Células inmunes en sangre y expresión de immune checkpoints en esteatohepatitis no alcohólica y su asociación con la enfermedad inflamatoria intestinal

La esteatohepatitis no alcohólica por depósito de grasa (NAFLD) es una patología que concurre en ciertas enfermedades inmunomediadas como la enfermedad inflamatoria intestinal (EII). Su forma más agresiva se conoce como NASH (esteatohepatitis no alcohólica). En ambas, se atribuye un mecanismo patogénico inflamatorio mediado por citocinas inflamatorias como TNF-alfa y poblaciones linfocitarias como Th1 y Th17. No obstante, los estudios al respecto son muy escasos y con una visión parcial. En el presente trabajo se ha planteado la realización de un estudio completo del número de poblaciones de la respuesta inmunitaria, tanto innata como adaptativa, circulantes en sangre. La hipótesis de trabajo sugiere que una regulación diferenciada de la respuesta inmunitaria puede ser responsable de la evolución hacia un NAFLD en pacientes con EII. El objetivo es encontrar un perfil celular diferencial entre los pacientes con EII que no evoluciona hacia NAFLD o NASH y los que sí. Se han estudiado 9 pacientes con NASH+EII, 9 con EII y 10 con NASH como grupo control. Además, se han incluido 149 sujetos controles sanos del Banco de Sangre y Tejidos de Cantabria. En ellos se han medido distintas poblaciones celulares de respuesta inmunitaria: linfocitos T efectores, de memoria, naïve, células T reguladoras (Treg) y subtipos de células T helper; linfocitos B durante sus distintos estadios madurativos, células mieloides supresoras (MDSCs) y células linfoides innatas (ILC); así como el nivel de expresión de varios immune checkpoints. Varias subpoblaciones de la respuesta inmunitaria han resultado significativamente diferentes entre grupos, como las células Treg y Th17, y los subtipos 1 y 2 de las ILC. No se han encontrado diferencias importantes en la expresión de immune checkpoints basales y tras tres días de estimulación. En este trabajo ha sido posible establecer el protocolo para medir ILC en sangre periférica, cuyos niveles podrían ser de valor en cuanto a la distinción de EII respecto a EII con progresión hacia NAFLD, paralelamente a lo que se ha sugerido en el tejido hepático.Máster en Biología Molecular y Biomedicin

Innate and Adaptive Immunity Alterations in Metabolic Associated Fatty Liver Disease and Its Implication in COVID-19 Severity

The coronavirus infectious disease 2019 (COVID-19) pandemic has hit the world, affecting health, medical care, economies and our society as a whole. Furthermore, COVID-19 pandemic joins the increasing prevalence of metabolic syndrome in western countries. Patients suffering from obesity, type II diabetes mellitus, cardiac involvement and metabolic associated fatty liver disease (MAFLD) have enhanced risk of suffering severe COVID-19 and mortality. Importantly, up to 25% of the population in western countries is susceptible of suffering from both MAFLD and COVID-19, while none approved treatment is currently available for any of them. Moreover, it is well known that exacerbated innate immune responses are key in the development of the most severe stages of MAFLD and COVID-19. In this review, we focus on the role of the immune system in the establishment and progression of MAFLD and discuss its potential implication in the development of severe COVID-19 in MAFLD patients. As a result, we hope to clarify their common pathology, but also uncover new potential therapeutic targets and prognostic biomarkers for further research.Funding: This research received funding by the ISCIII (COV20/0170 and PI19/01509) and Cantabria Goverment (2020 UIC22-PUB-0019) to ML-H

Myeloid-derived suppressor cells are increased in lung transplant recipients and regulated by immunosuppressive therapy

Lung transplantation remains as a primary treatment for end-stage lung diseases. Although remarkable improvement has been achieved due to the immunosuppressive protocols, long-term survival for lung transplant recipients (LTR) is still limited. In the last few decades, an increasing interest has grown in the study of dysregulation of immune mechanisms underlying allograft failure. In this regard, myeloid-derived suppressor cells (MDSCs) could play an important role in the promotion of graft tolerance due to their immune regulatory function. Here, we describe for the first time circulating subsets MDSCs from LTR at several time points and we evaluate the relationship of MDSCs with sort-term lung transplant outcomes. Although no effect of MDSCs subsets on short-term clinical events was observed, our results determine that Mo-MDSCs frequencies are increased after acute cellular rejection (ACR), suggesting a possible role for Mo-MDSCs in the development of chronic lung allograft dysfunction (CLAD). Therefore, whether MDSCs subsets play a role as biomarkers of chronic rejection remains unknown and requires further investigations. Also, the effects of the different immunosuppressive treatments on these subpopulations remain under research and further studies are needed to establish to what extend MDSCs immune modulation could be responsible for allograft acceptance.FUNDING: This work was supported by grants from the FIS-ISCII (PI16/ 01585) to ML-H and NVAL16/22 to DS. ACKNOWLEDGMENTS We are grateful to María José Ortı́z González (IDIVAL, Santander, Spain) for her excellent technical support. ACKNOWLEDGMENTS: We are grateful to María José Ortı́z González (IDIVAL, Santander, Spain) for her excellent technical support

Innate and adaptive immune assessment at admission to predict clinical outcome in covid-19 patients

