Question

Damage-Associated Molecular Patterns (DAMPs) are endogenous molecules released by necrotic cells during tissue injury and that, similarly to Pathogen-Associated Molecular Patterns (PAMPs), trigger an inflammatory response. How do you think inflammation is triggered in response to tissue injury?

	A.	DAMPs activate the complement system directly by binding complement C1 and triggering the classical pathway.
	B.	DAMPs bind to TLRs on various cell types including neutrophils and tissue-resident macrophages, which then attract other immune cell types. Moreover, intracellular proteins that are never found extracellularly, could be recognized by lymphocytes as non-self.
	C.	DAMPs directly activate Tc lymphocytes via the TCR.
	D.	All of the above.

Answer 1

DAMP is an alarming signal by cells to indicate a type of cell death, mostly necrotic cell death. Although TCR and complement C1 is also part of immune response in the organisms but they are not directly involved with DAMP induced necrosis during tissue injury. This pathway is triggered by a number of receptors, chemokines and cytokines. Therefore, best answer would be “ B. DAMPs bind to TLRs on various cell types including neutrophils and tissue-resident macrophages, which then attract other immune cell types. Moreover, intracellular proteins that are never found extra-cellularly, could be recognized by lymphocytes as non-self”.