Search Results (210)

Background/Objectives: Chimpanzee adenoviral-vectored vaccines have proven to be both safe and effective, with a manufacturing and distribution pipeline capable of rapid global supply, as demonstrated during the COVID-19 pandemic. Yellow fever is a mosquito-borne viral hemorrhagic disease endemic in parts of Africa and Latin America, and although an effective live attenuated vaccine exists, its use is limited by safety and eligibility restrictions. Moreover, large outbreaks continue to expose critical challenges, such as an insufficient vaccine supply, reliance on fractional dosing, and slow and difficult-to-scale manufacturing processes. Here, we report the design, development and in vivo immunogenicity of multiple yellow fever virus (YFV) antigen constructs based on the pre-membrane (prM) and envelope (E) proteins—with or without the transmembrane domain (TM or ΔTM)—delivered using the ChAdOx1 adenoviral vector. Methods: Four ChAdOx1 YF vaccines were developed, and immunogenicity was evaluated. The efficacy of the full-length YF envelope vaccine was also tested in Balb/c mice. Results/Conclusions: In contrast to previously described orthoflavivirus vaccines on the same platform, the full-length antigen elicited superior immunogenicity and conferred protection against intracranial challenge with the YF17D virus in mice. Notably, this protection was comparable to that induced by the licensed YF17D vaccine, highlighting the promise of this platform as a next-generation yellow fever vaccine candidate. Full article

It is widely accepted that modern humans display distinctive vertebral and intervertebral disc (IVD) morphologies that evolved to meet the biomechanical demands of habitual terrestrial bipedalism. This study synthesizes macro- and microstructural differences in the lumbar spine to clarify how human specializations compare with those of extant apes. The skeletal sample consisted of 240 humans, 20 chimpanzees, and 25 gorillas. The CT scan sample comprised 180 humans and eight chimpanzees. Histological analysis of the IVD was performed on 10 humans and four ape specimens. Vertebral bodies and discs were measured. Histological analyses employed hematoxylin–eosin, Von Kossa, and Van Gieson staining. Statistical analyses included ANOVA with Bonferroni-corrected t-tests or Welch’s ANOVA and Games–Howell post hoc tests. Regression analyses were performed using ordinary least-squares estimation, and differences between regression lines were assessed using ANCOVA. Humans and chimpanzees differed significantly in vertebral body proportions, bone volume fraction, IVD thickness, apophyseal ring thickness, annulus fibrosus lamellar organization, endplate and subchondral bone thickness, and vascularization at the bone–endplate interface. These results indicate substantial evolutionary modification of the human vertebral body and IVD, enhancing rotational mobility and resistance to axial loading, key functional requirements for maintaining upright posture and efficient bipedal locomotion. Full article

Despite increasing reports of zoonotic simian foamy virus (SFV) infections globally, knowledge of its genetic adaptation in humans and impact on viral transmission and pathogenicity remains limited. We obtained complete SFV genomes using metagenomics analysis of viral isolates from peripheral blood lymphocytes (PBLs) and throat specimens from a worker (Case 6) and source chimpanzee (B1) that bit him. We analyzed viral diversity in three genomic regions (LTR, tas, and bet) involved in replication and latency using longitudinal specimens (PBLs, throat, saliva, urine, and semen) from Case 6 over five years, and PBLs from B1 and five additional chimpanzees over three years. Proviral loads were measured using a validated qPCR assay. Phylogenetic analysis revealed nearly identical SFV genomes in Case 6 and B1. Overall, bet sequences exhibited high genetic stability across body compartments and over time, with evidence of compartmentalization in Case 6 urine and semen specimens. G→A substitutions in GG and GA motifs in bet indicated heterogeneous APOBEC-associated editing across hosts and anatomical compartments following zoonotic transmission. Case 6 had significant deletions in the LTR region that were absent in B1 and other chimpanzees. Length variation in tas, including truncated forms, was observed across longitudinal specimens from Case 6, B1, and other chimpanzees. Proviral loads were consistently low and undetectable in most Case 6 urine specimens. Together, analysis of this SFV transmission pair identifies genomic changes likely to affect viral replication and persistence, highlighting mechanisms that may limit secondary transmission and pathogenicity of SFV in humans. Full article

