Identification of Immunoreactive Leishmania infantum Protein Antigens to Asymptomatic Dog Sera through Combined Immunoproteomics and Bioinformatics Analysis

Abstract

Leishmania infantum is the etiologic agent of zoonotic visceral leishmaniasis (VL) in countries in the Mediterranean basin, where dogs are the domestic reservoirs and represent important elements in the transmission of the disease. Since the major focal areas of human VL exhibit a high prevalence of seropositive dogs, the control of canine VL could reduce the infection rate in humans. Efforts toward this have focused on the improvement of diagnostic tools, as well as on vaccine development. The identification of parasite antigens including suitable major histocompatibility complex (MHC) class I- and/or II-restricted epitopes is very important since disease protection is characterized by strong and long-lasting CD8+ T and CD4+ Th1 cell-dominated immunity. In the present study, total protein extract from late-log phase L. infantum promastigotes was analyzed by two-dimensional western blots and probed with sera from asymptomatic and symptomatic dogs. A total of 42 protein spots were found to differentially react with IgG from asymptomatic dogs, while 17 of these identified by Coommasie stain were extracted and analyzed. Of these, 21 proteins were identified by mass spectrometry; they were mainly involved in metabolism and stress responses. An in silico analysis predicted that the chaperonin HSP60, dihydrolipoamide dehydrogenase, enolase, cyclophilin 2, cyclophilin 40, and one hypothetical protein contain promiscuous MHCI and/or MHCII epitopes. Our results suggest that the combination of immunoproteomics and bioinformatics analyses is a promising method for the identification of novel candidate antigens for vaccine development or with potential use in the development of sensitive diagnostic tests.

Antibody levels to Malassezia pachydermatis and Staphylococcus pseudintermedius in atopic dogs and their relationship with lesion scores

“…The severity of the skin lesions was determined based on the CADLI. 13 The same investigator evaluated all subjects.…”

“…11,12 The aim of this study was to investigate levels of allergen-specific IgE, IgG1 and IgG2 directed against M. pachydermatis and S. pseudintermedius, with total IgG levels, then correlate them with lesion severity in cAD as defined by the Canine Atopic Dermatitis Lesion Index (CADLI). 13…”

Immunogenicity Prediction by VaxiJen: A Ten Year Overview

“…Dogs are the domestic reservoirs of the parasite Leishmania infantum (L. infantum) causing visceral leishmaniasis (VL) in humans and dogs [180]. The control of canine VL could reduce human infection rates.…”

“…The control of canine VL could reduce human infection rates. Agallou et al [180] analyzed the total protein extract from latelog phase L. infantum promastigotes using two-dimensional western blots and probing with sera from asymptomatic and symptomatic dogs. Fourty-two protein spots were found to react differentially with IgG from asymptomatic dogs.…”

Detection of Leishmania (L.) infantum in stray dogs by molecular techniques with sensitive species-specific primers

“…It is estimated that about 700 autochthonous VL human cases due to L. infantum are reported yearly and the average seroprevalence in domestic dogs is up to 25%, which has exhibited an expansion toward new locations in Europe by the increased mobility of dogs in association with other determinants of global change, such as climatic alterations and international tourism (Maia & Cardoso 2015). Also, the major focal areas of human VL exhibit a high prevalence of seropositive dogs (Athanasiou et al 2012;Agallou et al 2016). In urban areas, the dog is considered the main reservoir, whereas wild carnivores are the most important reservoirs in rural areas (Acha & Szyfres 2003).…”