Tumor necrosis factor receptor 2 activation elicits sex-specific effects on cortical myelin proteins and functional recovery in a model of multiple sclerosis.

Multiple sclerosis (MS), a demyelinating autoimmune disease of the central nervous system (CNS), predominately affects females compared to males. Tumor necrosis factor (TNF), a pro-inflammatory cytokine, signaling through TNF receptor 1 contributes to inflammatory disease pathogenesis. In contrast, TNF receptor 2 signaling is neuroprotective. Current anti-TNF MS therapies are shown to be detrimental to patients due to pleiotropic effects on both pro- and anti-inflammatory functions. Using a non-pertussis toxin (nPTX) experimental autoimmune encephalomyelitis (EAE) model in C57BL/6 mice, we systemically administered a TNFR2 agonist (p53-sc-mTNFR2) to investigate behavioral and pathophysiological changes in both female and male mice. Our data shows that TNFR2 activation alleviates motor and sensory symptoms in females. However, in males, the agonist only alleviates sensory symptoms and not motor. nPTX EAE induction in TNFR2 global knockout mice caused exacerbated motor symptoms in females along with an earlier day of onset, but not in males. Our data demonstrates that TNFR2 agonist efficacy is sex-specific for alleviation of motor symptoms, however, it effectively reduces mechanical hypersensitivity in both females and males. Altogether, these data support the therapeutic promise TNFR2 agonism holds as an MS therapeutic and, more broadly, to treat central neuropathic pain.

Deletion of the non-adjacent genes UL148 and UL148D impairs human cytomegalovirus-mediated TNF receptor 2 surface upregulation.

Human cytomegalovirus (HCMV) is a prototypical ß-herpesvirus which frequently causes morbidity and mortality in individuals with immature, suppressed, or senescent immunity. HCMV is sensed by various pattern recognition receptors, leading to the secretion of pro-inflammatory cytokines including tumor necrosis factor alpha (TNFα). TNFα binds to two distinct trimeric receptors: TNF receptor (TNFR) 1 and TNFR2, which differ in regard to their expression profiles, affinities for soluble and membrane-bound TNFα, and down-stream signaling pathways. While both TNF receptors engage NFκB signaling, only the nearly ubiquitously expressed TNFR1 exhibits a death domain that mediates TRADD/FADD-dependent caspase activation. Under steady-state conditions, TNFR2 expression is mainly restricted to immune cells where it predominantly submits pro-survival, proliferation-stimulating, and immune-regulatory signals. Based on the observation that HCMV-infected cells show enhanced binding of TNFα, we explored the interplay between HCMV and TNFR2. As expected, uninfected fibroblasts did not show detectable levels of TNFR2 on the surface. Intriguingly, however, HCMV infection increased TNFR2 surface levels of fibroblasts. Using HCMV variants and BACmid-derived clones either harboring or lacking the ULb' region, an association between TNFR2 upregulation and the presence of the ULb' genome region became evident. Applying a comprehensive set of ULb' gene block and single gene deletion mutants, we observed that HCMV mutants in which the non-adjacent genes UL148 or UL148D had been deleted show an impaired ability to upregulate TNFR2, coinciding with an inverse regulation of TACE/ADAM17.

Tumor Necrosis Factor Receptor 2 (TNFR2): An Emerging Target in Cancer Therapy.

Despite the great success of TNF blockers in the treatment of autoimmune diseases and the identification of TNF as a factor that influences the development of tumors in many ways, the role of TNFR2 in tumor biology and its potential suitability as a therapeutic target in cancer therapy have long been underestimated. This has been fundamentally changed with the identification of TNFR2 as a regulatory T-cell (Treg)-stimulating factor and the general clinical breakthrough of immunotherapeutic approaches. However, considering TNFR2 as a sole immunosuppressive factor in the tumor microenvironment does not go far enough. TNFR2 can also co-stimulate CD8+ T-cells, sensitize some immune and tumor cells to the cytotoxic effects of TNFR1 and/or acts as an oncogene. In view of the wide range of cancer-associated TNFR2 activities, it is not surprising that both antagonists and agonists of TNFR2 are considered for tumor therapy and have indeed shown overwhelming anti-tumor activity in preclinical studies. Based on a brief summary of TNFR2 signaling and the immunoregulatory functions of TNFR2, we discuss here the main preclinical findings and insights gained with TNFR2 agonists and antagonists. In particular, we address the question of which TNFR2-associated molecular and cellular mechanisms underlie the observed anti-tumoral activities of TNFR2 agonists and antagonists.

