Figure 3. AhR modulates multiple aspects of host responses to infection.

Infection triggers an integrated series of responses by the host that seek to reduce pathogen proliferation, and ultimately eliminate invaders from the body. Host mechanisms include barrier cells and innate responses, such as promote inflammation, which contain and control infection while the adaptive immune system is activated. If an insufficient response is initiated or the response is not sustained, then complete pathogen elimination may not be achieved. Similarly, if the activated effector mechanisms are poorly controlled, then excessive damage to host tissue, and sometimes death, can ensue. AhR, either through its absence or activation by exogenous ligands, has been shown to influence multiple stages of the host response to acute primary infection.