Immune checkpoint inhibitors cause side effects ranging from autoimmune endocrine disorders to severe cardiotoxicity. Periodic Fasting mimicking diet (FMD) cycles are emerging as promising enhancers of a wide range of cancer therapies including immunotherapy. Here, either FMD cycles alone or in combination with anti-OX40/anti-PD-L1 are much more effective than immune checkpoint inhibitors alone in delaying melanoma growth in mice. FMD cycles in combination with anti-OX40/anti-PD-L1 also show a trend for increased effects against a lung cancer model. As importantly, the cardiac fibrosis, necrosis and hypertrophy caused by immune checkpoint inhibitors are prevented/reversed by FMD treatment in both cancer models whereas immune infiltration of CD3+ and CD8+ cells in myocardial tissues and systemic and myocardial markers of oxidative stress and inflammation are reduced. These results indicate that FMD cycles in combination with immunotherapy can delay cancer growth while reducing side effects including cardiotoxicity.
© 2023. Springer Nature Limited.

The authors determined the effect of the GLP-1 receptor agonist liraglutide on endothelial surface expression of vascular cell adhesion molecule (VCAM)-1 in murine apolipoprotein E knockout atherosclerosis. Contrast-enhanced ultrasound molecular imaging using microbubbles targeted to VCAM-1 and control microbubbles showed a 3-fold increase in endothelial surface VCAM-1 signal in vehicle-treated animals, whereas in the liraglutide-treated animals the signal ratio remained around 1 throughout the study. Liraglutide had no influence on low-density lipoprotein cholesterol or glycated hemoglobin, but reduced TNF-α, IL-1β, MCP-1, and OPN. Aortic plaque lesion area and luminal VCAM-1 expression on immunohistology were reduced under liraglutide treatment.
© 2023 The Authors.

Although tumor-infiltrating regulatory T (Treg) cells play a pivotal role in tumor immunity, how Treg cell activation are regulated in tumor microenvironments remains unclear. Here, we found that mice deficient in the inhibitory immunoreceptor CD300a on their dendritic cells (DCs) have increased numbers of Treg cells in tumors and greater tumor growth compared with wild-type mice after transplantation of B16 melanoma. Pharmacological impairment of extracellular vesicle (EV) release decreased Treg cell numbers in CD300a-deficient mice. Coculture of DCs with tumor-derived EV (TEV) induced the internalization of CD300a and the incorporation of EVs into endosomes, in which CD300a inhibited TEV-mediated TLR3-TRIF signaling for activation of the IFN-β-Treg cells axis. We also show that higher expression of CD300A was associated with decreased tumor-infiltrating Treg cells and longer survival time in patients with melanoma. Our findings reveal the role of TEV and CD300a on DCs in Treg cell activation in the tumor microenvironment.
© 2021, Nakazawa et al.

Mechanisms that govern transcriptional regulation of inflammation in atherosclerosis remain largely unknown. Here, we identify the nuclear transcription factor c-Myb as an important mediator of atherosclerotic disease in mice. Atherosclerosis-prone animals fed a diet high in cholesterol exhibit increased levels of c-Myb in the bone marrow. Use of mice that either harbor a c-Myb hypomorphic allele or where c-Myb has been preferentially deleted in B cell lineages revealed that c-Myb potentiates atherosclerosis directly through its effects on B lymphocytes. Reduced c-Myb activity prevents the expansion of atherogenic B2 cells yet associates with increased numbers of IgM-producing antibody-secreting cells (IgM-ASCs) and elevated levels of atheroprotective oxidized low-density lipoprotein (OxLDL)-specific IgM antibodies. Transcriptional profiling revealed that c-Myb has a limited effect on B cell function but is integral in maintaining B cell progenitor populations in the bone marrow. Thus, targeted disruption of c-Myb beneficially modulates the complex biology of B cells in cardiovascular disease.
Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.

Ox40 ligand (Ox40L) locus genetic variants are associated with the risk for systemic lupus erythematosus (SLE); however, it is unclear how Ox40L contributes to SLE pathogenesis. In this study, we evaluated the contribution of Ox40L and its cognate receptor, Ox40, using in vivo agonist and antagonist approaches in the NZB × NZW (NZB/W) F1 mouse model of SLE. Ox40 was highly expressed on several CD4 Th cell subsets in the spleen and kidney of diseased mice, and expression correlated with disease severity. Treatment of aged NZB/W F1 mice with agonist anti-Ox40 mAbs potently exacerbated renal disease, which was accompanied by activation of kidney-infiltrating T cells and cytokine production. The agonist mAbs also induced activation and inflammatory gene expression in splenic CD4 T cells, including IFN-regulated genes, increased the number of follicular helper T cells and plasmablasts in the spleen, and led to elevated levels of serum IgM and enhanced renal glomerular IgM deposition. In a type I IFN-accelerated lupus model, treatment with an antagonist Ox40:Fc fusion protein significantly delayed the onset of severe proteinuria and improved survival. These data support the hypothesis that the Ox40/Ox40L pathway drives cellular and humoral autoimmune responses during lupus nephritis in NZB/W F1 mice and emphasize the potential clinical value of targeting this pathway in human lupus.
Copyright © 2017 by The American Association of Immunologists, Inc.