Biology subjects

Contreras, V.

Publications and source records attributed to Contreras, V..

9 recordsLinked to original sources

bioRxiv2025

Disease progression is associated with differential neutrophil maturation in Mycobacterium tuberculosis-infected macaques

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), is associated with clinical diversity and outcomes ranging from latent TB to active TB with distinct pathophysiologies. However, our understanding of the innate immune mechanisms related to the protection or progression of TB is limited. Among innate immune cells, the role of neutrophils is not fully elucidated, as they have been shown to exhibit both protective and harmful capacities in TB. This duality suggests possible differences in the nature and type of neutrophils present during the infection, generating different effects. We hypothesized that Mtb infection induces changes in neutrophil phenotype and function, influencing the infection outcomes. In order to decipher the link between neutrophils and disease progression, we used a cynomolgus macaque model of human TB. Based on clinical, bacteriological, and positron emission tomography with X-ray computed tomography (PET/CT) scan parameters, animals were stratified into two categories: animals that rapidly progressed to an active form of TB, designated as "fast progressors", and "slow progressors", which include low symptomatic or asymptomatic animals. In this study, we identified transcriptomic signatures of type I interferons and neutrophil degranulation in macaques with fast progression to active TB, which were not observed in animals with slow TB progression. Unsuppervised mass cytometry analysis showed the emergence of blood immature neutrophils (CD101+ CD10-) in fast progressing animals. In addition, circulating neutrophils from infected animals displayed capacities to modulate TNF- production and cytotoxic function of CD8 T cells in a contact-dependent mechanism. In the lungs, neutrophils infiltration in granuloma was higher in fast progressors and specifically located in the lymphocyte-rich region in lesions. These data suggest that specific neutrophil subpopulations are associated with disease progression. Furthermore, these data suggest that neutrophils may modulate CD8 T cells functions, which in turn contribute to the loss of Mtb control and fuel inflammation. AUTHORS SUMMARYMycobacterium tuberculosis (Mtb) infection in humans is associated with a wide range of disease progression, ranging from latent tuberculosis (TB) to active TB. Understanding immune factors leading to the control of the infection or disease progression is essential to identify new biomarkers and targets for host-directed therapies. Innate immunity plays an important role in inflammatory imbalance observed in active TB, among which neutrophils have both beneficial and detrimental roles. Using a macaque model developing a broad range of clinical forms of TB, we seek to understand the links between neutrophils and disease progression. We found that rapid progression to active TB leads to type I interferon signalling and neutrophil activation. In the blood, immature neutrophils were enriched when the disease progressed. In case of severe TB, Neutrophils also infiltrate a specific region of lung TB lesions rich in T lymphocytes, whereas they could modulate CD8 T cells. Our study provides new insights into the role of neutrophils in TB progression.

immunology↗

bioRxiv2023

Multimodal mucosal and systemic immune characterization of a novel non-human primate trachoma model highlights the critical role of local immunity during acute phase disease

BackgroundTrachoma -the leading cause of blindness worldwide as a result of infection-is caused by repeated Chlamydia trachomatis (Ct) conjunctival infections. Disease 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 the severity of reinfections. The immune system is a pivotal aspect of disease, involved in disease aggravation, but also key for exploitation in development of 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 revealed an early phase influx of T cells in the conjunctiva and elevated interleukins 4, 8, and 5, before a later phase monocytic influx accompanied by a decrease in other immune cells, and tear fluid cytokines returning to initial levels. Conclusion/SignificanceOur NHP model accurately reproduces acute trachoma clinical signs, allowing for the precise assessment of the local immune responses in infected eyes. A progressing immune response occurred for weeks after exposure to Ct, which subsided into persistence of innate immune responses. Understanding these local responses is the first step towards using the model to assess new vaccine and therapeutic strategies to prevent disease. Author SummaryChlamydia trachomatis is the leading infectious cause of blindness worldwide. The pathogenesis of trachoma is more complicated than other types of bacterial conjunctivitis: clinical signs of trachoma are rooted in repeated Chlamydia trachomatis infections of the inner eyelid surfaces, which roughens the skin. This lead to eyelid deformation and lashes rubbing on the cornea, which across multiple years of abrasion, ends with corneal opacification. The immune system is a pivotal aspect of disease, involved in disease aggravation, but also key for exploitation in development of a trachoma vaccine. Here we describe a non-human primate model of trachoma that accurately reproduces acute human eye disease, allowing for the precise assessment of the local immune responses in infected eyes. A progressing immune response occurred 4 weeks after exposure to Ct, which subsided into persistence of innate immune responses. Understanding these local responses is the first step towards using the model to assess new vaccine and therapeutic strategies to prevent disease.

