Soluble MICA in endometriosis pathophysiology: Impairs NK cell degranulation and effector functions.

PROBLEM: Endometriosis exhibits several immune dysfunctions, including deficient natural killer (NK) cell cytotoxicity. MICA (MHC class I chain-related molecule A) is induced by biological stress and soluble MICA (sMICA) negatively modulates the expression of the activating receptor, NKG2D, reducing NK cells activities. We investigated the involvement of soluble MICA in NK cell-deficient activity in endometriosis. METHODS OF STUDY: sMICA levels (serum and peritoneal fluid-PF) were evaluated by ELISA. Circulating NK cell subsets quantification and its NKG2D receptor expression, NK cell cytotoxicity and CD107a, IFN-γ and IL-10 expressions by NK cells stimulated with K562 cells were determined by flow cytometry. RESULTS: We found higher sMICA levels (serum and PF) in endometriosis, especially in advanced and deep endometriosis. Endometriosis presented lower percentages of CD56dim CD16+ cytotoxic cells and impaired NK cell responses upon stimulation, resulting in lower CD107a and IFN-γ expressions, and deficient NK cell cytotoxicity. NK cell stimulation in the MICA-blocked condition (mimicking the effect of sMICA) showed decreased cytotoxicity in initial endometriosis stages and the emergence of a negative correlation between CD107a expression and sMICA levels. CONCLUSIONS: We suggest that soluble MICA is a potential player in endometriosis pathophysiology with involvement in disease progression and severity, contributing to NK cell impaired IFN-γ response and degranulation. NK cell compartment exhibits multiple perturbations, including quantitative deficiency and impaired cytotoxicity, contributing to inadequate elimination of ectopic endometrial tissue.

Markers of Natural Killer Cell Exhaustion in HIV/HCV Coinfection and Their Dynamics After HCV Clearance Mediated by Direct-Acting Antivirals.

Background: Liver fibrosis is a leading cause of morbimortality in people with HIV/hepatitis C virus (HCV). Natural killer (NK) cells are linked with amelioration of liver fibrosis; however, NK cells from individuals coinfected with HIV/HCV with cirrhosis display impaired functionality and high PD-1 expression. Here, we aimed to study PD-1, TIGIT, and Tim3 as potential exhaustion markers in NK cells from persons coinfected with HIV/HCV with mild and advanced liver fibrosis. We also evaluated the role of PD-1 expression on NK cells after HCV clearance by direct-acting antivirals (DAAs). Methods: Peripheral blood mononuclear cells were isolated from individuals coinfected with HIV/HCV (N = 54; METAVIR F0/F1, n = 27; F4, evaluated by transient elastography, n = 27). In 26 participants, samples were collected before, at the end of, and 12 months after successful DAA treatment. The frequency, immunophenotype (PD-1, TIGIT, and Tim3 expression), and degranulation capacity (CD107a assay) of NK cells were determined by flow cytometry. Results: Unlike PD-1, Tim3 and TIGIT were comparably expressed between persons with mild and advanced fibrosis. Degranulation capacity was diminished in NK/TIGIT+ cells in both fibrosis stages, while NK/PD-1+ cells showed a lower CD107a expression in cirrhotic cases. Twelve months after DAA treatment, those with advanced fibrosis showed an improved NK cell frequency and reduced NK/PD-1+ cell frequency but no changes in CD107a expression. In individuals with mild fibrosis, neither PD-1 nor NK cell frequency was modified, although the percentage of NK/CD107a+ cells was improved at 12 months posttreatment. Conclusions: Although DAA improved exhaustion and frequency of NK cells in cirrhotic cases, functionality was reverted only in mild liver fibrosis, remarking the importance of an early DAA treatment.

Autologous, allogeneic hematopoietic cell transplantation and CAR-T/NK therapy: what is their real importance in PTCL?

Peripheral T cell lymphoma (PTCL) is a rare and aggressive type of non-Hodgkin's lymphoma that affects mature T cells. This type of cancer is characterized by the abnormal growth of T cells, which can accumulate in the lymph nodes, spleen, bone marrow, and other organs, leading to a variety of symptoms. PTCLs are often difficult to diagnose and treat, and they have a poorer prognosis than other types of lymphoma. However, recent advancements in treatment options, such as targeted therapies have shown promise in improving outcomes for patients with PTCL. Here, we discuss the use of autologous and allogeneic hematopoietic cell transplantation (HCT) as a treatment strategy for patients with PTCL, as well as the recent treatment approaches based on advanced cellular therapy. The current evidence for the use of HCT in PTCL is mainly derived from registry data, retrospective studies, and expert opinion, as randomized trials are limited due to the low incidence and histological heterogeneity of PTCL subtypes.

