Human CD300 receptors expression, regulation and function in the immune system. Implication in human immunodeficiency virus type 1 infection.

201 p.Las moléculas CD300 se expresan en la superficie de células del sistema inmunitario. Estos receptores modulan numerosos procesos inmunológicos y se ha descrito que tienen un papel importante en la inmunopatogenia de distintas enfermedades, incluyendo infecciones virales. El objetivo principal de este trabajo ha sido investigar la expresión, regulación de la expresión y función de los receptores CD300 en distintas células inmunitarias de individuos sanos, y estudiar cómo esto se altera durante la infección por el virus de la inmunodeficiencia humana (VIH)-1. En esta tesis doctoral, observamos que el patrón de expresión de los receptores CD300 es distinto entre poblaciones y subpoblaciones de células inmunitarias, así como entre adultos y recién nacidos. Además, describimos que la activación de los monocitos mediada por CD300c y CD300e es menor en recién nacidos que en adultos. En el contexto de la infección por VIH-1, en primer lugar observamos que la expresión de las moléculas CD300e y CD300f en monocitos de pacientes infectados por VIH-1 bajo cART se asocia con el número de linfocitos T CD4+ y una mayor producción de TNF en respuesta al LPS, pero no en pacientes vacunados con la vacuna frente al VIH-1 MVA-B. También descubrimos que la expresión del receptor CD300a está alterada en las células NK CD56neg en pacientes infectados por VIH-1 no tratados y que este receptor inhibe la degranulación y la producción de citoquinas mediada a través del receptor CD16 en células NK de pacientes infectados por VIH-1. Después, observamos que la expresión del receptor CD300a está alterada también en linfocitos T CD4+ de pacientes infectados por VIH-1 y que su expresión se asocia con marcadores de progresión de la enfermedad. Por último, demostramos que el CD300a identifica una población de linfocitos T CD4+CD45RA- con una mayor susceptibilidad a la infección por VIH-1

Altered Expression of CD300a Inhibitory Receptor on CD4+ T Cells From Human Immunodeficiency Virus-1-Infected Patients: Association With Disease Progression Markers

The ability of the CD300a inhibitory receptor to modulate immune cell functions and its involvement in the pathogenesis of many diseases has aroused a great interest in this molecule. Within human CD4+ T lymphocytes from healthy donors, the inhibitory receptor CD300a is differentially expressed among different T helper subsets. However, there are no data about the expression and regulation of CD300a receptor on CD4+ T cells from human immunodeficiency virus (HIV)-1-infected patients. The objective of this study was to investigate the expression of CD300a on CD4+ T cells from HIV-infected patients on suppressive combined antiretroviral therapy (cART) and cART naïve patients. Our results have demonstrated that the expression levels of this inhibitory receptor were higher on CD4+ T cells from HIV-1 infected subjects compared with healthy donors, and that cART did not reverse the altered expression of CD300a receptor in these patients. We have observed an increase of CD300a expression on both PD1+CD4+ and CD38+CD4+ T cells from HIV-1 infected people. Interestingly, a triple positive (CD300a+PD1+CD38+) subset was expanded in naïve HIV-1 infected patients, while it was very rare in healthy donors and patients on cART. Finally, we found a negative correlation of CD300a expression on CD4+ T lymphocytes and some markers associated with HIV-1 disease progression. Thus, our results show that HIV-1 infection has an impact in the regulation of CD300a inhibitory receptor expression levels, and further studies will shed light into the role of this cell surface receptor in the pathogenesis of HIV infection

Innate and adaptive immune defects associated with lower SARS-CoV-2 BNT162b2 mRNA vaccine response in elderly people

