Differential requirement of neutralizing antibodies and T cells on protective immunity to SARS-CoV-2 variants of concern.

The current COVID-19 vaccines protect against severe disease, but are not effective in controlling replication of the Variants of Concern (VOCs). Here, we used the existing pre-clinical models of severe and moderate COVID-19 to evaluate the efficacy of a Spike-based DNA vaccine (pCTV-WS) for protection against different VOCs. Immunization of transgenic (K18-hACE2) mice and hamsters induced significant levels of neutralizing antibodies (nAbs) to Wuhan and Delta isolates, but not to the Gamma and Omicron variants. Nevertheless, the pCTV-WS vaccine offered significant protection to all VOCs. Consistently, protection against lung pathology and viral load to Wuhan or Delta was mediated by nAbs, whereas in the absence of nAbs, T cells controlled viral replication, disease and lethality in mice infected with either the Gamma or Omicron variants. Hence, considering the conserved nature of CD4 and CD8 T cell epitopes, we corroborate the hypothesis that induction of effector T-cells should be a main goal for new vaccines against the emergent SARS-CoV-2 VOCs.

Promotion of neutralizing antibody-independent immunity to wild-type and SARS-CoV-2 variants of concern using an RBD-Nucleocapsid fusion protein.

Both T cells and B cells have been shown to be generated after infection with SARS-CoV-2 yet protocols or experimental models to study one or the other are less common. Here, we generate a chimeric protein (SpiN) that comprises the receptor binding domain (RBD) from Spike (S) and the nucleocapsid (N) antigens from SARS-CoV-2. Memory CD4+ and CD8+ T cells specific for SpiN could be detected in the blood of both individuals vaccinated with Coronavac SARS-CoV-2 vaccine and COVID-19 convalescent donors. In mice, SpiN elicited a strong IFN-γ response by T cells and high levels of antibodies to the inactivated virus, but not detectable neutralizing antibodies (nAbs). Importantly, immunization of Syrian hamsters and the human Angiotensin Convertase Enzyme-2-transgenic (K18-ACE-2) mice with Poly ICLC-adjuvanted SpiN promotes robust resistance to the wild type SARS-CoV-2, as indicated by viral load, lung inflammation, clinical outcome and reduction of lethality. The protection induced by SpiN was ablated by depletion of CD4+ and CD8+ T cells and not transferred by antibodies from vaccinated mice. Finally, vaccination with SpiN also protects the K18-ACE-2 mice against infection with Delta and Omicron SARS-CoV-2 isolates. Hence, vaccine formulations that elicit effector T cells specific for the N and RBD proteins may be used to improve COVID-19 vaccines and potentially circumvent the immune escape by variants of concern.

CoronaVac and ChAdOx1 Vaccination and Gamma Infection Elicited Neutralizing Antibodies against the SARS-CoV-2 Delta Variant.

The emergence of new SARS-CoV-2 variants represents a constant threat to world public health. The SARS-CoV-2 Delta variant was identified in late 2020 in India; since then, it has spread to many other countries, replacing other predominant lineages and raising concerns about vaccination efficiency. We evaluated the sensitivity of the Delta variant to antibodies elicited by COVID-19 vaccinated (CoronaVac and ChAdOx1) and convalescent individuals previously infected by earlier lineages and by the Gamma variant. No reduction in the neutralizing efficacy of the Delta variant was observed when compared to B lineage and a reduced neutralization was observed for the Gamma variant. Our results indicate that neutralization of the Delta variant is not compromised in individuals vaccinated by CoronaVac or ChAdOx1; however, a reduction in neutralization efficacy is expected for individuals infected by the Gamma variant, highlighting the importance of continuous vaccination even for previously infected individuals.

Protective Immunity against Gamma and Zeta Variants after Inactivated SARS-CoV-2 Virus Immunization.

