Publications by authors named "Suzu S"

We have demonstrated that the cellular protein M-Sec promotes the transmission of human T-cell leukemia virus type 1 (HTLV-1) in vitro and in vivo. Here, we show how HTLV-1 utilizes M-Sec for its efficient transmission. HTLV-1-infected CD4+ T cells expressed M-Sec at a higher level than uninfected CD4+ T cells.

View Article and Find Full Text PDF
Article Synopsis
  • HIV-1-infected individuals on antiretroviral therapy still face higher risks of non-AIDS-related health issues due to ongoing chronic inflammation, marked by specific changes in monocytes like increased CD16 subsets and elevated soluble markers sCD163 and sCD14.
  • The study reveals that IL-10, an anti-inflammatory cytokine, can activate monocytes by increasing CD16 and other soluble markers through multiple signaling pathways, including Stat3 and AMPK.
  • Additionally, the HIV-1 protein Nef promotes the production of IL-10 in macrophages, suggesting that IL-10 contributes to the persistent activated state of monocytes in individuals who have achieved viral suppression.
View Article and Find Full Text PDF

Unlabelled: Fibrocytes were reported to be host cells for HIV-1, but the immunological recognition of HIV-1-infected fibrocytes has not been studied. Here, we investigated the recognition of HIV-1-infected fibrocytes by HIV-1-specific CD8 T cells. CD8 T cells specific for five HIV-1 epitopes (HLA-A*24:02-restricted, HLA-B*52:01-restricted, and HLA-C*12:02-restricted epitopes) produced IFN-γ and expressed CD107a after coculture with HIV-1-infected fibrocytes.

View Article and Find Full Text PDF

Interleukin 32 (IL-32) is a proinflammatory cytokine secreted from several kinds of cancer cells. In the present study, we investigated the significance of IL-32 in lung adenocarcinoma by immunohistochemistry and bioinformatics analysis. IL-32 was positive in cancer cells of 21 cases (9.

View Article and Find Full Text PDF

Sinus macrophages in draining lymph nodes (DLNs) are involved in anti-tumor immune reactions. CD169 (Sialoadhesin, Siglec-1) is expressed on sinus macrophages and is considered a surrogate marker for the immunostimulatory phenotype of macrophages. In this study, the significance of sinus macrophages in immunotherapy was evaluated using mouse models.

View Article and Find Full Text PDF

Purpose: This study investigated the expression of interleukin 32 (IL-32) in hepatoblastoma, the most common primary pediatric liver tumor, and its possible roles in tumorigenesis.

Methods: IL-32 expression was investigated in two hepatoblastoma cell lines (Hep G2 and HuH 6) in the steady state and after co-culture with macrophages by RNA-seq analysis and RT-qPCR, and after stimulation with chemotherapy. Cultured macrophages were stimulated by IL-32 isoforms followed by RT-qPCR and western blot analysis.

View Article and Find Full Text PDF

Despite effective antiretroviral therapy, HIV-1 persists in cells, including macrophages, which is an obstacle to cure. However, the precise role of macrophages in HIV-1 infection remains unclear because they reside in tissues that are not easily accessible. Monocyte-derived macrophages are widely used as a model in which peripheral blood monocytes are cultured and differentiated into macrophages.

View Article and Find Full Text PDF
Article Synopsis
  • The cytokine IL-32 is found at high levels in HIV-1-infected individuals, but its role is complex as it can both inhibit and stimulate HIV-1 production in different types of immune cells.
  • IL-32 inhibits HIV-1 in monocyte-derived macrophages (MDMs) through the activation of SAMHD1, but this effect is lost when SAMHD1 is depleted, distinguishing its action from that in CD4 T cells.
  • Additionally, IL-32 promotes immunosuppressive molecules and enhances MDM motility, suggesting that its overall impact may favor the progression of HIV-1 infection despite some inhibitory effects.
View Article and Find Full Text PDF

Tumor-associated macrophages (TAMs) have protumor functions in various cancers. However, their significance in hepatoblastoma, the most common liver tumor in children, remains unclear. The aim of this study was to explore the potential roles of TAMs in hepatoblastoma.

