The Peptidoglycan Recognition Proteins PGRPLA and PGRPLB Regulate Anopheles Immunity to Bacteria and Affect Infection by Plasmodium

J Innate Immun. 2017;9(4):333-342. doi: 10.1159/000452797. Epub 2017 May 12.


Peptidoglycan recognition proteins (PGRPs) form a family of immune regulators that is conserved from insects to mammals. In the malaria vector mosquito Anophelescoluzzii, the peptidoglycan receptor PGRPLC activates the immune-deficiency (Imd) pathway limiting both the microbiota load and Plasmodium infection. Here, we carried out an RNA interference screen to examine the role of all 7 Anopheles PGRPs in infections with Plasmodium berghei and P. falciparum. We show that, in addition to PGRPLC, PGRPLA and PGRPS2/PGRPS3 also participate in antiparasitic defenses, and that PGRPLB promotes mosquito permissiveness to P. falciparum. We also demonstrate that following a mosquito blood feeding, which promotes growth of the gut microbiota, PGRPLA and PGRPLB positively and negatively regulate the activation of the Imd pathway, respectively. Our data demonstrate that PGRPs are important regulators of the mosquito epithelial immunity and vector competence.

Keywords: Anopheles; Antimicrobial peptides; Bacteria; Drosophila; Immune-deficiency pathway; Microbiota; Peptidoglycan recognition protein; Plasmodium.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anopheles / immunology*
  • Bacterial Infections / immunology*
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Gastrointestinal Microbiome
  • Host-Parasite Interactions
  • Humans
  • Immunity, Innate
  • Insect Proteins / genetics
  • Insect Proteins / metabolism*
  • Malaria / immunology
  • Malaria / metabolism*
  • Mosquito Vectors
  • Plasmodium berghei / immunology*
  • Plasmodium falciparum / immunology*
  • RNA, Small Interfering / genetics
  • Signal Transduction


  • Carrier Proteins
  • Insect Proteins
  • RNA, Small Interfering
  • peptidoglycan recognition protein