Flagella proteins are found in the extracellular matrix of lung tissue. How do the cells of the lung detect these proteins? a. complement system b. toll-like receptors c. eosinophils d. NOD e. helper T-cells

The correct answer is b.

Explanation:

TLRs are transmembrane type proteins  1, they are abundantly expressed in fibroblasts and epithelial cells, as well as in cells of the immune system, including macrophages, dendritic cells, B and T lymphocytes, and their expression is regulated by pathogens, cytokines, microenvironmental factors, and possibly endogenous ligands. Due to their location and the type of ligands that bind them, these receptors have been divided into two large groups: the TLRs of cytoplasmic membranes (TLRs 1, 2, 4, 5, 6 and 10) and the TLRs of endosomal membranes (TLRs 3 , 7, 8 and 9). TLR5 located in the basolateral membrane of epithelial cells recognizes flagellin, a structural protein that makes up flagella.