View Article and Find Full Text PDF

Hepatoblastoma is the most common pediatric liver tumor, but little research has been done on the role of macrophages in hepatoblastoma. The purpose of this study was to gain insight into potential roles for macrophages in hepatoblastoma. Paraffin-embedded specimens from 56 patients who underwent surgical resection were examined with immunohistochemical staining for the macrophage-specific markers, Iba1 and CD163.

View Article and Find Full Text PDF
Article Synopsis
  • Human T-cell leukemia virus type 1 (HTLV-1) primarily spreads between cells, and the protein M-Sec is crucial for this process.
  • In HTLV-1 carriers, CD4+ T cells express M-Sec, which is induced by the viral protein Tax, while T cells from non-carriers do not show this expression.
  • Reducing M-Sec levels leads to decreased viral infection and impacts cellular structures necessary for the virus, suggesting M-Sec enhances viral spread through promoting membrane protrusions and Gag protein clustering.
View Article and Find Full Text PDF

Recent studies have revealed that tissue macrophages are derived from yolk sac precursors or fetal liver monocytes, in addition to bone marrow monocytes. The relative contribution of these cells to the tissue macrophage pool is not fully understood, but embryo-derived cells are supposed to be more important because of their capacity to self-renew. Here, we show the presence of adult bone marrow-derived macrophages that retain self-renewing capacity.

View Article and Find Full Text PDF
Article Synopsis
  • HIV-1 enhances the formation of tunneling nanotubes (TNTs) in cells, which helps in transmitting the virus between macrophages, and this process is influenced by the protein M-Sec.
  • The study found that when M-Sec is present, HIV-1 increases the number and size of TNTs in U87 cells, leading to better viral transmission, but knocking down M-Sec slows down viral production.
  • The research suggests that M-Sec is crucial for both creating TNTs and facilitating the movement of cells, making it a key player in the early stages of HIV-1 infection.
View Article and Find Full Text PDF

Objectives: Infiltration of macrophages through the tyrosine kinase receptor CSF1R is a poor prognosis factor in various solid tumors. Indeed, these tumors produce CSF1R ligand, macrophage colony-stimulating factor (M-CSF) or interleukin-34 (IL-34). However, the significance of these cytokines, particularly, the newly discovered IL-34 in haematological malignancies, is not fully understood.

View Article and Find Full Text PDF
Article Synopsis
  • Monocyte-derived fibrocytes play a significant role in the pathogenesis of myelofibrosis (MF), with findings indicating that serum amyloid P can suppress their differentiation and improve MF outcomes.
  • The study revealed that MPN patients with MF and the V617F mutation have a higher percentage of SLAMF7 monocytes, and this is positively correlated with the severity of the mutation and levels of interleukin-1ra (IL-1ra).
  • Elotuzumab (Elo), an anti-SLAMF7 antibody, shows promise as a potential treatment for MF by independently inhibiting fibrocyte differentiation and alleviating associated symptoms in preclinical models.
View Article and Find Full Text PDF
Article Synopsis
  • The c-fms proto-oncogene, also known as M-CSFR or CSF-1R, is found on various malignant tumor cells and myeloid cells, and was found to be overexpressed in adult T-cell leukemia/lymphoma (ATLL).
  • In the study, M-CSFR signaling was linked to the growth of lymphoma cells, and inhibiting M-CSFR led to increased cell death (apoptosis) in these lymphoma cells.
  • The ATL-T cell line produced M-CSF and IL-34, ligands for M-CSFR, which were also co-expressed in most ATLL cases, suggesting that targeting M-CSFR could serve as a promising therapeutic strategy for ATLL through
View Article and Find Full Text PDF

Apolipoprotein E (ApoE) belongs to a class of cellular proteins involved in lipid metabolism. ApoE is a polymorphic protein produced primarily in macrophages and astrocytes. Different isoforms of ApoE have been associated with susceptibility to various diseases including Alzheimer's and cardiovascular diseases.