Background/Objectives: Segmental duplications (SDs) are major drivers of genome evolution and structural variation in primates, particularly within acrocentric chromosomes, where rDNA arrays and duplicated sequences are densely clustered. However, the evolutionary dynamics of rDNA-linked SDs across great ape lineages have remained poorly characterized due to longstanding technical limitations in genome assembly. Here, we investigate the organization, copy number variation, and evolutionary conservation of acrocentric SDs in great apes by integrating fluorescence in situ hybridization (FISH) with comparative analyses of telomere-to-telomere (T2T) genome assemblies. Methods: Using eight human-derived fosmid probes targeting SD-enriched regions flanking rDNA arrays, we analyzed multiple individuals from chimpanzee, bonobo, gorilla, and both Bornean and Sumatran orangutans. Results: Our FISH analyses revealed extensive lineage-specific variation in SD copy number and chromosomal distribution, with pronounced heteromorphism in African great apes, particularly gorillas, and more conserved patterns in orangutans. Several SDs showed fixed duplications across species, while others exhibited high levels of polymorphism and individual-specific organization. Conclusions: Comparison with T2T assemblies confirmed consistent genomic localization for a subset of probes, whereas others displayed partial discordance, highlighting the persistent challenges in resolving highly repetitive and structurally dynamic regions even with state-of-the-art assemblies. Genome-wide analyses further revealed species-specific enrichment of SDs on rDNA-bearing chromosomes, with chimpanzees and bonobos showing higher proportions than gorillas, and contrasting patterns between the two orangutan species. Overall, our results demonstrate that rDNA-linked SDs represent highly dynamic genomic compartments that have undergone differential expansion and remodeling during great ape evolution. These regions contribute substantially to inter- and intra-species structural variation and provide a mechanistic substrate for lineage-specific genome evolution, underscoring the importance of integrating cytogenetic and T2T-based approaches to fully capture the complexity of duplicated genomic landscapes. Full article

The behavior of individual animals reflects both internal states and external context. For captive animals, their early life experiences can influence later adjustment, particularly their social competence. In addition, the way in which they are housed and their current social grouping context are important factors affecting the expression of social skills. Here, the social behavior of 39 chimpanzees (Pan troglodytes) was observed to assess whether differences existed due to how the apes were reared and grouped. Behaviors recorded related specifically to five main components: Sociability, Grooming, Play, Responsibility and Aggression. Chimpanzees in larger groups groomed and played more, while those housed in pairs or trios displayed more and spent more time alone. Mother-reared chimpanzees took more responsibility for soliciting grooming, and interactions between grouping and rearing on chimpanzee agonistic display rates highlighted how both hand- and mother-reared chimpanzees display more if housed in small groups rather than large. Implications for the optimal management and welfare of this highly intelligent and social species are discussed in light of the importance of early life experiences in modulating the impact of current social environment on chimpanzee social profiles. Full article