The persistent circulation of SARS-CoV-2 represents an ongoing global threat due to the emergence of new viral variants that can sometimes evade the immune system of previously exposed or vaccinated individuals. We conducted a follow-up study of adult individuals that had received an inactivated SARS-CoV-2 vaccine, evaluating antibody production and neutralizing activity over a period of 6 months. In addition, we performed mice immunization with inactivated SARS-CoV-2, and evaluated the immune response and pathological outcomes against Gamma and Zeta variant infection. Vaccinated individuals produced high levels of antibodies with robust neutralizing activity, which was significantly reduced against Gamma and Zeta variants. Production of IgG anti-S antibodies and neutralizing activity robustly reduced after 6 months of vaccination. Immunized mice demonstrated cellular response against Gamma and Zeta variants, and after viral infection, reduced viral loads, IL-6 expression, and histopathological outcome in the lungs. TNF levels were unchanged in immunized or not immunized mice after infection with the Gamma variant. Furthermore, serum neutralization activity rapidly increases after infection with the Gamma and Zeta variants. Our data suggest that immunization with inactivated WT SARS-CoV-2 induces a promptly responsive cross-reactive immunity response against the Gamma and Zeta variants, reducing COVID-19 pathological outcomes.

Phenotypic, functional and serological aspects of genotypic-specific immune response of experimental T. cruzi infection.

The complexity and multifactorial characteristics of Chagas disease pathogenesis hampers the establishment of appropriate experimental/epidemiological sets, and therefore, still represents one of the most challenging fields for novel insights and discovery. In this context, we used a set of attributes including phenotypic, functional and serological markers of immune response as candidates to decode the genotype-specific immune response of experimental T. cruzi infection. In this investigation, we have characterized in C57BL/6 J mice, the early (parasitemia peak) and late (post-parasitemia peak) aspects of the immune response elicited by T. cruzi strains representative of TcI, TcII or TcVI. The results demonstrated earlier parasitemia peak for TcII/Y strain followed by TcVI/CL-Brener and TcI/Colombiana strains. A panoramic overview of phenotypic and functional features of the TCD4+, TCD8+ and B-cells from splenocytes demonstrated that mice infected with TcI/Colombiana strain exhibited at early stages of infection low levels of most cytokine+ cells with a slight increase at late stages of infection. Conversely, mice infected with TcII/Y strain presented an early massive increase of cytokine+ cells, which decreases at late stages. The TcVI/CL-Brener strain showed an intermediate profile at early stages of infection with a slight increase later on at post-peak of parasitemia. The panoramic analysis of immunological connectivity demonstrated that early after infection, the TcI/Colombiana strain trigger immunological network characterized by a small number of connectivity, selectively amongst cytokines that further shade towards the late stages of infection. In contrast, the TcII/Y strain elicited in more imbricate networks early after infection, comprising a robust number of interactions between pro-inflammatory mediators, regulatory cytokines and activation markers that also decrease at late infection. On the other hand, the infection with TcVI/CL-Brener strain demonstrated an intermediate profile with connectivity axes more stable at early and late stages of infection. The analysis of IgG2a reactivity to AMA, TRYPO and EPI antigens revealed that at early stages of infection, the genotype-specific reactivity to AMA, TRYPO and EPI to distinguish was higher for TcI/Colombiana as compared to TcII/Y and TcVI/CL while, at late stages of infection, higher reactivity to AMA was observed in mice infected with TcVI/CL and TcII/Y strains. The novel systems biology approaches and the use of a flow cytometry platform demonstrated that distinct T. cruzi genotypes influenced in the phenotypic and functional features of the host immune response and the genotype-specific serological reactivity during early and late stages of experimental T. cruzi infection.

Contributions of IFN-γ and granulysin to the clearance of Plasmodium yoelii blood stage.

P. vivax-infected Retics (iRetics) express human leukocyte antigen class I (HLA-I), are recognized by CD8+ T cells and killed by granulysin (GNLY) and granzymes. However, how Plasmodium infection induces MHC-I expression on Retics is unknown. In addition, whether GNLY helps control Plasmodium infection in vivo has not been studied. Here, we examine these questions using rodent infection with the P. yoelii 17XNL strain, which has tropism for Retics. Infection with P. yoelii caused extramedullary erythropoiesis, reticulocytosis and expansion of CD8+CD44+CD62L- IFN-γ-producing T cells that form immune synapses with iRetics. We now provide evidence that MHC-I expression by iRetic is dependent on IFN-γ-induced transcription of IRF-1, MHC-I and ß2-microglobulin (ß2-m) in erythroblasts. Consistently, CTLs from infected wild type (WT) mice formed immune synapses with iRetics in an IFN-γ- and MHC-I-dependent manner. When challenged with P. yoelii 17XNL, WT mice cleared parasitemia and survived, while IFN-γ KO mice remained parasitemic and all died. ß2-m KO mice that do not express MHC-I and have virtually no CD8+ T cells had prolonged parasitemia, and 80% survived. Because mice do not express GNLY, GNLY-transgenic mice can be used to assess the in vivo importance of GNLY. Parasite clearance was accelerated in GNLY-transgenic mice and depletion of CD8+ T cells ablated the GNLY-mediated resistance to P. yoelii. Altogether, our results indicate that in addition to previously described mechanisms, IFN-γ promotes host resistance to the Retic-tropic P. yoelii 17XNL strain by promoting MHC-I expression on iRetics that become targets for CD8+ cytotoxic T lymphocytes and GNLY.

