T cell Development Defintions

Anergy: Unresponsiveness to antigenic stimulus

 The CD4+ T cell received only the TCR engagement signal and none other, therefore anergy  was experienced.  

 

Notch: A surface receptor that when bound is cleaved to release a transcriptional regulator that regulates cell fate decisions. Notch activation is required for T cell development and determines whether a lymphocyte precursor becomes a B vs. T cell.

 When Notch 1+ is added to stromal cells in an assay system, this induces the development of T cells rather than B cells.

 

Death by Neglect: Apoptosis of developing T cells (Typically CD4+ & CD8+ T cells) that results when they do not receive TCR signals of adequate affinity.

 

Most T cells (about 90%) undergo death by neglect in the Thymus because their receptors do not specifically recognize self MHC molecules.