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Loredan, D. G.

Publications and source records attributed to Loredan, D. G..

2 recordsLinked to original sources

A role for BCL6 in maintaining CX3CR1+ CD4+ T cells during helminth infection

Distinct subsets of T lymphocytes express CX3CR1 under inflammatory conditions, but little is known about CX3CR1+ CD4+ T cells during Type 2 inflammation in helminth infections. Here, we used a fate-mapping mouse model to characterize CX3CR1+ CD4+ T cells during both acute Nippostrongylus brasiliensis and chronic Schistosoma mansoni helminth infections, revealing CX3CR1+ CD4+ T cells to be an activated tissue homing subset with varying capacity for cytokine production. Tracking these cells over time revealed that maintenance of CX3CR1 itself along with a TH2 phenotype conferred a survival advantage in the inflamed tissue. Single-cell RNA-sequencing analysis of fate-mapped CX3CR1+ CD4+ T cells from both the peripheral tissue and the spleen revealed a considerable level of diversity and identified a distinct population of BCL6+ TCF-1+ PD1+ CD4+ T cells in the spleen during helminth infections. Conditional deletion of BCL6 in CX3CR1+ cells result in fewer CX3CR1+ CD4+ during infection, indicating a role in sustaining CD4+ T cell responses to helminth infections. Overall, our studies revealed the behavior and heterogeneity of CX3CR1+ CD4+ T cells during Type 2 inflammation in helminth infections and identified BCL6 to be important in their maintenance.

immunology↗

Single-cell analysis of CX3CR1+ cells reveal a pathogenic role for BIRC5+ myeloid proliferating cells driven by Staphylococcus aureus leukotoxins

Our previous studies identified a population of stem cell-like proliferating myeloid cells within inflamed tissues that could serve as a reservoir for tissue macrophages to adopt different activation states depending on the microenvironment. By lineage tracing cells derived from CX3CR1+ precursors in mice during infection and profiling by scRNA-seq, here we identify a cluster of BIRC5+ myeloid cells that expanded in the liver during either chronic infection with the parasite Schistosoma mansoni or the bacterial pathogen Staphylococcus aureus. In the absence of tissue damaging toxins, S. aureus infection does not elicit these BIRC5+ cells. Moreover, deletion of BIRC5 from CX3CR1 expressing cells results in improved survival during S. aureus infection. Hence, the combination of scRNA-Seq and genetic fate mapping CX3CR1+ cells revealed a toxin dependent pathogenic role for BIRC5 in myeloid cells during S. aureus infection.

immunology↗