Title
Role of the PD-1/PD-L1 Pathway in Experimental Trypanosoma cruzi Infection and Potential Therapeutic Options
Date Issued
23 June 2022
Access level
open access
Resource Type
journal article
Publisher(s)
Frontiers Media S.A.
Abstract
Chagas disease (CD) is a neglected chronic infection caused by the protozoan parasite Trypanosoma cruzi (T. cruzi). A significant portion of infected people develops cardiac or digestive alterations over a lifetime. Since several chronic infections associated with antigen persistence and inflammation have been shown to lead to T cell exhaustion, new therapies targeting co-inhibitory receptors to regain T cell activity are under consideration. This study explored immune therapeutic approaches targeting the inhibitory PD-1/PD-L pathway in an experimental model for CD. Infected PD-L1 knockout mice (PD-L1 KO) showed increased systemic parasitemia in blood although no significant differences in parasite load were observed in different organs. Furthermore, we found no significant differences in the frequency of activated T cells or proinflammatory cytokine production when compared to WT counterparts. PD-L1 deficiency led to the production of IL-10 by CD8+ T cells and an upregulation of Tim-3 and CD244 (2B4). Unexpectedly, the lack of PD-L1 did not contribute to a significantly improved T cell response to infection. Single blockade and combined blockade of PD-1 and Tim-3 using monoclonal antibodies confirmed the results observed in infected. PD-L1 KO mice. Our results describe for the first time that the interruption of the PD-1/PD-L1 axis during acute T. cruzi infection does not necessarily enhance the immune response against this parasite. Its interruption favors increased levels of parasitemia and sustained upregulation of other co-inhibitory receptors as well as the production of regulatory cytokines. These results suggest that the clinical application of immune therapeutic approaches targeting the PD-1/PD-L1 axis in CD might be risky and associated with adverse events. It highlights that more research is urgently needed to better understand the immune regulation of T cells in CD before designing immune therapeutic approaches for a clinical context.
Volume
13
Language
English
OCDE Knowledge area
Inmunología Parasitología
Scopus EID
2-s2.0-85133845709
PubMed ID
Source
Frontiers in Immunology
ISSN of the container
16643224
Sponsor(s)
YA was supported by DAAD (Deutscher Akademischer Austausch Dienst) German Academic Exchange Service with Research Grant for Doctoral Students and Young Academics (500154434) Ref.# 91537601. RIG was a recipient of a Merit-based Ph.D. scholarship from the Konrad Adenauer Foundation (KAS), Germany. We thank the staff from the BNITM Animal Facility, Christiane Steeg and Ulricke Richardt for their excellent technical support. YA. expresses her sincere gratitude to the DAAD (Deutscher Akademischer Austausch Dienst) for their generous support during her stay in Germany. RG thanks the Konrad Adenauer Foundation (KAS, Germany) for the scholarship and support.
Sources of information: Directorio de Producción Científica Scopus