF-alpha, GM-CSF, and Mip-1alpha using a Luminex assay. Differential changes in cytokines between cohorts were analyzed. Associations between cytokine levels and their changes with overall survival were evaluated. . Patients treated with ipilimumab showed a global increase of all cytokines after treatment initiation. A high level of IL-8 at baseline was associated with worse prognosis regardless of treatment. Baseline increased IL-2 levels predicted sensitivity to ipilimumab, while high IL-6 and TNF-alpha predicted resistance. An on-treatment increase in IL-4 levels in patients treated with immune-chemotherapy was associated with a better overall survival. . The addition of ipilimumab to standard chemotherapy in SCLC modulates the serum levels of cytokines. Baseline levels and their change over time relate to overall survival. Blood-based biomarkers are convenient for patients, and our results support prospective validation of cytokines as predictive biomarkers for ipilimumab in SCLC.
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http://dx.doi.org/10.1080/2162402X.2019.1593810DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6492977PMC
March 2019

Human Cytomegalovirus Antigen Presentation by HLA-DR+ NKG2C+ Adaptive NK Cells Specifically Activates Polyfunctional Effector Memory CD4+ T Lymphocytes.

Front Immunol 2019 3;10:687. Epub 2019 Apr 3.

Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain.

Natural killer (NK) cells play a dual role in the defense against viral pathogens by directly lysing infected cells as well as by regulating anti-viral T cell immunity. Infection by human cytomegalovirus (HCMV) promotes a persistent expansion of NKG2C+ adaptive NK cells which have been shown to display enhanced antibody-dependent responses against infected targets and associated to viral control in transplanted patients. Based on gene expression data showing increased transcription of CIITA and several genes related to the MHC class II pathway in adaptive NK cells, we explored their putative capacity for antigen presentation to CD4+ T cells. Phenotypic analysis confirmed a preferential steady-state expression of HLA-DR by circulating NKG2C+ adaptive NK cells in healthy individuals. Expression of HLA-DR in NKG2C+ adaptive NK cells was variable and unrelated to the expression of activation (i.e., CD69 and CD25) or differentiation (i.e., FcRγ chain, CD57) markers, remaining stable over time at the individual level. Incubation of purified NK cells with HCMV complexed with serum specific antibodies induced an up-regulation of surface HLA-DR concomitant to CD16 loss whereas no changes in CD80/CD86 co-stimulatory ligands were detected. In addition, surface CX3CR1 decreased upon antigen-loading while HLA-DR+ NK cells maintained a CCR7-, CXCR3 homing profile. Remarkably, HCMV-loaded purified NK cells activated autologous CD4+ T cells in an HLA-DR dependent manner. The fraction of T lymphocytes activated by antigen-loaded NK cells was smaller than that stimulated by monocyte-derived dendritic cells, corresponding to CD28-negative effector-memory CD4+ T cells with cytotoxic potential. Antigen presentation by NK cells activated a polyfunctional CD4+ T cell response characterized by degranulation (CD107a) and the secretion of Th1 cytokines (IFNγ and TNFα). Overall, our data discloses the capacity of NKG2C+ adaptive NK cells to process and present HCMV antigens to memory CD4+ cytotoxic T cells, directly regulating their response to the viral infection.
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http://dx.doi.org/10.3389/fimmu.2019.00687DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6456717PMC
July 2020

NK Cell Infiltrates and HLA Class I Expression in Primary HER2 Breast Cancer Predict and Uncouple Pathological Response and Disease-free Survival.

Clin Cancer Res 2019 03 6;25(5):1535-1545. Epub 2018 Dec 6.

Cancer Research Program, IMIM (Institut Hospital del Mar d'Investigacions Mèdiques), Barcelona, Spain.

Purpose: We investigated the value of tumor-infiltrating NK (TI-NK) cells and HLA class I tumor expression as biomarkers of response to neoadjuvant anti-HER2 antibody-based treatment in breast cancer.