The immune factors associated with impaired SARS-CoV-2 vaccine response in the elderly are mostly unknown. We studied old and young people vaccinated with SARS-CoV-2 BNT162b2 mRNA before and after the first and second dose. Aging was associated with a lower anti-RBD IgG levels and a decreased magnitude and polyfunctionality of SARS-CoV-2 specific T cell response. The dramatic decrease in thymic function in the elderly, which fueled alteration in T cell homeostasis, and lower CD161+ T cell levels were associated with decreased T cell response two months after vaccination. Additionally, a deficient dendritic cell (DC) homing, activation and Toll like receptor (TLR)-mediated function, along with a proinflammatory functional profile in monocytes, were observed in the elderly, which was also related to lower specific T cell response after vaccination. These findings might be relevant for the improvement of the current vaccination strategies and for the development of new vaccine prototypes.This study was funded by Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades, Junta de Andalucia (CV20-85418 and P20_00906, DOC-01659 and DOC-00963); Consejeria de Salud, Junta de Andalucia (RH-0037-2020), Instituto de Salud Carlos III (CP19/00159, FI17/00186, FI19/00083, PI19/01172, CM20/00243) Fondos FEDER, and National Spanish Research Council (CSIC).N

Migration and activation marker expressing in monocytes subset in mild and several/critical patients (S/C)

S2 Fig. Migration and activation marker expressing in monocytes subset in mild and several/critical patients (S/C).Peer reviewe

Immune defects associated with lower SARS-CoV-2 BNT162b2 mRNA vaccine response in aged people

The immune factors associated with impaired SARS-CoV-2 vaccine response in elderly people are mostly unknown. We studied individuals older than 60 and younger than 60 years, who had been vaccinated with SARS-CoV-2 BNT162b2 mRNA, before and after the first and second dose. Aging was associated with a lower anti–RBD IgG levels and a decreased magnitude and polyfunctionality of SARS-CoV-2–specific T cell response. The dramatic decrease in thymic function in people > 60 years, which fueled alteration in T cell homeostasis, and their lower CD161+ T cell levels were associated with decreased T cell response 2 months after vaccination. Additionally, deficient DC homing, activation, and TLR-mediated function, along with a proinflammatory functional profile in monocytes, were observed in the > 60-year-old group, which was also related to lower specific T cell response after vaccination. These findings might be relevant for the improvement of the current vaccination strategies and for the development of new vaccine prototypes.This work was supported by the Consejería de Transformación Económica, Industria, Conocimiento y Universidades, Junta de Andalucía grants CV20-85418 and P20_00906 and by research contracts DOC-01659 and DOC-00963, as well as by Consejería de Salud, Junta de Andalucía research contract RH-0037-2020 and Instituto de Salud Carlos III CP19/00159, FI17/00186, FI19/00083, PI19/01127, and CM20/00243 from Fondos FEDER. ERM was supported by the Spanish Research Council (CSIC). We thank all the community volunteers, participants from the IBiS, Chema Niño, and the nursing staff from Virgen del Rocío University Hospital who have taken part in this project. We also thank Alicia Gutierrez and Esperanza Muñoz for reviewing the manuscript. In memoriam Silvio Manuel Pérez Martín.Peer reviewe

S1 Fig - Clinical, laboratory data and inflammatory biomarkers at baseline as early discharge predictors in hospitalized SARS-CoV-2 infected patients

A, Predictive models for hospital discharge during the first week in mild patients. B, Predictive models for worsening of clinical status during the first week in patients who were admitted mildly ill. AUC, area under the curve.Peer reviewe

Activation, homing and maturation marker expression in different monocyte subsets

Data are expressed by percentage and interquartile range. Medians fluorescence intensitive (MFI) were calculated in those markets that have a high rate of expression.Peer reviewe

Clinical, laboratory data and inflammatory biomarkers at baseline as early discharge predictors in hospitalized SARS-CoV-2 infected patients

