ABSTRACT
Respiratory infections are an extraordinary threat to human health and are among the top ten causes of death globally, accounting for over half of all-cause mortality. According to the World Health Organization, the third and fourth leading causes of death in 2019 were chronic obstructive pulmonary disease and lower respiratory infections. A surge in research dedicated to critical factors of human innate immune defense, known as antimicrobial peptides (AMPs), has identified the prominent roles of these peptides in antimicrobial efficacy, immunomodulation, and anticancer activity. Through antimicrobial activity and immunomodulation, AMPs enact direct killing against pathogens, show pro- and anti-inflammatory effects, modulate epithelial integrity, and ultimately impact the progression of various lung diseases. Throughout this chapter, we define how AMPs are components of the host immune defense against environmental pathogens, how they regulate inflammation of the respiratory epithelium, and future directions of these peptides in treating pulmonary diseases and even lung cancer. Advancements in AMP design show great promise as alternative therapeutics to treat and prevent multidrug-resistant bacterial infections and as anticancer therapies with heightened antitumor effectivity and protection against malignancy.