Peripheral blood persistence and expansion of transferred non-genetically modified Natural Killer cells might not be necessary for clinical activity.

Natural killer (NK) cells are innate lymphocytes that react without previous exposition to virus infected or malignant cells and stimulate adaptive immune response to build a long-lasting immunity against it. To that end, tissue resident NK cells are predominantly regulatory as opposed to cytotoxic. In the hematopoietic stem cell transplant (HSCT) setting, which curative potential relies on the graft versus leukemia effect, NK cells are known to play a significant role. This knowledge has paved the way to the active investigation on its anti-tumor effect outside the stem cell transplant scenario. Based on the relevant literature on the adoptive transfer of non-genetically modified NK cells for the treatment of relapsed/refractory acute leukemia and on our own experience, we discuss the role of donor cell peripheral blood persistence and expansion and its lack of correlation with anti-leukemia activity.

In vitro differentiation of myeloid suppressor cells (MDSC-like) from an immature myelomonocytic precursor THP-1.

BACKGROUND: Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population with a potent suppressor profile that regulates immune responses. These cells are one of the main components of the microenvironment of several diseases, including solid and hematologic tumors, autoimmunities, and chronic inflammation. However, their wide use in studies is limited due to they comprehend a rare population, which is difficult to isolate, expand, differentiate, and maintain in culture. Additionally, this population has a complex phenotypic and functional characterization. OBJECTIVE: To develop a protocol for the in vitro production of MDSC-like population from the differentiation of the immature myeloid cell line THP-1. METHODS: We stimulated THP-1 with G-CSF (100 ng/mL) and IL-4 (20 ng/mL) for seven days to differentiate into the MDSC-like profile. At the end of the protocol, we characterized these cells phenotypically and functionally by immunophenotyping, gene expression analysis, cytokine release dosage, lymphocyte proliferation, and NK-mediated killing essays. RESULTS: We differentiate THP-1 cells in an MDSC-like population, named THP1-MDSC-like, which presented immunophenotyping and gene expression profiles compatible with that described in the literature. Furthermore, we verified that this phenotypic and functional differentiation did not deviate to a macrophage profile of M1 or M2. These THP1-MDSC-like cells secreted several immunoregulatory cytokines into the microenvironment, consistent with the suppressor profile related to MDSC. In addition, the supernatant of these cells decreased the proliferation of activated lymphocytes and impaired the apoptosis of leukemic cells induced by NK cells. CONCLUSIONS: We developed an effective protocol for MDSC in vitro production from the differentiation of the immature myeloid cell line THP-1 induced by G-CSF and IL-4. Furthermore, we demonstrated that THP1-MDSC-like suppressor cells contribute to the immune escape of AML cells. Potentially, these THP1-MDSC-like cells can be applied on a large-scale platform, thus being able to impact the course of several studies and models such as cancer, immunodeficiencies, autoimmunity, and chronic inflammation.

Suppression of CD56bright NK cells in breast cancer patients is associated with the PD-1 and TGF-ßRII expression.

BACKGROUND: Natural killer (NK) cells, as professional cytotoxic cells, play a key role against cancer in the early and metastatic stages. Their functional defects are highly associated with the initiation or progression of breast cancer (BC). Here, we investigated the phenotypic characterization of NK cells in 26 newly diagnosed BC patients in comparison to 12 healthy counterparts. METHODS: Expression of CXCR3 and PD-1, and also NKG2D, and TGF-ßRII were studied on CD56dim and CD56bright NK cells from fresh peripheral blood (PB) samples using flow cytometry. The plasma levels of IFN-γ and soluble MIC-A levels were also assessed by ELISA. RESULTS: Both CD56dim and CD56bright NK subtypes showed lower CXCR3 and NKG2D expression in BC patients than healthy subjects. Furthermore, patients' CD56bright NK cells significantly showed higher expression levels of TGF-ßRII and PD-1. Interestingly, increased concentration of MIC-A level in plasma of BC patients was associated with the higher TGF-ßRII and PD-1 expression in all NK cells, while the plasma level of IFN-γ was associated with the lower TGF-ßRII expression on CD56bright NK cells in these patients. CONCLUSION: Our results demonstrated phenotypically suppressed-NK cells, especially in the CD56bright subset of BC patients. It specifies their potential incompetence and outlines decrement of their anti-tumor activity, which could be interrelated with the tumor pathogenesis, TME immunosuppression, and so disease progression. The induction of compensatory mechanisms revives NK cells function and could be used in combination with the conventional treatments as a putative therapeutic approach for targeted immunotherapy.