A mística de Simone Weil e a análise dos sonhos: aproximações entre a fenomenologia e a psicologia analítica / The mystic of Simone Weil and the analysis of dreams: approximation between the phenomenology and the analytical psychology / El místico de Simone Weil y la analisis de los sueños: acercamiento entre la fenomenologia y la psicologia analítica

Neste trabalho, pretendemos fazer dialogar âmbitos da existência que raramente são vistos reunidos: a análise de sonhos, numa abordagem da Psicologia Analítica num encontro com a daseinsanálise, e a experiência mística. Para tanto, lançamos mão de um sonho de um de meus pacientes e os relatos de Simone Weil, mística judia do século XX. Nesse sentido, meu paciente trouxe um sonho emblemático no qual se evidencia que o âmbito espiritual de sua existência estava recebendo pouca atenção. Vemos que os sonhos podem assumir o papel de apontar ao Dasein que diferentes âmbitos existenciais estão sendo negligenciados. De modo semelhante, para a Psicologia Analítica, a individuação apresenta-se como encontro de âmbitos inconscientes da existência não considerados pelo caráter unilateral da consciência. A experiência mística, entendida como relação de pessoalidade com Deus, no cristianismo, é um desses âmbitos e, quando negligenciada, pode produzir uma limitação na liberdade existencial do indivíduo. O mundo técnico parece desqualificar experiências não apreensíveis pela razão lógica, mas a existência pode sustentar sua essencial liberdade e permanecer aberta, plural e afeita às explosões de possibilidades que o Dasein, em última instância, é. A daseinsanálise é prática psicoterápica apoiada na Fenomenologia Hermenêutica de Heidegger e aponta para o acolhimento da diversidade infindável de possibilidades existenciais que perpassam o Dasein. Para a Psicologia Analítica, o processo de individuação, que recebe dos sonhos sentidos próprios, aponta na direção de diálogo profícuo entre a consciência e o universo plural, dinâmico e aberto do inconsciente. O mistério, doador de sentidos, pode ser um ângulo donde é possível um encontro entre a Fenomenologia e a Psicologia Analítica.

In this work, we intend to make ambits of existence that are rarely seen together dialogue: dream analysis, in an approach of Analytical Psychology in an encounter with daseinsanalysis, and the mystical experience. To this end, we made use of a dream from one of my patients and Simone Weil's reports, a mystical Jew from the 20th Century. In this sense, my patient brought an emblematic dream which revealed that the spiritual ambit of his existence was receiving little attention. We see that dreams can assume the role of pointing to Dasein that different existential ambits are being neglected. Similarly, for Analytical Psychology, individuation presents itself as an encounter of unconscious ambits of existence not considered by the unilateral feature of consciousness. The mystical experience, understood as the personal relationship with God, in Christianity, is one of these ambits and, when neglected, can produce a limitation on the existential liberty of the individual. The technical world seems to disqualify experiences that are not apprehensible by logical reason, but the existence can sustain the essential liberty and remain open, plural and prone to the explosion of possibilities that Dasein, ultimately, is. The daseinsanalys is a psychotherapeutic practice sustained by Heidegger's Hermeneutic Phenomenology and points to welcoming the everlasting diversity of existential possibilities that cross Dasein. For the Analytical Psychology, the process of individuation, which receives from dreams its own senses, points towards a fertile dialogue between consciousness and the plural universe, dynamic and open from the unconscious. The mystery, donor of meanings, can be an angle from which a meeting between Phenomenology and Analytical Psychology is possible.

