Immune response molecules that recognize

Dmg receptors are chemical entities which are typically, but not exclusively, small molecules that interact with cellular components, frequently at the plasma membrane level (1,2). There are many types of receptors heat, light, immune, hormone, ion channel, toxin, and vims are but a few that can excite a cell. The receptor concept can be appHed generally to signal recognition processes where a chemical or physical signal is recognized. This recognition is translated into response (Fig. 3) and the process can be seen as a flow of information. 

The cells of the immune system communicate with each other particularly intensively. The T-cell receptor plays a central role in the activation of T lymphocytes (see p. 296). The cell at the top has been infected with a virus, and it indicates this by presenting a viral peptide (violet) with the help of a class 1 MHC protein (yellow and green). The combination of the two molecules is recognized by the dimeric T-cell receptor (blue) and converted into a signal that activates the T cell (bottom) and thereby enhances the immune response to the virus. 

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