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It is of international priority to develop a vaccine against sexually transmitted Chlamydia trachomatis infections to combat the continued global spread of the infection. The optimal immunization strategy still remains to be fully elucidated. The aim of this study was to evaluate immunization strategies in a nonhuman primate (NHP) model. Cynomolgus macaques (Macaqua fascicularis) were immunized following different multi-component prime-boost immunization-schedules and subsequently challenged with C. trachomatis SvD in the lower genital tract. The immunization antigens included the recombinant protein antigen CTH522 adjuvanted with CAF01 or aluminium hydroxide, MOMP DNA antigen and MOMP vector antigens (HuAd5 MOMP and MVA MOMP). All antigen constructs were highly immunogenic raising significant systemic C. trachomatis-specific IgG responses. In particularly the CTH522 protein vaccinated groups raised a fast and strong pecificsIgG in serum. The mapping of specific B cell epitopes within the MOMP showed that all vaccinated groups, recognized epitopes near or within the variable domains (VD) of MOMP, with a consistent VD4 response in all animals. Furthermore, serum from all vaccinated groups were able to in vitro neutralize both SvD, SvE and SvF. Antibody responses were reflected on the vaginal and ocular mucosa, which showed detectable levels of IgG. Vaccines also induced C. trachomatis-specific cell mediated responses, as shown by in vitro stimulation and intracellular cytokine staining of peripheral blood mononuclear cells (PBMCs). In general, the protein (CTH522) vaccinated groups established a multifunctional CD4 T cell response, whereas the DNA and Vector vaccinated groups also established a CD8 T cells response. Following vaginal challenge with C. trachomatis SvD, several of the vaccinated groups showed accelerated clearance of the infection, but especially the DNA group, boosted with CAF01 adjuvanted CTH522 to achieve a balanced CD4/CD8 T cell response combined with an IgG response, showed accelerated clearance of the infection.

The residual life of transmission line overhead conductors under conditions of fretting fatigue is an important asset management issue for electric network operators. The current industry practice for overhead conductor residual life estimation relies heavily on experimentally generated fatigue curves or rule-based expert systems. The current experiment-based methods do not consider specific conductor-clamp configurations and are based on the simple flexion model. This approach results in large uncertainties in service life predictions and are limited to a failure criterion based on the first wire failure in the conductor. Rule-based expert systems also have limited applicability since they lack physical representation of the fretting fatigue process. Given the limitations of the current methods, the objective of this work is to propose a framework that combines physics-based models and probability theory to estimate the residual life of overhead conductors considering either single or multiple wire failure criteria. To illustrate this procedure, a finite element model of a Bersfort conductor-clamp system is used to assess the contact conditions and internal stress states in the wires of the conductor. Results from the numerical model are then used to develop a fretting fatigue criterion that is a function of the contact energy dissipation mechanisms, contact stresses, and the plain fatigue resistance of the wires. Probability of failure of each contact point between wires and between wires and clamp is computed using the fretting fatigue criterion. With this information, the most probable locations of fretting fatigue failure are identified in the conductor. The predictions for the locations of failure are validated with available literature data for the same conductor-clamp configuration. Given the probabilities of failures at each contact point, the probability of failure of the conductor is derived with the Poisson binomial distribution. Fragility curves are presented for the first through the third wire failures in the conductor. The fragility curves are validated through comparisons with available literature data on the same conductor-clamp configuration. Fatigue curves are also generated from the fragility model for the first wire failure and compared against experimentally generated fatigue curves.

Abstract Development of new vaccines tailored for difficult-to-target diseases is hampered by a lack of diverse adjuvants for human use, and none of the currently available adjuvants induce Th17 cells. Here, we develop a liposomal adjuvant, CAF®10b, that incorporates Mincle and Toll-like receptor 9 agonists. In parallel mouse and non-human primate studies comparing to CAF® adjuvants already in clinical trials, we report species-specific effects of adjuvant composition on the quality and magnitude of the responses. When combined with antigen, CAF®10b induces Th1 and Th17 responses and protection against a pulmonary infection with Mycobacterium tuberculosis in mice. In non-human primates, CAF®10b induces higher Th1 responses and robust Th17 responses detectable after six months, and systemic and pulmonary Th1 and Th17 recall responses, in a sterile model of local recall. Overall, CAF®10b drives robust memory antibody, Th1 and Th17 vaccine-responses via a non-mucosal immunization route across both rodent and primate species.

