A combination of vaccination approaches will likely be necessary to fully control the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Here, we show that modified vaccinia ...Ankara (MVA) vectors expressing membrane-anchored pre-fusion stabilized spike (MVA/S) but not secreted S1 induced strong neutralizing antibody responses against SARS-CoV-2 in mice. In macaques, the MVA/S vaccination induced strong neutralizing antibodies and CD8+ T cell responses, and conferred protection from SARS-CoV-2 infection and virus replication in the lungs as early as day 2 following intranasal and intratracheal challenge. Single-cell RNA sequencing analysis of lung cells on day 4 after infection revealed that MVA/S vaccination also protected macaques from infection-induced inflammation and B cell abnormalities and lowered induction of interferon-stimulated genes. These results demonstrate that MVA/S vaccination induces neutralizing antibodies and CD8+ T cells in the blood and lungs and is a potential vaccine candidate for SARS-CoV-2.
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•Generated MVA-based COVID-19 vaccine encoding prefusion-stabilized spike (MVA/S)•MVA/S vaccination induces strong nAb response and CD8+ T cell response in macaques•MVA/S vaccine protects macaques from SARS-CoV-2 infection and lung immunopathology•MVA/S vaccine prevents infection-induced inflammation and B cell abnormalities in lungs
Modified vaccinia Ankara (MVA) vector-based vaccines are attractive because of their excellent safety and ability to induce long-lived humoral and cellular immunity in humans. Routhu et al. show that an MVA-based COVID-19 vaccine encoding prefusion-stabilized spike (MVA/S) induces strong neutralizing antibody and CD8+ T cell responses and protects macaques from SARS-CoV2 infection, immunopathology, and infection-induced B cell abnormalities in the lungs.
Lymph nodes (LN) and their resident T follicular helper CD4+ T cells (Tfh) are a critical site for HIV replication and persistence. Therefore, optimizing antiviral activity in lymphoid tissues will ...be needed to reduce or eliminate the HIV reservoir. In this study, we retained effector immune cells in LN of cART-suppressed, SIV-infected rhesus macaques by treatment with the lysophospholipid sphingosine-1 phosphate receptor modulator FTY720 (fingolimod). FTY720 was remarkably effective in reducing circulating CD4+ and CD8+ T cells, including those with cytolytic potential, and in increasing the number of these T cells retained in LN, as determined directly in situ by histocytometry and immunohistochemistry. The FTY720-induced inhibition of T cell egress from LN resulted in a measurable decrease of SIV-DNA content in blood as well as in LN Tfh cells in most treated animals. In conclusion, FTY720 administration has the potential to limit viral persistence, including in the critical Tfh cellular reservoir. These findings provide rationale for strategies designed to retain antiviral T cells in lymphoid tissues to target HIV remission.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
SARS-CoV-2-induced hypercytokinemia and inflammation are critically associated with COVID-19 severity. Baricitinib, a clinically approved JAK1/JAK2 inhibitor, is currently being investigated in ...COVID-19 clinical trials. Here, we investigated the immunologic and virologic efficacy of baricitinib in a rhesus macaque model of SARS-CoV-2 infection. Viral shedding measured from nasal and throat swabs, bronchoalveolar lavages, and tissues was not reduced with baricitinib. Type I interferon (IFN) antiviral responses and SARS-CoV-2-specific T cell responses remained similar between the two groups. Animals treated with baricitinib showed reduced inflammation, decreased lung infiltration of inflammatory cells, reduced NETosis activity, and more limited lung pathology. Importantly, baricitinib-treated animals had a rapid and remarkably potent suppression of lung macrophage production of cytokines and chemokines responsible for inflammation and neutrophil recruitment. These data support a beneficial role for, and elucidate the immunological mechanisms underlying, the use of baricitinib as a frontline treatment for inflammation induced by SARS-CoV-2 infection.
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•SARS-CoV-2-infected RMs mimic signatures of inflammation seen in COVID-19 patients•Baricitinib suppresses production of pro-inflammatory cytokines in lung macrophages•Baricitinib limits recruitment of neutrophils to the lung and NETosis•Baricitinib preserves innate antiviral and SARS-CoV-2-specific T cell responses
Using a rhesus macaque infection model, it is shown that baricitinib treatment started early after infection effectively resolves inflammatory signatures in airway macrophages, with decreased lung pathology and neutrophil infiltration.
