RESUMO
There is an urgent need to understand severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-host interactions involved in virus spread and pathogenesis, which might contribute to the identification of new therapeutic targets. In this study, we investigated the presence of SARS-CoV-2 in postmortem lung, kidney, and liver samples of patients who died with coronavirus disease (COVID-19) and its relationship with host factors involved in virus spread and pathogenesis, using microscopy-based methods. The cases analyzed showed advanced stages of diffuse acute alveolar damage and fibrosis. We identified the SARS-CoV-2 nucleocapsid (NC) in a variety of cells, colocalizing with mitochondrial proteins, lipid droplets (LDs), and key host proteins that have been implicated in inflammation, tissue repair, and the SARS-CoV-2 life cycle (vimentin, NLRP3, fibronectin, LC3B, DDX3X, and PPARγ), pointing to vimentin and LDs as platforms involved not only in the viral life cycle but also in inflammation and pathogenesis. SARS-CoV-2 isolated from a patient´s nasal swab was grown in cell culture and used to infect hamsters. Target cells identified in human tissue samples included lung epithelial and endothelial cells; lipogenic fibroblast-like cells (FLCs) showing features of lipofibroblasts such as activated PPARγ signaling and LDs; lung FLCs expressing fibronectin and vimentin and macrophages, both with evidence of NLRP3- and IL1ß-induced responses; regulatory cells expressing immune-checkpoint proteins involved in lung repair responses and contributing to inflammatory responses in the lung; CD34+ liver endothelial cells and hepatocytes expressing vimentin; renal interstitial cells; and the juxtaglomerular apparatus. This suggests that SARS-CoV-2 may directly interfere with critical lung, renal, and liver functions involved in COVID-19-pathogenesis.
Assuntos
COVID-19 , Humanos , COVID-19/patologia , Fibronectinas , Vimentina , SARS-CoV-2 , Células Endoteliais , Proteína 3 que Contém Domínio de Pirina da Família NLR , PPAR gama , Pulmão , Inflamação/patologia , Rim , FígadoRESUMO
Developing affordable and easily manufactured SARS-CoV-2 vaccines will be essential to achieve worldwide vaccine coverage and long-term control of the COVID-19 pandemic. Here the development is reported of a vaccine based on the SARS-CoV-2 receptor-binding domain (RBD), produced in the yeast Pichia pastoris. The RBD was modified by adding flexible N- and C-terminal amino acid extensions that modulate protein/protein interactions and facilitate protein purification. A fed-batch methanol fermentation with a yeast extract-based culture medium in a 50 L fermenter and an immobilized metal ion affinity chromatography-based downstream purification process yielded 30-40 mg/L of RBD. Correct folding of the purified protein was demonstrated by mass spectrometry, circular dichroism, and determinations of binding affinity to the angiotensin-converting enzyme 2 (ACE2) receptor. The RBD antigen also exhibited high reactivity with sera from convalescent individuals and Pfizer-BioNTech or Sputnik V vaccinees. Immunization of mice and non-human primates with 50 µg of the recombinant RBD adjuvanted with alum induced high levels of binding antibodies as assessed by ELISA with RBD produced in HEK293T cells, and which inhibited RBD binding to ACE2 and neutralized infection of VeroE6 cells by SARS-CoV-2. Additionally, the RBD protein stimulated IFNγ, IL-2, IL-6, IL-4 and TNFα secretion in splenocytes and lung CD3+-enriched cells of immunized mice. The data suggest that the RBD recombinant protein produced in yeast P. pastoris is suitable as a vaccine candidate against COVID-19.