Objectives: Adenoviruses (Ads) are among the most used vectors for gene therapy; human Ad serotype 5-derived (HuAd5) vectors are the most frequently used for gene transfer applications. However, Ad5 infection is endemic in humans, and 20% of the Western population has neutralizing antibodies (nAbs). Pre-existing immunity against HuAd5 represents a major issue for many gene therapy applications. In our study, we evaluated several Ad serotypes derived from chimpanzees (ChAds) in vitro and in vivo to assess their transduction efficiency in various cell types and tissues. We aimed at identifying Ad serotypes able either to transduce “challenging” cell types or to represent a possible alternative to Ad5-derived vectors with comparable infectivity and tropism. Methods: We evaluated the efficacy of transduction of twelve ChAds vectors expressing enhanced green fluorescent protein (EGFP) in human embryonic kidney cells, as well as human leukemic and human mesenchymal stem cells, using flow cytometry to determine the percentage of EGFP-expressing cells and their mean fluorescent intensity (MFI). We observed the highest transduction efficiency in the serotype CV1 ChAd; therefore, we proceeded to evaluate toxicity and biodistribution in vivo. Results: After in vitro evaluation of twelve ChAds serotypes, we observed that the CV1 serotype was the most efficient in transducing both leukemia cell lines (HL-60 and NB-4) and human mesenchymal stem cells. Furthermore, in vivo analysis of the CV1 serotype induced an inflammatory reaction similar to what was observed after HuAd5 administration. Conclusions: ChAds vectors represent an effective alternative for the transduction of cells resistant to HuAd5 infection, such as mesenchymal stem cells and leukemic cells. In addition, we observed that the CV1 ChAd serotype presented a transduction profile similar to HuAd5 in vitro and induced a similar inflammatory response in vivo; therefore, CV1 ChAd-derived vectors represent an interesting alternative for gene therapy applications. Full article

To address the challenges of high computational costs, susceptibility to local optima, and heavy reliance on manual intervention in multi-physics parameter optimization for symmetric acoustic metamaterials, an enhanced Chimp Optimization Algorithm (DADCOA) is proposed in this paper. This algorithm integrates the double chaotic initialization strategy (DCS), adaptive multimodal convergence mechanism (AMC), and dual-weight pinhole imaging update operator (DWPI). It employs a Logistic–Tent composite chaotic mapping strategy for population initialization, significantly enhancing distribution uniformity within high-dimensional parameter spaces. An AMC factor is then introduced to dynamically balance global exploration and local exploitation based on the real-time evolutionary state of the population. A dual-weight population update mechanism, incorporating distance and historical contributions, is integrated with a pinhole imaging opposition-based learning strategy to improve population diversity. Additionally, a composite single objective error feedback local differential mutation operation is introduced to improve optimization accuracy for coupled multi-physics objectives. Experimental validation based on the CEC 2022 test function suite and an acoustic metamaterial parameter optimization model demonstrates that compared to the standard COA algorithm and existing improved algorithms, the DADCOA algorithm reduces simulation time by 28.46% to 60.76% while maintaining high accuracy. This approach effectively addresses the challenges of high computational cost, stringent accuracy requirements, and composite single objective coupling in COMSOL physical parameter optimization, providing an effective solution for the design of acoustic metamaterials based on symmetric structures. Full article

Background: The development of effective tuberculosis (TB) vaccines beyond BCG remains an urgent global health priority, especially for prevention of pulmonary TB in adults. While most current strategies focus on enhancing T-cell immunity, the potential of trained immunity to broadly augment both innate and adaptive responses remains underexplored in TB vaccinology. Given the central role of dendritic cells (DCs) as bridges between innate and adaptive immunity, we hypothesized that inducing trained immunity in DCs could optimize subsequent T-cell responses. Previous studies have identified Rv2299c as a promising adjuvant of other antigens by promoting DC maturation; however, whether it could be used as a standalone protective antigen of TB vaccine remains unclear. Methods: We constructed a chimpanzee adenovirus-vectored TB vaccine candidate expressing Rv2299c (rAd-Rv2299c), and evaluated its immunogenicity and protective efficacy in murine models. Results: rAd-Rv2299c vaccine effectively induced a trained immunity phenotype in DCs, as evidenced by upregulated MHC-II and CD86 expression and increased pro-inflammatory cytokine (TNF-α, IL-6, IL-1β and IL-12p70) secretion. Moreover, its immunization promoted the generation of antigen-specific polyfunctional T cells, and robustly enhanced both Th1 and Th17-type immune responses. In a murine challenge model, vaccination significantly reduced bacterial loads in the lung and spleen and attenuated pulmonary inflammation, which was associated with robust recall T-cell immune responses. Conclusions: rAd-Rv2299c confers anti-TB protection by inducing trained immunity in DCs and promoting polyfunctional T-cell responses, thereby offering valuable experimental evidence and conceptual insights for the development of next-generation TB vaccines. Full article