Experimental Design: TI-NK cells and HLA-I were determined by IHC in pretreatment tumor biopsies from two cohorts of patients with HER2-positive breast cancer [discovery cohort ( = 42) and validation cohort ( = 71)]. Tumor-infiltrating lymphocytes (TIL) were scored according to international guidelines. Biomarker association with pathologic complete response (pCR) and disease-free survival (DFS) was adjusted for prognostic factors. Gene set variation analysis was used for determining immune cell populations concomitant to NK-cell enrichment in HER2-positive tumors from the Cancer Genome Atlas ( = 190).

Results: TI-NK cells were significantly associated with pCR in the discovery cohort as well as in the validation cohort ( < 0.0001), independently of clinicopathologic factors. A ≥3 TI-NK cells/50x high-power field (HPF) cutoff predicted pCR in the discovery and validation cohort [OR, 188 (11-3154); OR, 19.5 (5.3-71.8)]. Presence of TI-NK cells associated with prolonged DFS in both patient cohorts [HR, 0.07 (0.01-0.6); = 0.01; HR, 0.3 (0.08-1.3); = 0.1]. NK-, activated dendritic- and CD8 T-cell gene expression signatures positively correlated in HER2-positive tumors, supporting the value of NK cells as surrogates of effective antitumor immunity. Stratification of patients by tumor HLA-I expression identified patients with low and high relapse risk independently of pCR.

Conclusions: This study identifies baseline TI-NK cells as an independent biomarker with great predictive value for pCR to anti-HER2 antibody-based treatment and points to the complementary value of tumor HLA-I status for defining patient prognosis independently of pCR.
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http://dx.doi.org/10.1158/1078-0432.CCR-18-2365DOI Listing
March 2019

Interplay between Natural Killer Cells and Anti-HER2 Antibodies: Perspectives for Breast Cancer Immunotherapy.

Front Immunol 2017 13;8:1544. Epub 2017 Nov 13.

Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain.

Overexpression of the human epidermal growth factor receptor 2 (HER2) defines a subgroup of breast tumors with aggressive behavior. The addition of HER2-targeted antibodies (i.e., trastuzumab, pertuzumab) to chemotherapy significantly improves relapse-free and overall survival in patients with early-stage and advanced disease. Nonetheless, considerable proportions of patients develop resistance to treatment, highlighting the need for additional and co-adjuvant therapeutic strategies. HER2-specific antibodies can trigger natural killer (NK) cell-mediated antibody-dependent cellular cytotoxicity and indirectly enhance the development of tumor-specific T cell immunity; both mechanisms contributing to their antitumor efficacy in preclinical models. Antibody-dependent NK cell activation results in the release of cytotoxic granules as well as the secretion of pro-inflammatory cytokines (i.e., IFNγ and TNFα) and chemokines. Hence, NK cell tumor suppressive functions include direct cytolytic killing of tumor cells as well as the regulation of subsequent antitumor adaptive immunity. Albeit tumors with gene expression signatures associated to the presence of cytotoxic lymphocyte infiltrates benefit from trastuzumab-based treatment, NK cell-related biomarkers of response/resistance to HER2-specific therapeutic antibodies in breast cancer patients remain elusive. Several variables, including (i) the configuration of the patient NK cell repertoire; (ii) tumor molecular features (i.e., estrogen receptor expression); (iii) concomitant therapeutic regimens (i.e., chemotherapeutic agents, tyrosine kinase inhibitors); and (iv) evasion mechanisms developed by progressive breast tumors, have been shown to quantitatively and qualitatively influence antibody-triggered NK cell responses. In this review, we discuss possible interventions for restoring/enhancing the therapeutic activity of HER2 therapeutic antibodies by harnessing NK cell antitumor potential through combinatorial approaches, including immune checkpoint blocking/stimulatory antibodies, cytokines and toll-like receptor agonists.
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http://dx.doi.org/10.3389/fimmu.2017.01544DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5694168PMC
November 2017

Elusive Role of the CD94/NKG2C NK Cell Receptor in the Response to Cytomegalovirus: Novel Experimental Observations in a Reporter Cell System.

Front Immunol 2017 24;8:1317. Epub 2017 Oct 24.