Assuntos
COVID-19 , SARS-CoV-2 , Animais , Humanos , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Células HEK293 , Pandemias/prevenção & controle , Glicoproteína da Espícula de Coronavírus , Camundongos , PrimatasRESUMO
COVID-19 is a respiratory viral disease caused by a new coronavirus called SARS-CoV-2. This disease has spread rapidly worldwide with a high rate of morbidity and mortality. The receptor-binding domain (RBD) of protein spike (S) mediates the attachment of the virus to the host's cellular receptor. The RBD domain constitutes a very attractive target for subunit vaccine development due to its ability to induce a neutralizing antibody response against the virus. With the aim of boosting the immunogenicity of RBD, it was fused to the extracellular domain of CD154, an immune system modulator molecule. To obtain the chimeric protein, stable transduction of HEK-293 was carried out with recombinant lentivirus and polyclonal populations and cell clones were obtained. RBD-CD was purified from culture supernatant and further characterized by several techniques. RBD-CD immunogenicity evaluated in mice and non-human primates (NHP) indicated that recombinant protein was able to induce a specific and high IgG response after two doses. NHP sera also neutralize SARS-CoV-2 infection of Vero E6 cells. RBD-CD could improve the current vaccines against COVID-19, based in the enhancement of the host humoral and cellular response. Further experiments are necessary to confirm the utility of RBD-CD as a prophylactic vaccine and/or booster purpose.
RESUMO
CIGB-247 is a vascular endothelial growth factor (VEGF)-based active immunotherapy and it is currently under investigation for cancer treatment. This specific active immunotherapy encompasses two vaccine candidates that use a human VEGF variant molecule as antigen, in combination with two clinically tested adjuvants: VSSP or aluminum phosphate. CIGB-247 has been evaluated in patients with advanced solid tumors, recruited in two phase I clinical trials, and it has been shown to be safe and immunogenic by activating both cellular and humoral immune responses against human VEGF. The immunization induces specific IgG antibodies, and also shows as effect, the reduction of free-VEGF levels within platelets (platelet-derived free VEGF). The production of systemic IgG antibodies and the presence of VEGF in another compartment, almost exclusively within platelets, have arisen some questions about this effect detected in the vaccinated-cancer patients. Based on some relevant published works about platelet endocytosis and VEGF pharmacodynamics during bevacizumab treatment as well as the phase I clinical data of CIGB-247, this investigation aims to hypothesize and analyze the potential mechanisms involved in the reduction of platelet-derived free VEGF as a result of vaccination with CIGB-247.Abbreviations: FcγR: Fc gamma receptors; IC: immune complexes; VEGF: vascular endothelial growth factor; VEGFR1: vascular endothelial growth factor receptor 1; VEGFR2: vascular endothelial growth factor receptor 2.
Assuntos
Vacinas Anticâncer , Neoplasias , Humanos , Imunoglobulina G , Imunoterapia Ativa , Neoplasias/terapia , Fator de Crescimento Derivado de Plaquetas , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio VascularRESUMO
COVID-19 pandemic poses a serious threat to human health; it has completely disrupted global stability, making vaccine development an important goal to achieve. Monoclonal antibodies play an important role in subunit vaccines strategies. In this work, nine murine MAbs against the RBD of the SARS-CoV-2 spike protein were obtained by hybridoma technology. Characterization of purified antibodies demonstrated that five of them have affinities in the order of 108 L/mol. Six MAbs showed specific recognition of different recombinant RBD-S antigens in solution. Studies of the additivity index of anti-RBD antibodies, by using a novel procedure to determine the additivity cut point, showed recognition of at least five different epitopes. The MAbs CBSSRBD-S.11 and CBSSRBD-S.8 revealed significant neutralizing capacity against SARS-CoV-2 in an ACE2-RBD binding inhibition assay (IC50 = 85.5pM and IC50 = 122.7pM, respectively) and in a virus neutralizing test with intact SARS-CoV-2 (VN50 = 0.552 nM and VN50 = 4.854 nM, respectively) when D614G strain was used to infect Vero cells. Also CBSSRBD-S.11 neutralized the SARS-CoV-2 strains Alpha and Beta: VN50 = 0.707 nM and VN50 = 0.132 nM, respectively. The high affinity CBSSRBD-S.8 and CBSSRBD-S.7 recognized different epitopes, so they are suitable for the development of a sandwich ELISA to quantitate RBD-S recombinant antigens in biomanufacturing processes, as well as in pharmacokinetic studies in clinical and preclinical trials.
