Free Articles at Neutron Marketing Article Publishing and Distribution

Make cash!

Add By AdBrite

Author Spotlight

	imzee Articles: 80

	AdamPeters Articles: 58

	JaneTompsett Articles: 5

	wslaunchers Articles: 5

	Eva Articles: 5

More Sponsors

HTML Article

Here is Regulatory T Cells (Treg) formatted for use on a website.

Return to Regulatory T Cells (Treg)

<h2>Regulatory T Cells (Treg)</h2>by Stephen Jones 
 
Early 
development and differentiation of nascent T cells that migrate from bone 
marrow to become mature, na�ve T cells, which are capable of responding to 
antigen takes place inside the thymus. Around 1010 TCR (T cell receptor) 
variations are generated in developing T lymphocyte clones through a random 
process of somatic cell gene reorganization. During this process, often T-cells 
recognizing self-antigens are generated. Due to the ability of these self-reactive 
T-cells to elicit an autoimmune attack, they are permanently removed by the 
thymus through negative selection and clonal deletion. But, some of them manage 
to escape the thymic defenses and harbor themselves in the peripheral lymphoid 
organs. In periphery, T lymphocytes undergo further differentiation into 
effectors of various immune functions. <o:p /> 
 
One 
of many immunotolerance mechanisms that immune system has developed to 
distinguish between self and non-self antigens is regulatory T cells or Tregs. 
These cells are recently characterized specialized T-cell subsets that actively 
suppress a variety of immune responses. Researchers have broadly classified 
Tregs into natural and adaptive Tregs. Natural Tregs are CD4+CD25+ T-cells 
that originate in the thymus and play a significant role in immune homeostasis 
and protection against autoimmunity. Adaptive Tregs are non-regulatory CD4+ T-cells 
that have up-regulated CD25 expression during pathological and inflammatory 
conditions such as cancers and infections. <o:p /> 
 
Although 
the principal immunosuppressive mechanism of Tregs remains elusive, several in 
vivo experimental models have indicated that Tregs secrete large amounts of 
immunosuppressants including IL-9, IL-10 and TGF-β upon activation. These 
lymphokines are capable of inhibiting activation of Th1, Th2 cells and CTLs 
required for cell-mediated immunity, inflammation and antibody production. 
Certain recent experimental data and results even indicate that IL-2-IL-2R 
signaling is vital for development, maintenance, survival, expansion and 
suppressive activity of Tregs. Increased expression of certain other 
characteristic markers including CTLA-4, glucocorticoid-inducible tumor 
necrosis factor receptor (GITR) and OX40 has been identified on Tregs whose 
function inside these cells is still not clear. The TCRs displayed on Tregs are 
capable of recognizing and interacting with any peptide-MHC class II ligand 
having certain range of avidity. But, the contribution of TCR signaling and 
role of TCR-ligand interactions towards regulatory T-cell development needs to 
be determined. <o:p /> 
 
Several 
elegant experiment using transgenic mice and retrovirus mediate over expression 
studies, researchers have identified FoxP3, a transcription factor, to be a 
specific molecular marker essential for the development and function of Tregs. 
The primary evidence regarding the involvement of FoxP3 in the development of 
Tregs was provided by the experiments of Sakaguchi et al, (ref ?) in 
patients suffering from IPEX, a rare and fatal human autoimmune disorder. In 
these patients, mutated FoxP3 gene causes improper development of Tregs 
resulting in hyperactivation of T-cells reactive to self-antigens. Recently, 
experiments have clearly shown that retroviral mediated introduction of FoxP3 
into conventional CD4+ T-cells converts them into regulatory T-cells. <o:p /> 
 
The 
emergence of regulatory T-cells and role of FoxP3 as a critical player in the 
negative control of a of various normal and pathological immune responses holds 
great promise for the development of novel therapies useful for the treatment 
of autoimmune diseases in humans. However, there are several questions that 
remain to be answered including the basic biology of the Tregs, various ligands 
responsible for thymic selection of these cells, the exact function of FoxP3 in 
relation with various markers present on Tregs and most importantly, the 
mechanisms by which Tregs exert their suppressive effects. A better 
understanding of manipulating FoxP3 and Tregs would enable us to harness the 
tremendous therapeutic potential in various clinical situations including Type 
I diabetes, Multiple sclerosis, GVHD, rheumatoid arthritis, allergy, and 
cancers. <o:p /> 
 
 
<h3>About the Author</h3>

IMGENEX
India Pvt Ltd. the only biotech company in Orissa and one of its kinds in
Eastern <o:p />

<st1:country-region w:st="on"><st1:place w:st="on">India</st1:place></st1:country-region>.
IMGENEX India started in Oct as an outsourcing branch of  <a href="http://www.imgenex.com">IMGENEX
Corporation</a> , <st1:place w:st="on"><st1:city w:st="on">San Diego</st1:city>,
 <st1:country-region w:st="on">USA</st1:country-region></st1:place>.  Find out more information about  <a href="http://imgenex.com/Regulatory_cell.php">Regulator
T-cells</a>(Treg) .<o:p />

Article Source <a href="http://www.free-article-submit.com">Free Article Submit</a>