SPACEFLIGHT INDUCED REACTIVATION OF LATENT EPSTEIN-BARR VIRUS
(EPSTEIN-BARR)
Research Area: Immune System
Expeditions: 5, 6, 11-17
Principal Investigator(s): ● Raymond P. Stowe, PhD, Microgen Laboratories, La Marque,
Texas
RESEARCH OBJECTIVES
The Spaceflight-Induced Reactivation of Latent Epstein-Barr Virus (Epstein-Barr) experiment
performs tests to study changes in the human immune function using blood and urine samples
collected before and after spaceflight. The study provides insight for possible countermeasures
to prevent the potential development of infectious illness in crew members during flight.
EARTH BENEFITS
This type of study sheds light on infectious diseases, how they are related to stress here on
Earth, and how they can be treated.
SPACE BENEFITS
In the United States, approximately 90% of adults have been infected with Epstein-Barr virus
(EBV), one of the most common human viruses. It establishes a lifelong dormant infection
inside the body, but can be reactivated by illness or stress. Once active, it can cause infectious
mononucleosis (also known as mono). Decreased cellular immune function is observed during
and after human spaceflight. With longer-duration space missions, latent viruses are more likely
to become reactivated, placing the crew at risk of developing and spreading infectious illness. If
this is the case, drug therapies must be created to protect crew members during long-term and
interplanetary missions (ie, trips to Mars). This study will help provide information related to
immune function and virus activity in space to develop such remedies and ensure future
exploratory space missions.
RESULTS
A goal of the Epstein-Barr Virus (EBV) study was to determine whether changes in EBV gene
expression (reactivation) occurred after short- and long-duration spaceflight. All astronaut and
control subjects (24) tested positive for antibodies indicating past EB infection. In shuttle
astronauts, a pattern of immediate-early and early viral gene transcription (the first step in
gene production) was observed indicative of EBV reactivation. Altogether, there was a
significant increase in the number of immediate early and early gene replications in shuttle
astronaut samples as compared to healthy control samples. Although EBV reactivation did
occur in shuttle astronauts, productive EBV replication in peripheral blood B-lymphocytes did
not. In contrast, samples from 3 ISS astronauts after flight show strong evidence that complete
productive EBV replication is occurring in the peripheral blood B cells of these astronauts, and
data clearly show full activation EBV in the B-cells of ISS astronauts. For these crew members
who flew longer (6 months) in space, latent gene expression and late lytic (involves the
destruction of the host cell) gene transcripts were both more frequent and diverse. Overall,