Infection of dogs by Leishmania infantum elicits a general response of IgG subclasses

Abstract

Leishmania infantum is the etiological agent of zoonotic visceral leishmaniasis. In endemic areas, canine infections are considered the main source of infection for human populations. Therefore, any control of human leishmaniasis must include the control of canine infections. Chemotherapy of leishmaniasis is inadequate and canine immunoprophylaxis has important limitations. Reports on the response of infected dogs are abundant but no clear picture of immune events has emerged. To shed some light on these shortcomings the specific IgG subclass response was followed in 20 Beagle dogs experimentally infected with L. infantum using monoclonal antibodies (MAb) specific for canine IgG1, IgG2, IgG3 and IgG4, along with ELISA and flow cytometry. Results showed that parasitic infection elicits a general response of all IgG subclasses, with a predominant IgG1 response and without any evidence of IgG1/IgG2 dichotomy. These findings suggest that the inconsistent results reported previously could be related to the lack of specific reagents and not to the actual differences in the immune response of infected animals. Differential IgG subclass reactivity in ELISA and cytometry and the analysis of the reacting antigens could facilitate the diagnosis and prognosis of the disease and provide a useful tool for adequate therapeutics and vaccine development against leishmaniasis.

O Uso Terapêutico De Células-Tronco Mesenquimais Pode Ser Um Meio De Transmissão Da Leishmaniose

“…Espera-se que, durante a leishmaniose visceral canina (LVC), os cães sintomáticos e aqueles com alto parasitismo estejam associados a um aumento nas imunoglobulinas IgG, IgG2, IgM, IgA e IgE, enquanto os cães assintomáticos e aqueles com baixo parasitismo estejam associados a um aumento na IgG1 (REIS, 2009). O curso crônico da doença, o atraso na soroconversão, as reações cruzadas nos testes são todos mecanismos conhecidos que dificultam o diagnóstico e podem fazer com que a doença seja detectada várias semanas após a infecção (REIS, 2009;OLÍAS-MOLERO, 2020).…”

Antileishmanial Drug Discovery and Development: Time to Reset the Model?

“…Leishmanial infection elicits a strong immune response in the infected host, which leads to the resolution of the process or the extension of the disease [110,111,[160][161][162][163][164]. Information on the fine-tuning of the immune system is yet fragmentary, and the laboratory models, particularly mice [165,166], are not adequate, since the Th1/Th2 dichotomy apparently is not found in any of the actual hosts of VL, humans, and dogs [167][168][169][170][171] and is surely an oversimplification [172,173].…”