Background The SARS-CoV-2 pandemic has overwhelmed hospital services due to the rapid transmission of the virus and its severity in a high percentage of cases. Having tools to predict which patients can be safely early discharged would help to improve this situation. Methods Patients confirmed as SARS-CoV-2 infection from four Spanish hospitals. Clinical, demographic, laboratory data and plasma samples were collected at admission. The patients were classified into mild and severe/critical groups according to 4-point ordinal categories based on oxygen therapy requirements. Logistic regression models were performed in mild patients with only clinical and routine laboratory parameters and adding plasma pro-inflammatory cytokine levels to predict both early discharge and worsening. Results 333 patients were included. At admission, 307 patients were classified as mild patients. Age, oxygen saturation, Lactate Dehydrogenase, D-dimers, neutrophil-lymphocyte ratio (NLR), and oral corticosteroids treatment were predictors of early discharge (area under curve (AUC), 0.786; sensitivity (SE) 68.5%; specificity (S), 74.5%; positive predictive value (PPV), 74.4%; and negative predictive value (NPV), 68.9%). When cytokines were included, lower interferon-γ-inducible protein 10 and higher Interleukin 1 beta levels were associated with early discharge (AUC, 0.819; SE, 91.7%; S, 56.6%; PPV, 69.3%; and NPV, 86.5%). The model to predict worsening included male sex, oxygen saturation, no corticosteroids treatment, C-reactive protein and Nod-like receptor as independent factors (AUC, 0.903; SE, 97.1%; S, 68.8%; PPV, 30.4%; and NPV, 99.4%). The model was slightly improved by including the determinations of interleukine-8, Macrophage inflammatory protein-1 beta and soluble IL-2Rα (CD25) (AUC, 0.952; SE, 97.1%; S, 98.1%; PPV, 82.7%; and NPV, 99.6%). Conclusions Clinical and routine laboratory data at admission strongly predict non-worsening during the first two weeks; therefore, these variables could help identify those patients who do not need a long hospitalization and improve hospital overcrowding. Determination of pro-inflammatory cytokines moderately improves these predictive capacities.This work was supported by Consejeria de Salud y Familia (research Project COVID-0005-2020 and Research Contract RH-0037-2020 to JV); Consejería de Transformación Económica, Industria, Conocimiento y Universidades (PY20/01276 to APG); Instituto de Salud Carlos III (CP19/00159 to AGV, CP19/00146 to AR, FI19/00304 to EMM, FI19/00083 to MCGC, "a way to make Europe, and COV20/00698 to support COHVID-GS), Red Temática de Investigación Cooperativa en SIDA (RD16/0025/0020, RD16/0025/0006 and RD16/0025/0026), Fondos FEDER; Centro de Investigación Biomédica en Red de Enfermedades Infecciosas-ISCIII (CB21/13/00020) Madrid, Spain. ERM was supported by the Spanish Research Council (CSIC). AR is also supported by a grant from IISPV through the project “2019/IISPV/05” (Boosting Young Talent), by GeSIDA through the “III Premio para Jóvenes Investigadores”. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe

Receiver operating curve (ROC) analyses to evaluate the ability of clinical and laboratory data to predict discharge during the first week

AUC, area under the curve; SE, sensitivity; S, specificity; PPV, positive predictive value; NPV, negative predictive value. SpO2, peripheral capillary oxygen saturation; CRP, C-reactive protein; LDH, Lactate dehydrogenase; NLR, neutrophil/lymphocyte ratio; TNF-α; tumor necrosis factor α; IL-6, interleukine-6; IL-8, interleukine-8; IL-1β, interleukine-1β; MIP-1β, macrophage inflammatory proteins 1β; sCD25, soluble receptor interleukine-2; IP-10, interferon γ-induced protein 10.Peer reviewe

Baseline characteristics of the mild patients who were discharged and worsened during the first week

Quantitative variables are expressing as number (percentage) or median (interquartile range). Pa value for differences between patients who were or not discharged. Pb value for differences between patients who who did and did not get wore. SpO2, peripheral capillary oxygen saturation; CRP, C-reactive protein; LDH, Lactate dehydrogenase; NLR, neutrophil/lymphocyte ratio.Peer reviewe