Persistent patrolling with multiple Unmanned Aerial Vehicles (UAVs) remains challenging due to dynamic surveillance priorities, heterogeneous node importance, and evolving operational constraints. We present the novel Chimpanzee Troop Algorithm for Patrolling (CTAP), a decentralized policy inspired by chimpanzees fission–fusion dynamics and territorial behavior. CTAP provides three capabilities: (i) on-the-fly patrol-group instantiation, (ii) importance-aware territorial partitioning of the patrol graph, and (iii) adaptive boundary expansion via a lightweight shared-memory overlay that coordinates neighboring groups without centralization. Unlike the Ant Colony Optimization (ACO), Heuristic Pathfinder Conscientious Cognitive (HPCC), Recurrent LSTM Path-Maker (RLPM), State-Exchange Bayesian Strategy (SEBS), and Dynamic Task Assignment via Auctions (DTAP) baselines, CTAP couples local-idleness reduction with controlled edge-exploration, yielding stable coverage under shifting demand. We evaluate these approaches across multiple maps and fleet sizes using the average weighted idleness, global worst-weighted idleness, and Time-Normalized Idleness metrics. CTAP reduces the average weighted idleness by 7% to 22% and the global worst-weighted idleness by 30–65% relative to the strongest competitor and attains the lowest Time-Normalized Idleness in every configuration. These results show that a simple, communication-limited, partition-based policy enables robust, scalable patrolling suitable for resource-constrained UAV teams in smart-city environments. Full article

Tetanus is a life-threatening neurological disease affecting vertebrate species, including primates. Here, we present a case of severe generalized tetanus in a juvenile male chimpanzee (Pan troglodytes) that was rescued from the illegal wildlife trade and admitted to a rehabilitation center in the Republic of Congo. Upon arrival, the chimpanzee presented with deep, contaminated constrictive wounds, trismus, generalized rigidity, and stimulus-induced tonic spasms accompanied by transient apnea, while remaining conscious. A presumptive clinical diagnosis was made, after which integrated care began immediately. This included meticulous wound debridement and irrigation, passive immunization with antitoxin, initiation of active immunization, metronidazole with adjunctive penicillin G, diazepam-based spasm control, multimodal analgesia, and low-stimulation nursing with oxygen supplementation, enteral nutrition, and temporary urinary catheterization. Aerobic wound culture yielded mixed flora, and a Gram stain of the feces showed large Gram-positive rods with terminal spores. Hematology tests revealed leucopenia with neutropenia and severe thrombocytopenia. The spasms ceased by day 5, at which point the diazepam dose was reduced and oral intake was increased. By week 8, he had made a full clinical recovery and was successfully reintegrated into his group. This case supports the use of pragmatic, sanctuary-adapted protocols and systematic vaccination. Full article

CEACAMs are involved in a variety of physiological processes including cell adhesion, regulating the immune system, serving as entry receptors for a variety of pathogens, and regulating insulin receptor levels. Earlier studies identified five peptides from the N domain of human CEACAM1 that have stimulatory activity on human neutrophils. We compared the CEACAM N domain sequences, and also the amino acid sequences of the five CEACAM1 N domain peptides with biological activity in human neutrophils, among selected primates. Close similarity of the N domains was observed in the primates examined. The CEACAM1 N domains were more similar within great apes, Old World monkeys, New World monkeys, and lemurs/tarsiers than between groups. Differences in the amino acid sequences of some active peptides were observed among species; some differences are predicted to result in a loss of activity in the human neutrophil system. One amino acid change in the CD66a-1 peptide region that results in the loss of neutrophil activating activity in humans was observed in bonobos but not in the closely related chimpanzee which inhabits the opposite side of the Congo river. The same amino acid change was found to be a very rare event in humans. Changes in the CD66a-2 and CD66a-3 peptide regions were also observed in select human populations, some of which were differentially present in the chimpanzee and bonobo, as well as others that were not found in the other primates studied. In addition, a haplotype involving SNPs resulting in amino acid changes immediately adjacent to peptides CD66a-1, 3, and 7 were found in select human populations. Since CEACAM1 serves as a receptor for multiple infectious agents, selective pressure of an unidentified pathogen could be responsible for these differences. Given the diverse activities of CEACAM1 in humans, variant alleles in these domains might also have diverse effects in different populations. Full article