Indolent NK-Cell Lymphoproliferative Disorder of the Gastrointestinal Tract - a Report of two Cases of a new Provisional Entity on the World Health Organization Classification of Hematolymphoid Tumors.

Indolent NK-cell lymphoproliferative disorder of the gastrointestinal tract is a new provisional entity listed in the structure of the forthcoming fifth edition of the World Health Organization (WHO) Classification of Hematolymphoid Tumors. It was first named as "NK-cell enteropathy" and "Lymphomatoid gastropathy" by two independent series a decade ago. Molecular or cytogenetic studies have lent support to the clonal/neoplastic nature of this entity. Herein we add two of such cases that still challenge pathologists and were previously diagnosed as aggressive lymphomas of NK/T derivation.

Deep immunophenotyping reveals biomarkers of multisystemic inflammatory syndrome in children in a Latin American cohort.

BACKGROUND: Multisystemic inflammatory syndrome in children (MIS-C) is a life-threatening disease that occurs 2-5 weeks after severe acute respiratory syndrome coronavirus 2 exposure and is characterized by severe multisystemic inflammation. Early recognition of MIS-C is key to prognosis; therefore, establishing clinical and laboratory biomarkers that predict complications is urgently needed. OBJECTIVE: We characterized the immune response and clinical features of patients with acute MIS-C and determined biomarkers of disease in a cohort of 42 Latin American patients. METHODS: Immune characterization was performed using flow cytometry from peripheral mononuclear cells and severe acute respiratory syndrome coronavirus 2-specific humoral and cellular response was performed using flow cytometry, enzyme-linked immunospot, enzyme-linked immunosorbent assay, and neutralizing antibody assays. RESULTS: MIS-C is characterized by robust T-cell activation and cytokine storm. We uncovered that while C-X-C motif chemokine ligand (CXCL) 9, IL-10, CXCL8, CXCL10, IL-6, and IL-18 are significantly elevated in patients with shock, while CCL5 was increased in milder disease. Monocyte dysregulation was specifically associated with KD-like MIS-C. Interestingly, MIS-C patients show a natural killer cell degranulation defect that is persistent after 6 months of disease presentation, suggesting it could underlie disease susceptibility. Most MIS-C had gastrointestinal involvement, and higher levels of neopterin were identified in their stools, potentially representing a biomarker of intestinal inflammation in MIS-C. Severe acute respiratory syndrome coronavirus 2-specific cellular response and neutralizing antibodies were identifiable in convalescent MIS-C patients, suggesting sustained immunity. CONCLUSION: Clinical characterization and comprehensive immunophenotyping of Chilean MIS-C cohort provide valuable insights in understanding immune dysregulation in MIS-C and identify relevant biomarkers of disease that could be used to predict severity and organ involvement.

Linfomas de células T/NK das regiões oral e maxilofacial: um estudo multicêntrico / T/NK cell lymphomas of the oral and maxillofacial regions: a multicenter study