Department of Experimental and Health Sciences, University Pompeu Fabra, Barcelona, Spain.

Human cytomegalovirus (HCMV) infection promotes the differentiation and persistent expansion of a mature NK cell subset, which displays high surface levels of the activating CD94/NKG2C NK cell receptor, together with additional distinctive phenotypic and functional features. The mechanisms underlying the development of adaptive NK cells remain uncertain but some observations support the involvement of a cognate interaction of CD94/NKG2C with ligand(s) displayed by HCMV-infected cells. To approach this issue, the heterodimer and its adaptor (DAP12) were expressed in the human Jurkat leukemia T cell line; signaling was detected by transfection of a reporter plasmid encoding for Luciferase (Luc) under NFAT/AP1-dependent control. Engagement of the receptor by solid-phase bound CD94- or NKG2C-specific monoclonal antibodies (mAbs) triggered Luc expression. Moreover, reporter activation was detectable upon interaction with HLA-E+ 721.221 (.221-AEH) cells, as well as with 721.221 cells incubated with synthetic peptides, which stabilized surface expression of endogenous HLA-E; the response was specifically antagonized by soluble NKG2C- and HLA-E-specific mAbs. By contrast, activation of Jurkat-NKG2C+ was undetectable upon interaction with Human Fetal Foreskin Fibroblasts (HFFF) infected with HCMV laboratory strains (i.e., AD169, Towne), regardless of their differential ability to preserve surface HLA-E expression. On the other hand, infection with two clinical isolates or with the endotheliotropic TB40/E strain triggered Jurkat-NKG2C+ activation; yet, this response was not inhibited by blocking mAbs and was independent of CD94/NKG2C expression. The results are discussed in the framework of previous observations supporting the hypothetical existence of specific ligand(s) for CD94/NKG2C in HCMV-infected cells.
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http://dx.doi.org/10.3389/fimmu.2017.01317DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5660692PMC
October 2017

Impact of Zygosity on Bimodal Phenotype Distributions.

Biophys J 2017 Jul;113(1):148-156

Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain. Electronic address:

Allele number, or zygosity, is a clear determinant of gene expression in diploid cells. However, the relationship between the number of copies of a gene and its expression can be hard to anticipate, especially when the gene in question is embedded in a regulatory circuit that contains feedback. Here, we study this question making use of the natural genetic variability of human populations, which allows us to compare the expression profiles of a receptor protein in natural killer cells among donors infected with human cytomegalovirus with one or two copies of the allele. Crucially, the distribution of gene expression in many of the donors is bimodal, which indicates the presence of a positive feedback loop somewhere in the regulatory environment of the gene. Three separate gene-circuit models differing in the location of the positive feedback loop with respect to the gene can all reproduce the homozygous data. However, when the resulting fitted models are applied to the hemizygous donors, one model (the one with the positive feedback located at the level of gene transcription) is superior in describing the experimentally observed gene-expression profile. In that way, our work shows that zygosity can help us relate the structure and function of gene regulatory networks.
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http://dx.doi.org/10.1016/j.bpj.2017.05.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5510722PMC
July 2017

Antibody-Dependent NK Cell Activation Differentially Targets EBV-Infected Cells in Lytic Cycle and Bystander B Lymphocytes Bound to Viral Antigen-Containing Particles.

J Immunol 2017 07 19;199(2):656-665. Epub 2017 Jun 19.

University Pompeu Fabra, Barcelona 08003, Spain;

