cross-presentation §

Where the dendritic cell expresses exogenous proteins on its MHC class I molecules. Activation of t-cells by this pathway is known as cross-priming.

This is important in activating the CD8+ t-cell in the case of infection, especially for example, if the virus has a tropism that stops it from infecting a dendritic cell. The respective CD8+ t-cell would otherwise not be activated.

Not all APCs

Cross presentation is most efficiently performed by certain subsets of dendritic cells that are present in both humans and mice. Transcription factor BATF3 and chemokine receptor XCR1, are both present in one of such subsets.