Peptidoglycan recognition proteins (PGRPs) specifically bind to peptidoglycans, and play crucial roles as pattern recognition receptors (PRRs) in mediating innate immune responses. In this study, we identified and characterized a PGRP (HaPGRP-D) from the cotton bollworm, Helicoverpa armigera. Sequence analysis indicated that HaPGRP-D is an amidase-type PGRP. Expression of HaPGRP-D was upregulated in the hemocytes of H. armigera larvae after injecting Gram-negative Escherichia coli, Gram-positive Staphylococcus aureus, or chromatography beads. T...