NK cells have been reported to respond against EBV-infected B cells in the lytic cycle and to control the viral infection involving IFN-γ secretion. Early reports proposed a role for NK cell Ab-dependent cellular cytotoxicity (ADCC) triggered via FcγR-IIIA (CD16) in the response to EBV. In the current study, we revisited this issue, showing that serum from EBV individuals triggered vigorous NK cell degranulation and cytokine production (i.e., TNF-α and IFN-γ) against EBV-infected cells, enhancing NK cell activation. The effect was preferentially directed against cells in the lytic phase and was associated with surface expression of the gp350/220 envelope Ag. In contrast, binding of gp350 particles, released by EBV-infected cells, to B cell lines or autologous primary B lymphocytes also promoted specific Ab-dependent NK cell degranulation and TNF-α production but induced minimal IFN-γ secretion. In that case, target cell damage appeared marginal compared with the effect of a control anti-CD20 Ab (rituximab) at concentrations that triggered similar NK cell activation, indicating that cell-associated gp350 particles may divert the cytolytic machinery, impairing its direct action on the plasma membrane. These observations support that Ab-dependent NK cell activation plays an important role in the control of EBV, enhancing NK cell effector functions against infected B cells in the lytic cycle. In contrast, the data reveal that gp350 particles bound to bystander B cells trigger Ab-dependent NK cell degranulation and TNF-α but not cytotoxicity or IFN-γ production, potentially favoring the progression of viral infection.
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http://dx.doi.org/10.4049/jimmunol.1601574DOI Listing
July 2017

Dual Role of Natural Killer Cells on Graft Rejection and Control of Cytomegalovirus Infection in Renal Transplantation.

Front Immunol 2017 16;8:166. Epub 2017 Feb 16.

Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain; Department of Nephrology, Hospital del Mar, Barcelona, Spain.

Allograft rejection constitutes a major complication of solid organ transplantation requiring prophylactic/therapeutic immunosuppression, which increases susceptibility of patients to infections and cancer. Beyond the pivotal role of alloantigen-specific T cells and antibodies in the pathogenesis of rejection, natural killer (NK) cells may display alloreactive potential in case of mismatch between recipient inhibitory killer-cell immunoglobulin-like receptors (KIRs) and graft HLA class I molecules. Several studies have addressed the impact of this variable in kidney transplant with conflicting conclusions; yet, increasing evidence supports that alloantibody-mediated NK cell activation FcγRIIIA (CD16) contributes to rejection. On the other hand, human cytomegalovirus (HCMV) infection constitutes a risk factor directly associated with the rate of graft loss and reduced host survival. The levels of HCMV-specific CD8 T cells have been reported to predict the risk of posttransplant infection, and KIR-B haplotypes containing activating KIR genes have been related with protection. HCMV infection promotes to a variable extent an adaptive differentiation and expansion of a subset of mature NK cells, which display the CD94/NKG2C-activating receptor. Evidence supporting that adaptive NKG2C NK cells may contribute to control the viral infection in kidney transplant recipients has been recently obtained. The dual role of NK cells in the interrelation of HCMV infection with rejection deserves attention. Further phenotypic, functional, and genetic analyses of NK cells may provide additional insights on the pathogenesis of solid organ transplant complications, leading to the development of biomarkers with potential clinical value.
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http://dx.doi.org/10.3389/fimmu.2017.00166DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5311043PMC
February 2017

Targeting NK-cell checkpoints for cancer immunotherapy.

Curr Opin Immunol 2017 Apr 23;45:73-81. Epub 2017 Feb 23.

Centro de Investigacion Medica Aplicada (CIMA), Pamplona, Spain; Departamento de Inmunologia e Inmunoterapia, Clinica Universidad de Navarra, Pamplona, Spain; Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Spain. Electronic address:

Natural Killer (NK) cells are cytotoxic lymphocytes specialized in early defense against virus-infected and transformed cells. NK-cell function is regulated by activating and inhibitory surface receptors recognizing their ligands on transformed cells. Modulation of NK numbers and/or function by a variety of agents such as cytokines and monoclonal antibodies may result in enhanced anti-tumor activity. Recombinant cytokines (i.e., IL-15 and IL-2), antibodies blocking inhibitory receptors (i.e., KIR, NKG2A and TIGIT) and agonists delivering signals via CD137, NKG2D and CD16 stand out as the most suitable opportunities. These agents can be used to potentiate NKcell- mediated antibody-dependent cellular cytotoxicity (ADCC) against antibody-coated tumor cells, offering potential for multiple combinatorial immunotherapy strategies against cancer.
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http://dx.doi.org/10.1016/j.coi.2017.01.003DOI Listing
April 2017

Adaptive NKG2C+ NK Cell Response and the Risk of Cytomegalovirus Infection in Kidney Transplant Recipients.

