Navigation Links
Immunity stronger at night than during day

The immune system's battle against invading bacteria reaches its peak activity at night and is lowest during the day.

Experiments with the laboratory model organism, Drosophila melanogaster, reveal that the specific immune response known as phagocytosis oscillates with the body's circadian rhythm, according to Stanford researchers who presented their findings at the American Society for Cell Biology (ASCB) 48th Annual Meeting, Dec. 13-17, 2008 in San Francisco.

"These results suggest that immunity is stronger at night, consistent with the hypothesis that circadian proteins upregulate restorative functions such as specific immune responses during sleep, when animals are not engaged in metabolically costly activities," explains Mimi Shirasu-Hiza of Stanford University.

Shirasu-Hiza and her colleague David Schneider turned to the fruit fly, Drosophila melanogaster, as the model system to help them define the relationship between innate immunity and circadian rhythm, which is the oscillating protein clock or timing mechanism in cells.

Circadian rhythm paces the human body as well as the fruit fly through its days and nights, setting the rest/activity cycle that cues when to eat, sleep and mate over a 24-hour cycle.

In phagocytosis, the innate immune response targeted by the Stanford researchers, specific immune cells engulf and destroy the bacteria invading the body.

In humans, immune responses such as phagocytosis not only are involved in clearing bacterial infection but also are implicated in a growing number of human diseases, including cancer and neurodegenerative disorders.

In previous experiments, the researchers noted that flies sick with bacterial infection lost their circadian rhythm and that flies lacking circadian rhythm were highly susceptible to infection.

The flies were infected with two different bacterial pathogens, Listeria monocytogenes and Streptococcus pneumoniae.

To determine whether circadian proteins regulate immunity, the scientists infected flies with these pathogens at different times of day or night.

The flies infected at night had a better chance of surviving than did the flies infected during the day. In addition, the researchers also detected low phagocytic activity in some flies with a mutated circadian clock.


Contact: Cathy Yarbrough
American Society for Cell Biology

Related biology news :

1. Making flies sick reveals new role for growth factors in immunity
2. Survivors of 1918 flu pandemic protected with a lifetime immunity to virus
3. Pathogen virulence proteins suppress plant immunity
4. New type of vaccines deliver stronger and faster immune response
5. As sticky as a gecko... but 10 times stronger!
6. Groundbreaking discovery may lead to stronger antibiotics
7. Natural childbirth linked to stronger baby bonding than C-sections
8. A stronger future for the elderly
9. Building a stronger roof over your head: 3 little pigs project begins first tests
10. A stronger heart with flavonoids
11. Stronger EPA leadership needed to improve water quality in Mississippi River
Post Your Comments:
(Date:4/28/2016)... First quarter 2016:   , Revenues amounted to ... of 2015 The gross margin was 49% (27) ... operating margin was 40% (-13) Earnings per share rose ... was SEK 249.9 M (21.2) , Outlook   ... The operating margin for 2016 is estimated to exceed ...
(Date:4/19/2016)... 20, 2016 The new GEZE ... compact web-based "all-in-one" system solution for all door components. ... or the door interface with integration authorization management system, ... systems. The minimal dimensions of the access control and ... building installations offer considerable freedom of design with regard ...
(Date:4/14/2016)... April 14, 2016 BioCatch ... Detection, today announced the appointment of Eyal Goldwerger ... role. Goldwerger,s leadership appointment comes at a ... of the deployment of its platform at several of ... technology, which discerns unique cognitive and physiological factors, is ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... June 23, 2016 Houston Methodist Willowbrook ... Cy-Fair Sports Association to serve as their official ... Houston Methodist Willowbrook will provide sponsorship support, athletic ... with association coaches, volunteers, athletes and families. ... Cy-Fair Sports Association and to bring Houston Methodist ...
(Date:6/23/2016)... 2016   EpiBiome , a precision microbiome engineering ... debt financing from Silicon Valley Bank (SVB). The financing ... advance its drug development efforts, as well as purchase ... "SVB has been an incredible strategic partner to us ... bank would provide," said Dr. Aeron Tynes Hammack ...
(Date:6/23/2016)... 2016 Apellis Pharmaceuticals, Inc. today announced ... of its complement C3 inhibitor, APL-2. The trials ... dose studies designed to assess the safety, tolerability, ... in healthy adult volunteers. Forty subjects ... single dose (ranging from 45 to 1,440mg) or ...
(Date:6/23/2016)... Francisco, CA (PRWEB) , ... June 23, 2016 ... ... (EDC) software, is exhibiting at the Pennsylvania Convention Center and will showcase its ... Annual conference. ClinCapture will also be presenting a scientific poster on Disrupting Clinical ...
Breaking Biology Technology: