The genome of human herpes virus 8, which is associated with Kaposi's sarcoma, encodes proteins with similarities to cytokines and chemokines including a homologue of IL-6. Although the function of these viral proteins is unclear, they might have the potential to modulate the immune system. For viral IL-6 (vIL-6), it has been demonstrated that it stimulates IL-6-dependent cells, indicating that the IL-6R system is used. IL-6 binds to IL-6R, and the IL-6/IL-6R complex associates with gp130 which dimerizes and initiates intracellular signaling. Cells that only express gp130 but no IL-6R cannot be stimulated by IL-6 unless a soluble form of the IL-6R is present. This type of signaling has been shown for hematopoietic progenitor cells, endothelial cells, and smooth muscle cells. In this paper we show that purified recombinant vIL-6 binds to gp130 and stimulates primary human smooth muscle cells. IL-6R fails to bind vIL-6 and is not involved in its signaling. A Fc fusion protein of gp130 turned out to be a potent inhibitor of vIL-6. Our data demonstrate that vIL-6 is the first cytokine which directly binds and activates gp130. This property points to a possible role of this viral cytokine in the pathophysiology of human herpes virus 8.

Download full-text PDF

Source
http://dx.doi.org/10.4049/jimmunol.164.9.4672DOI Listing

Publication Analysis

Top Keywords

viral il-6
8
human herpes
8
herpes virus
8
smooth muscle
8
muscle cells
8
il-6
6
gp130
6
cells
6
vil-6
5
il-6r
5

Similar Publications

Rationale: COVID-19-associated acute-respiratory distress syndrome (C-ARDS) results from a direct viral injury associated with host excessive innate immune response mainly affecting the lungs. However, cytokine profile in the lung compartment of C-ARDS patients has not been widely studied, nor compared to non-COVID related ARDS (NC-ARDS).

Objectives: To evaluate caspase-1 activation, IL-1 signature, and other inflammatory cytokine pathways associated with tissue damage using post-mortem lung tissues, bronchoalveolar lavage fluids (BALF), and serum across the spectrum of COVID-19 severity.

View Article and Find Full Text PDF

Trametes robiniophila Murr. extract alleviates influenza-induced lung injury by regulating gut microbiota and metabolites.

J Pharm Biomed Anal

January 2025

School of Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan 250355, China; State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China. Electronic address:

Trametes robiniophila Murr. (Huaier) is a traditional medicinal fungus known for its pharmacological properties, including heat-clearing, detoxifying, anti-inflammatory, and antitumor effects. Our previous research has demonstrated its antiviral activity, but the exact therapeutic mechanisms remain unclear.

View Article and Find Full Text PDF

Infection with Influenza A virus (IAV) induces severe inflammatory responses and lung injury, contributing significantly to mortality and morbidity rates. Alterations in the microbial composition of the lungs and intestinal tract resulting from infection could influence disease progression and treatment outcomes. Xiyanping (XYP) injection has demonstrated efficacy in clinical treatment across various viral infections.

View Article and Find Full Text PDF

Immune responses in children with secondary infection of mycoplasma pneumoniae after COVID-19: focus on eosinophils and IgE.

BMC Infect Dis

January 2025

Luoyang Research Center for Inheritance and Innovation of Chinese Historical Civilization, Luoyang Institute of Science and Technology School of Marxism (LIT), No. 90 Wangcheng Avenue, Luolong District, Luoyang City, Henan Province, China.

Background: The COVID-19 (SARS-CoV-2) epidemic has posed a major challenge to global public health, especially in children. Some children may experience secondary infection with Mycoplasma pneumoniae after SARS-CoV-2 infection, which has attracted widespread attention. Studies have shown that eosinophils play an important role in respiratory tract infections and are involved in regulating immune responses and inflammatory processes.

View Article and Find Full Text PDF

The Role of Inflammatory Parameters and Antibody Seroconversion on COVID-19 Outcomes in Patients with Central Obesity.

Acta Med Indones

October 2024

1. Division of Endocrinology, Metabolism, and Diabetes, Department of Internal Medicine, Faculty of Medicine Universitas Indonesia-Dr. Cipto Mangunkusumo National General Hospital, Jakarta, Indonesia. 2. Metabolic Disorder, Cardiovascular and Aging Research Center, Indonesian Medical Education and Research Institute, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia..

Background: Central obesity increases the risk of developing poor outcomes of COVID-19. The pro-inflammatory state and antibody dysfunction are thought to contribute to poor outcomes; however, the evidence is unclear.

Methods: This is a cohort study among COVID-19 patients with central obesity in Dr.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!