in-vivo-imaging-uncovers-migratory-behavior-leukocytes-within

<em>In Vivo</em> Imaging Uncovers the Migratory Behavior of Leukocytes within the Joints

Leukocytes are blood-borne cells derived from the bone marrow that must migrate into tissues to mediate inflammation. Controlling this migration, ...

St. Marianna University School of Medicine

Epstein-Barr virus (EBV)-positive T- or NK-cell neoplasms show progressive systemic inflammation and abnormal blood coagulation causing hemophagocytic lymphohistiocytosis (HLH). It was reported that inflammatory cytokines were produced and secreted by EBV-positive neoplastic T- or NK-cells. These cytokines can induce the differentiation of monocytes into macrophages leading to HLH. To clarify which products of EBV-positive neoplastic T- or NK-cells have effects on monocytes, we performed a co-culture assay of monocytes with the supernatants of EBV-positive T- or NK-cell lines. The expression of differentiation markers, the phagocytosis ability, and the mRNA expression of the inflammatory cytokines of THP-1, a monocytic cell line, clearly increased after culturing with the supernatants from EBV-NK-cell lines. Co-culturing with the supernatants promoted the expression of CD80 and CD206 as well as M1 and M2 macrophage markers in human monocytes. Co-culturing with the supernatants of EBV-NK-cell lines significantly enhanced the procoagulant activity and the tissue factor expression of monocytes. Interferon (IFN)-γ was elevated extremely not only in the supernatant of EBV-NK-cell lines but also in the plasma of EBV-positive NK-cell neoplasms patients accompanying HLH. Finally, we confirmed that IFN-γ directly enhanced the differentiation into M1-like macrophages and the procoagulant activity of monocytes. Our findings suggest that IFN-γ may potentially serve as a therapeutic target to regulate HLH in EBV-positive NK-cell neoplasms.

Interferon-γ Produced by EBV-Positive Neoplastic NK-Cells Induces Differentiation into Macrophages and Procoagulant Activity of Monocytes, Which Leads to HLH.

Systemic chronic active Epstein-Barr virus infection (sCAEBV) is an EBV-positive T- or NK-cell neoplasm revealing persistent systemic inflammation. Twenty-five percent of sCAEBV patients accompany angiopathy. It is crucial to clarify the mechanisms of angiopathy development in sCAEBV because angiopathy is one of the main causes of death. Interleukin-1β (IL-1β) is reported to be involved in angiopathy onset. We investigated if IL-1β plays a role as the inducer of angiopathy of sCAEBV. We detected elevated IL-1β levels in four out of 17 sCAEBV patient's plasma. Interestingly, three out of the four had clinically associated angiopathy. None of the other patients with undetectable level of IL-1β had angiopathy. In all patients with high plasma levels of IL-1β and vascular lesions, EBV-infected cells were CD4-positive T cells. In one patient with high plasma IL-1β, the level of  mRNA of the monocytes was 17.2 times higher than the level of the same patient's EBV-infected cells in peripheral blood. In Ea.hy926 cells, which are the models of vascular endothelial cells, IL-1β inhibited the proliferation and induced the surface coagulation activity. IL-1β is a potent biomarker and a potent therapeutic target to treat sCAEBV accompanying angiopathy.

The Plasma Level of Interleukin-1β Can Be a Biomarker of Angiopathy in Systemic Chronic Active Epstein-Barr Virus Infection.

A 45-year-old man who was a sibling donor for allogeneic peripheral blood stem cell transplantation (allo-PBSCT) was administered 7.2 mg of pegfilgrastim for stem cell collection. Peripheral blood stem cells were collected 4 days after administration of pegfilgrastim (Day 4) and 4.32 × 10 /kg of CD34-positive cells per recipient body weight were obtained. Fever of 38 ℃ or higher and left submandibular pain appeared on Day 6. Ultrasonography and contrast-enhanced computed tomography (CT) showed wall thickening of the carotid artery and the abdominal aorta. We carefully excluded the possibilities of cardiovascular and autoimmune diseases by thorough examination, and ultimately diagnosed pegfilgrastim-induced aortitis. The patient's fever resolved rapidly after treatment with prednisolone (PSL) 1 mg/kg. We began to taper PSL after eight days. Sixty-one days after starting PSL, we confirmed that abdominal aortic wall thickening had improved by contrast-enhanced CT. We continued to taper off PSL and stopped 141 days later with no relapse thereafter. This is the first case report of pegfilgrastim-induced aortitis in an allo-PBSCT donor. Careful monitoring is warranted when administering pegfilgrastim to donors even without past medical history.

