BPIFA1 Human

BPIFA1 is a member of the BPI fold protein superfamily, which is characterized by the presence of the bactericidal/permeability-increasing protein fold (BPI fold) . This fold is formed by two similar domains arranged in a “boomerang” shape . The BPIFA1 gene sequence predicts four transcripts (splice variants), with three mRNA variants being well characterized . The resulting BPIFA1 protein is secreted and expressed at high levels in the mucosa of the airways, including the olfactory and respiratory epithelium, as well as in salivary glands .

BPIFA1 is expressed at very high levels in the mucosa of the airways, including the olfactory and respiratory epithelium, and salivary glands . It is also found at high levels in the oropharyngeal epithelium, including the tongue and tonsils, and at moderate levels in various other tissues and glands, such as the pituitary, testis, lung, bladder, blood, prostate, pancreas, and digestive tract . The protein can be detected on the apical side of epithelial cells and in airway surface liquid, nasal mucus, and sputum .

BPIFA1 plays a crucial role in the innate immune responses of the upper airways . It is a lipid-binding protein with high specificity for the surfactant phospholipid dipalmitoylphosphatidylcholine (DPPC) . BPIFA1 reduces the surface tension in secretions from airway epithelia and inhibits the formation of biofilm by pathogenic Gram-negative bacteria, such as Pseudomonas aeruginosa and Klebsiella pneumoniae . Additionally, BPIFA1 displays antibacterial activity against Gram-negative bacteria .

BPIFA1 is thought to be involved in inflammatory responses to irritants in the upper airways and may serve as a potential molecular marker for the detection of micrometastasis in non-small-cell lung cancer . Diseases associated with BPIFA1 include adenoiditis and eye disease . The protein’s role in the innate immune system and its antibacterial properties make it a significant target for research in respiratory diseases and infections .

Human recombinant BPIFA1 is produced using recombinant DNA technology, which involves inserting the BPIFA1 gene into a suitable expression system, such as bacteria, yeast, or mammalian cells. This allows for the large-scale production of the protein for research and therapeutic purposes. Recombinant BPIFA1 retains the functional properties of the native protein and is used in various studies to understand its role in immune responses and its potential therapeutic applications.