J Immunol 2017 01 2;198(1):94-101. Epub 2016 Dec 2.

Institut Hospital del Mar d'Investigacions Mèdiques, Barcelona 08003, Spain;

CMV infection in kidney transplant recipients (KTRs) has been associated with an increased risk for graft loss and reduced host survival. CMV promotes persistent expansions of NK cells expressing the CD94/NKG2C receptor. The NKG2C (KLRC2) gene is frequently deleted, and copy number influences the adaptive response of NKG2C NK cells. The distribution of NKG2C NK cells and NKG2C genotypes (NKG2C, NKG2C, NKG2C) were studied in cross-sectional (n = 253) and prospective (n = 122) KTR cohorts. Assessment of CMV viremia was restricted to symptomatic cases in the retrospective study, but was regularly monitored in the prospective cohort. Overall, the proportions of NKG2C NK cells were significantly higher in KTRs who had suffered posttransplant symptomatic CMV infection in the cross-sectional study. Yet, along the prospective follow-up (3, 6, 12, and 24 mo), posttransplant NKG2C NK cell expansions were not observed in every patient with detectable viremia who received preemptive antiviral therapy, suggesting that the adaptive NK cell response may be inversely related with the degree of CMV control. Remarkably, the incidence of posttransplant viremia was reduced among cases with high pretransplant levels of NKG2C NK cells. The NKG2C genotype distribution was comparable in KTR and healthy controls, and greater proportions of NKG2C cells were detected in NKG2C than in NKG2C patients. Yet, a trend toward increased NKG2C and reduced NKG2C frequencies associated with symptomatic infection was appreciated in both cohorts. Altogether, our results indirectly support that adaptive NKG2C NK cells are involved in the control of CMV in KTRs.
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http://dx.doi.org/10.4049/jimmunol.1601236DOI Listing
January 2017

Development of the adaptive NK cell response to human cytomegalovirus in the context of aging.

Mech Ageing Dev 2016 09 24;158:23-6. Epub 2016 Jun 24.

Immunology, Univ. Pompeu Fabra, Doctor Aiguader 88, Barcelona 08003, Spain.

Human cytomegalovirus (HCMV) establishes a highly prevalent life-long latent infection. Though generally subclinical, HCMV infection may have severe consequences during fetal development and in immunocompromised individuals. Based on epidemiological studies HCMV(+) serology has been associated with the development of atherosclerosis, immune senescence and an increase mortality rate in elderly people. Such long-term detrimental effects of the viral infection presumably result from an inefficient immune control of the pathogen, depending on the quality and evolution of the individual host-pathogen relationship. Together with antigen-specific T lymphocytes, NK cells play an important role in anti-viral immune defense. HCMV promotes in some individuals the differentiation and persistent steady state expansion of an NK cell subset bearing the CD94/NKG2C activating receptor. The relationship between this adaptive NK cell response to HCMV and aging is overviewed.
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http://dx.doi.org/10.1016/j.mad.2016.06.010DOI Listing
September 2016

Interaction of the LILRB1 inhibitory receptor with HLA class Ia dimers.

Eur J Immunol 2016 07 2;46(7):1681-90. Epub 2016 Jun 2.

Immunology Unit, University Pompeu Fabra, Barcelona, Spain.

