Mammalian defensins are abundant in the cytoplasmic azurophilic granules of neutrophils, Paneth cells of the small intestine and some macrophages. Human a-defensin-1 (HNP-1) is a peptide possessing both broad antimicrobial (both Gram-positive and Gram-negative bacteria) and cytotoxic activities. HNP-1 reduces adenoviral infection by more than 95%.
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