Abstract Background The fight against COVID-19 requires mass vaccination strategies, and vaccines inducing durable cross-protective responses are still needed. Inactivated vaccines have proven lasting efficacy against many pathogens and good safety records. They contain multiple protein antigens that may improve response breadth and can be easily adapted every year to maintain preparedness for future seasonally emerging variants. Methods The vaccine dose was determined using ELISA and pseudoviral particle-based neutralization assay in the mice. The immunogenicity was assessed in the non-human primates with multiplex ELISA, neutralization assays, ELISpot and intracellular staining. The efficacy was demonstrated by viral quantification in fluids using RT-qPCR and respiratory tissue lesions evaluation. Results Here we report the immunogenicity and efficacy of VLA2001 in animal models. VLA2001 formulated with alum and the TLR9 agonist CpG 1018™ adjuvant generate a Th1-biased immune response and serum neutralizing antibodies in female BALB/c mice. In male cynomolgus macaques, two injections of VLA2001 are sufficient to induce specific and polyfunctional CD4+ T cell responses, predominantly Th1-biased, and high levels of antibodies neutralizing SARS-CoV-2 infection in cell culture. These antibodies also inhibit the binding of the Spike protein to human ACE2 receptor of several variants of concern most resistant to neutralization. After exposure to a high dose of homologous SARS-CoV-2, vaccinated groups exhibit significant levels of protection from viral replication in the upper and lower respiratory tracts and from lung tissue inflammation. Conclusions We demonstrate that the VLA2001 adjuvanted vaccine is immunogenic both in mouse and NHP models and prevent cynomolgus macaques from the viruses responsible of COVID-19.

BackgroundTrachoma is a leading cause of infection-related blindness worldwide. This disease is caused by recurrent Chlamydia trachomatis (Ct) infections of the conjunctiva and develops in two phases: i) active (acute trachoma, characterized by follicular conjunctivitis), then long-term: ii) scarring (chronic trachoma, characterized by conjunctival fibrosis, corneal opacification and eyelid malposition). Scarring trachoma is driven by the number and severity of reinfections. The immune system plays a pivotal role in trachoma including exacerbation of the disease. Hence the immune system may also be key to developing a trachoma vaccine. Therefore, we characterized clinical and local immune response kinetics in a non-human primate model of acute conjunctival Ct infection and disease.Methodology/principal findingsThe conjunctiva of non-human primate (NHP, Cynomolgus monkeys-Macaca fascicularis-) were inoculated with Ct (B/Tunis-864 strain, B serovar). Clinical ocular monitoring was performed using a standardized photographic grading system, and local immune responses were assessed using multi-parameter flow cytometry of conjunctival cells, tear fluid cytokines, immunoglobulins, and Ct quantification. Clinical findings were similar to those observed during acute trachoma in humans, with the development of typical follicular conjunctivitis from the 4th week post-exposure to the 11th week. Immunologic analysis indicated an early phase influx of T cells in the conjunctiva and elevated interleukins 4, 8, and 5, followed by a late phase monocytic influx accompanied with a decrease in other immune cells, and tear fluid cytokines returning to initial levels.Conclusion/significanceOur NHP model accurately reproduces the clinical signs of acute trachoma, allowing for an accurate assessment of the local immune responses in infected eyes. A progressive immune response occurred for weeks after exposure to Ct, which subsided into a persistent innate immune response. An understanding of these local responses is the first step towards using the model to assess new vaccine and therapeutic strategies for disease prevention.

High-voltage electrical cables are prone to saline corrosion, mostly in coastal environments. Steel wires are a crucial element in withstanding the mechanical solicitations of commonly used aluminum conductor steel reinforced (ACSR) cables. An experimental accelerated corrosion test was made, using salt spray tests on greased and ungreased ACSR cables and individual galvanized steel wires. The corrosion mechanism occurring on the specimens was observed by optical microscopy for several durations of corrosion, to determine the evolution of the galvanic layer and steel substrate degradation. This study was completed by an SEM (Scanning Electron Microscopy) and Raman spectroscopy analysis to characterize the corrosion products occurring on the galvanized steel wires. An estimation of the evolution of the mean zinc thickness loss is also given, for each type of specimen. It is shown that the loss rate of the zinc layer is significantly reduced by the presence of aluminum layers around the steel wires and by the effect of the grease. Tensile tests were made on the exposed galvanized steel wires which led to fracture surface observations to assess the effect of corrosion on the evolution of mechanical properties.

