Methods for diagnosis of canine leishmaniasis and immune response to infection

https://www.repositorio.ufop.br/bitstream/123456789/1043/1/ARTIGO_ParasiteDensityImpaired.pdf

Parasite density and impaired biochemical/hematological status are associated with severe clinical aspects of canine visceral leishmaniasis

https://www.cell.com/parasitology/pdf/S0169-4758(00)01651-3.pdf

Evolutionarily Conserved Proteins as Prominent Immunogens during Leishmania Infections

This study compared a panel of 10 enzyme-linked immunosorbent assays (ELISAs) for the serodiagnosis of Mediterranean visceral leishmaniasis (MVL). The ELISAs were based on either one of the following Leishmania antigens: crude soluble Leishmania antigens (SLAs), recombinant (r) antigens (namely: rgp63, rK39, gene B protein, r H2A and r H2B histones proteins, rLACK, rPSA-2, r P20) and purified lipophosphoglycan. Most of the test antigens showed good performance (sensitivity > 85%, specificity > 80%). rK39 and SLA-based ELISA gave the best results in terms of sensitivity (100%) and predictive value of the negative (100%). The best specificity (97%) and the best predictive value of the positive (92%) were obtained with rK39. These results show that several Leishmania antigens are suitable to design a diagnostic ELISA of MVL. However, recombinant proteins add little to the classic crude SLA, which still represents a very good and less costly alternative.

Comparative evaluation of elisas based on ten recombinant or purified leishmania antigens for the serodiagnosis of mediterranean visceral leishmaniasis

Vaccination with a plasmid DNA cocktail encoding the nucleosomal histones of Leishmania confers protection against murine cutaneous leishmaniosis.

In this study we show that sera from dogs naturally infected with Leishmania infantum contain antibodies that specifically react against the parasite H2B and H4 histones. The Leishmania H2B and the amino-terminal region of the histone H4, expressed as fusion proteins, when confronted with sera from canine viscerocutaneous leishmaniasis (VCL) dogs, were recognized by 63% and 47%, respectively. No reactivity was detected when sera from dogs naturally infected with pathogens other than Leishmania were used. Using a collection of synthetic peptides covering the complete sequence of both proteins, we have determined that the main linear antigenic determinants are located in the amino-terminal domains of these histones. The humoral response against histones H2B and H4 induced during canine leishmaniasis was found to be specific for Leishmania histones, since no cross-reactivity of the VCL sera with mammal histones was observed. Also, a comparative study of the prevalence of antibodies among VCL sera against the four core histones of L. infantum was performed. Although a large heterogeneity of the humoral responses against these proteins was found, histones H2A and H3 seem to be more prevalent immunogens than histones H2B and H4 during canine natural leishmaniasis. The origin of the anti-histone humoral response and its possible implications in the pathogenesis of Leishmania infection are discussed.

M J Perez

Papers

Antigenicity of the Leishmania infantum histones H2B and H4 during canine viscerocutaneous leishmaniasis