Search

Abstract An influenza vaccine approach that overcomes the problem of viral sequence diversity and provides long-lived heterosubtypic protection is urgently needed to protect against pandemic influenza viruses. Here, to determine if lung-resident effector memory T cells induced by cytomegalovirus (CMV)-vectored vaccines expressing conserved internal influenza antigens could protect against lethal influenza challenge, we immunize Mauritian cynomolgus macaques (MCM) with cynomolgus CMV (CyCMV) vaccines expressing H1N1 1918 influenza M1, NP, and PB1 antigens (CyCMV/Flu), and challenge with heterologous, aerosolized avian H5N1 influenza. All six unvaccinated MCM died by seven days post infection with acute respiratory distress, while 54.5% (6/11) CyCMV/Flu-vaccinated MCM survived. Survival correlates with the magnitude of lung-resident influenza-specific CD4 + T cells prior to challenge. These data demonstrate that CD4 + T cells targeting conserved internal influenza proteins can protect against highly pathogenic heterologous influenza challenge and support further exploration of effector memory T cell-based vaccines for universal influenza vaccine development.

ABSTRACT Rhesus cytomegalovirus expressing simian immunodeficiency virus (RhCMV/SIV) vaccines protect ~59% of vaccinated rhesus macaques against repeated limiting-dose intra-rectal exposure with highly pathogenic SIVmac239M, but the exact mechanism responsible for the vaccine efficacy is unknown. It is becoming evident that complex interactions exist between gut microbiota and the host immune system. Here, we aimed to investigate if the rhesus gut microbiome impacts RhCMV/SIV vaccine-induced protection. Three groups of 15 rhesus macaques naturally pre-exposed to RhCMV were vaccinated with RhCMV/SIV vaccines. Rectal swabs were collected longitudinally both before SIV challenge (after vaccination) and post-challenge and were profiled using 16S rRNA based microbiome analysis. We identified ~2,400 16S rRNA amplicon sequence variants (ASVs), representing potential bacterial species/strains. Global gut microbial profiles were strongly associated with each of the three vaccination groups, and all animals tended to maintain consistent profiles throughout the pre-challenge phase. Despite vaccination group differences, by using newly developed compositional data analysis techniques, we identified a common gut microbial signature predictive of vaccine protection outcome across the three vaccination groups. Part of this microbial signature persisted even after SIV challenge. We also observed a strong correlation between this microbial signature and an early signature derived from whole blood transcriptomes in the same animals. Our findings indicate that changes in gut microbiomes are associated with RhCMV/SIV vaccine-induced protection and early host response to vaccination in rhesus macaques.IMPORTANCEThe human immunodeficiency virus (HIV) has infected millions of people worldwide. Unfortunately, still there is no vaccine that can prevent or treat HIV infection. A promising pre-clinical HIV vaccine based on rhesus cytomegalovirus (RhCMV) expressing simian immunodeficiency virus (SIV) antigens (RhCMV/SIV) provides sustained, durable protection against SIV challenge in ~59% of vaccinated rhesus macaques. There is an urgent need to understand the cause of this protection vs non-protection outcome. In this study, we profiled the gut microbiomes of 45 RhCMV/SIV vaccinated rhesus macaques and identified gut microbial signatures that were predictive of RhCMV/SIV vaccination groups and vaccine protection outcomes. These vaccine protection-associated microbial features were significantly correlated with early vaccine-induced host immune signatures in whole blood from the same animals. These findings show that the gut microbiome may be involved in RhCMV/SIV vaccine-induced protection, warranting further research into the impact of the gut microbiome in human vaccine trials.

IntroductionSpontaneous control of chronic-phase HIV/SIV viremia is often associated with the expression of specific MHC class I allotypes. HIV/SIV-specific CD8+ cytotoxic T lymphocytes (CTLs) restricted by these MHC class I allotypes appear to be critical for viremic control. Establishment of the elite controller (EC) phenotype is predictable in SIVmac239-infected Indian rhesus macaques (RMs), with approximately 50% of Mamu-B*08+ RMs and 20% of Mamu-B*17+ RMs becoming ECs. Despite extensive characterization of EC-associated CTLs in HIV/SIV-infected individuals, the precise mechanistic basis of elite control remains unknown. Because EC and non-EC viral load trajectories begin diverging by day 14 post-infection, we hypothesized that hyperacute innate immune responses may contribute to viremic control.MethodsTo gain insight into the immunological factors involved in the determination of EC status, we vaccinated 16 Mamu-B*08+ RMs with Vif and Nef to elicit EC-associated CTLs, then subjected these 16 vaccinees and an additional 16 unvaccinated Mamu-B*08+ controls to repeated intrarectal SIVmac239 challenges. We then performed whole-blood transcriptomic analysis of all 32 SIVmac239-infected Mamu-B*08+ RMs and eight SIVmac239-infected Mamu-B*08– RMs during the first 14 days of infection.ResultsVaccination did not provide protection against acquisition, but peak and setpoint viremia were significantly lower in vaccinees relative to controls. We did not identify any meaningful correlations between vaccine-induced CTL parameters and SIVmac239 acquisition rate or chronic-phase viral loads. Ultimately, 13 of 16 vaccinees (81%) and 7 of 16 controls (44%) became ECs (viremia ≤ 10,000 vRNA copies/mL plasma for ≥ 4 weeks). We identified subsets of immunomodulatory genes differentially expressed (DE) between RM groupings based on vaccination status, EC status, and MHC class I genotype. These DE genes function in multiple innate immune processes, including the complement system, cytokine/chemokine signaling, pattern recognition receptors, and interferon-mediated responses.DiscussionA striking difference in the kinetics of differential gene expression among our RM groups suggests that Mamu-B*08-associated elite control is characterized by a robust, rapid innate immune response that quickly resolves. These findings indicate that, despite the association between MHC class I genotype and elite control, innate immune factors in hyperacute SIV infection preceding CTL response development may facilitate the establishment of the EC phenotype.

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb) is a deadly infectious disease having a major impact on global health. Using the CMV vector for development of novel vaccines is a promising new strategy that elicits strong and durable, high frequency memory T cell responses against heterologous immunogens. We conducted functional transcriptomic analysis of whole blood samples collected from cohorts of rhesus (Rh) macaques that were administered RhCMV/TB vector using a prime-boost strategy. Two modified CMV vectors were used in this study, including 68-1 RhCMV/TB-6Ag (encoding 6 Mtb protein immunogens, including Ag85A, ESAT-6, Rv3407, Rv2626, Rpf A, and Rpf D) and its attenuated variant, 68-1 RhCMV/Δpp71-TB-6Ag (a cell-to-cell spread-deficient vaccine vector lacking the Rh110 gene encoding the pp71 tegument protein). Bulk mRNA sequencing, differential gene expression, and functional enrichment analyses showed that these RhCMV/TB vaccines induce the innate and adaptive immune responses with specific transcriptomic signatures, including the IL-15-induced protective gene signature previously defined to be linked with protection against simian immunodeficiency virus (SIV) by the 68-1 RhCMV/SIV vaccine. While both vectors exhibited a transcriptomic response of the IL-15 protective signature in whole blood, we show that lack of pp71 does not maintain induction of the protective signature for the full duration of the study compared to the parental non-attenuated vector. Our observations indicate that RhCMV vector vaccines induce a transcriptomic response in whole blood that include a conserved IL-15 signature of which vector-encoded pp71 is an important component of response durability that upon future Mtb challenge may define specific vaccine protection outcomes against Mtb infection.

Abstract Zika virus (ZikV) infection during pregnancy can cause congenital Zika syndrome (CZS) and neurodevelopmental delay in infants, of which the pathogenesis remains poorly understood. We utilize an established female pigtail macaque maternal-to-fetal ZikV infection/exposure model to study fetal brain pathophysiology of CZS manifesting from ZikV exposure in utero. We find prenatal ZikV exposure leads to profound disruption of fetal myelin, with extensive downregulation in gene expression for key components of oligodendrocyte maturation and myelin production. Immunohistochemical analyses reveal marked decreases in myelin basic protein intensity and myelinated fiber density in ZikV-exposed animals. At the ultrastructural level, the myelin sheath in ZikV-exposed animals shows multi-focal decompaction, occurring concomitant with dysregulation of oligodendrocyte gene expression and maturation. These findings define fetal neuropathological profiles of ZikV-linked brain injury underlying CZS resulting from ZikV exposure in utero. Because myelin is critical for cortical development, ZikV-related perturbations in oligodendrocyte function may have long-term consequences on childhood neurodevelopment, even in the absence of overt microcephaly.

Lymphoedema is a swelling in part of the body due to an obstructed flow of lymphatic fluid. Extant literature mainly targets coping strategies in females having breast cancer related lymphoedema. This research aims to explore the coping strategies of males living with lymphoedema, secondary to cancer treatment. Semi-structured, in-depth interviews were conducted with 13 males aged between 50 to 85 years. Five themes emerged namely: adjusting attire, changing lifestyle activity, distracting the mind, leaning onto available support and immersing in spirituality. Males described wearing loose, easy-to-wear clothing over swollen body parts. Changes in lifestyle included pacing of activities, avoiding/modifying activities to avoid injury and incorporating treatment in their daily routine. Distraction was enabled though immersion in work, engaging in hobbies and humorous banter. Participants also coped by expressing gratitude, living in the present moment, accepting situations over which they lacked control, connecting with nature, and turning to their religious beliefs. There is a need for health professionals to explore the illness narratives and coping strategies of males living with lymphoedema as this impacts their overall well-being. Interventions targeting coping strategies for males with lymphoedema should address the physical, emotional, psychological and spiritual domains of well-being.

Various electrical drive systems have widely implemented the classical cascaded field-oriented control (FOC) topology, including speed loop, current loop, and modulation. On the other hand, modulated model predictive control (M2PC) has been employed recently for different applications for faster dynamic response and better power quality. The FOC topology's speed and current control loops can be merged to simplify the control system structure and improve the system dynamics. Therefore, a noncascaded speed loop controller employing M2PC for permanent magnet synchronous motors is introduced. The required simulation work has been developed to analyze the algorithm performance compared to proportional integral (PI), noncascaded model predictive control, and M2PC controllers. In addition, it has been applied practically through a dedicated testing rig, and results are investigated showing its merits including harmonic content, dynamic behavior, and robustness against parameter mismatch.

Lymphoedema arises when the lymphatic system has been damaged and may occur secondary to cancer treatment. While much of the extant literature focuses on quality of life in females with breast cancer- related lymphoedema, this study explores the impact of living with lymphoedema secondary to cancer treatment in males. Semi-structured interviews were conducted with 13 male participants, aged between 50 to 85 years. Data collected were analysed using interpretative phenomenological analysis. The super-ordinate theme 'Hit by a wave' encompasses the profound impact of lymphoedema on the participants' quality of life. The males expressed body image concerns and struggled with feelings of frustration, anger, anxiety and depression. Physical changes such as weight increase, disrupted sleep, pain, swollen genitals and urinary difficulties were experienced. Changes in lifestyle were also expressed, such as an increased dependence on carers; work-related and role changes. Nevertheless, many participants endorsed the need to focus on the present moment and expressed a heightened appreciation of authenticity in life. By understanding the unique narratives of males with lymphoedema, health care practitioners together with patients can formulate care plans that truly resonate with the needs, concerns, and experiences of males living with lymphoedema.

The low-voltage electric machine (EM) is a core technology for transportation electrification, and features like high power density and compact volume are essential prerequisites. However, these requirements are usually in conflict with the reliability property of EM, especially in the safety-critical industry such as aviation. Therefore, an appropriate balance between high-performance and reliability needs to be found. Often, the over-engineering method is applied to ensure safety, although it might have a detrimental effect on the EM volume. To address this issue, the EM reliability assessment is included at the EM design stage through the physics of failure (PoF) theory. In EMs, the windings play a key role in electromechanical energy conversion, but their insulation system is subject to frequent failure and represents a reliability bottleneck. Therefore, in-depth research on the root causes of insulation breakdown is beneficial for EM reliability improvement purposes. Indeed, increasing awareness and knowledge on the mechanism of the insulation degradation process and the related lifetime modeling enables the growth of appropriate tools for achieving reliability targets since the first EM design steps. In this work, the main aspects of the insulation system, in terms of materials and manufacturing, are first reviewed. Then, the principal stresses experienced by the winding insulation system are deeply discussed with the purpose of building a profound understanding of the PoF. Finally, an overview of the most common insulation lifetime prediction models is presented, and their use for accomplishing the reliability-oriented design (RoD) and the remaining useful life (RUL) estimation are examined.