Role of CD200 in dendritic cells infection by Leishmania (Leishmania) amazonensis

• Grant number: 25/02593-6
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: July 01, 2025
• End date: May 31, 2028
• Field of knowledge: Biological Sciences - Parasitology - Protozoology of Parasites
• Principal Investigator: Mauro Javier Cortez Véliz
• Grantee: Osayanne Fernandes Martins Lopes
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Leishmaniasis is a neglected tropical disease caused by Leishmania protozoa. The disease establishment and the infection process depend on the host-parasite interaction. Macrophages, neutrophils, and dendritic cells (DCs) are the main targets of Leishmania during the infection process. DCs are essential for the development of adaptive immunity against the parasite since they present the antigen to T cells. However, studies indicate that Leishmania can alter the cellular and immunological processes of DCs, reducing the surface molecule expression necessary in the antigen presentation process or preventing their migration to the lymph nodes. On the other hand, amastigotes of L. (L.) amazonensis are capable of inducing the CD200 expression in macrophages, a host immunosuppressive glycoprotein which, by binding to its receptor CD200R, favors the parasite proliferation and intracellular survival, as it inhibits the nitric oxide leishmanicidal mechanism in infected cells. Considering the CD200 expression importance in L. (L.) amazonensis infection, the main objective of this project will be to determine the role of this ligand in the parasite's infection process in DC. In vitro infections of bone marrow-derived DCs from mice with lesions and axenic amastigotes will be carried out to observe the infection profile in these cells (proliferation and survival in these cells) and treatments with anti-CD200 antibodies will be used in in vitro DC and in vivo infections to analyze the importance of CD200 in infection associated with DCs. The project aims to study the importance of CD200 in DCs in an attempt to unravel the gaps in the immune response of animals with leishmaniasis. (AU)