Targeting FROUNT with disulfiram suppresses macrophage accumulation and its tumor-promoting properties.

Tumor-associated macrophages affect tumor progression and resistance to immune checkpoint therapy. Here, we identify the chemokine signal regulator FROUNT as a target to control tumor-associated macrophages. The low level FROUNT expression in patients with cancer correlates with better clinical outcomes.

Combined treatment with HMGN1 and anti-CD4 depleting antibody reverses T cell exhaustion and exerts robust anti-tumor effects in mice.

Background: Transient depletion of CD4 T cells results in tumor suppression and survival benefit in murine models; however, the tumor progression and recurrence still occur over more long-term monitoring of mice. Thus, we explored an additional strategy to enhance endogenous immune responses by an alarmin, high mobility group nucleosome binding protein 1 (HMGN1).

Methods: The anti-tumor effects of HMGN1, anti-CD4 depleting antibody, and their combined treatment were monitored in the Colon26 or the B16F10 subcutaneous murine models.

Lung fibroblasts express a miR-19a-19b-20a sub-cluster to suppress TGF-β-associated fibroblast activation in murine pulmonary fibrosis.

Lung fibroblasts play a pivotal role in pulmonary fibrosis, a devastating lung disease, by producing extracellular matrix. MicroRNAs (miRNAs) suppress numerous genes post-transcriptionally; however, the roles of miRNAs in activated fibroblasts in fibrotic lungs remain poorly understood. To elucidate these roles, we performed global miRNA-expression profiling of fibroblasts from bleomycin- and silica-induced fibrotic lungs and investigated the functions of miRNAs in activated lung fibroblasts.

Long-Lasting Graft-Derived Donor T Cells Contribute to the Pathogenesis of Chronic Graft-versus-Host Disease in Mice.

Chronic graft-versus-host disease (cGVHD) is a major complication in long-term survivors of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Graft-derived T cells (T) have been implicated in the induction of cGVHD; however, the extent of their contribution to the pathogenesis of cGVHD remains unclear. Using a mouse model of cGVHD, we demonstrate that T predominate over hematopoietic stem cell-derived T cells generated (T) in cGVHD-affected organs such as the liver and lung even at day 63 after allo-HSCT.

A rare subset of skin-tropic regulatory T cells expressing Il10/Gzmb inhibits the cutaneous immune response.

Foxp3 regulatory T cells (Tregs) migrating from the skin to the draining lymph node (dLN) have a strong immunosuppressive effect on the cutaneous immune response. However, the subpopulations responsible for their inhibitory function remain unclear. We investigated single-cell gene expression heterogeneity in Tregs from the dLN of inflamed skin in a contact hypersensitivity model.

Reduced supply of monocyte-derived macrophages leads to a transition from nodular to diffuse lesions and tissue cell activation in silica-induced pulmonary fibrosis in mice.

Pulmonary fibrosis (PF) is an intractable disorder with a poor prognosis. Lung macrophages have been reported to regulate both progression and remission of bleomycin-induced diffuse PF. However, it remains unclear how macrophages contribute to silica-induced progressive nodular PF and the associated tissue cell responses in vivo.

Robust Antitumor Effects of Combined Anti-CD4-Depleting Antibody and Anti-PD-1/PD-L1 Immune Checkpoint Antibody Treatment in Mice.

Depletion of CD4(+) cells in tumor-bearing mice has strong antitumor effects. However, the mechanisms underlying these effects and the therapeutic benefits of CD4(+) cell depletion relative to other immunotherapies have not been fully evaluated. Here, we investigated the antitumor effects of an anti-CD4-depleting mAb as a monotherapy or in combination with immune checkpoint mAbs.

Loss of lymph node fibroblastic reticular cells and high endothelial cells is associated with humoral immunodeficiency in mouse graft-versus-host disease.

Graft-versus-host disease (GVHD) is a major risk factor for prolonged humoral immunodeficiency and vaccine unresponsiveness after allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, the underlying mechanisms for this immunodeficiency are poorly understood. In this article, we describe previously overlooked impacts of GVHD on lymph node (LN) stromal cells involved in humoral immune responses.

Tracking and quantification of dendritic cell migration and antigen trafficking between the skin and lymph nodes.

Skin-derived dendritic cells (DCs) play a crucial role in the maintenance of immune homeostasis due to their role in antigen trafficking from the skin to the draining lymph nodes (dLNs). To quantify the spatiotemporal regulation of skin-derived DCs in vivo, we generated knock-in mice expressing the photoconvertible fluorescent protein KikGR. By exposing the skin or dLN of these mice to violet light, we were able to label and track the migration and turnover of endogenous skin-derived DCs.

Tracking of intertissue migration reveals the origins of tumor-infiltrating monocytes.

Myeloid cells such as monocytes and monocyte-derived macrophages promote tumor progression. Recent reports suggest that extramedullary hematopoiesis sustains a sizable reservoir of tumor-infiltrating monocytes in the spleen. However, the influence of the spleen on tumor development and the extent to which spleen monocytes populate the tumor relative to bone marrow (BM) monocytes remain controversial.

Qualitative rather than quantitative changes are hallmarks of fibroblasts in bleomycin-induced pulmonary fibrosis.

Pulmonary fibrosis is characterized by accumulation of activated fibroblasts that produce excessive amounts of extracellular matrix components such as collagen type I. However, the dynamics and activation signatures of fibroblasts during fibrogenesis remain poorly understood, especially in vivo. We examined changes in lung tissue cell populations and in the phenotype of activated fibroblasts after acute injury in a model of bleomycin-induced pulmonary fibrosis.

Coordinated changes in DNA methylation in antigen-specific memory CD4 T cells.

Memory CD4(+) T cells are central regulators of both humoral and cellular immune responses. T cell differentiation results in specific changes in chromatin structure and DNA methylation of cytokine genes. Although the methylation status of a limited number of gene loci in T cells has been examined, the genome-wide DNA methylation status of memory CD4(+) T cells remains unexplored.

Cellular and molecular mechanisms of chronic inflammation-associated organ fibrosis.

Organ fibrosis is a pathological condition associated with chronic inflammatory diseases. In fibrosis, excessive deposition of extracellular matrix (ECM) severely impairs tissue architecture and function, eventually resulting in organ failure. This process is mediated primarily by the induction of myofibroblasts, which produce large amounts of collagen I, the main component of the ECM.

Myeloid cell population dynamics in healthy and tumor-bearing mice.

Tumor growth is often associated with the aberrant systemic accumulation of myeloid-derived suppressor cells (MDSCs), which are a heterogenous population of cells composed of polymorphonuclear neutrophils, monocytes, macrophages, dendritic cells and early myeloid precursors. These MDSCs are thought to suppress anti-tumor T cell responses in both tumor tissues and secondary lymphoid tissues. Accumulation of MDSCs in these target tissues is a dynamic process associated with medullary and extramedullary myelopoiesis and subsequent cellular migration.