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:6/24/2016)... ... ... Marcy was in a crisis. Her son James, eight, was out of control. Prone to ... , “When something upset him, he couldn’t control his emotions,” remembers Marcy. “If there ... my other children and say he was going to kill them. If we were ...
(Date:6/24/2016)... ... June 24, 2016 , ... Global law firm Greenberg Traurig, P.A. announced that ... chosen by their peers for this recognition are considered among the top 2 percent ... special honors as members of this year’s Legal Elite Hall of Fame: Miami ...
(Date:6/24/2016)... ... June 24, 2016 , ... Comfort Keepers® of San Diego, ... and the Road To Recovery® program to drive cancer patients to and from their ... to ensure the highest quality of life and ongoing independence. Getting to and ...
(Date:6/24/2016)... ... June 24, 2016 , ... People across the U.S. are sharpening their pencils ... an essay contest in which patients and their families pay tribute to a genetic ... 2016 National Society of Genetic Counselors (NSGC) Annual Education Conference (AEC) this September. ...
(Date:6/24/2016)... York, NY (PRWEB) , ... June 24, 2016 ... ... publication Haute Living, is proud to recognize Dr. Barry M. Weintraub as a ... that “the most beautiful women in the world, and the most handsome men, ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... , June 23, 2016 Research ... MEMS Devices Medical Market Analysis 2016 - Forecast to 2022" ... The report contains up to date financial data ... analysis. Assessment of major trends with potential impact on the ... analysis of market segmentation which comprises of sub markets, regional ...
(Date:6/23/2016)... , June 23, 2016 , ... on Thursday, July 7, 2016 , , , , LOCATION: ... , , , , EXPERT PANELISTS:  , , , ... Senior Industry Analyst, Christi Bird; Senior Industry Analyst, Divyaa Ravishankar and ... The global pharmaceutical industry is witnessing an exceptional era. ...
(Date:6/23/2016)...  Guerbet announced today that it has been named ... . One of 12 suppliers to receive ... support of Premier members through exceptional local customer service ... to lower costs. ... outstanding customer service from Premier," says Massimo Carrara ...
Breaking Medicine Technology: