SCID Caused by Defective T Cell Activation

Another rare form of SCID is caused by mutation in a gene encoding Orai1, a component of the CRAC channel

(see Chapter 7). Antigen receptor signaling leads to the activation of the y isoform of phospholipase C (PLCy) and the inositol trisphosphate (IP3)-dependent release of calcium ions from the endoplasmic reticulum and mitochondria (see Chapter 7). The released calcium is replenished by store-operated CRAC channels that facilitate an influx of extracellular calcium. This process is crucial for lymphocyte activation, and it is defective in cells with mutant ORAI1 . A similar phenotype is observed in patients with mutations in STIM1, which encodes an endoplasmic reticulum protein that senses the depletion of calcium stores and contributes to the opening of the CRAC channel. Patients with ORAI1 and STIM1 mutations do not exhibit a defect in T cell development, but their T cells cannot be properly activated.

Was this article helpful?

0 0
How To Bolster Your Immune System

How To Bolster Your Immune System

All Natural Immune Boosters Proven To Fight Infection, Disease And More. Discover A Natural, Safe Effective Way To Boost Your Immune System Using Ingredients From Your Kitchen Cupboard. The only common sense, no holds barred guide to hit the market today no gimmicks, no pills, just old fashioned common sense remedies to cure colds, influenza, viral infections and more.

Get My Free Audio Book

Post a comment