Assuntos
Anticorpos Monoclonais/metabolismo , Vacinas contra COVID-19/imunologia , COVID-19/diagnóstico , SARS-CoV-2/fisiologia , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , Anticorpos Monoclonais/genética , COVID-19/imunologia , Vacinas contra COVID-19/genética , Ensaios Clínicos como Assunto , Feminino , Engenharia Genética , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Domínios e Motivos de Interação entre Proteínas/genética , Desenvolvimento de Vacinas , Vacinas de Subunidades Antigênicas/genéticaRESUMO
Introducción: El CIGB-258 es un péptido inmunomodulador con propiedades antiinflamatorias. Objetivos: Establecer la frecuencia de dosis y el tiempo de tratamiento con el péptido CIGB-258, para pacientes críticos con COVID-19. Además, definir los criterios de uso y el esquema terapéutico del péptido, para pacientes graves con COVID-19. Métodos: Se incluyeron 9 pacientes críticos y 3 pacientes graves. Las evaluaciones clínicas, radiológicas y de laboratorio se registraron de acuerdo al protocolo establecido. Se obtuvieron muestras de suero antes y después del tratamiento con la CIGB-258, para la determinación de los biomarcadores de la inflamación. Resultados: Se estableció el protocolo de actuación con el péptido CIGB-258, el cual consiste en la administración intravenosa de 1 mg del péptido cada 12 horas a los pacientes críticos. La dosis debe aumentarse a 2 mg cada 12 horas, para los pacientes que no muestren mejoría clínica y radiológica en 24 horas. Después de la extubación, los pacientes deben recibir 1 mg de CIGB-258 al día, durante otros tres días. Los pacientes graves deben recibir 1 mg de CIGB-258 cada 12 horas, hasta que resuelvan su condición clínica. Conclusiones: CIGB-258 mostró un buen perfil de seguridad. El protocolo de actuación establecido contribuyó a que todos los pacientes críticos se recuperaran de la dificultad respiratoria y fueran extubados. Los pacientes graves mejoraron considerablemente. Los niveles de los biomarcadores asociados con hiperinflamación y las citocinas disminuyeron significativamente durante el tratamiento(AU)
Introduction: CIGB-258 is an immunomodulatory peptide with anti-inflammatory properties. Objectives: To establish the therapeutic schedule with CIGB-258 peptide for COVID-19 critically ill patients. In addition, to define the criteria for use and schedule of this peptide for COVID-19 seriously ill patients. Methods: 9 critically ill patients and 3 seriously ill patients were included in this study. Clinical, radiological and laboratory evaluations were recorded according to the established protocol. Serum samples were obtained before and after treatment with CIGB-258, for the determination of the inflammation biomarkers. Results: The therapeutic protocol was established with the CIGB-258 peptide, which consists of intravenous administration of 1 mg of peptide every 12 hours for critically ill patients. The dose should be increased to 2 mg every 12 hours, for patients who do not show clinical and radiological improvement in 24 hours. After extubation, patients should receive 1 mg of CIGB-258 daily, for another three days. Seriously ill patients should receive 1 mg of CIGB-258 every 12 hours, until their clinical condition resolves. Conclusions: CIGB-258 showed an excellent safety profile. The established therapeutic protocol contributed to all critically ill patients recovering from respiratory distress and being extubated. Seriously ill patients improved considerably. The levels of the biomarkers associated with hyperinflammation and cytokines decreased significantly during treatment(AU)
Assuntos
Humanos , Masculino , Feminino , Estado Terminal/terapia , Chaperonina 60 , Medicamentos de Referência , Síndrome da Liberação de Citocina/epidemiologia , COVID-19/tratamento farmacológicoRESUMO
