Biology subjects

Jiang, R. R.

Publications and source records attributed to Jiang, R. R..

3 recordsLinked to original sources

bioRxiv2026

Increased Expression and Altered Functional Activities of Immune Receptors TREM1, PD-L1, and Others on Hematopoietic Progenitor Cells in a Mouse Model of Rheumatoid Arthritis

Hematopoietic stem and progenitor cells (HSPCs) sustain the production of hundreds of billions of new cells per day to maintain our blood and immune system. In this process, HSPCs regulate the hematopoietic output by sensing and integrating diverse physiological cues. Thus, HSPCs express many receptors traditionally studied for their functions in the immune system, and this allows HSPCs to directly detect microbial compounds, endogenous danger signals, cytokines, and other inflammatory mediators. However, how the expression levels of such receptors on HSPCs change under chronic inflammation and how such changes alter HSPC functions and immune cell production remains unexplored. Working in a murine model of rheumatoid arthritis, we demonstrate the induction of microbial sensors TLR2 and CD14, orphan inflammatory receptor TREM1, and checkpoint receptor PD-L1 on HSPCs and particularly the myeloid progenitor cells in the arthritis-afflicted mice. Furthermore, we demonstrate that the stimulation of HSPCs through these receptors in culture can significantly alter the dynamics of cell expansion and differentiation, with distinct responses from HSPCs of arthritis-afflicted versus healthy control mice. We hypothesize that the induction and stimulation of HSPCs through these immune receptors under chronic inflammation may impact the output and functional properties of their immune cell progeny, positing HSPCs as central players in the pathogenic inflammatory responses of rheumatoid arthritis and potentially other chronic inflammatory diseases. HIGHLIGHTSO_LIHematopoietic progenitor cells in murine models of rheumatoid arthritis show an upregulation of immune receptors TREM1, PD-L1, TLR2, and CD14. C_LIO_LIStimulation of murine hematopoietic stem and progenitor cells through these receptors in culture alters the dynamics of their expansion and differentiation. C_LIO_LIIn such cultures, hematopoietic stem and progenitor cells from mice afflicted with rheumatoid arthritis show altered responses to stimulation as compared to healthy controls. C_LI

immunology↗

bioRxiv2025

Trained Immunity Affecting Dendritic Cell Differentiation and Function in Rheumatoid Arthritis

Rheumatoid arthritis affects [~]0.5-1% of the adult population and results in joint inflammation, chronic pain, and many systemic comorbidities. Immune and inflammatory tissue damage is the main pathogenic mechanism in rheumatoid arthritis, and involves the hyperactivation of both innate and adaptive immune systems. Trained immunity has become well established as an important feature of the innate immune system that allows the host to mount functionally altered immune responses based on their previous history of immune exposures, independently of the classical adaptive immunological memory. However, the role of trained immunity in systemic autoimmune and inflammatory disorders remains poorly understood. In the current work, we demonstrate that emergency myelopoiesis is induced in chronic rheumatoid arthritis in murine models and acts not only to enhance innate immune cell numbers but also to produce functionally altered innate immune cells. Such effects are cell-intrinsic to hematopoietic stem and progenitor cells (HSPCs) and persist independently of the inflammatory disease milieu. Importantly, these trained immunity mechanisms impact not only macrophages but also dendritic cells, which are the major antigen presenting cells that bridge the innate and adaptive immune responses. Trained dendritic cells show changes in global gene expression profiles, and significantly altered responses to recall immune stimulation and capacity for T cell activation. This study therefore represents the first demonstration of dendritic cell trained immunity in rheumatoid arthritis.

immunology↗

bioRxiv2019

Human immune cells infiltrate the lesioned spinal cord and impair recovery after spinal cord injury in humanized mice

Summary PointsO_LIImmune compromised mice require ~4 months of engraftment with human umbilical cord blood CD34+ stem cells to develop a full and functional human immune system\nC_LIO_LIThe human neuroinflammatory response elicited after spinal cord injury in humanized mice is limited at 2 months post-engraftment but matures by 4 months\nC_LIO_LIIntraspinal neuroinflammation consists of a florid human T cell and macrophage response, and human T cells co-localize with human macrophages\nC_LIO_LIA human intraspinal neuroinflammatory response exacerbates lesion pathology and impairs functional recovery\nC_LI\n\nAbstractHumanized mice are a useful tool to help better understand how the human immune system responds to central nervous system (CNS) injury. However, the optimal parameters for using humanized mice in preclinical CNS injury models have not been established. Here, we show that it takes 3-4 months after engraftment of neonatal immune compromised mice with human umbilical cord stem cells to generate a robust human immune system. Indeed, sub-optimal human immune cell responses occurred when humanized mice received spinal contusion injuries at 2 months vs. 4 months post-engraftment. Human T cells directly contact human macrophages within the spinal cord lesion of these mice and the development of a mature human immune system was associated with worse lesion pathology and neurological recovery. Together, data in this report establish an optimal experimental framework for using humanized mice to help translate promising preclinical therapies for CNS injury.

neuroscience↗