Zika virus (ZIKV) infection has a profound impact on the fetal nervous system. The postnatal period is also a time of rapid brain growth, and it is important to understand the potential ...neurobehavioral consequences of ZIKV infection during infancy. Here we show that postnatal ZIKV infection in a rhesus macaque model resulted in long-term behavioral, motor, and cognitive changes, including increased emotional reactivity, decreased social contact, loss of balance, and deficits in visual recognition memory at one year of age. Structural and functional MRI showed that ZIKV-infected infant rhesus macaques had persistent enlargement of lateral ventricles, smaller volumes and altered functional connectivity between brain areas important for socioemotional behavior, cognitive, and motor function (e.g. amygdala, hippocampus, cerebellum). Neuropathological changes corresponded with neuroimaging results and were consistent with the behavioral and memory deficits. Overall, this study demonstrates that postnatal ZIKV infection in this model may have long-lasting neurodevelopmental consequences.
Antiretroviral therapy (ART) is not curative due to the persistence of a reservoir of HIV-infected cells, particularly in tissues such as lymph nodes, with the potential to cause viral rebound after ...treatment cessation. In this study, fingolimod (FTY720), a lysophospholipid sphingosine-1-phosphate receptor modulator is administered to SIV-infected rhesus macaques at initiation of ART to block the egress from lymphoid tissues of natural killer and T-cells, thereby promoting proximity between cytolytic cells and infected CD4+ T-cells. When compared with the ART-only controls, FTY720 treatment during the initial weeks of ART induces a profound lymphopenia and increases frequencies of CD8+ T-cells expressing perforin in lymph nodes, but not their killing capacity; FTY720 also increases frequencies of cytolytic NK cells in lymph nodes. This increase of cytolytic cells, however, does not limit measures of viral persistence during ART, including intact proviral genomes. After ART interruption, a subset of animals that initially receives FTY720 displays a modest delay in viral rebound, with reduced plasma viremia and frequencies of infected T follicular helper cells. Further research is needed to optimize the potential utility of FTY720 when coupled with strategies that boost the antiviral function of T-cells in lymphoid tissues.
Nonhuman primates used in biomedical research may experience clinically significant weight loss for a variety of reasons. Episodes of anorexia (complete loss of appetite) or hyporexia (decreased ...appetite) can result in significant weight loss, potentially altering animal welfare and scientific studies. The FDA has approved several appetite stimulants for use in domestic species, but currently none are approved for use in NHP. Treatment of inappetence and weight loss in NHP often relies on the extralabel use of these compounds. Capromorelin is a ghrelin receptor agonist. As a growth hormone secretagogue, capromorelin increases appetite, leading to weight gain. Studies in several species have shown a positive correlation between capromorelin administration and weight gain; in 2017, an oral solution of capromorelin received FDA approval for use in dogs. We tested this solution in healthy adult rhesus macaques ( n = 3 males and 3 females) for its effects on body weight and insulin like growth factor-1 (IGF-1). A control group ( n = 2 males and 2 females) was used for comparison. Treated macaques received a 3 mg/kg oral dose daily for 7 d. Clinical signs were observed daily. Weights were collected before, during and at the end of treatment. Blood was drawn before, during and after treatment for measurement of IGF-1 levels and standard hematology and biochemistry parameters. Baseline-adjusted mean body weights and IGF-1 levels were significantly higher in treated as compared with control monkeys after 7 d of beginning treatment (body weight of 10.5 ± 0.1 kg (mean ± SEM) and 10.1 ± 0.1 kg, respectively; IGF-1 of 758 ± 43 ng/mL and 639 ± 22 ng/mL, respectively). Capromorelin administration was not associated with appreciable changes in hematologic and biochemical values in treated macaques. These findings suggest that capromorelin may be useful for treating inappetence and weight loss in NHP, and based on blood analysis, a 7-d course of treatment does not appear to cause acute toxicity.