microbiology↗

bioRxiv2023

ACE2 mimetic antibody potently neutralizes all SARS-CoV-2 variants and fully protects in XBB.1.5 challenged monkeys

The rapid evolution of SARS-CoV-2 to variants with improved transmission efficiency and reduced sensitivity to vaccine-induced humoral immunity has abolished the protective effect of licensed therapeutic human monoclonal antibodies (mAbs). To fill this unmet medical need and protect vulnerable patient populations, we isolated the P4J15 mAb from a previously infected, vaccinated donor, with <20 ng/ml neutralizing activity against all Omicron variants including the latest XBB.2.3 and EG.1 sub-lineages. Structural studies of P4J15 in complex with Omicron XBB.1 Spike show that the P4J15 epitope shares [~]93% of its buried surface area with the ACE2 contact region, consistent with an ACE2 mimetic antibody. Although SARS-CoV-2 mutants escaping neutralization by P4J15 were selected in vitro, these displayed lower infectivity, poor binding to ACE2, and the corresponding escape mutations are accordingly rare in public sequence databases. Using a SARS-CoV-2 XBB.1.5 monkey challenge model, we show that P4J15 confers complete prophylactic protection. We conclude that the P4J15 mAb has potential as a broad-spectrum anti-SARS-CoV-2 drug.

microbiology↗

bioRxiv2023

A novel adjuvant formulation induces robust Th1/Th17 memory and mucosal recall responses in Non-Human Primates

After clean drinking water, vaccination is the most impactful global health intervention. However, development of new vaccines against difficult-to-target diseases is hampered by the lack of diverse adjuvants for human use. Of particular interest, none of the currently available adjuvants induce Th17 cells. Here, we develop and test an improved liposomal adjuvant, termed CAF(R)10b, that incorporates a TLR-9 agonist. In a head-to-head study in non-human primates (NHPs), immunization with antigen adjuvanted with CAF(R)10b induced significantly increased antibody and cellular immune responses compared to previous CAF(R) adjuvants, already in clinical trials. This was not seen in the mouse model, demonstrating that adjuvant effects can be highly species specific. Importantly, intramuscular immunization of NHPs with CAF(R)10b induced robust Th17 responses that were observed in circulation half a year after vaccination. Furthermore, subsequent instillation of unadjuvanted antigen into the skin and lungs of these memory animals led to significant recall responses including transient local lung inflammation observed by Positron Emission Tomography-Computed Tomography (PET-CT), elevated antibody titers, and expanded systemic and local Th1 and Th17 responses, including >20% antigen-specific T cells in the bronchoalveolar lavage. Overall, CAF(R)10b demonstrated an adjuvant able to drive true memory antibody, Th1 and Th17 vaccine-responses across rodent and primate species, supporting its translational potential.

immunology↗

bioRxiv2022

Impact of variants of concern on SARS-CoV-2 viral dynamics in non-human primates.

The impact of variants of concern (VoC) on SARS-CoV-2 viral dynamics remains poorly understood and essentially relies on observational studies subject to various sorts of biases. In contrast, experimental models of infection constitute a powerful model to perform controlled comparisons of the viral dynamics observed with VoC and better quantify how VoC escape from the immune response. Here we used molecular and infectious viral load of 78 cynomolgus macaques to characterize in detail the effects of VoC on viral dynamics. We first developed a mathematical model that recapitulate the observed dynamics, and we found that the best model describing the data assumed a rapid antigen-dependent stimulation of the immune response leading to a rapid reduction of viral infectivity. When compared with the historical variant, all VoC except beta were associated with an escape from this immune response, and this effect was particularly sensitive for delta and omicron variant (p<10-6 for both). Interestingly, delta variant was associated with a 1.8-fold increased viral production rate (p=0.046), while conversely omicron variant was associated with a 14-fold reduction in viral production rate (p<10-6). During a natural infection, our models predict that delta variant is associated with a higher peak viral RNA than omicron variant (7.6 log10 copies/mL 95% CI 6.8 - 8 for delta; 5.6 log10 copies/mL 95% CI 4.8 - 6.3 for omicron) while having similar peak infectious titers (3.7 log10 PFU/mL 95% CI 2.4 - 4.6 for delta; 2.8 log10 PFU/mL 95% CI 1.9 - 3.8 for omicron). These results provide a detailed picture of the effects of VoC on total and infectious viral load and may help understand some differences observed in the patterns of viral transmission of these viruses.

microbiology↗

bioRxiv2021

The route of vaccine administration determines whether blood neutrophils undergo long-term phenotypic modifications

