Apolipophorin-III mediates antiplasmodial epithelial responses in Anopheles gambiae (G3) mosquitoes.
BACKGROUND
Apolipophorin-III (ApoLp-III) is known to play an important role in lipid transport and innate immunity in lepidopteran insects. However, there is no evidence of involvement of ApoLp-IIIs in the immune responses of dipteran insects such as Drosophila and mosquitoes.


RESULTS
We report the molecular and functional characterization of An. gambiae apolipophorin-III (AgApoLp-III). Mosquito ApoLp-IIIs have diverged extensively from those of lepidopteran insects; however, the predicted tertiary structure of AgApoLp-III is similar to that of Manduca sexta (tobacco hornworm). We found that AgApoLp-III mRNA expression is strongly induced in the midgut of An. gambiae (G3 strain) mosquitoes in response to Plasmodium berghei infection. Furthermore, immunofluorescence stainings revealed that high levels of AgApoLp-III protein accumulate in the cytoplasm of Plasmodium-invaded cells and AgApoLp-III silencing increases the intensity of P. berghei infection by five fold.


CONCLUSIONS
There are broad differences in the midgut epithelial responses to Plasmodium invasion between An. gambiae strains. In the G3 strain of An. gambiae AgApoLp-III participates in midgut epithelial defense responses that limit Plasmodium infection.
Mosquito Immunity and Vector Competence Unit, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America.
Lalita
L
Gupta
Ju Young
JY
Noh
Yong Hun
YH
Jo
Seung Han
SH
Oh
Sanjeev
S
Kumar
Mi Young
MY
Noh
Yong Seok
YS
Lee
Sung-Jae
SJ
Cha
Sook Jae
SJ
Seo
Iksoo
I
Kim
Yeon Soo
YS
Han
Carolina
C
Barillas-Mury
D000595:Amino Acid Sequence; D000818:Animals; D000852:Anopheles / Q000276:immunology* / Q000469:parasitology; D001053:Apolipoproteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D001483:Base Sequence; D015153:Blotting, Western; D004064:Digestive System / Q000276:immunology / Q000378:metabolism / Q000469:parasitology; D004848:Epithelium / Q000276:immunology / Q000378:metabolism / Q000469:parasitology; D005260:Female; D015870:Gene Expression; D006790:Host-Parasite Interactions; D019476:Insect Proteins / Q000737:chemistry / Q000145:classification / Q000276:immunology*; D007303:Insect Vectors / Q000276:immunology / Q000469:parasitology; D051379:Mice; D008807:Mice, Inbred BALB C; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D010962:Plasmodium berghei / Q000276:immunology* / Q000502:physiology; D017510:Protein Folding; D017433:Protein Structure, Secondary; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
D001053:Apolipoproteins; D019476:Insect Proteins; D012333:RNA, Messenger; C042470:apolipophorin III