Leukocyte immunoglobulin-like receptor subfamily B member 1 (LILRB1) has been reported to interact with a wide spectrum of HLA class I (HLA-I) molecules, albeit with different affinities determined by allelic polymorphisms and conformational features. HLA-G dimerization and the presence of intracellular Cys residues in HLA-B7 have been shown to be critical for their recognition by LILRB1. We hypothesized that dimerization of classical HLA class Ia molecules, previously detected in exosomes, might enhance their interaction with LILRB1. A soluble LILRB1-Fc fusion protein and a sensitive cellular reporter system expressing a LILRB1-ζ chimera were employed to assess receptor interaction with different HLA class Ia molecules transfected in the human lymphoblastoid 721.221 cell line. Under these conditions, intracellular Cys residues and HLA-I dimerization appeared associated with increased LILRB1 recognition. On the other hand, a marginal interaction of LILRB1 with primary monocytic cells, irrespective of their high HLA-I expression, was enhanced by type I interferon (IFN). This effect appeared disproportionate to the cytokine-induced increase of surface HLA-I expression and was accompanied by detection of HLA class Ia dimers. Altogether, the results support that a regulated assembly of these noncanonical HLA-I conformers during the immune response may enhance the avidity of their interaction with LILRB1.
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http://dx.doi.org/10.1002/eji.201546149DOI Listing
July 2016

Relationship of NKG2C Copy Number with the Distribution of Distinct Cytomegalovirus-Induced Adaptive NK Cell Subsets.

J Immunol 2016 05 18;196(9):3818-27. Epub 2016 Mar 18.

Institut Hospital del Mar d'Investigacions Mèdiques, Barcelona 08003, Spain; Universitat Pompeu Fabra, Barcelona 08002, Spain; and

CD94/NKG2C and lack of FcεRγ (FcRγ) expression are considered markers of the adaptive NK cell response to human CMV (HCMV) infection. Despite the fact that FcRγ(-) and NKG2C(bright) NK cells share some phenotypic, epigenetic, and functional features, their relationship remains unclear. To address this issue, a systematic analysis of NKG2C(bright) and FcRγ expression was carried out in NK cells from a cohort of healthy young adults (n = 81) considering NKG2C copy number, previously related to the magnitude of NKG2C(+) NK cell expansion. NKG2C(bright) and FcRγ(-) NK cells coincided in a subgroup of HCMV(+) individuals, pointing to a common host-virus interaction pattern. Even though FcRγ loss was often confined to expanded NKG2C(bright) NK cells, both markers appeared occasionally dissociated, consistent with the existence of distinct adaptive NK cell subsets. Remarkably, FcRγ loss was mostly accumulated within the NKG2C(bright) subset in NKG2C(+/+) subjects, whereas NKG2C(-)FcRγ(-) NK cell subpopulations were more frequently detected in NKG2C(+/del) donors and also in NKG2C(del) (/del) individuals, independently of activating killer Ig-like receptor expression. The distribution of other NK receptors (i.e., killer Ig-like receptor, LILRB1, or CD57) supported a sequential differentiation from NKG2C(bright)FcRγ(+) to NKG2C(bright)FcRγ(-) NK cells. Noticeably, NKG2C(bright) NK cells produced more TNF-α in response to Ab-dependent activation, regardless of their FcRγ levels. Moreover, the TNF-α response of NKG2C(-)FcRγ(-) subpopulations was lower than that of concurrent NKG2C(bright)FcRγ(-) NK cells, further supporting that FcRγ levels and enhanced potential for cytokine production are uncoupled. Overall, our data extend the characterization of adaptive NK cell subsets that differentiate in response to HCMV, supporting a relationship between their distribution and NKG2C copy number.
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http://dx.doi.org/10.4049/jimmunol.1502438DOI Listing
May 2016

Natural Killer Cell-Based Immunotherapy in Acute Myeloid Leukemia: Lessons for the Future.

Clin Cancer Res 2016 Apr 22;22(8):1831-3. Epub 2016 Feb 22.

Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain. University Pompeu Fabra, Barcelona, Spain.

The article by Curti and colleagues highlights the potential of natural killer (NK) cell-based adoptive cellular immunotherapy in oncology, currently boosted by advances in the knowledge on NK cell biology and in theirex vivoGMP manipulation. Several issues deserve attention to fully achieve the translation of these advances to the clinic.
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http://dx.doi.org/10.1158/1078-0432.CCR-15-3168DOI Listing
April 2016

Analysis of memory-like natural killer cells in human cytomegalovirus-infected children undergoing αβ+T and B cell-depleted hematopoietic stem cell transplantation for hematological malignancies.

