Peptidoglycan recognition proteins (PGRPs) form a family of
immune regulators that is conserved
from insects to mammals. In the malaria vector mosquito
Anopheles
coluzzii
, the peptidoglycan
receptor PGRPLC activates the Imd pathway limiting both t
he microbiota load and
Plasmodium
infection. Here, we carried out an RNAi screen to examine the rol
e of all seven
Anopheles
PGRPs in
infections with
Plasmodium berghei
and
Plasmodium falciparum
. We show that, in addition to
PGRPLC, PGRPLA and PGRPS2/S3 also participate in antiparas
itic 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, respective
ly. Our data demonstrate that PGRPs
are important regulators of the mosquito epithelial immunity and vector comp
etence.