En el presente trabajo pretendemos hacer dialogar diferentes ámbitos de la existencia que raramente son vistos juntos: el análisis de los sueños en un abordaje de la Psicología Analítica en encuentro con el análisis existencial (daseinanálise) y la experiencia mística. Para esto, tomamos un sueño de uno de mis pacientes y los relatos de Simone Weil, mística judía del siglo XX. En este sentido, mi paciente trajo un sueño emblemático en el cual se evidencia que el ámbito espiritual de su existencia estaba recibiendo poca atención. Observamos que los sueños pueden asumir el papel de señalar al Dasein que diferentes ámbitos existenciales están siendo descuidados. De modo similar, para la Psicología Analítica, la individuación se presenta como el encuentro de ámbitos inconscientes de la existencia no considerados por el carácter unilateral de la consciencia. Por otra parte, la experiencia mística, entendida como la relación de la personalidad con Dios, en el cristianismo, es uno de esos ámbitos y cuando es descuidada puede producir una limitación en la libertad existencial del individuo. El mundo técnico parece descalificar las experiencias no comprensibles por la razón lógica, sin embargo, la existencia puede mantener su esencial libertad y permanecer abierta, plural y afectiva ante las explosiones de posibilidades que el Dasein, en última instancia es. El análisis existencial es una práctica psicoterapéutica apoyada en la Fenomenología Hermenéutica de Heidegger y apunta al acogimiento de una infinita diversidad de posibilidades existenciales que atraviesan el Dasein. Para la Psicología Analítica, el proceso de individuación - que recibe de los sueños sentidos propios-, señala en dirección a un diálogo prolífico entre la consciencia y el universo plural, dinámico y abierto del inconsciente. Finalmente, el misterio, donador de sentidos, puede ser un ángulo por el cual es posible un encuentro entre la Fenomenología y la Psicología Analítica.

A mística de Simone Weil e a análise dos sonhos: aproximações fenomenológicas / Simone Weil's Mystics and the Analysis of Dreams: Phenomenological Approaches

Neste trabalho, pretendemos fazer dialogar âmbitos da existência que raramente são vistos reunidos: a análise de sonhos, numa abordagem daseinsanalítica, e a experiência mística. Para tanto, lançamos mão de um sonho de um de meus pacientes e os relatos de Simone Weil, mística judia do século XX. Nesse sentido, meu paciente trouxe um sonho emblemático onde evidencia-se que o âmbito espiritual de sua existência estava recebendo pouca atenção. Vemos que os sonhos podem assumir o papel de apontar ao Dasein que diferentes âmbitos existenciais estão sendo negligenciados. A experiência mística, entendida como relação de pessoalidade com Deus, é um desses âmbitos e, quando negligenciada, pode produzir uma limitação na liberdade existencial do dasein. O mundo técnico parece desqualificar experiências não apreensíveis pela razão lógica, mas a existência pode sustentar sua essencial liberdade e permanecer aberta, plural e afeita às explosões de possibilidades que o Dasein, em última instância, é. A daseinsanálise é prática psicoterápica apoiada na fenomenologia hermenêutica de Heidegger e aponta para o acolhimento da diversidade infindável de possibilidades existenciais que atravessam o Dasein

In this work, we intend to relate different scopes of existence, which are rarely connected: dream analysis, in a daseinsanalysis approach, and the mystic experience. For that purpose, we resorted to a dream of one of my patients and Simone Weil's reports, a mystic Jew who lived in the XX century.In these terms, my patient brought an iconic dream,revealing that the spiritual sphere of his existence was lacking the necessary attention. We can affirm that dreams play the role of showing the Dasein the existential scopes thatare being neglected. The mystic experience, understood as the personal relationship with God, is one of these areas and, when neglected, can limit the existential freedom of dasein. The technical world seems to disqualify any experiences that are not apprehensible by logical reason, but the existence can sustain its essential freedom and remain open, multiple andinured to the variety of possibilities that the Dasein, ultimately, represents. Thedaseinsanalysis is a psychotherapeutic practice sustained by Heidegger's hermeneutics phenomenology and points to welcoming the everlasting diversity of existential possibilities that integrate the Dasein

Cross-talk between lung cancer and bones results in neutrophils that promote tumor progression.

