title: A new role for an old antimicrobial: lysozyme c-1 can function to protect malaria parasites in Anopheles mosquitoes.
abstract: BACKGROUND
  Plasmodium requires an obligatory life stage in its mosquito host. The parasites encounter a number of insults while journeying through this host and have developed mechanisms to avoid host defenses. Lysozymes are a family of important antimicrobial immune effectors produced by mosquitoes in response to microbial challenge.
  
  
  RESULTS
  A mosquito lysozyme was identified as a protective agonist for Plasmodium. Immunohistochemical analyses demonstrated that Anopheles gambiae lysozyme c-1 binds to oocysts of Plasmodium berghei and Plasmodium falciparum at 2 and 5 days after infection. Similar results were observed with Anopheles stephensi and P. falciparum, suggesting wide occurrence of this phenomenon across parasite and vector species. Lysozyme c-1 did not bind to cultured ookinetes nor did recombinant lysozyme c-1 affect ookinete viability. dsRNA-mediated silencing of LYSC-1 in Anopheles gambiae significantly reduced the intensity and the prevalence of Plasmodium berghei infection. We conclude that this host antibacterial protein directly interacts with and facilitates development of Plasmodium oocysts within the mosquito.
  
  
  CONCLUSIONS
  This work identifies mosquito lysozyme c-1 as a positive mediator of Plasmodium development as its reduction reduces parasite load in the mosquito host. These findings improve our understanding of parasite development and provide a novel target to interrupt parasite transmission to human hosts.
authors.affiliation: Department of Entomology, University of Wisconsin, Madison, Wisconsin, United States of America.
authors.forename: Mayur K
authors.initials: MK
authors.lastname: Kajla
authors.forename: Lei
authors.initials: L
authors.lastname: Shi
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.forename: Shirley
authors.initials: S
authors.lastname: Luckhart
authors.forename: Jianyong
authors.initials: J
authors.lastname: Li
authors.forename: Susan M
authors.initials: SM
authors.lastname: Paskewitz
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000852:Anopheles / Q000187:drug effects / Q000201:enzymology* / Q000469:parasitology*; D000890:Anti-Infective Agents / Q000378:metabolism*; D000906:Antibodies / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development; D015169:Colony Count, Microbial; D004064:Digestive System / Q000187:drug effects / Q000201:enzymology; D055785:Gene Knockdown Techniques; D020868:Gene Silencing / Q000187:drug effects; D006801:Humans; D008288:Malaria / Q000469:parasitology*; D008969:Molecular Sequence Data; D009113:Muramidase / Q000737:chemistry / Q000378:metabolism*; D033661:Oocysts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D010271:Parasites / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D010858:Pigmentation / Q000187:drug effects; D010962:Plasmodium berghei / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D010963:Plasmodium falciparum / Q000166:cytology / Q000187:drug effects / Q000502:physiology
chemical_list: D000890:Anti-Infective Agents; D000906:Antibodies; D009113:Muramidase