Humoral immune response to haptens of L. (L.) infantum chagasi by detection of specific and natural antibodies in experimental and natural visceral leishmaniasis

• Grant number: 17/14675-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: December 01, 2019
• End date: April 30, 2023
• Field of knowledge: Biological Sciences - Parasitology - Protozoology of Parasites
• Principal Investigator: Heitor Franco de Andrade Junior
• Grantee: Camila Aparecida de Carvalho
• Host Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

There is a large amount of immunoglobulins in the serum of patients and animals with visceral leishmaniasis (VL), which may be involved in or resulting from its pathogenesis. Antigenic characterization of antibodies produced in VL is poorly defined and can be targeted to antigens of different classes, such as proteins, glycoproteins and carbohydrates. The involvement of haptens in the humoral immune response during VL is poorly explored, especially when considering its extensive membrane or glycocalyx composition of Leishmania spp. parasites, being influential in mechanisms of evasion and modulation of the immune response of the host. The usual ELISA tests have limitations in detecting antibodies directed to other antigenic groups, such as haptens, due to binding characteristics of the solid support. This will only be possible through the identification, characterization and transformation of haptens for affinity to the solid support. For this, haptens will be conjugated to supporting proteins that allow their application in ELISA, allowing the characterization of antibodies specific to this antigenic group. We intend to characterize the reactivity profile of IgG, IgM and IgA antibodies against these haptens in serum samples with experimental and natural VL by Leishmania (L.) infantum chagasi. The occurrence of natural antibodies (anti-±-gal) will also be determined in the study groups and the possible occurrence of cross-reactivity will be evaluated. The study and development of alternative methods for the detection of antibodies against haptens during VL directly influence the elucidation of the role of antibodies during the disease and the interpretation of the serological tests used for its diagnosis.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

APARECIDA DE CARVALHO, CAMILA; MITSUYOSHI HIRAMOTO, ROBERTO; REGINA MEIRELES, LUCIANA; FRANCO DE ANDRADE JUNIOR, HEITOR. Serum antibodies blocked by glycan antigens in canine visceral leishmaniasis serology are mostly IgA immune complexes. Parasitology, v. 148, n. 12, p. 1509-1515, OCT 2021. (17/14675-0, 17/26558-9)

DE CARVALHO, CAMILA APARECIDA; FERRAO, THIAGO FIDELIS; CAVALCANTE, FERNANDA SIQUEIRA; NOVAIS DE FREITAS, FLAVIA REGINA; MEIRELES, LUCIANA REGINA; DE ANDRADE JUNIOR, HEITOR FRANCO. Early high avidity specific IgG production in experimental hamster visceral leishmaniasis. Parasitology Research, v. 119, n. 11, AUG 2020. (17/26558-9, 17/14675-0)