Lung cancer is the leading cause of cancer mortality around the world. The lack of detailed understanding of the cellular and molecular mechanisms participating in the lung tumor progression restrains the development of efficient treatments. Recently, by using state-of-the-art technologies, including in vivo sophisticated Cre/loxP technologies in combination with lung tumor models, it was revealed that osteoblasts activate neutrophils that promote tumor growth in the lung. Strikingly, genetic ablation of osteoblasts abolished lung tumor progression via interruption of SiglecFhigh-expressing neutrophils supply to the tumor microenvironment. Interestingly, SiglecFhigh neutrophil signature was associated with worse lung adenocarcinoma patients outcome. This study identifies novel cellular targets for lung cancer treatment. Here, we summarize and evaluate recent advances in our understanding of lung tumor microenvironment.

Targeting glioblastoma-derived pericytes improves chemotherapeutic outcome.

Glioblastoma is the most common malignant brain cancer in adults, with poor prognosis. The blood-brain barrier limits the arrival of several promising anti-glioblastoma drugs, and restricts the design of efficient therapies. Recently, by using state-of-the-art technologies, including thymidine kinase targeting system in combination with glioblastoma xenograft mouse models, it was revealed that targeting glioblastoma-derived pericytes improves chemotherapy efficiency. Strikingly, ibrutinib treatment enhances chemotherapeutic effectiveness, by targeting pericytes, improving blood-brain barrier permeability, and prolonging survival. This study identifies glioblastoma-derived pericyte as a novel target in the brain tumor microenvironment during carcinogenesis. Here, we summarize and evaluate recent advances in the understanding of pericyte's role in the glioblastoma microenvironment.

Pericytes in the Premetastatic Niche.

The premetastatic niche formed by primary tumor-derived molecules contributes to fixation of cancer metastasis. The design of efficient therapies is limited by the current lack of knowledge about the details of cellular and molecular mechanisms involved in the premetastatic niche formation. Recently, the role of pericytes in the premetastatic niche formation and lung metastatic tropism was explored by using state-of-the-art techniques, including in vivo lineage-tracing and mice with pericyte-specific KLF4 deletion. Strikingly, genetic inactivation of KLF4 in pericytes inhibits pulmonary pericyte expansion and decreases metastasis in the lung. Here, we summarize and evaluate recent advances in the understanding of pericyte contribution to premetastatic niche formation. Cancer Res; 78(11); 2779-86. ©2018 AACR.

Perivascular cell αv integrins as a target to treat skeletal muscle fibrosis.

Fibrosis following injury leads to aberrant regeneration and incomplete functional recovery of skeletal muscle, but the lack of detailed knowledge about the cellular and molecular mechanisms involved hampers the design of effective treatments. Using state-of-the-art technologies, Murray et al. (2017) found that perivascular PDGFRß-expressing cells generate fibrotic cells in the skeletal muscle. Strikingly, genetic deletion of αv integrins from perivascular PDGFRß-expressing cells significantly inhibited skeletal muscle fibrosis without affecting muscle vascularization or regeneration. In addition, the authors showed that a small molecule inhibitor of αv integrins, CWHM 12, attenuates skeletal muscle fibrosis. From a drug-development perspective, this study identifies a new cellular and molecular target to treat skeletal muscle fibrosis.

Glioblastoma-activated pericytes support tumor growth via immunosuppression.

Glioblastoma multiforme is the most common and aggressive primary brain tumor, with an extremely poor prognosis. The lack of detailed knowledge about the cellular and molecular mechanisms involved in glioblastoma development restricts the design of efficient therapies. A recent study using state-of-art technologies explores the role of pericytes in the glioblastoma microenvironment. Glioblastoma-activated pericytes develop an immunosuppressive phenotype, reducing T-cell activation through the induction of an anti-inflammatory response. Strikingly, pericytes support glioblastoma growth in vitro and in vivo. Here, we describe succinctly the results and implications of the findings reported in pericytes' and glioblastomas' biology. The emerging knowledge from this study will be essential for the treatment of brain tumors.

Pericytes modulate myelination in the central nervous system.

