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Yolande Rousseau yolande.rousseau at wanadoo.fr
Sat Oct 23 05:07:30 EST 1999


Une de mes amies, prof d'anglais, vient de commencer dans un nouvel
établissement. Elle donne des cours à des étudiants qui sont en BTS bio et
elle n'est pas du tout familière avec ce nouveau vocabulaire. Je joins un
texte. Si j'arrive à avoir la traduction, cela lui rendra un grand service.
De plus une fois qu'elle se sera fait son propre lexique elle sera sauvée
car ce sont toujours les mêmes mots qui reviennent.  Je comprends que ça
demande du temps c'est pourquoi je l'envoie à différents groupes. Chacun
peut en faire un morceau en ne commençant pas forcément par le début;  Grand
merci d'avance
Yo
One-step-Immunoreaction

Photometric enzyme lmmunoassay for the quantitative.  In vitro determination
of soluble human IL-2 receptor/CD25.
 In streptavidin-coated microtiter plates.

Background information
Antigen or mitogen-activated T-cells of the Immune system produce the
lymphokine Interleukin-2 (IL-2), which acts as growth factor on T-cells and
B-cells.  The activation by IL-2 is mediated by IL-2 receptors IL-2R) on
this cells. The expression rate of IL-2R corresponds with the IL-2
activation.  During activation, soluble IL-2R (slL-2R) is cleaved off and
circulates as a soluble marker for lymphocyte activation in serum and
plasma.
Three different types of receptor can be distinguished and which can
independently be expressed in different cells:
Is permanently expressed even on resting lymphocytes, while IL-2Ra is found
only after activation and can thus be an Indicator for cell activation.
Although IL-2P43, In contrast to IL-2Ra, is able to transduce -intracellular
signals.  The activation, proliferation and expansion of cells under
physiological conditions are effected exclusively by binding of IL-2 to the
'high affinity' IL-2R complex.

Applications
In many cases, elevated sIL-2R levels in serum or plasma reflect
pathological changes of the Immune system.  Measurement of siL-2R levels is
used as a research tool for investigations on the activation of cellular
immune system.

Autoimmune Diseases, rheumatoidic arthritis (synovial fluid and serum),
bacterial endocarditis, systemic lupus erythrematosus (SLE), Crohn's
disease, multiple sclerosis, Guillain-Barré-syndrome, Basedow's disease,
diabetes type 1.
Hematological Disorders: T-cell leukemia, hairy-cell leukemia,
Hodgkin's disease, non-Hodgkin-lymphoma (B-and T-cell).
Organ Transplantation: detection of organ repulsion reactions and viral
Infects.
Infectious diseases: tuberculosis, malaria, leprosy, IJDS (HIV), hepatitis
B, Epstein-Barr-Virus (EBV) Infections.

Test principle

The assay uses two mouse monoclonal antibodies directed against two
different epitopes of SiL-2R.  One of the antibodies (clone 3GlO) Inhibits
the IL-2 dependent cell activation by blocking the receptor.  During the
first incubation step, siL-2R in standards or samples is bound
simultaneously by the biotinylated coating antibody and the peroxidase
conjugated detection antibody (one-step-immunoreaction).The resulting Immune
complex is bound via the biotinylated coated antibody to the
strept-avidin-coated microtiter plate. subsequent washing, the perioxidase
bound in the complex is developed by ABTS substrate solution and the
intensity of the resulting colour is determined photometrically. The colour
intensity is proportional to the concentration of iIL-2R.  Standards of
defined concentration are run in each assay and allow the construction of a
calibration curve by piotting  absorbance versus concentration.  The siL-2R
concentration of unknown samples is calculated from this calibration curve.






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