Background/Objectives: Varicella-zoster virus (VZV) causes herpes zoster (HZ/shingles), particularly in older adults with weakened cell-mediated immunity (CMI), which is essential for controlling VZV reactivation and reducing HZ severity. Currently vaccines, like recombinant subunit or live-attenuated vaccine, showed shortcomings in eliciting CD8⁺ T-cell responses. Addressing this, we utilized the novel replication-defective chimpanzee adenovirus vector ChAdOx1 to construct the ChAdOx1-VZV (CVE) vaccine, using full-length glycoprotein E (gE) as antigen. This study evaluated the immunogenicity of a heterologous intramuscular (IM) prime/intranasal (IN) boost regimen with the aim of developing a novel VZV vaccine candidate. Methods: BALB/c mice were immunized with CVE using homologous or heterologous prime-boost regimens via IM or IN. And cynomolgus macaques were immunized intramuscularly with three doses of CVE. Cellular responses were assessed by intracellular cytokine staining (ICS) and IFN-γ ELISpot using splenocytes and PBMCs. Humoral responses were evaluated by serum gE-IgG ELISA and bone-marrow LLPC ELISpot. Memory subsets and tissue-resident T cells were analyzed by flow cytometry. Results: Heterologous IM prime/IN boost CVE regimen markedly enhanced both cellular and humoral responses, especially CD8⁺ T-cell responses. The induced LLPC and memory T cell responses indicate the potential for long-term protection against herpes zoster. In cynomolgus macaques, CVE induced robust serum gE-specific IgG responses and strong IFN-γ secreting T-cell activity, supporting the immunogenicity of CVE in a genetically distinct primate model and enhancing its clinical translational potential. Conclusions: CVE induces potent cellular and humoral immunogenicity, with IM prime/IN boost vaccination. Cross species immunogenicity observed in nonhuman primates further strengthens the translational relevance of this platform. These findings support CVE as a promising herpes zoster vaccine candidate and provide a rationale for continued evaluation in human-relevant systems. Full article

Human immunodeficiency virus (HIV), comprising two distinct types, HIV-1 and HIV-2, remains one of the most significant global health challenges, originating from multiple cross-species transmissions of simian immunodeficiency viruses (SIVs) in the early 20th century. This review traces the evolutionary trajectory of HIV from zoonotic spillover to its establishment as a global pandemic. HIV-1, the principal strain responsible for AIDS, emerged from SIVcpz in Central African chimpanzees, with phylogenetic evidence indicating initial human transmission between the 1920s and 1940s in present day Democratic Republic of Congo. The virus disseminated through colonial trade networks, reaching the Caribbean by the 1960s before establishing endemic transmission in North America and Europe. HIV’s extraordinary genetic diversity—driven by high mutation rates (~10⁻⁵ mutations per base per replication cycle) and frequent recombination events—has generated multiple groups, subtypes, and circulating recombinant forms (CRFs) with distinct epidemiological patterns. HIV-1 Group M, comprising subtypes A through L, accounts for over 95% of global infections, with subtype C predominating in sub-Saharan Africa and Asia, while subtype B dominates in Western Europe and North America. The extensive genetic heterogeneity of HIV significantly impacts diagnostic accuracy, antiretroviral therapy efficacy, and vaccine development, as subtypes exhibit differential biological properties, transmission efficiencies, and drug resistance profiles. Contemporary advances, including next-generation sequencing (NGS) for surveillance, broadly neutralizing antibodies for cross-subtype prevention and therapy, and long-acting antiretroviral formulations to improve adherence, have transformed HIV management and prevention strategies. NGS enables near real-time surveillance of drug resistance mutations and inference of transmission networks where it is available, although access and routine application remain uneven across regions. Broadly neutralizing antibodies demonstrate cross-subtype efficacy, while long-acting formulations have the potential to improve treatment adherence. This review synthesizes recent evidence and offers actionable recommendations to optimize clinical and public health responses—including the routine use of genotypic resistance testing where feasible, targeted use of phylogenetic analysis for outbreak investigation, and the development of region-specific diagnostic and treatment algorithms informed by local subtype prevalence. While the understanding of HIV’s evolutionary dynamics has substantially improved and remains essential, translating this knowledge into universally implemented intervention strategies remains a key challenge for achieving the UNAIDS 95-95-95 targets and the goal of ending AIDS as a public health threat by 2030. Full article