Aortitis after administration of pegfilgrastim to a healthy donor for peripheral blood stem cell collection.

Systemic chronic active Epstein-Barr virus disease (sCAEBV) is a rare and fatal neoplasm, involving clonally proliferating Epstein-Barr virus (EBV)-infected T cells or natural killer cells. Patients with sCAEBV have abnormal titers of anti-EBV antibodies in their peripheral blood, but their significance is unknown. We retrospectively investigated titers and their relationship with the clinical features of sCAEBV using the data collected by the Japanese nationwide survey. Eighty-four patients with sCAEBV were analyzed. The anti-EBV nuclear antigen (EBNA) antibody, targeting EBNA-expressing EBV-positive cells, was found in 87.5% of children (<15 years old), 73.7% of adolescents and young adults (15-39 years old), and 100% of adults (≥40 years old). Anti-EBNA antibody titers were significantly lower and anti-VCA-IgG antibody titers significantly higher in patients with sCAEBV than those in healthy controls ( < 0.0001). Patients with high anti-VCA-IgG and anti-early antigen-IgG antibody (antibodies against the viral particles) levels had significantly better 3-year overall survival rates than those with low titers, suggesting that patients with sCAEBV have a reduced immune response to EBV-infected cells.

Clinical significance of anti-Epstein-Barr virus antibodies in systemic chronic active Epstein-Barr virus disease.

Excessive activation of immune cells by environmental factors, such as infection or individual genetic risk, causes various autoimmune diseases.  species are gram-positive bacteria that colonize the nasopharynx, respiratory tract, gastrointestinal tract, genitourinary tract, and skin. Group A  (GAS) species cause various symptoms, ranging from mild infections, such as tonsillitis and pharyngitis, to serious infections, such as necrotizing fasciitis and streptococcal toxic shock syndrome. The contribution of GAS infections to several autoimmune diseases, including acute rheumatic fever, vasculitis, and neuropsychiatric disorders, has been studied. In this review, we focus on the association between streptococcal infections and autoimmune diseases, and discuss current research on the mechanisms underlying the initiation and progression of autoimmune diseases.

Streptococcal infection and autoimmune diseases.

Alemtuzumab, a humanized monoclonal antibody against CD52, is approved for graft-versus-host disease (GVHD) prophylaxis in allogeneic hematopoietic stem cell transplantation (allo-HSCT) due to its strong immunosuppressive effects. We report the case of a 26-year-old woman with systemic chronic active Epstein-Barr virus disease (sCAEBV) who underwent allo-HSCT from an HLA-matched sibling donor with alemtuzumab-based GVHD prophylaxis. Her EBV-infected cells were CD4-positive T cells. Flow cytometry revealed an expansion of CD52-expressing CD4-positive T cells in peripheral blood (PB) with elevated EBV-DNA load. After treatment with alemtuzumab (0.16 mg/kg on Days  - 10 and  - 9), the CD4-positive cell fraction in PB declined rapidly, while EBV-DNA simultaneously decreased to an undetectable level. The conditioning regimen consisted of fludarabine (25 mg/m, Days  - 7 to  - 3), melphalan (40 mg/m, Days  - 3 to  - 2), and total body irradiation (TBI, 4 Gy, Day  - 1). The serum concentration of alemtuzumab at transplantation was 0.36 μg/mL. Cyclosporine was given from Day  - 1, and short-term methotrexate was given on Days 1, 3, and 6. The transplantation was successful, with no GVHD or severe infections. Earlier administration of alemtuzumab may not only reduce prolonged post-transplant immunosuppression but also speed up elimination of EBV-infected cells before transplantation for sCAEBV.

Targeting EBV-infected T cells with alemtuzumab: a novel approach to systemic chronic active EBV disease.