Multiple sclerosis is a highly prevalent chronic demyelinating disease of the central nervous system. Remyelination is the major therapeutic goal for this disorder. The lack of detailed knowledge about the cellular and molecular mechanisms involved in myelination restricts the design of effective treatments. A recent study by using [De La Fuente et al. (2017) Cell Reports, 20(8): 1755-1764] by using state-of-the-art techniques, including pericyte-deficient mice in combination with induced demyelination, reveal that pericytes participate in central nervous system regeneration. Strikingly, pericytes presence is essential for oligodendrocyte progenitors differentiation and myelin formation during remyelination in the brain. The emerging knowledge from this research will be important for the treatment of multiple sclerosis.

Adipocytes role in the bone marrow niche.

Adipocyte infiltration in the bone marrow follows chemotherapy or irradiation. Previous studies indicate that bone marrow fat cells inhibit hematopoietic stem cell function. Recently, Zhou et al. (2017) using state-of-the-art techniques, including sophisticated Cre/loxP technologies, confocal microscopy, in vivo lineage-tracing, flow cytometry, and bone marrow transplantation, reveal that adipocytes promote hematopoietic recovery after irradiation. This study challenges the current view of adipocytes as negative regulators of the hematopoietic stem cells niche, and reopens the discussion about adipocytes' roles in the bone marrow. Strikingly, genetic deletion of stem cell factor specifically from adipocytes leads to deficiency in hematopoietic stem cells, and reduces animal survival after myeloablation, The emerging knowledge from this research will be important for the treatment of multiple hematologic disorders. © 2017 International Society for Advancement of Cytometry.

Macrophages Generate Pericytes in the Developing Brain.

Pericytes are defined by their anatomical location encircling blood vessels' walls with their long projections. The exact embryonic sources of cerebral pericytes remain poorly understood, especially because of their recently revealed diversity. Yamamoto et al. (Sci Rep 7(1):3855, 2017) using state-of-the-art techniques, including several transgenic mice models, reveal that a subpopulation of brain pericytes are derived from phagocytic macrophages during vascular development. This work highlights a new possible ancestor of brain pericytes. The emerging knowledge from this research may provide new approaches for the treatment of several neurodevelopmental disorders in the future.

LepR+ cells dispute hegemony with Gli1+ cells in bone marrow fibrosis.

Bone marrow fibrosis is a reactive process, and a central pathological feature of primary myelofibrosis. Revealing the origin of fibroblastic cells in the bone marrow is crucial, as these cells are considered an ideal, and essential target for anti-fibrotic therapy. In 2 recent studies, Decker et al. (2017) and Schneider et al. (2017), by using state-of-the-art techniques including in vivo lineage-tracing, provide evidence that leptin receptor (LepR)-expressing and Gli1-expressing cells are responsible for fibrotic tissue deposition in the bone marrow. However, what is the relationship between these 2 bone marrow cell populations, and what are their relative contributions to bone marrow fibrosis remain unclear. From a drug development perspective, these works bring new cellular targets for bone marrow fibrosis.

Endothelial Cells as Precursors for Osteoblasts in the Metastatic Prostate Cancer Bone.

Prostate cancer cells metastasize to the bones, causing ectopic bone formation, which results in fractures and pain. The cellular mechanisms underlying new bone production are unknown. In a recent study, Lin and colleagues, by using state-of-the-art techniques, including prostate cancer mouse models in combination with sophisticated in vivo lineage-tracing technologies, revealed that endothelial cells form osteoblasts induced by prostate cancer metastasis in the bone. Strikingly, genetic deletion of osteorix protein from endothelial cells affected prostate cancer-induced osteogenesis in vivo. Deciphering the osteoblasts origin in the bone microenvironment may result in the development of promising new molecular targets for prostate cancer therapy.

Endothelial cells maintain neural stem cells quiescent in their niche.

Niches are specialized microenvironments that regulate stem cells' activity. The neural stem cell (NSC) niche defines a zone in which NSCs are retained and produce new cells of the nervous system throughout life. Understanding the signaling mechanisms by which the niche controls the NSC fate is crucial for the success of clinical applications. In a recent study, Sato and colleagues, by using state-of-the-art techniques, including sophisticated in vivo lineage-tracing technologies, provide evidence that endothelial amyloid precursor protein (APP) is an important component of the NSC niche. Strikingly, depletion of APP increased NSC proliferation in the subventricular zone, indicating that endothelial cells negatively regulate NSCs' growth. The emerging knowledge from this research will be important for the treatment of several neurological diseases.