Skip to main content
. Author manuscript; available in PMC: 2013 Aug 1.
Published in final edited form as: Clin Immunol. 2012 Jun 5;144(2):127–138. doi: 10.1016/j.clim.2012.05.010

Figure 1.

Figure 1

Activation of a T cell inflammatory response. 1) A steady-state APC such as an immature DC internalizes an insoluble protein antigen. 2) The antigen is then processed and broken down into immuno-dominant peptides that can be presented by the MHC-II molecule on the surface of the APC. 3) Internalization and processing of the antigen triggers the activation of the DC, thus forming a mature DC (mDC). 4) Presentation of the antigen by the mDC in the context of the MHC-II molecule to the TCR on a naïve T cell is known as Signal 1. 5) mDC expresses costimulatory molecules which delivers an activation signal to naïve T cells this is known as Signal 2. 6) The presentation of an antigen in presence of costimulatory signals triggers the development of a T cell inflammatory response towards that antigen.