Os linfomas representam um grupo importante, complexo e heterogêneo de distúrbios proliferativos malignos originados a partir das células do tecido linfoide. Os linfomas de células T/NK maduras representam 12,7% a 26,2% dos linfomas não-Hodgkin, são condições relativamente raras, e a incidência da maioria das neoplasias aumenta com a idade. Portanto, o objetivo desse estudo é avaliar as características clinicopatológicas e imunoistoquímicas de uma série de linfomas de células T/NK maduras que acometem as regiões oral e maxilofacial e fornecer uma revisão atualizada da literatura sobre as bases biológicas desse grupo de doenças malignas. Casos diagnosticados como linfomas maduros de células T/NK afetando a região oral e maxilofacial foram recuperados retrospectivamente de seis centros de patologia oral e maxilofacial, e seus diagnósticos foram confirmados por meio de lâminas coradas com hematoxilina e eosina, reações imuno-histoquímicas e hibridização in situ para detecção do vírus Epstein-Barr (EBV). Um total de 22 casos foram incluídos neste estudo. Onze (50%) consistiam em linfomas extranodais de células T/NK, tipo nasal; oito (36,4%) eram linfomas periféricos de células T, sem outra especificação; dois (9,1%) eram leucemia/linfomas de células T, tipo adulto e um (4,5%) era um linfoma anaplásico de grandes células ALK-positivo. No geral, houve predomínio do sexo masculino, com média de idade de 55 anos. O palato foi o local mais acometido (50%), e os tumores geralmente se apresentavam como úlceras destrutivas e dolorosas. O EBV estava presente em todos os casos de linfoma de células T/NK extranodal tipo nasal, mas estava ausente nos outros subtipos.

Lymphomas represent an important, complex, and heterogeneous group of malignant proliferative disorders arising from lymphoid tissue cells. Mature T/NK cell lymphomas represent 12.7% to 26.2% of non-Hodgkin lymphomas, are relatively rare conditions, and the incidence of most neoplasms increases with age. Therefore, the aim of this study is to evaluate the clinicopathological and immunohistochemical characteristics of a series of mature T/NK cell lymphomas that affect the oral and maxillofacial regions and to provide an updated review of the literature on the biological basis of this group of malignancies. Cases diagnosed as mature T/NK cell lymphomas affecting the oral and maxillofacial region were retrospectively retrieved from six oral and maxillofacial pathology centers, and their diagnoses were confirmed by hematoxylin-and-eosinstained slides, immunohistochemical reactions, and in situ hybridization for detection of Epstein-Barr virus (EBV). A total of 22 cases were included in this study. Eleven (50%) consisted of extranodal T/NK cell lymphomas, nasal type; eight (36.4%) were peripheral T-cell lymphomas, not otherwise specified; two (9.1%) were T-cell leukemia/lymphomas, adult type and one (4.5%) was an ALK-positive anaplastic large cell lymphoma. Overall, there was a predominance of males, with a mean age of 55 years. The palate was the most affected site (50%), and the tumors usually presented as destructive and painful ulcers. EBV was present in all cases of nasal type extranodal T/NK cell lymphoma but was absent in the other subtypes.

Myosin 1g and 1f: A Prospective Analysis in NK Cell Functions.

NK cells are contained in the ILC1 group; they are recognized for their antiviral and antitumor cytotoxic capacity; NK cells also participate in other immune response processes through cytokines secretion. However, the mechanisms that regulate these functions are poorly understood since NK cells are not as abundant as other lymphocytes, which has made them difficult to study. Using public databases, we identified that NK cells express mRNA encoding class I myosins, among which Myosin 1g and Myosin 1f are prominent. Therefore, this mini-review aims to generate a model of the probable participation of Myosin 1g and 1f in NK cells, based on information reported about the function of these myosins in other leukocytes.

Adoptive immunotherapy with double-bright (CD56bright /CD16bright ) expanded natural killer cells in patients with relapsed or refractory acute myeloid leukaemia: a proof-of-concept study.

Patients with acute myeloid leukaemia (AML) have a five-year survival rate of 28·7%. Natural killer (NK)-cell have anti-leukaemic activity. Here, we report on a series of 13 patients with high-risk R/R AML, treated with repeated infusions of double-bright (CD56bright /CD16bright ) expanded NK cells at an academic centre in Brazil. NK cells from HLA-haploidentical donors were expanded using K562 feeder cells, modified to express membrane-bound interleukin-21. Patients received FLAG, after which cryopreserved NK cells were thawed and infused thrice weekly for six infusions in three dose cohorts (106 -107 cells/kg/infusion). Primary objectives were safety and feasibility. Secondary endpoints included overall response (OR) and complete response (CR) rates at 28-30 days after the first infusion. Patients received a median of five prior lines of therapy, seven with intermediate or adverse cytogenetics, three with concurrent central nervous system (CNS) leukaemia, and one with concurrent CNS mycetoma. No dose-limiting toxicities, infusion-related fever, or cytokine release syndrome were observed. An OR of 78·6% and CR of 50·0% were observed, including responses in three patients with CNS disease and clearance of a CNS mycetoma. Multiple infusions of expanded, cryopreserved NK cells were safely administered after intensive chemotherapy in high-risk patients with R/R AML and demonstrated encouraging outcomes.

