Figure 2.

Autophagy induction by TLR stimulation. Activation of TLR can induce autophagy for pathogen elimination. Stimulation of TLR4 with LPS in a TRIF-dependent, MyD88-independent signaling pathway, and stimulation of endosomal TLR7 with two different TLR7 ligands via the MyD88-dependent pathway induces autophagosome formation and eliminates Mycobacteria bacilli, even though mycobacteria are normally not associated with TLR7 signaling. Atg proteins such as Atg5, Beclin-1, and PI3K are required for the formation of an autophagosome.