BACKGROUND: CIGB-247 is a cancer therapeutic vaccine that uses as antigen a variant of human vascular endothelial growth factor (VEGF) mixed with the bacterially-derived adjuvant VSSP. CIGB-247 has been already evaluated in two phase I clinical trials (CENTAURO and CENTAURO-2), showing to be safe and immunogenic in advanced cancer patients selected under well-defined and controlled clinical conditions. Surviving patients were submitted to monthly re-immunizations and some of them showed objective clinical benefits. Based on these results, a compassionate use program (CUP) with CIGB-247 was initiated for patients that did not meet the strict entry criteria applied for the CENTAURO and CENTAURO-2 clinical trials, but could potentially benefit from the application of this cancer therapeutic vaccine. RESULTS: Polyclonal IgM, IgA and IgG antibodies specific for VEGF were detected by ELISA in serum samples from patients vaccinated with 400 µg of antigen combined with 200 µg of VSSP. Polyclonal antibody response showed no cross reactivity for other VEGF family member molecules like VEGF-C and VEGF-D. Serum from immunized individuals was able to block the binding of VEGF to its receptors VEGFR2 and VEGFR1. IgG fraction purified from immune sera shared the aforementioned characteristics and also inhibited the interaction between VEGF and the therapeutic recombinant antibody bevacizumab, an anti-angiogenic drug approved for the treatment of different tumors. No serious adverse events attributable to CIGB-247 have been documented yet in participants of the CIGB-247 CUP. The present paper is a first report of our findings concerning the humoral response and safety characteristics in treated CIGB-247 CUP cancer patients. The study has provided the unique opportunity of not only testing CIGB-247 in a broader clinical spectrum sample of Cuban cancer patients, but also within the context of the day-to-day clinical practice and treatment settings for these diseases in Cuban medical institutions. CONCLUSIONS: The CIGB-247 CUP has demonstrated that immunization and follow-up of a variety of cancer patients, under day-to-day clinical practice conditions in several Cuban medical institutions, replicate our previous findings in clinical trials: CIGB-247 is safe and immunogenic.
Assuntos
Vacinas Anticâncer/imunologia , Imunoterapia Ativa/métodos , Neoplasias/imunologia , Proteolipídeos/imunologia , Fator A de Crescimento do Endotélio Vascular/imunologia , Adjuvantes Imunológicos , Ensaios de Uso Compassivo , Feminino , Humanos , Imunidade Humoral , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Pessoa de Meia-Idade , Neoplasias/terapia , Resultado do Tratamento , Vacinação , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
Diabetic foot ulcer is one of the most frightened diabetic complications leading to amputation disability and early mortality. Diabetic wounds exhibit a complex networking of inflammatory cytokines, local proteases, and reactive oxygen and nitrogen species as a pathogenic polymicrobial biofilm, overall contributing to wound chronification and host homeostasis imbalance. Intralesional infiltration of epidermal growth factor (EGF) has emerged as a therapeutic alternative to diabetic wound healing, reaching responsive cells while avoiding the deleterious effect of proteases and the biofilm on the wound's surface. The present study shows that intralesional therapy with EGF is associated with the systemic attenuation of pro-inflammatory markers along with redox balance recovery. A total of 11 diabetic patients with neuropathic foot ulcers were studied before and 3 weeks after starting EGF treatment. Evaluations comprised plasma levels of pro-inflammatory, redox balance, and glycation markers. Pro-inflammatory markers such as erythrosedimentation rate, C-reactive protein, interleukin-6, soluble FAS, and macrophage inflammatory protein 1-alpha were significantly reduced by EGF therapy. Oxidative capacity, nitrite/nitrate ratio, and pentosidine were also reduced, while soluble receptor for advanced glycation end-products significantly increased. Overall, our results indicate that the local intralesional infiltration of EGF translates in systemic anti-inflammatory and antioxidant effects, as in attenuation of the glycation products' negative effects.