EBER+ extranodal NK/T lymphoma in patient with idiopathic CD4 lymphocytopenia.

Idiopathic CD4 lymphocytopenia (ICL) not related to HIV is an infrequent and severe condition with no etiology defined until now. The concomitant presence of an underlying disease, especially an oncohematological process, could be related to the immune physiopathology and the development of the immunosuppressive state. On the other hand, Epstein Barr virus is a well-known oncogenic pathogen described in the development of several types of lymphoma which might be reactivated in the ICL. There is still no specific treatment for this syndrome, so the therapeutic scope for these patients is the treatment of opportunistic diseases and the administration of specific antimicrobials as prophylaxis. We present a patient with an uncommon association of an ICL and an extranodal T/NK lymphoma with detection of VEB nuclear RNA by in situ hybridization (EBER). Diagnosis was challenging which led the health team to carry out many studies over several months.

La linfocitopenia CD4 idiopática (ICL) no relacionada al HIV es una condición grave e infrecuente sin una etiología aún definida. La presencia de una enfermedad subyacente, especialmente un proceso oncohematológico, podría tener relación en la fisiopatología del proceso inmunológico. Por otro lado, el virus Epstein Barr (VEB) es bien conocido por ser un patógeno oncogénico descrito en el desarrollo de diversos tipos de linfomas, el cual podría ser reactivado en estados de inmunosupresión severa. No existe aún un tratamiento específico para este síndrome, por lo que el objetivo terapéutico en estos pacientes radica en el manejo profiláctico y activo de las distintas enfermedades oportunistas ante las cuales son susceptibles. Se presenta un paciente con un déficit grave de linfocitos CD4 de causa idiopática, y un diagnóstico posterior de linfoma T/NK extraganglionar con detección de RNA nuclear de VEB por hibridización in situ (EBER), una asociación poco descrita en la literatura médica.

EBER + extranodal NK/T lymphoma in patient with idiopathic CD4 lymphocytopenia / Linfoma T/NK EBER positivo en paciente con linfocitopenia CD4 idiopática

Abstract Idiopathic CD4 lymphocytopenia (ICL) not related to HIV is an infrequent and severe condition with no etiology defined until now. The concomitant presence of an underlying disease, especially an oncohematological process, could be related to the immune physiopathology and the development of the im munosuppressive state. On the other hand, Epstein Barr virus is a well-known oncogenic pathogen described in the development of several types of lymphoma which might be reactivated in the ICL. There is still no specific treatment for this syndrome, so the therapeutic scope for these patients is the treatment of opportunistic diseases and the administration of specific antimicrobials as prophylaxis. We present a patient with an uncommon asso ciation of an ICL and an extranodal T/NK lymphoma with detection of VEB nuclear RNA by in situ hybridization (EBER). Diagnosis was challenging which led the health team to carry out many studies over several months

Resumen La linfocitopenia CD4 idiopática (ICL) no relacionada al HIV es una condición grave e infrecuente sin una etiología aún definida. La presencia de una enfermedad subyacente, especialmente un proceso oncohematológico, podría tener relación en la fisiopatología del proceso inmunológico. Por otro lado, el virus Epstein Barr (VEB) es bien conocido por ser un patógeno oncogénico descrito en el desarrollo de diversos tipos de linfomas, el cual podría ser reactivado en estados de inmunosupresión severa. No existe aún un tratamiento específico para este síndro me, por lo que el objetivo terapéutico en estos pacientes radica en el manejo profiláctico y activo de las distintas enfermedades oportunistas ante las cuales son susceptibles. Se presenta un paciente con un déficit grave de linfocitos CD4 de causa idiopática, y un diagnóstico posterior de linfoma T/NK extraganglionar con detección de RNA nuclear de VEB por hibridización in situ (EBER), una asociación poco descrita en la literatura médica.

Lipid emulsion therapy in women with recurrent pregnancy loss and repeated implantation failure: The role of abnormal natural killer cell activity.

