Navigation Links
T-Cell Duplication Delayed Up to 3 Days After Infection
Date:4/11/2008

Finding challenges conventional theory on how immune system responds to invaders

FRIDAY, April 11 (HealthDay News) -- Immune system T-cells don't begin to multiply until up to three days after infection, an unexpected finding that changes current thinking about how the immune system responds to infection.

Researchers at the Scripps Research Institute in La Jolla, Calif., said this delay in T-cell proliferation may be an evolutionary safeguard against the risk of an autoimmune response caused by a sudden increase in T-cells.

It had been believed that memory T-cells (which recognize pathogens from previous infections) began to multiply much sooner than naive T-cells.

"It was thought that memory T-cells responded more effectively to infection by starting cell division earlier than naive cells and by multiplying more rapidly after that," Lindsay Whitton, a professor in the neuropharmacology department, said in a prepared statement. "Our study shows that neither assumption is true. Even though memory cells detected and responded to virus infection within a few hours, they did not begin to divide until after a lengthy delay. After that, cell division was rapid for both naive and memory cells."

Once proliferation of both types of cells started, there was a greater accumulation of memory T-cells, possibly because there were already more of them prior to infection, Whitton said.

The findings were published in April 10 online issue of the Public Library of Science Pathogens.

In this study, the Scripps team used laboratory animals to trace the proliferation of CD4 and CD8 memory T-cells. CD4 cells help regulate the immune system's response to pathogens such as bacteria and viruses, while CD8 cells attack infected cells and may be play a role in transplant rejection.

"The principal conclusions from our study are that, in a virus-infected animal, both naive and memory CD4 T-cells shows a similar and extended delay of approximately 72 hours before they begin to divide, and that this is true in both lymphoid and non-lymphoid tissues. This delay occurred despite the fact that the viral antigen reached T-cell-stimulatory levels within six to 12 hours after infection," Whitton said.

She and her colleagues "were very much surprised by the discovery that memory cells didn't begin proliferation sooner than their naive counterparts. Memory T-cells are central to the protective immunity of infections and vaccinations, because they act against subsequent encounters with specific microorganisms. Compared to naive cells, memory T-cells can be triggered by lower antigen levels, and their initial response to infection, such as the production of cytokines, is more rapid and more effective."

More information

The Nemours Foundation has more about the immune system.



-- Robert Preidt



SOURCE: Scripps Research Institute, news release, April 10, 2008


'/>"/>
Copyright©2008 ScoutNews,LLC.
All rights reserved

Related medicine news :

1. Cells on path to becoming mature T-cells more flexible than commonly thought
2. Inverted DNA turns quiet developmental gene into a potent driver of t-cell lymphoma
3. Stimulating Thymus Reactivates T-Cell Production
4. EpiVax receives JDRF program funding to develop diabetes drug using natural regulatory T-cells
5. Tumors use enzyme to recruit regulatory T-cells and suppress immune response
6. A tumor of the pancreas mimicked by colonic duplication?
7. Less education may lead to delayed awareness of Alzheimers onset
8. Mandatory Accreditation Delayed Until September 2009
9. FDA Sunscreen Labeling Decision Delayed Another Month, Leading U.S. Physician to Say, Enough Is Enough
10. Wyeth Receives FDA Approval of Protonix for Delayed-Release Oral Suspension
11. Delayed angioplasty -- big bucks, no bang
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/21/2017)... , ... April 21, 2017 , ... ... system, has partnered with O2X , an active lifestyle company that provides ... improving the health of firefighters, police offers, first responders, military officers and others ...
(Date:4/21/2017)... Santa Rosa, CA (PRWEB) , ... April 21, ... ... with St. Joseph Health held the much anticipated Regional Primary Care Spring Symposium ... vital role in the local medical community, offering physicians and healthcare providers an ...
(Date:4/21/2017)... City, UT (PRWEB) , ... April 21, 2017 , ... ... solutions, recently partnered with Advanced Patient Care of Utah (APCUT) and has appointed Rex ... for the next chapter of growth for our agency and our ability to provide ...
(Date:4/21/2017)... ... April 21, 2017 , ... During April 21-23, Super-Sod will join the ... festival offers entertainment for everyone — from the avid gardener to the landscape admirer ... high quality event held in a grand venue, and we are certainly looking forward ...
(Date:4/21/2017)... ... April 21, 2017 , ... National pest management association survey conducted in ... bed bug infestations over the 5-year period. In 2015 10% or US$750 million per ... bed bug infested properties. , The health and economic consequences of bed bug ...
Breaking Medicine News(10 mins):
(Date:4/18/2017)...  Astute Medical, Inc., developer of biomarkers for better ... at the 2017 National Kidney Foundation (NKF) Spring ... April 22. Physicians will present data on two biomarkers, ... for acute kidney injury (AKI) during the management of ... Elevated levels of TIMP-2 and IGFBP-7 have been ...
(Date:4/18/2017)... , April 18, 2017 Research and ... the United States Molecular Imaging Equipment and Radiopharmaceuticals Market, Forecast ... ... molecular imaging equipment revenues as well as growth in the ... will provide value to market participants that design and manufacture ...
(Date:4/18/2017)... TAMPA, Fla. , April 18, 2017 WellCare ... Health Plans, Inc. (NYSE: WCG), announced today it will award ... Kentucky to reduce tobacco use and promote smoke-free ... Center for Smoke-Free Policy conference hosted by the University of ... first time WellCare, the state,s largest Medicaid managed care organization, ...
Breaking Medicine Technology: