Immunity Commons^™

Stat3 Inhibits Type I Interferon Signaling In Type I Conventional Dendritic Cells, Taylor Chrisikos

Dissertations & Theses (Open Access)

Conventional dendritic cells (cDCs) are an essential immune population, responsible for controlling adaptive immunity and tolerance. Recently, type I cDCs (cDC1s) have been delineated as a distinct cDC subset, uniquely responsible for coordinating T cell-mediated immunity against pathogens and tumors. Although the importance of cDC1s is now well established, the mechanisms that regulate cDC1 function remain largely unknown. Signal Transducer and Activator of Transcription 3 (STAT3) mediates the intracellular signaling of interleukin 10 (IL-10), an immunosuppressive cytokine. Therefore, we hypothesized that STAT3 and IL-10 inhibit cDC1 function and induction of T cell-mediated immunity. Herein, we show that IL-10 inhibits polyinosinic:polycytidylic …

Investigating The Role Of Quaking In Antigen Uptake And Cross-Presentation By Dendritic Cells, Yating Li

Dissertations & Theses (Open Access)

Dendritic cells (DCs) are considered the most potent antigen presenting cells (APC) due to their superior capability of cross-presenting exogenous antigens to CD8⁺ T cell for strong adaptive immune responses. They internalize foreign antigens by phagocytosis, endocytosis or macropinocytosis, which are then processed in endosomal compartments and loaded onto MHC Class I molecules. However, the molecular mechanisms regulating exogenous antigen uptake and cross-presentation by DCs are not fully understood.

In this study, we discovered that an RNA-binding protein, Quaking (QKI) plays a pivotal role in antigen uptake by DCs. Our previous studies in neural stem cells and microglia have …

Immune Recognition Of Self Nucleic Acids Driven By Endogenous Antimicrobial Peptides: Role In Autoimmunity, Dipyaman Ganguly

Dissertations & Theses (Open Access)

Innate immune recognition of extracellular host-derived self-DNA and self-RNA is prevented by endosomal seclusion of the Toll-like receptors (TLRs) in the dendritic cells (DCs). However, in psoriasis plasmacytoid dendritic cells have been found to be able to sense self-DNA molecules in complex with the endogenous cationic antimicrobial peptide LL37, which are internalized into the endosomal compartments and thus can access TLR9. We investigated whether this endogenous peptide can also interact with extracellular self-RNA and lead to DC activation. We found that LL37 binds self-RNA as well as self-DNA going into an electrostatic interaction; forms micro-aggregates of nano-scale particles protected from …