Characterization of Adaptive Immune Responses to Oropouche Virus (OROV) Infection (OROV-IMM)
Oropouche virus (OROV), a re-emerging South American arbovirus causing dengue-like fever and occasional neurological complications, is expanding its circulation towards more densely populated areas in French Guiana, as evidenced by recent cases near Cayenne in 2026. While animal models indicate that B cell-mediated humoral immunity is critical for viral control, the human antibody response to OROV remains poorly characterized. Despite WHO-led international research efforts, there is currently no vaccine, antiviral treatment, or described human monoclonal antibody against OROV - a major gap that hinders therapeutic and vaccine development. Identifying human neutralizing monoclonal antibodies could offer a promising therapeutic option, particularly for vulnerable populations such as pregnant women.
Aperçu de l'étude
Statut
Les conditions
Intervention / Traitement
Description détaillée
The goal of this project is to characterize the adaptive immune response to OROV infection during the convalescent phase.
The study is based on three complementary populations: (1) 17 adults with confirmed past OROV infection (2020) who will be recontacted for follow-up sampling; (2) 50 adults recruited prospectively from a village with ∼80% seroprevalence, aiming to include at least 20 seropositive individuals for robust analysis of antigen-specific B and T cell responses; and (3) an exploratory cohort of 1 to 10 newly confirmed OROV cases identified during the study period in the Cayenne region, enrolled during the convalescent phase (≥1 month post-diagnosis) to complement the immunological analyses conducted in the first two populations.
A 20 ml blood sample is collected, along with data collection (mainly health data), at the time of enrollment.
The study involves: (1) confirming past OROV infection by detecting OROV-specific polyclonal antibodies in plasma; and (2) characterizing OROV-specific B and T cell responses. Key methodological steps include: isolation of OROV-specific B cells by flow cytometry followed by single-cell culture and stimulation to generate human monoclonal antibodies; screening of secreted mAbs against OROV antigens combined with VDJ sequencing to characterize immunoglobulin repertoires; and structural characterization of neutralizing mAbs using cryo-electron microscopy and nano-imaging to identify conserved epitopes.
Type d'étude
Inscription (Estimé)
Critères de participation
Critère d'éligibilité
Âges éligibles pour étudier
Accepte les volontaires sains
Sexes éligibles pour l'étude
Méthode d'échantillonnage
Population étudiée
The study population lives in French Guiana in 3 different areas (Saül, Trois Sauts, and Cayenne and its surroundings), and eligible individuals (Populations 1 and 3) or those residing in a high-seroprevalence geographic area (Population 2) were identified by the National Reference Center (CNR) for Arboviruses at the Institut Pasteur of French Guiana (IPG) as part of arbovirus virological surveillance in French Guiana.
La description
Inclusion Criteria:
For all:
- Adults (≥18 years old)
- Willingness to participate in the study after explanation and signing of the informed consent form
Study population 1:
- Presenting a laboratory-confirmed OROV infection, defined by a positive real-time RT-PCR and/or positive seroneutralization performed as part of the management of and response to the 2020 OROV epidemic in Saül.
Study population 2:
- Residing in Trois-Sauts for at least 5 years
Study population 3:
- Presenting a laboratory-confirmed OROV infection, defined by a positive real-time RT-PCR and/or positive seroneutralization, identified in the Cayenne area and surrounding localities during the study period, as part of the surveillance activities of the CNR for Arboviruses (IPG).
Exclusion Criteria:
For all:
- Pregnant women.
- Individuals presenting with severe chronic pathologies (notably active cancer, primary or secondary immunodeficiency, immunosuppressive treatment, HIV infection, or autoimmune diseases), according to the information declared by the participants.
Plan d'étude
Comment l'étude est-elle conçue ?
Détails de conception
- Modèles d'observation: OTHER
- Perspectives temporelles: PROSPECTIVE
Cohortes et interventions
Groupe / Cohorte |
Intervention / Traitement |
|---|---|
|
adults with confirmed past OROV infection (2020) recruited from Saül
|
A 20-ml blood sample |
|
adults recruited from Trois-Sauts with ∼80% seroprevalence
|
A 20-ml blood sample |
|
newly confirmed OROV cases identified during the study period in the Cayenne region
|
A 20-ml blood sample |
Que mesure l'étude ?
Principaux critères de jugement
Mesure des résultats |
Description de la mesure |
Délai |
|---|---|---|
|
Characterization of the adaptive immune response to OROV infection during the convalescent phase.
Délai: 12 months
|
OROV-specific polyclonal antibodies will be detected in participants' plasma to confirm prior infection. |
12 months
|
Mesures de résultats secondaires
Mesure des résultats |
Description de la mesure |
Délai |
|---|---|---|
|
Isolate OROV-specific B cells (recognizing the Gn_Gc antigenic complex) and generate human monoclonal antibodies by single B cell culture.
Délai: 12 months
|
Isolation of OROV-specific B cells by flow cytometry, followed by culture and stimulation of single B cells to generate and identify human monoclonal antibodies specific to OROV. |
12 months
|
|
Screening of secreted mAbs using OROV antigens and VDJ sequencing to characterize immunoglobulin repertoires.
Délai: 12 months
|
secreted mAbs using OROV antigens and VDJ sequencing will be screened to characterize immunoglobulin repertoires. |
12 months
|
|
Structural characterization of neutralizing mAbs by cryo-EM and nano-imaging to identify conserved epitopes.
Délai: 12 months
|
cryo-EM and nano-imaging will be performed on neutralizing mAbs to characterize structurally the mAbs |
12 months
|
Collaborateurs et enquêteurs
Parrainer
Dates d'enregistrement des études
Dates principales de l'étude
Début de l'étude (Estimé)
Achèvement primaire (Estimé)
Achèvement de l'étude (Estimé)
Dates d'inscription aux études
Première soumission
Première soumission répondant aux critères de contrôle qualité
Première publication (Réel)
Mises à jour des dossiers d'étude
Dernière mise à jour publiée (Réel)
Dernière mise à jour soumise répondant aux critères de contrôle qualité
Dernière vérification
Plus d'information
Termes liés à cette étude
Termes MeSH pertinents supplémentaires
- Infections
- Infections par virus à ARN
- Maladies virales
- Infections à Bunyaviridae
- Techniques d'investigation
- Manipulation des échantillons
- Techniques de laboratoire clinique
- Techniques et procédures de diagnostic
- Diagnostic
- Perforation
- Procédures chirurgicales, opératoires
- Collection d'échantillons de sang
Autres numéros d'identification d'étude
- 2026-047_OROV-IMM
- 2026-A01467-44 (Autre identifiant: ID-RCB)
Informations sur les médicaments et les dispositifs, documents d'étude
Étudie un produit pharmaceutique réglementé par la FDA américaine
Étudie un produit d'appareil réglementé par la FDA américaine
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