Haematologica 2016 Mar 11;101(3):371-81. Epub 2015 Dec 11.

Dipartimento di Medicina Sperimentale and Centro di Eccellenza per la Ricerca Biomedica, Università di Genova, Italy.

We analyzed the impact of human cytomegalovirus infection on the development of natural killer cells in 27 pediatric patients affected by hematological malignancies, who had received a HLA-haploidentical hematopoietic stem cell transplantation, depleted of both α/β+ T cells and B cells. In line with previous studies in adult recipients of umbilical cord blood transplantation, we found that human cytomegalovirus reactivation accelerated the emergence of mature natural killer cells. Thus, most children displayed a progressive expansion of a memory-like natural killer cell subset expressing NKG2C, a putative receptor for human cytomegalovirus, and CD57, a marker of terminal natural killer cell differentiation. NKG2C(+)CD57(+) natural killer cells were detectable by month 3 following hematopoietic stem cell transplantation and expanded until at least month 12. These cells were characterized by high killer Ig-like receptors (KIRs) and leukocyte inhibitory receptor 1 (LIR-1) and low Siglec-7, NKG2A and Interleukin-18Rα expression, killed tumor targets and responded to cells expressing HLA-E (a NKG2C ligand). In addition, they were poor Interferon-γ producers in response to Interleukin-12 and Interleukin-18. The impaired response to these cytokines, together with their highly differentiated profile, may reflect their skewing toward an adaptive condition specialized in controlling human cytomegalovirus. In conclusion, in pediatric patients receiving a type of allograft different from umbilical cord blood transplantation, human cytomegalovirus also induced memory-like natural killer cells, possibly contributing to controlling infections and reinforcing anti-leukemia effects.
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http://dx.doi.org/10.3324/haematol.2015.134155DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4815729PMC
March 2016

Adaptive natural killer cell response to cytomegalovirus and disability progression in multiple sclerosis.

Mult Scler 2016 05 11;22(6):741-52. Epub 2015 Sep 11.

Immunology Unit, University Pompeu Fabra, Spain/ Hospital del Mar Medical Research Institute, Spain.

Background: Human cytomegalovirus (HCMV) causes a highly prevalent infection which may have a multifaceted impact on chronic inflammatory disorders. However, its potential influence in multiple sclerosis (MS) remains controversial. The HCMV-host interaction may induce an adaptive reconfiguration of the natural killer (NK) cell compartment, whose hallmark is a persistent expansion of peripheral NKG2C+ NK-cells.

Objective: The purpose of this study was to evaluate whether the HCMV-driven NKG2C+ NK-cell expansion is related to the MS clinical course.

Methods: Multicentre analysis of NKG2C expression and genotype according to HCMV serostatus and time of assignment of irreversible disability scores in 246 MS patients prospectively followed up in our institutions.

Results: NKG2C expression was unrelated to disease-modifying drugs, remained stable under steady-state conditions, and was higher in HCMV(+) NKG2C(+/+) homozygous individuals. NKG2C+ NK-cell expansion in HCMV(+) patients, as compared to HCMV(+) or HCMV(-) patients with lower NKG2C+ NK-cells proportions, conferred a lower risk of progression in Cox regression analysis (Expanded Disability Status Scale (EDSS)>3.0, hazard ratio (HR)=0.33, 95% confidence interval (CI) 0.15-0.71, p=0.005; EDSS>5.5, HR=0.23, 95% CI 0.07-0.74, p=0.014). Neither HCMV serostatus nor NKG2C genotype appeared to be related to disability progression.

Conclusions: HCMV may exert a beneficial influence on MS, decreasing the risk of disability progression in those patients displaying a virus-driven NKG2C+ NK-cell expansion.
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http://dx.doi.org/10.1177/1352458515601215DOI Listing
May 2016

NK Cell and Ig Interplay in Defense against Herpes Simplex Virus Type 1: Epistatic Interaction of CD16A and IgG1 Allotypes of Variable Affinities Modulates Antibody-Dependent Cellular Cytotoxicity and Susceptibility to Clinical Reactivation.

