Navigation Links
Helper T cell


A helper (or TH) T cell is a T cell (a type of white blood cell) which has on its surface antigen receptors that can bind to fragments of antigens displayed by the Class II MHC molecules found on professional antigen-presenting cells (APCs).

Once bound to an antigen, the TH cell proliferates and differentiates into activated TH cells and memory TH cells.

  • Activated TH cells secrete cytokines, proteins or peptides that stimulate other lymphocytes; the most common is interleukin-2 (IL-2), which is a potent T cell growth factor. Activated, proliferating TH cells can differentiate into two major subtypes of cells, Th1 and Th2 cells. These subtypes are defined on the basis of specific cytokines produced. Th1 cells produce interferon-gamma and interleukin 12, while Th2 cells produce interleukin-4 , interleukin-5 and interleukin-13.
  • Memory TH cells are specific to the antigen they first encountered and can be called upon during the secondary immune response .

Most TH cells have present on the cell surface the protein CD4 , which is attracted to portions of the Class II MHC molecule. This affinity keeps the TH cell and the target cell bound closely together during antigen-specific activation. TH cells with CD4 surface protein are called CD4+ T cells. The decrease in number of CD4+ T cells is the primary mechanism by which HIV causes AIDS.


'"/>


(Date:8/6/2015)... 2015  Today, U.S. Congressman Mike Honda ... to learn firsthand how Silicon Valley technologies can ... a world leader in multi-factor identity management and ... federal agencies and commercial organizations achieve new levels ... "The vast majority of network breaches can be ...
(Date:8/5/2015)... August 5, 2015 Transparency Market ... Recognition Market - Global Industry Analysis, Size, Share, Growth, ... for facial recognition is forecast to reach US$ 2,671.8 ... demand for surveillance systems by civil and government agencies. ... crimes and terrorist activities across the globe that would ...
(Date:8/3/2015)... 2015 Synaptics, Inc. (Nasdaq: SYNA ), ... that members of the executive management team will present ... Technology Leadership Forum on Tuesday, August 11, 2015 at ... at the Sonnenalp Resort in Vail, CO. ... forward-looking information. An audio webcast of the event will ...
Breaking Biology News(10 mins):Rep. Honda to Visit Crossmatch in Redwood City 2Facial Recognition Market Expected to Reach US$ 2.67 Bn by 2022, at a CAGR of 9.5% From 2015 - 2022: Transparency Market Research 2Facial Recognition Market Expected to Reach US$ 2.67 Bn by 2022, at a CAGR of 9.5% From 2015 - 2022: Transparency Market Research 3Facial Recognition Market Expected to Reach US$ 2.67 Bn by 2022, at a CAGR of 9.5% From 2015 - 2022: Transparency Market Research 4Facial Recognition Market Expected to Reach US$ 2.67 Bn by 2022, at a CAGR of 9.5% From 2015 - 2022: Transparency Market Research 5Facial Recognition Market Expected to Reach US$ 2.67 Bn by 2022, at a CAGR of 9.5% From 2015 - 2022: Transparency Market Research 6
... well-known fairy tale, Rumpelstiltskin used magic to weave straw into ... to turn straw (and other forms of biomass) into today,s ... in which minute particles of gold dot the surface of ... two materials are strong enough to breaks the O-O bond ...
... Dec. 4, 2012 A recent ABC News report ... ensure greater security in large childcare facilities. While the use ... unwanted visitors and protect children from exiting the facility, the ... come in and out of the building. Slava Volman, owner ...
... CA Plants grow upward from a tip of undifferentiated ... stem cells at the center of the meristem divide and ... to form plant organs, such as leaves and flowers. In ... into a quiescent state and form a barrier that not ...
Cached Biology News:Gases from grasses 2Gases from grasses 3Slava Volman Responds to Use of Biometrics for Security in Childcare Facilities 2Plant organ development breakthrough 2
Other biology definitionOther Tags