Summary: Isolation of viable immune cells from tissues is critically important to characterize cellular and molecular processes during homeostasis and disease. Here, we provide an optimized protocol to achieve high yields of viable intestinal lamina propria mononuclear cells (LPMCs). We describe steps for intestinal tissue collection from humans and nonhuman primates, followed by mechanical disruption and enzymatic digestion. Furthermore, we detail characterization of the mononuclear phagocyte (MP) subtypes by flow cytometry analysis. The protocol is repeatable and scalable for downstream applications.For complete details on the use and execution of this protocol, please refer to Cavarelli et al. (2022). : Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.

The use of aluminum in civil engineering applications has increased significantly over the past decades. Aluminum is a durable, lightweight, and recyclable material that can provide alternative structural solutions for building power transmission towers. In order to achieve this objective, it is necessary to develop structural members that take advantage of specific properties of the material, such as low density, high strength, resistance to corrosion, and the geometric flexibility that aluminum extrusions provide to design robust and easy-to-assemble structures. This paper presents a section optimization study of an existing medium-voltage steel 120–160 kV lattice tower owned by Hydro-Québec, considering the use of various extruded aluminum sections. The proposed optimized aluminum sections are compared with the steel sections of the existing tower. The study’s main objective is to optimize the tower’s aluminum sections. A SAP2000 structural finite element stick model of the tower coupled to a Matlab optimization routine is used to optimize the aluminum sections. ASCE10-15 and CSA-S157-17R22 standards are used to impose the design constraints for selecting the optimized aluminum square and octagonal hollow sections, with and without stiffeners. This study proposes optimized section shapes suitable for constructing aluminum lattice transmission towers. The study reveals that the proposed aluminum tower prototype is twice as light as its steel counterpart. The aluminum members’ price is also very competitive compared to steel.

Background: The resurgence of whooping cough in many countries highlights the crucial need for a better understanding of the pathogenesis of respiratory infection by Bordetella pertussis. Exposure of baboons to B. pertussis by the intranasal and intra-tracheal routes is a recently described preclinical model that reproduces both B. pertussis infection of humans and whooping cough disease. Here, we tested both intranasal and intranasal+intra-tracheal exposure routes and assessed their impact on disease development and immunity. Methods: Young baboons were intranasally exposed to the B1917 clinical isolate, representative of circulating strains in Europe, or its green-fluorescent protein expressing derivative. Animals were followed for pertussis symptoms and bacterial colonization and by in vivo probe-based confocal laser endomicroscopy (pCLE) imaging. Sero-conversion and protection against subsequent infection were then evaluated. Results: Seroconversion and bacterial colonization of both the nasopharynx and trachea was observed in baboons exposed to B. pertussis by the intranasal route only, and also in those animals challenged by both the intranasal and intra-tracheal routes together. However, baboons exposed solely by the intranasal route developed only mild clinical symptoms, with no paroxysmal cough. These animals were protected against re-infection by B. pertussis. Conclusions: Intranasal exposure of baboons to B. pertussis does not induce disease but elicits immune mechanisms that protect them from subsequent exposure to the bacteria. These findings suggest that the intranasal route of inoculation in this non-human primate model could be used in the pre-clinical evaluation of nasal candidate vaccines against pertussis.

Vaccination is one of the most efficient public healthcare measures to fight infectious diseases. Nevertheless, the immune mechanisms induced in vivo by vaccination are still unclear. The route of administration, an important vaccination parameter, can substantially modify the quality of the response. How the route of administration affects the generation and profile of immune responses is of major interest. Here, we aimed to extensively characterize the profiles of the innate and adaptive response to vaccination induced after intradermal, subcutaneous, or intramuscular administration with a modified vaccinia virus Ankara model vaccine in non-human primates. The adaptive response following subcutaneous immunization was clearly different from that following intradermal or intramuscular immunization. The subcutaneous route induced a higher level of neutralizing antibodies than the intradermal and intramuscular vaccination routes. In contrast, polyfunctional CD8+ T-cell responses were preferentially induced after intradermal or intramuscular injection. We observed the same dichotomy when analyzing the early molecular and cellular immune events, highlighting the recruitment of cell populations, such as CD8+ T lymphocytes and myeloid-derived suppressive cells, and the activation of key immunomodulatory gene pathways. These results demonstrate that the quality of the vaccine response induced by an attenuated vaccine is shaped by early and subtle modifications of the innate immune response. In this immunization context, the route of administration must be tailored to the desired type of protective immune response. This will be achieved through systems vaccinology and mathematical modeling, which will be critical for predicting the efficacy of the vaccination route for personalized medicine.