J Immunol 2015 Aug 15;195(4):1676-84. Epub 2015 Jul 15.

Inmunogenética e Histocompatibilidad, Instituto de Investigación Sanitaria Puerta de Hierro, 28222 Majadahonda, Madrid, Spain;

HSV-1 latently infects most humans, causing a variable clinical picture that depends, in part, on host genetic factors. Both IgG and its cellular FcRs, CD16A and CD32A-C (encoded by FCGR3A and FCGR2A-C, respectively, on chromosome 1), display polymorphisms that could affect their defensive function. Of potential relevance are a FCGR3A dimorphism resulting in CD16A-valine/phenylalanine-158 allotypes with different IgG affinity, variations conditioning NK cell expression of CD32B or CD32C, and IgG1 H chain (IGHG1) and kappa-chain (IGKC) polymorphisms determining allotypes designated G1m and Km. In this study, we assessed the contribution of Ig genetic variations and their interaction with FcR polymorphism to HSV-1 susceptibility, as well as their impact on NK cell-mediated Ab-dependent cellular cytotoxicity (ADCC). Our results show an epistatic interaction between IGHG1 and FCGR3A such that the higher affinity CD16A-158V/V genotype associates with an asymptomatic course of HSV-1 infection only in homozygotes for G1m3. Furthermore, CD16A-158V and G1m3 allotypes enhanced ADCC against opsonized HSV-1-infected fibroblasts. Conversely, Km allotypes and CD32B or CD32C expression on NK cells did not significantly influence HSV-1 susceptibility or ADCC. NK cells degranulating against immune serum-opsonized HSV-1-infected fibroblasts had heterogeneous phenotypes. Yet, enhanced ADCC was observed among NK cells showing a differentiated, memory-like phenotype (NKG2C(bright)NKG2A(-)CD57(+)FcRγ(-)), which expand in response to human CMV. These results extend our knowledge on the importance of immunogenetic polymorphisms and NK cell-Ab interplay in the host response against HSV-1 and point to the relevance of interactions between immune responses elicited during chronic coinfection by multiple herpesviruses.
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http://dx.doi.org/10.4049/jimmunol.1500872DOI Listing
August 2015

Antibody-mediated response of NKG2Cbright NK cells against human cytomegalovirus.

J Immunol 2015 Mar 9;194(6):2715-24. Epub 2015 Feb 9.

Institut Hospital del Mar d'Investigacions Mèdiques, 08003 Barcelona, Spain

Human CMV (HCMV) infection promotes a variable and persistent expansion of functionally mature NKG2C(bright) NK cells. We analyzed NKG2C(bright) NK cell responses triggered by Abs from HCMV(+) sera against HCMV-infected MRC5 fibroblasts. Specific Abs promoted the degranulation (i.e., CD107a expression) and the production of cytokines (TNF-α and IFN-γ) by a significant fraction of NK cells, exceeding the low natural cytotoxicity against HCMV-infected targets. NK cell-mediated Ab-dependent cell-mediated cytotoxicity was limited by viral Ag availability and HLA class I expression on infected cells early postinfection and increased at late stages, overcoming viral immunoevasion strategies. Moreover, the presence of specific IgG triggered the activation of NK cells against Ab-opsonized cell-free HCMV virions. As compared with NKG2A(+) NK cells, a significant proportion of NKG2C(bright) NK cells was FcεR γ-chain defective and highly responsive to Ab-driven activation, being particularly efficient in the production of antiviral cytokines, mainly TNF-α. Remarkably, the expansion of NKG2C(bright) NK cells in HCMV(+) subjects was related to the overall magnitude of TNF-α and IFN-γ cytokine secretion upon Ab-dependent and -independent activation. We show the power and sensitivity of the anti-HCMV response resulting from the cooperation between specific Abs and the NKG2C(bright) NK-cell subset. Furthermore, we disclose the proinflammatory potential of NKG2C(bright) NK cells, a variable that could influence the individual responses to other pathogens and tumors.
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http://dx.doi.org/10.4049/jimmunol.1402281DOI Listing
March 2015