SARS-CoV-2 vaccines should induce broadly cross-reactive humoral and T cell responses to protect against emerging variants of concern (VOCs). Here, we inactivated the furin cleavage site (FCS) of ...spike expressed by a modified vaccinia Ankara (MVA) virus vaccine (MVA/SdFCS) and found that FCS inactivation markedly increased spike binding to human ACE2. After vaccination of mice, the MVA/SdFCS vaccine induced eightfold higher neutralizing antibodies compared with MVA/S, which expressed spike without FCS inactivation, and protected against the Beta variant. We next added nucleocapsid to the MVA/SdFCS vaccine (MVA/SdFCS-N) and tested its immunogenicity and efficacy via intramuscular (IM), buccal (BU), or sublingual (SL) routes in rhesus macaques. IM vaccination induced spike-specific IgG in serum and mucosae (nose, throat, lung, and rectum) that neutralized the homologous (WA-1/2020) and heterologous VOCs, including Delta, with minimal loss (<2-fold) of activity. IM vaccination also induced both spike- and nucleocapsid-specific CD4 and CD8 T cell responses in the blood. In contrast, the SL and BU vaccinations induced less spike-specific IgG in secretions and lower levels of polyfunctional IgG in serum compared with IM vaccination. After challenge with the SARS-CoV-2 Delta variant, the IM route induced robust protection, the BU route induced moderate protection, and the SL route induced no protection. Vaccine-induced neutralizing and non-neutralizing antibody effector functions positively correlated with protection, but only the effector functions correlated with early protection. Thus, IM vaccination with MVA/SdFCS-N vaccine elicited cross-reactive antibody and T cell responses, protecting against heterologous SARS-CoV-2 VOC more effectively than other routes of vaccination.
Pathologists are an integral part of One Health as they are a critical component of the multidisciplinary team that diagnoses zoonotic diseases and discovers emerging pathogens. Both human and ...veterinary pathologists are uniquely positioned to identify clusters or trends in patient populations that can be caused by an infectious agent and preface emerging outbreaks. The repository of tissue samples available to pathologists is an invaluable resource that can be used to investigate a variety of pathogens. One Health is an encompassing approach that focuses on optimizing the health of humans, animals (domesticated and sylvatic), and the ecosystem, including plants, water, and vectors. In this integrated and balanced approach, multiple disciplines and sectors from local and global communities work together to promote overall well-being of the 3 components and address threats such as emerging infectious diseases and zoonoses. Zoonoses are defined as infectious diseases that are spread between animals and humans through different mechanisms, including direct contact, food, water, vectors, or fomites. This review highlights examples in which human and veterinary pathologists were an integral part of the multisectoral team that identified uncommon etiologic agents or pathologies that had not been elucidated clinically. As the team discovers an emerging infectious disease, pathologists develop and validate tests for epidemiologic and clinical use and provide surveillance data on these diseases. They define the pathogenesis and pathology that these new diseases cause. This review also presents examples that demonstrate the crucial role pathologists play in diagnosing zoonoses that have an impact on the food supply and the economy.
Ongoing SARS-CoV-2 vaccine development is focused on identifying stable, cost-effective, and accessible candidates for global use, specifically in low and middle-income countries. Here, we report the ...efficacy of a rapidly scalable, novel yeast expressed SARS-CoV-2 specific receptor-binding domain (RBD) based vaccine in rhesus macaques. We formulated the RBD immunogen in alum, a licensed and an emerging alum adsorbed TLR-7/8 targeted, 3M-052-alum adjuvants. The RBD+3M-052-alum adjuvanted vaccine promoted better RBD binding and effector antibodies, higher CoV-2 neutralizing antibodies, improved Th1 biased CD4+T cell reactions, and increased CD8+ T cell responses when compared to the alum-alone adjuvanted vaccine. RBD+3M-052-alum induced a significant reduction of SARS-CoV-2 virus in respiratory tract upon challenge, accompanied by reduced lung inflammation when compared with unvaccinated controls. Anti-RBD antibody responses in vaccinated animals inversely correlated with viral load in nasal secretions and BAL. RBD+3M-052-alum blocked a post SARS-CoV-2 challenge increase in CD14+CD16++ intermediate blood monocytes, and Fractalkine, MCP-1, and TRAIL in the plasma. Decreased plasma analytes and intermediate monocyte frequencies correlated with reduced nasal and BAL viral loads. Lastly, RBD-specific plasma cells accumulated in the draining lymph nodes and not in the bone marrow, contrary to previous findings. Together, these data show that a yeast expressed, RBD-based vaccine+3M-052-alum provides robust immune responses and protection against SARS-CoV-2, making it a strong and scalable vaccine candidate.
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