Peripheral CD8 T cell tolerance is a checkpoint in both autoimmune disease and anti-cancer immunity. Despite its importance, the relationship between tolerance-induced states and other CD8 T cell differentiation states remains unclear. Using flow cytometric phenotyping, single-cell RNA sequencing (scRNA-seq), and chromatin accessibility profiling, we demonstrated that in vivo peripheral tolerance to a self-antigen triggered a fundamentally distinct differentiation state separate from exhaustion, memory, and functional effector cells but analogous to cells defectively primed against tumors.
View Article and Find Full Text PDFMalaria is caused by Plasmodium species transmitted by Anopheles mosquitoes. Following a mosquito bite, Plasmodium sporozoites migrate from skin to liver, where extensive replication occurs, emerging later as merozoites that can infect red blood cells and cause symptoms of disease. As liver tissue-resident memory T cells (Trm cells) have recently been shown to control liver-stage infections, we embarked on a messenger RNA (mRNA)-based vaccine strategy to induce liver Trm cells to prevent malaria.
View Article and Find Full Text PDFThorough understanding of the role of CD4 T cells in immunity can be greatly assisted by the study of responses to defined specificities. This requires knowledge of -derived immunogenic epitopes, of which only a few have been identified, especially for the mouse C57BL/6 background. We recently developed a TCR transgenic mouse line, termed PbT-II, that produces CD4 T cells specific for an MHC class II (I-A)-restricted epitope and is responsive to both sporozoites and blood-stage .
View Article and Find Full Text PDFExpert Rev Vaccines
February 2021
Introduction: Tissue-resident memory T cells (T cells) are powerful mediators of protracted adaptive immunity to infection in peripheral organs. Harnessing T cells through vaccination hence promises unprecedented potential for protection against infection. A paramount example of this is malaria, a major infectious disease for which immunity through traditional vaccination strategies remains challenging.
View Article and Find Full Text PDFLiver resident-memory CD8 T cells (T cells) can kill liver-stage -infected cells and prevent malaria, but simple vaccines for generating this important immune population are lacking. Here, we report the development of a fully synthetic self-adjuvanting glycolipid-peptide conjugate vaccine designed to efficiently induce liver T cells. Upon cleavage in vivo, the glycolipid-peptide conjugate vaccine releases an MHC I-restricted peptide epitope (to stimulate -specific CD8 T cells) and an adjuvant component, the NKT cell agonist α-galactosylceramide (α-GalCer).
View Article and Find Full Text PDFLiver-resident memory CD8 T (T) cells remain in and constantly patrol the liver to elicit rapid immunity upon antigen encounter and can mediate efficient protection against liver-stage Plasmodium infection. This finding has prompted the development of immunization strategies where T cells are activated in the spleen and then trapped in the liver to form T cells. Here, we identify PbRPL6, a H2-K-restricted epitope from the putative 60S ribosomal protein L6 (RPL6) of Plasmodium berghei ANKA, as an optimal antigen for endogenous liver T cell generation and protection against malaria.
View Article and Find Full Text PDFMalaria causes hepatic inflammation and damage, which contribute to disease severity. The pro-inflammatory cytokine interleukin (IL)-1α is released by non-hematopoietic or hematopoietic cells during liver injury. This study established the role of IL-1α in the liver pathology caused by blood-stage P.
View Article and Find Full Text PDFA complete understanding of the mechanisms underlying the acquisition of protective immunity is crucial to improve vaccine strategies to eradicate malaria. However, it is still unclear whether recognition of damage signals influences the immune response to Plasmodium infection. Adenosine triphosphate (ATP) accumulates in infected erythrocytes and is released into the extracellular milieu through ion channels in the erythrocyte membrane or upon erythrocyte rupture.
View Article and Find Full Text PDFPurpose: Trachoma, caused by the bacterium Chlamydia trachomatis, is a chronic, recurrent inflammatory disease that affects the cornea and conjunctiva. Trachoma is the leading infectious cause of avoidable blindness worldwide. Its prevalence is higher among individuals of low socioeconomic status, and trachoma is common in indigenous communities.
View Article and Find Full Text PDFDendritic cells (DCs) are phagocytes that are highly specialized for antigen presentation. Heterogeneous populations of macrophages and DCs form a phagocyte network inside the red pulp (RP) of the spleen, which is a major site for the control of blood-borne infections such as malaria. However, the dynamics of splenic DCs during Plasmodium infections are poorly understood, limiting our knowledge regarding their protective role in malaria.
View Article and Find Full Text PDFThis study reports on the design, synthesis and antiparasitic activity of three new semi-synthetic naphthoquinones structurally related to the naturally-occurring lapachol and lapachone. Of the compounds tested, 3-(3-methylbut-1-en-1-yl)-1,4-dioxo-1,4-dihydronaphthalen-2-yl acetate (1) was the most active against Plasmodium falciparum among both natural and semi-synthetic naphthoquinones, showing potent and selective activity. Compound 1 was able to reduce the in vitro parasite burden, in vitro parasite cell cycle, as well as the blood parasitemia in Plasmodium berghei-infected mice.
View Article and Find Full Text PDFThe antimalarial activities of physalins B, D, F, and G (1-4), isolated from Physalis angulata, were investigated. In silico analysis using the similarity ensemble approach (SEA) database predicted the antimalarial activity of each of these compounds, which were shown using an in vitro assay against Plasmodium falciparum. However, treatment of P.
View Article and Find Full Text PDFObjectives: Although endoscopic treatment provides a high rate of success in children with grades II-IV vesicoureteral reflux (VUR), its role in the management of grade V reflux has been questioned. In this study we reviewed our 21-yr experience of endoscopic treatment in children with grade V primary VUR.
Methods: We retrospectively reviewed the medical records of 132 children who underwent endoscopic treatment for primary grade V reflux from 1984 to 2004.