Discovery of markers of exposure specific to bites of Lutzomyia longipalpis, the vector of Leishmania infantum chagasi in Latin America
Authors: David Reynoso
Nicolas Collin
Fabiano Oliveira
Dia-Eldin Elnaiem
Ana Paula de Souza
Carlos H N Costa
Ivete Mendonca
Jesus G Valenzuela
Arlene Caldas
Ryan Jochim
Aldina Barral
Cláudia I Brodskyn
Amy Seitz
Camila Indiani de Oliveira
Petr Volf
Shaden Kamhawi
Clarissa Teixeira
Regis Gomes
Journal: PLoS Neglected Tropical Diseases (2010)
Discipline: IMMUNOLOGY
Keywords: Sand flies; Leishmania parasites; salivary molecules; markers; vector exposure
Affiliations: Vector Molecular Biology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America.

Abstract:  Background: Sand flies deliver Leishmania parasites to a host alongside salivary molecules that affect infection outcomes. Though some proteins are immunogenic and have potential as markers of vector exposure, their identity and vector specificity remain elusive. Methodology/principal findings: We screened human, dog, and fox sera from endemic areas of visceral leishmaniasis to identify potential markers of specific exposure to saliva of Lutzomyia longipalpis. Human and dog sera were further tested against additional sand fly species. Recombinant proteins of nine transcripts encoding secreted salivary molecules of Lu. longipalpis were produced, purified, and tested for antigenicity and specificity. Use of recombinant proteins corresponding to immunogenic molecules in Lu. longipalpis saliva identified LJM17 and LJM11 as potential markers of exposure. LJM17 was recognized by human, dog, and fox sera; LJM11 by humans and dogs. Notably, LJM17 and LJM11 were specifically recognized by humans exposed to Lu. longipalpis but not by individuals exposed to Lu. intermedia. Conclusions/significance: Salivary recombinant proteins are of value as markers of vector exposure. In humans, LJM17 and LJM11 emerged as potential markers of specific exposure to Lu. longipalpis, the vector of Leishmania infantum chagasi in Latin America. In dogs, LJM17, LJM11, LJL13, LJL23, and LJL143 emerged as potential markers of sand fly exposure. Testing these recombinant proteins in large scale studies will validate their usefulness as specific markers of Lu. longipalpis exposure in humans and of sand fly exposure in dogs. 

Retracted: No

PubPeer comments:
 Figure 5 shows blots with sera from Leishmania infected dogs and humans, as well as negative control. In the  Dog  LJL23 panel, one of the lanes from the negative sera appears to consist of a blank rectangular patch, with a very different noise pattern than the surrounding lanes. Could the authors please check? ![file] , 
 (trying this again, since my previous comment was moderated). Figure 5. * Green arrow: In the right LJL23 panel, the middle  - lane has a very different background than the other lanes. If the image is made a bit darker, it appears to show a smooth pinkish rectangle. ![file] , 
 Dear Dr. Elisabeth M Bik, I will check into this and get back to you. I will need to check all the figures from 2009-2010 when we were working on this paper. I will check the original western blot, the scanning images of the western blot as well as any other figures we prepared for this publication. As soon as I have this information I will provide an answer to these two questions. Best Regards, Jesus G. Valenzuela ,