Altered immune and/or inflammatory response plays an important role in cases of recurrent pregnancy loss (RPL) and repeated implantation failure (RIF). Exacerbation of the maternal immune response through increased NK cell activity and inflammatory cytokines can cause embryo rejection leading to abortion or embryo implantation failure. Immunosuppressors or immunomodulators can help or prevent this condition. Currently, lipid emulsion therapy (LET) has emerged as a treatment for RPL and RIF in women with abnormal NK cell activity, by decreasing the exacerbated immune response of the maternal uterus and providing a more receptive environment for the embryo. However, the mechanisms by which the intralipid acts to reduce NK cell activity are still unclear. In this review, we focus on the studies that conducted LET to treat patients with RPL and RIF with abnormal NK cell activity. We find that although some authors recommend LET as an effective intervention, more studies are necessary to confirm its effectiveness in restoring NK cell activity to normal levels and to comprehend the underlying mechanisms of the lipids action in ameliorating the maternal environment and improving the pregnancy rate.

Regulatory functions of NK cells during infections and cancer.

After recognition, NK cells can kill susceptible target cells through perforin-dependent mechanisms or by inducing death receptor-mediated apoptosis, and they can also secrete cytokines that are pivotal for immunomodulation. Despite the critical role as effector cells against tumors and virus-infected cells, NK cells have been implicated in the regulation of T cell-mediated responses in different models of autoimmunity, transplantation, and viral infections. Here, we review the mechanisms described for NK cell-mediated inhibition of adaptive immune responses, with spotlight on the emerging evidence of their regulatory role that shapes antitumor immune responses.

Enhancing innate immunity against virus in times of COVID-19: Trying to untangle facts from fictions.

INTRODUCTION: In light of the current COVID-19 pandemic, during which the world is confronted with a new, highly contagious virus that suppresses innate immunity as one of its initial virulence mechanisms, thus escaping from first-line human defense mechanisms, enhancing innate immunity seems a good preventive strategy. METHODS: Without the intention to write an official systematic review, but more to give an overview of possible strategies, in this review article we discuss several interventions that might stimulate innate immunity and thus our defense against (viral) respiratory tract infections. Some of these interventions can also stimulate the adaptive T- and B-cell responses, but our main focus is on the innate part of immunity. We divide the reviewed interventions into: 1) lifestyle related (exercise, >7 h sleep, forest walking, meditation/mindfulness, vitamin supplementation); 2) Non-specific immune stimulants (letting fever advance, bacterial vaccines, probiotics, dialyzable leukocyte extract, pidotimod), and 3) specific vaccines with heterologous effect (BCG vaccine, mumps-measles-rubeola vaccine, etc). RESULTS: For each of these interventions we briefly comment on their definition, possible mechanisms and evidence of clinical efficacy or lack of it, especially focusing on respiratory tract infections, viral infections, and eventually a reduced mortality in severe respiratory infections in the intensive care unit. At the end, a summary table demonstrates the best trials supporting (or not) clinical evidence. CONCLUSION: Several interventions have some degree of evidence for enhancing the innate immune response and thus conveying possible benefit, but specific trials in COVID-19 should be conducted to support solid recommendations.

NK Cell Activity and CD57+/NKG2Chigh Phenotype Are Increased in Men Who Have Sex With Men at High Risk for HIV.

Introduction: The HIV-exposed seronegative (HESN) status is for individuals who remain seronegative despite repeated exposure to HIV. One of the main cohorts within this group is men who have sex with men (MSM). Studies of this cohort have revealed different immunological and genetic mechanisms that can explain the phenomenon of natural HIV resistance. NK cells' higher effector capacity is related to natural resistance to HIV. Besides, a new population of NK cells with adaptive features was described recently. These cells are increased in some HESN cohorts and appear to be involved in better control of viral replication in primarily HIV-infected subjects. The present study evaluated the role of NK cells in the natural resistance to HIV-1 infection in MSM. Methodology: Phenotypic and functional features were evaluated in NK cells from two groups of MSM, at different risks of HIV infection, according to the number of sexual partners. The production of IFN-γ and ß-chemokines was included in the analysis, as well as the cytotoxic capacity and adaptive NK cell frequency. Genetic features, such as HLA and KIR allele frequencies, were also explored. Results: High-risk MSM exhibit an increased frequency of fully mature and CD57+/NKG2Chigh NK cells. These individuals also show higher cytotoxic capacity and IFN-γ production in response to K562 stimuli. NK cells with a CD107a+/IFN-γ+ functional profile were found more frequently and displayed higher IFN-γ production capacity among high-risk MSM than among low-risk MSM. The protective allele HLA-B∗18 was only present in the high-risk MSM group as well as HLA-B∗ 39. The protective phenotype KIR3DL1/S1-HLA-B∗Bw4, in a homozygous state, was particularly abundant in the high-risk population. Notably, some of these functional features were related to higher frequencies of mature and CD57+/NKG2Chigh NK cells, which, in turn, were associated with a higher number of sexual partners. Conclusion: The changes observed in the NK cell compartment can be driven by the magnitude of sexual exposure and immunological challenges of high-risk individuals, which could influence their resistance/susceptibility to HIV infection.

