Human Health in Extreme Conditions
Conditions
Brief summary
Living for long periods in extreme environments-like Antarctic research stations or space missions-can have a significant impact on human health, especially on the immune system. Scientists have observed that people in such isolated conditions often experience more infections and a reactivation of viruses that usually stay dormant in the body, such as Herpes viruses. These changes affect both parts of the immune system: the rapid-response "innate" system and the slower, more specific "adaptive" system. These immune disruptions may be caused by multiple stressors: ongoing psychological stress, disturbed sleep and light cycles (circadian rhythm disruption), and the challenges of living in confined, isolated, and extreme environments. While space missions and Antarctic overwintering programs have provided some insight into these issues, scientists still lack a detailed understanding of how the immune system adapts-or fails to adapt-over time in such conditions. To help fill this gap, the CHOICE Kerguelen 2 study will follow a group of healthy young adults who will spend one year (from November 2025 to November 2026) in Port-aux-Français, a remote French research station on the Kerguelen Islands in the sub-Antarctic. These volunteers are participating in a civic service program and will be living in a highly isolated environment for the duration of their mission. The CHOICE Kerguelen study is conducted in collaboration with the French Polar Institute (IPEV). The goal of the study is to collect and store a broad range of biological samples-including blood, saliva, stool, urine, and hair-from these volunteers at four time points during the time of their confinement on the Kerguelent Islands: tevery three months during their stay. These samples will be than analyzed to characterize the immune profiles and intestinal microbiota of the subjects assess eventual viral reactivations and stress biological markers. These analyses will allow to better understand how the immune system reacts to prolonged isolation, and to identify immune profiles that may develop under prolonged stress and limited social contact. The long-term aim of this project is not only to improve our understanding of human immunity in extreme environments, but also to inform medical research for people living with chronic illness. By studying healthy individuals placed in physically and mentally challenging environments, scientists can better understand how stress and isolation may weaken immune defenses. The findings may one day help design new approaches to support immune health in vulnerable populations.
Interventions
OTHERblood ponction
blood ponction
OTHERurines collection
urines collection
OTHERhair collection
hair collection
OTHERsaliva collection
saliva collection
OTHERstools collection
stools collection
Sponsors
University Hospital, Angers
Institut Polaire Français Paul Emile Victor
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
: * healthy people aged \> 18 years * Participant affiliated with or benefiting from a social security system * Participant has signed informed consent * Participant staying as an overwintering member at Kerguelen from November 2025 to November 2026 * Participant included in the CELREMED research project of the University Hospital of Angers on helathy volunteers in the context of CHOICE Kerguelen 1 protocol
Exclusion criteria
* age \< 18 years * Pregnant, breastfeeding, or postpartum woman * immunocompromised people (primary immunodeficiency, HIV infection or immunosupressive treatment) * Person refusing to participate in the study * Person with a history of autoimmune disease - -Person deprived of liberty by judicial or administrative decision * Person undergoing involuntary psychiatric treatment * Person subject to a legal protection measure
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| lymphocytes subsets during overwintering on the Kerguelen Islands | At inclusion (3 months after the beginning of overwintering) | lymphocytes subsets by flow cytometry |
| RNAsep during overwintering on the Kerguelen Islands | At inclusion (3 months after the beginning of overwintering ) | RNAseq |
| plasmatic cytokines during overwintering on the Kerguelen Islands | At inclusion (3 months after the beginning of overwintering ) | plasmatic cytokines by Bioplex |
| fecal microbiota | At inclusion (3 months after the beginning of overwintering ) | fecal microbiota by bacterial sequencing |
| hormonal stress markers during overwintering on the Kerguelen Islands | At inclusion (3 months after the beginning of overwintering ) | hormonal stress markers assessment in blood/urinary/hair by Elisa and nephelemetry |
| stress profile during overwintering on the Kerguelen Islands | At inclusion (3 months after the beginning of overwintering ) | psychological stress by CST test form |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| EBV viral reactivations during overwintering on the Kerguelen Islands | At inclusion (3 months after the beginning of overwintering ) | EBV in blood and saliva by quantitative PCR |
| CMV viral reactivations during overwintering on the Kerguelen Islands | At inclusion (3 months after the beginning of overwintering ) | CMV in blood and saliva by quantitative PCR |
| HSV viral reactivations during overwintering on the Kerguelen Islands | At inclusion (3 months after the beginning of overwintering ) | HSV in blood and saliva by quantitative PCR |
| TTV viral reactivations during overwintering on the Kerguelen Islands | At inclusion (3 months after the beginning of overwintering ) | TTV viral loads in blood and saliva by quantitative PCR |
Countries
French Southern and Antarctic Lands
Contacts
CONTACTCharline MIOT, MD
CONTACTAnthéa LOIEZ
PRINCIPAL_INVESTIGATORCharline MIOT, MD
University Hospital, Angers
Outcome results
None listed