View Article and Find Full Text PDF

Owing to the insufficient specificity of the anti-myeloproliferative leukemia protein (MPL) antibody in the original version of this Article, Figure 6 and parts of Figures 2a, 4e, and 5a do not represent the correct information. The corrected version of Figure 6 is in this correction and those of Figures 2a, 4e, and 5a are shown in the supplemental information.

View Article and Find Full Text PDF

Myelofibrosis (MF) may be caused by various pathogenic mechanisms such as elevation in circulating cytokine levels, cellular interactions and genetic mutations. However, the underlying mechanism of MF still remains unknown. Recent studies have revealed that fibrocytes, the spindle-shaped fibroblast-like hematopoietic cells, and the thrombopoietin (TPO)/myeloproliferative leukemia protein (MPL; TPO receptor) signaling pathway play a certain role in the development of MF.

View Article and Find Full Text PDF

Tunneling nanotubes (TNTs), the long membrane extensions connecting distant cells, have emerged as a novel form of cell-to-cell communication. However, it is not fully understood how and to what extent TNTs contribute to intercellular spread of pathogens including HIV-1. In this study, we show that HIV-1 promotes TNT formation per se via its protein Nef and a cellular protein M-Sec, which appears to mediate approximately half of viral spread among monocyte-derived macrophages (MDMs).

View Article and Find Full Text PDF

Background: Human immunodeficiency virus type 1 (HIV-1) must take advantage of its own proteins with two or more functions to successfully replicate. Although many attempts have been made to determine the function of viral proteins encoded in the HIV-1 genome, the role of the p2 peptide, a spacer between the capsid and the nucleocapsid in HIV-1 Gag in early-phase HIV infection still remains unclarified.

Results: In this study, we show that the p2 peptide enhances HIV-1 acute infection by increasing intracellular ATP production via the activation of mitochondrial cytochrome c oxidase (MT-CO) involved in the respiratory chain.

View Article and Find Full Text PDF
Article Synopsis
  • * This study reveals that differentiated fibrocytes can be infected by HIV-1 and exhibit a distinct, persistently infected phenotype, more so than macrophages.
  • * The research indicates fibrocytes produce active HIV-1 while resisting cell death, suggesting they could serve as long-lived reservoirs for the virus, highlighting their potential importance in strategies aimed at curing HIV-1.
View Article and Find Full Text PDF

Clear cell renal cell carcinoma (ccRCC) is one of most common cancers in urogenital organs. Although recent experimental and clinical studies have shown the immunogenic properties of ccRCC as illustrated by the clinical sensitivities to various immunotherapies, the detailed immunoregulatory machineries governing the tumorigenicity of human ccRCC remain largely obscure. In this study, we demonstrated the clinical significance and functional relevance of T-cell immunoglobulin and mucin domain-containing molecule-3 (TIM-3) expressed on tumor cells and myeloid cells in patients with ccRCC.

View Article and Find Full Text PDF

Macrophages (MΦ) are functionally classified into two types, anti-inflammatory M2 and pro-inflammatory M1. Importantly, we recently revealed that soluble HIV-1 proteins, particularly the pathogenetic protein Nef, preferentially activate M2-MΦ and drive them towards an M1-like MΦ, which might explain the sustained immune activation seen in HIV-1-infected patients. Here, we show that the preferential effect of Nef on M2-MΦ is mediated by TAK1 (TGF-β-activated kinase 1) and macropinocytosis.

View Article and Find Full Text PDF

M-CSF promotes the differentiation and survival of macrophages, and preferentially induces anti-inflammatory M2, rather than proinflammatory M1 macrophages. Recently, another cytokine, IL-32, was also shown to promote macrophage differentiation. In this article, we provide the first evidence, to our knowledge, that M-CSF has both additive and inhibitory effects on the macrophage-related activities of IL-32.

View Article and Find Full Text PDF