Overhauling CAR T Cells to Improve Efficacy, Safety and Cost.

Gene therapy is now surpassing 30 years of clinical experience and in that time a variety of approaches has been applied for the treatment of a wide range of pathologies. While the promise of gene therapy was over-stated in the 1990's, the following decades were met with polar extremes between demonstrable success and devastating setbacks. Currently, the field of gene therapy is enjoying the rewards of overcoming the hurdles that come with turning new ideas into safe and reliable treatments, including for cancer. Among these modalities, the modification of T cells with chimeric antigen receptors (CAR-T cells) has met with clear success and holds great promise for the future treatment of cancer. We detail a series of considerations for the improvement of the CAR-T cell approach, including the design of the CAR, routes of gene transfer, introduction of CARs in natural killer and other cell types, combining the CAR approach with checkpoint blockade or oncolytic viruses, improving pre-clinical models as well as means for reducing cost and, thus, making this technology more widely available. While CAR-T cells serve as a prime example of translating novel ideas into effective treatments, certainly the lessons learned will serve to accelerate the current and future development of gene therapy drugs.

Baculovirus AcMNPV induces type I interferons and NK/NKT cells-mediated protection against foot-and-mouth disease virus in mice.

Foot-and-mouth disease is a viral illness that affects cloven-hoofed animals causing serious economic losses. Inactivated vaccines against its causative agent, foot-and-mouth disease virus (FMDV), require approximately seven days to induce protection. Therefore, antiviral strategies are needed to provide earlier protection and to stop the spread of this highly contagious virus during outbreak situations. In this way, our group has previously demonstrated that the baculovirus (BV) Autographa californica multiple nucleopolyhedrovirus (AcMNPV), an insect virus with immunostimulant effects, induces a nonspecific antiviral status that protects C57BL/6 mice against a lethal challenge with FMDV A/Arg/01 at 3 hours or 3 days post inoculation. In this work, we studied the immunological mechanisms involved in this protection. Firstly, we compared the protection elicited by AcMNPV in wild type mice and in knock-out mice lacking the subunit IFNAR1 of the receptor for type I interferons (IFNs). Our results showed that type I IFNs are key to prevent the death of the animals after the FMDV challenge. On the other hand, we evaluated the role of NK and NKT cells by depleting these cell subsets with anti-NK1.1 monoclonal antibody. These cells proved to be necessary for the induction of IFN-γ by AcMNPV and to prevent the onset of a severe disease after the FMDV challenge. We propose BV as a novel tool for the development of antiviral strategies because of the high levels of IFNs induced and the NK/NKT cells-mediated immune response elicited.

Granzyme a in Chikungunya and other arboviral infections

Granzyme A (GzmA) is secreted by cytotoxic lymphocytes and has traditionally been viewed as a mediator of cell death. However, a growing body of data suggests the physiological role of GzmA is promotion of inflammation. Here, we show that GzmA is significantly elevated in the sera of chikungunya virus (CHIKV) patients and that GzmA levels correlated with viral loads and disease scores in these patients. Serum GzmA levels were also elevated in CHIKV mouse models, with NK cells the likely source. Infection of mice deficient in type I interferon responses with CHIKV, Zika virus, or dengue virus resulted in high levels of circulating GzmA. We also show that subcutaneous injection of enzymically active recombinant mouse GzmA was able to mediate inflammation, both locally at the injection site as well as at a distant site. Protease activated receptors (PARs) may represent targets for GzmA, and we show that treatment with PAR antagonist ameliorated GzmA- and CHIKV-mediated inflammation.