Systemic chronic active Epstein-Barr virus disease (sCAEBV) is a chemotherapy-resistant, EBV-positive T- or NK-cell lymphoproliferative disorder characterized by persistent systemic inflammation driven by the activation of EBV-infected cells. In this study, we explored BCL2, an anti-apoptotic factor implicated in various hematopoietic malignancies, as a potential therapeutic target for sCAEBV, focusing on the effects of its inhibitor, venetoclax. We confirmed BCL2 expression in EBV-positive T- and NK-cell lines and peripheral blood mononuclear cells (PBMCs) from sCAEBV patients using western blotting. Immunofluorescence staining further revealed BCL2 expression in EBV-infected cells within patient-derived PBMCs. Venetoclax treatment reduced the viability of EBV-positive cell lines and patient-derived PBMCs in a dose-dependent manner and induced apoptosis in these cells. Moreover, venetoclax suppressed the mRNA expression of the inflammatory cytokine IFN-γ in patient-derived PBMCs. To evaluate the in vivo effects of venetoclax, we utilized sCAEBV xenograft model generated by transplanting patient-derived PBMCs into NOD/Shi-scid/IL-2Rγnull mice. No engraftment of EBV-infected cells was observed in mice treated with venetoclax, whereas one out of three mice in the untreated group exhibited engraftment of EBV-positive cells and tumor formation. Venetoclax treatment showed an insignificant trend to reducing IFN-γ levels in peripheral blood in established xenograft models. To our knowledge, this is the first report to suggest that venetoclax exerts not only anti-tumor effects but also potential anti-inflammatory effects in sCAEBV. BCL2 represents a promising therapeutic target to address the two pathological characteristics of sCAEBV: malignancy and inflammation.

Effects of venetoclax, a BCL2 inhibitor, in systemic chronic active Epstein-Barr virus disease.

Systemic chronic active Epstein-Barr virus disease (sCAEBV) is an intractable disorder characterized by clonal proliferation of EBV-infected T- and NK-cells, leading to persistent systemic inflammation and progression to hemophagocytic lymphohistiocytosis (HLH). The EBV genome encodes 40 mature microRNAs known as miR-BARTs. The expression of miR-BARTs has been reported in other EBV-positive diseases and is associated with tumorigenesis. In this study, we investigated the expression of miR-BARTs in sCAEBV. Expression of miR-BARTs was highly abundant in 4 sCAEBV-derived EBV-positive T- or NK-cell lines and in EBV-infected T- or NK-cells from 23 sCAEBV patients. The highest expression levels were observed for miR-BART7-3p. Sequence analysis revealed no deletions in the EBV genome encoding miR-BARTs. Inhibition of miR-BART7-3p altered the expression of immune-related genes in sCAEBV-derived cell lines. Abundant miR-BART expression was also observed in patients' plasma, with miR-BART7-3p showing the highest levels. Notably, miR-BART7-3p expression was detected in macrophages within the spleen of an sCAEBV patient with HLH. These findings suggest that miR-BARTs are highly expressed and secreted by EBV-infected cells in sCAEBV. We hypothesize that secreted miR-BARTs may be taken up by monocytes, potentially regulating their functions and contributing to inflammation in sCAEBV. Further studies are needed to elucidate these mechanisms.

Article	Year
Interferon-γ Produced by EBV-Positive Neoplastic NK-Cells Induces Differentiation into Macrophages and Procoagulant Activity of Monocytes, Which Leads to HLH. Cancers\| PubMed ID: 34680246	2021
The Plasma Level of Interleukin-1β Can Be a Biomarker of Angiopathy in Systemic Chronic Active Epstein-Barr Virus Infection. Frontiers in microbiology\| PubMed ID: 35464987	2022
Aortitis after administration of pegfilgrastim to a healthy donor for peripheral blood stem cell collection. International journal of hematology\| PubMed ID: 37578593	2023
Clinical significance of anti-Epstein-Barr virus antibodies in systemic chronic active Epstein-Barr virus disease. Frontiers in microbiology\| PubMed ID: 38260896	2023
Streptococcal infection and autoimmune diseases. Frontiers in immunology\| PubMed ID: 38464518	2024
Targeting EBV-infected T cells with alemtuzumab: a novel approach to systemic chronic active EBV disease. International journal of hematology\| PubMed ID: 40304862	2025
Effects of venetoclax, a BCL2 inhibitor, in systemic chronic active Epstein-Barr virus disease. Scientific reports\| PubMed ID: 40425709	2025
Expression profiling of Epstein-Barr virus-derived microRNA in systemic chronic active EBV disease. International journal of hematology\| PubMed ID: 40711663	2025
Combined treatment with amlexanox and cytarabine induces apoptosis via the S100A6-Akt pathway in KMT2A::AFF1-positive acute lymphoblastic leukemia. Leukemia\| PubMed ID: 41053511	2025

Ayaka Ohashi

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