Assuntos
Pé Diabético/tratamento farmacológico , Fator de Crescimento Epidérmico/uso terapêutico , Proteínas Recombinantes/uso terapêutico , Idoso , Arginina/análogos & derivados , Arginina/sangue , Biomarcadores/sangue , Sedimentação Sanguínea , Proteína C-Reativa/análise , Quimiocina CCL3/sangue , Citocinas/sangue , Feminino , Humanos , Injeções Intralesionais , Lisina/análogos & derivados , Lisina/sangue , Masculino , Pessoa de Meia-Idade , Nitratos/sangue , Nitritos/sangue , Receptor para Produtos Finais de Glicação Avançada/sangue , Cicatrização , Receptor fas/sangueRESUMO
OBJECTIVES: Vascular endothelial growth factor (VEGF) is involved in physiological angiogenesis, but also is considered one of the key factors that promotes tumor angiogenesis. CIGB-247 is a VEGF-based vaccine that has been evaluated in phase I clinical trial patients with advanced solid tumors. This specific active immunotherapy is able to reduce platelet VEGF levels; however it is unknown whether this effect leads to a decrease in VEGF below the levels that can be observed in healthy individuals. The objective of the present study is to investigate platelet VEGF levels in cancer patients vaccinated with CIGB-247, and then compare these values with those obtained in healthy individuals. To achieve this, platelet VEGF levels of 62 cancer patients and 93 healthy individuals were compared. Cancer patients were those individuals recruited in CENTAURO and CENTAURO-2 clinical trials. RESULTS: Before vaccination, platelets of cancer patients carried more VEGF than the levels seen in platelet of healthy individuals. However, after vaccination, cancer patients had platelet VEGF values within the range established by healthy individuals, indicating that the antibody response elicited by CIGB-247 is not able to induce a complete suppression of VEGF. Vaccination with CIGB-247 helps to normalize VEGF levels within platelets.
Assuntos
Plaquetas/efeitos dos fármacos , Vacinas Anticâncer/administração & dosagem , Imunoterapia Ativa/métodos , Neoplasias/terapia , Neovascularização Patológica/prevenção & controle , Fator A de Crescimento do Endotélio Vascular/genética , Adjuvantes Imunológicos/administração & dosagem , Adolescente , Adulto , Idoso , Plaquetas/imunologia , Plaquetas/patologia , Estudos de Casos e Controles , Feminino , Expressão Gênica , Humanos , Imunidade Humoral/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Neoplasias/genética , Neoplasias/imunologia , Neoplasias/patologia , Neovascularização Patológica/genética , Neovascularização Patológica/imunologia , Neovascularização Patológica/patologia , Vacinação/métodos , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/imunologiaRESUMO
Two phase I clinical trials were conducted to evaluate, among other parameters, the humoral response elicited by a vascular endothelial growth factor (VEGF)-based therapeutic vaccine in cancer patients with advanced solid tumors. VEGF reduction was studied using an indirect methodology named as "Platelet VEGF". This methodology is based on the estimation of VEGF within platelets by subtracting the plasma VEGF level from the serum level and dividing this by the platelet count, and then this latter expression is additionally corrected by the hematocrit. However, there is broad debate, whether serum or plasma VEGF or platelet-derived VEGF measurements is the most appropriate strategy to study the changes that occur on ligand bioavailability when patients are submitted to a VEGF-based immunotherapy. The current research is a retrospective study evaluating the changes on VEGF levels in serum and plasma as well as platelet-derived measurements. Changes in VEGF levels were related with the humoral response seen in cancer patients after an active immunotherapy with a VEGF-based vaccine. The present study indicates that "Platelet VEGF" is the most reliable methodology to investigate the effect of VEGF-based immunotherapies on ligand bioavailability. "Platelet VEGF" was associated with those groups of individuals that exhibited the best specific humoral response and the variation of "Platelet VEGF" showed the strongest negative correlation with VEGF-specific IgG antibody levels. This methodology will be very useful for the investigation of this VEGF-based vaccine in phase II clinical trials and could be applied to immunotherapies directed to other growth factors that are actively sequestered by platelets.