Innate immunity modulates adaptive immunity and defines the magnitude, quality, and longevity of antigen-specific T- and B- cell immune memory. Various vaccine and administration factors influence the immune response to vaccination, including the route of vaccine delivery. We studied the dynamics of innate cell responses in blood using a preclinical model of non-human primates immunized with a live attenuated vaccinia virus, Modified vaccinia virus Ankara (MVA), and mass cytometry. We previously showed that MVA induces a strong, early, and transient innate response, but also late phenotypic modifications of blood myeloid cells after two months when injected subcutaneously. Here, we show that the early innate effector cell responses and plasma inflammatory cytokine profiles differ between subcutaneous and intradermal vaccine injection. Additionally, we show that the intradermal administration fails to induce more highly activated/mature neutrophils long after immunization, in contrast to subcutaneous administration. Different batches of antibodies, staining protocols and generations of mass cytometers were used to generate the two datasets that were compared. Mass cytometry data were analyzed in parallel using the same analytical pipeline based on three successive clustering steps, including SPADE, and categorical heatmaps were compared using the Manhattan distance to measure the similarity between cell cluster phenotypes. Overall, we show that the vaccine per se is not sufficient for the late phenotypic modifications of innate myeloid cells, which are evocative of innate immune training. Its route of administration is also crucial, likely by influencing the early innate response, and systemic inflammation, and the vaccine biodistribution.

immunology↗

bioRxiv2021

Immunization with synthetic SARS-CoV-2 S glycoprotein virus-like particles protects Macaques from infection

The SARS-CoV-2 pandemic causes an ongoing global health crisis, which requires efficient and safe vaccination programs. Here, we present synthetic SARS-CoV2 S glycoprotein-coated liposomes that resemble in size and surface structure virus-like particles. Soluble S glycoprotein trimers were stabilized by formaldehyde cross-linking and coated onto lipid vesicles (S-VLP). Immunization of cynomolgus macaques with S-VLPs induced high antibody titers and TH1 CD4+ biased T cell responses. Although antibody responses were initially dominated by RBD specificity, the third immunization boosted non-RBD antibody titers. Antibodies showed potent neutralization against the vaccine strain and the Alpha variant after two immunizations and robust neutralization of Beta and Gamma strains. Challenge of animals with SARS-CoV-2 protected all vaccinated animals by sterilizing immunity. Thus, the S-VLP approach is an efficient and safe vaccine candidate based on a proven classical approach for further development and clinical testing.

immunology↗

bioRxiv2020

Two-component spike nanoparticle vaccine protects macaques from SARS-CoV-2 infection

The SARS-CoV-2 pandemic is continuing to disrupt personal lives, global healthcare systems and economies. Hence, there is an urgent need for a vaccine that prevents viral infection, transmission and disease. Here, we present a two-component protein-based nanoparticle vaccine that displays multiple copies of the SARS-CoV-2 spike protein. Immunization studies show that this vaccine induces potent neutralizing antibody responses in mice, rabbits and cynomolgus macaques. The vaccine-induced immunity protected macaques against a high dose challenge, resulting in strongly reduced viral infection and replication in upper and lower airways. These nanoparticles are a promising vaccine candidate to curtail the SARS-CoV-2 pandemic.

immunology↗

bioRxiv2019

Targeting MOG to skin macrophages prevents EAE in macaques through TGFβ-induced peripheral tolerance

To study the effect of vaccination on tolerization to the myelin antigen MOG we used a macaque model of experimental autoimmune encephalitis (EAE) in which immunization with recombinant human myelin oligodendrocyte glycoprotein (rhMOG) elicits brain inflammation and demyelination mediated by MOG-specific autoreactive CD4+ T lymphocytes and anti-MOG IgG. For antigen targeting to tolerizing antigen presenting cells, we used a recombinant antibody directed to the Dendritic Cells (DC)-Asialoglycoprotein receptor (DC-ASGPR). The intradermal administration of an anti-DC-ASGPR-MOG fusion protein, but not a control anti-DC-ASGPR-PSA (prostate specific antigen) protein, protected monkeys committed to develop EAE. Although effective treatment did not modify anti-MOG IgG production, it prevented the CD4+ T lymphocyte activation and pro-inflammatory cytokine production. Moreover, animals treated with anti-DC-ASGPR-MOG experienced a rise of MOG-specific CD4+CD25+FOXP3+CD39+ regulatory T cells as well as a TGF{beta}1, TGF{beta}2 and IL-8 upsurge after rhMOG re-immunization. Our results indicate that the pathogenicity of autoantibodies directed to MOG is mitigated in the presence of MOG-specific regulatory lymphocytes. This vaccination scheme appears suitable to treat relapsing autoimmune diseases with identified autoantigens such as that harboring anti-MOG or anti-AQP4 autoantibodies.

immunology↗