Cholesterol, triglycerides, high-density lipoproteins (HDLs), low-density lipoproteins (LDLs), and very-low-density lipoproteins (VLDLs) were evaluated in chimpanzees at Tacugama Chimpanzee Sanctuary, Sierra Leone. Blood from 75 visually healthy chimpanzees was collected, centrifuged within one hour of collection, and analyzed at Choithram Hospital within 24 h. Statistical analyses assessed differences and interactions based on age, body condition score (BCS), housing group, and sex. HDLs varied widely by housing group; HDLs and LDLs were higher in males than in females. Cholesterol and LDLs were higher in prepubertal individuals while VLDLs and triglycerides were higher in postpubertal individuals. Lipid biomarker differences by age and age ∗ sex statistical interactions were not observed. These data represent a novel compilation of serum lipid biomarkers from a large population of sanctuary-housed Western chimpanzees (Pan troglodytes verus) within a range country, a population not previously studied with regard to serum lipid biomarkers. This study has documented significant differences compared to known values from managed chimpanzees and human reference ranges. The relationship of serum lipid biomarkers with health and disease in great apes remains understudied, but the present data set provides a basis for future studies to ascertain whether these differences are healthy biomarker variations or represent an elevated risk factor for disease. Full article

Chimpanzees (Pan troglodytes) rescued from the illegal wildlife trade often suffer from chronic, traumatic injuries that require specialized and prolonged medical treatment in wildlife rehabilitation centers. We present the case report of a two-year-old male chimpanzee admitted at the Tchimpounga Chimpanzee Rehabilitation Center in the Republic of Congo with a chronic periorbital abscess, likely caused by a machete wound sustained during the poaching of his mother. Despite receiving extended antimicrobial therapy, his condition was never fully controlled and progressed to a chronic orbital infection, causing him discomfort and producing chronic purulent discharge. Enucleation was performed under general anesthesia using ketamine and medetomidine, with surgical approach adapted to the distinctive orbital anatomy of chimpanzees. During the procedure, ligation of the optic nerve and ophthalmic vessels was required due to the confined orbital apex and extensive vascularization, ensuring adequate haemostasias and procedural safety. The chimpanzee made an uneventful postoperative recovery, resuming normal feeding and social behavior within 48 h, with complete wound healing occurring within two weeks. This case report highlights the importance of prompt surgical intervention when conservative medical management fails to resolve refractory ocular infections in chimpanzees. It also emphasizes the importance of specific anesthetic protocols, refined surgical techniques and tailored postoperative care in wildlife rehabilitation centers. Documenting and sharing detailed case reports such as this contributes to the limited veterinary literature on great ape surgery and supports evidence-based clinical decision-making to improve the welfare and treatment outcomes of rescued chimpanzees. Full article