During the COVID-19 pandemic, many studies have been carried out to evaluate different immune system components to search for prognostic biomarkers of the disease. A broad multiparametric antibody panel of cellular and humoral components of the innate and the adaptative immune response in patients with active SARS-CoV-2 infection has been evaluated in this study. A total of 155 patients were studied at admission into our center and were categorized according to the requirement of oxygen therapy as mild or severe (the latter being those with the requirement). The patients with severe disease were older and had high ferritin, D-dimer, C-reactive protein, troponin, interleukin-6 (IL-6) levels, and neutrophilia with lymphopenia at admission. Moreover, the patients with mild symptoms had significantly increased circulating non-classical monocytes, innate lymphoid cells, and regulatory NK cells. In contrast, severe patients had a low frequency of Th1 and regulatory T cells with increased activated and exhausted CD8 phenotype (CD8+CD38+HLADR+ and CD8+CD27-CD28-, respectively). The predictive model included age, ferritin, D-dimer, lymph counts, C4, CD8+CD27-CD28-, and non-classical monocytes in the logistic regression analysis. The model predicted severity with an area under the curve of 78%. Both innate and adaptive immune parameters could be considered potential predictive biomarkers of the prognosis of COVID-19 disease.Funding: This work was partially supported by the Cantabrian Government, grant number 2020UIC22-PUB-001, and by Instituto de Salud Carlos III, grant number COV20/00170

Immune Assessment of BNT162b2 m-RNA-Spike Based Vaccine Response in Adults

Vaccine efficacy is based on clinical data. Currently, the assessment of immune response after SARS-CoV-2 vaccination is scarce. A total of 52 healthcare workers were immunized with the same lot of BNT162b2 vaccine. The immunological response against the vaccine was tested using a T-specific assay based on the expression of CD25 and CD134 after stimulation with anti-N, -S, and -M specific peptides of SARS-CoV-2. Moreover, IgG anti-S2 and -RBD antibodies were detected using ELISA. Furthermore, the cell subsets involved in the response to the vaccine were measured in peripheral blood by flow cytometry. Humoral-specific responses against the vaccine were detected in 94% and 100% after the first and second doses, respectively. Therefore, anti-S T-specific responses were observed in 57% and 90% of the subjects after the first and second doses of the vaccine, respectively. Thirty days after the second dose, significant increases in T helper 1 memory cells (p < 0.001), peripheral memory T follicular helper (pTFH) cells (p < 0.032), and switched memory (p = 0.005) were observed. This study describes the specific humoral and cellular immune responses after vaccination with the new mRNA-based BNT162b2 vaccine. A mobilization of TFH into the circulation occurs, reflecting a specific activation of the immune system.Funding: This work was partially supported by the Cantabrian Government, grant number 2020UIC22-PUB-001, and from Instituto de Salud Carlos III, grant number COV20/00170

COVID-19 mRNA Based Vaccine Immune-Response Assessment in Nursing Home Residents for Public Health Decision

Nursing home residents (NHR) have been targeted as a vaccination priority due to their higher risk of worse outcome after COVID-19 infection. The mRNA-based vaccine BTN2b2 was first approved in Europe for NHRs. The assessment of the specific vaccine immune response (both humoral and cellular) at long term in NHRs has not been addressed yet. A representative sample of 624 NHR subjects in Northern region of Spain was studied to assess immune response against full vaccination with BTN2b2. The anti-S1 antibody levels and specific T cells were measured at two and six months after vaccination. 24.4% of NHR had a previous infection prior to vaccination. The remaining NHR were included in the full vaccination assessment group (FVA). After two months, a 94.9% of the FVA presented anti-S1 antibodies, whereas those seronegative without specific cellular response were 2.54%. At long-term, the frequency of NHR within the FVA group with anti-S1 antibodies at six months were 88.12% and the seronegative subjects without specific cellular response was 8.07%. The cellular immune assays complement the humoral test in the immune vaccine response assessment. Therefore, the cellular immune assessment in NHRs allows for the fine tuning of those seronegative subjects with potential competent immune responses against the vaccine

Myeloid-Derived Suppressor Cells in Kidney Transplant Recipients and the Effect of Maintenance Immunotherapy.

This work was supported by grants from the FIS-ISCII () to ML-H and to JO. This project also received funding from the European Union’s Horizon 2020 Research and Innovation Program under the Marie Skłodowska-Curie grant agreement number (www.instruct-h2020.eu).Myeloid-derived suppressor cells (MDSC) represent a heterogeneous group of myeloid regulatory cells that were originally described in cancer. Several studies in animal models point to MDSC as important players in the induction of allograft tolerance due to their immune modulatory function. Most of the published studies have been performed in animal models, and the data addressing MDSCs in human organ transplantation are scarce. We evaluated the phenotype and function of different MDSCs subsets in 38 kidney transplant recipients (KTRs) at different time points. Our data indicate that monocytic MDSCs (Mo-MDSC) increase in KTR at 6 and 12 months posttransplantation. On the contrary, the percentages of polymorphonuclear MDSC (PMN-MDSC) and early-stage MDSC (e-MDSC) are not significantly increased. We evaluated the immunosuppressive activity of Mo-MDSC in KTR and confirmed their ability to increase regulatory T cells (Treg) in vitro. Interestingly, when we compared the ability of Mo-MDSC to suppress T cell proliferation, we observed that tacrolimus, but not rapamycin-treated KTR, was able to inhibit CD4+ T cell proliferation in vitro. This indicates that, although mTOR inhibitors are widely regarded as supportive of regulatory responses, rapamycin may impair Mo-MDSC function, and suggests that the choice of immunosuppressive therapy may determine the tolerogenic pathway and participating immune cells that promote organ transplant acceptance in KTR.This work was supported by grants from the FIS-ISCII (PI16/01585) to ML-H and R01 AI139623-01 to JO. This project also received funding from the European Union’s Horizon 2020 Research and Innovation Program under the Marie Skłodowska-Curie grant agreement number 860003 (www.instruct-h2020.eu).S