Preferential Expansion of CD4+Foxp3+ Regulatory T Cells (Tregs) In Vitro by Tumor Necrosis Factor.

CD4+Foxp3+ regulatory T cells (Tregs) are a distinct subset of CD4 T cells that play indispensable role in the maintenance of immune homeostasis and prevention of deleterious immune responses to self-antigens. Tumor necrosis factor (TNF) is a key cytokine in the autoimmune inflammatory responses. The effect of TNF on Treg activity was extensively studied in the past decade. We for the first time reported that TNF through TNFR2 preferentially activates and expands Tregs. Our discovery is increasingly supported by the research community; however, some controversial results were reported. The differential results are likely caused by different experimental condition. A standard experiment protocol can help researchers to obtain more consistent results. In this chapter, we detail methods used to examine in vitro effect of exogenous TNF on the proliferative expansion of Tregs in unfractionated mouse CD4+ T cells. The related technic issues are analyzed and discussed.

Tumor necrosis factor receptor-2 (TNFR2): an overview of an emerging drug target.

INTRODUCTION: Tumor necrosis factor (TNF) receptor 2 (TNFR2) is one of two receptors of the cytokines, TNF and lymphotoxin-α. TNFR1 is a strong inducer of proinflammatory activities. TNFR2 has proinflammatory effects too, but it also elicits strong anti-inflammatory activities and has protective effects on oligodendrocytes, cardiomyocytes, and keratinocytes. The protective and anti-inflammatory effects of TNFR2 may explain why TNF inhibitors failed to be effective in diseases such as heart failure or multiple sclerosis, where TNF has been strongly implicated as a driving force. Stimulatory and inhibitory TNFR2 targeting hence attracts considerable interest for the treatment of autoimmune diseases and cancer. Areas covered: Based on a brief description of the pathophysiological importance of the TNF-TNFR1/2 system, we discuss the potential applications of TNFR2 targeting therapies. We also debate TNFR2 activation as a way forward in the search for TNFR2-specific agents. Expert opinion: The use of TNFR2 to target regulatory T-cells is attractive, but this approach is just one amongst many suitable targets. With respect to its preference for Treg stimulation and protection of non-immune cells, TNFR2 is more unique and thus offers opportunities for translational success.

Susceptibility to pulmonary tuberculosis: host genetic deficiency in tumor necrosis factor alpha (TNF-α) gene and tumor necrosis factor receptor 2 (TNFR2).

OBJECTIVE/BACKGROUND: The susceptibility to tuberculosis (TB) depends upon different factors, and the risk of developing diseases after infection with Mycobacterium tuberculosis ranges from 5% to 10%. This suggests that besides the mycobacterial itself, the host genetic factors may determine the differences in host susceptibility to TB. Among the important risk factors, cytokines and especially tumor necrosis factor alpha (TNF-α) genes, are thought to be responsible for regulating the protective immune responses. The TNF-α gene that encodes the cytokines TNF-α is located within the class III region of the major histocompatibility complex (MHC). The TNF-α gene and its receptors have significant suppressive effects on bacterial growth into macrophages. Tumor necrosis factor receptor 1 (TNFR1) is more responsible when apoptosis is needed but tumor necrosis factor receptor 2 (TNFR2) is involved in cell survival. TNF-α conducts its replicative effects on immune cells via the latter. Up to now, several polymorphisms within the promoter region of the TNF-α gene have been shown to be associated with susceptibility or resistance to TB in different ethnic groups. By contrast, the correlation of TNF-α gene with their receptors such as TNFR2 in susceptibility to TB has not been resolved yet. In this study, we aimed to analyze the single nucleotide polymorphisms (SNPs) in the TNF-α gene at the -238, -308, -857, and -863 positions, and compare the susceptibility to TB with polymorphisms at TNFR2 (T587G). METHODS: One hundred fifty-one tuberculosis patients (n=151) and 83 control subjects (n=83) were included in this study. Polymorphisms in the TNF promoter region, namely TNF (SNP), -238, -308, -857, and -863 were studied using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). For TNFR2 polymorphisms at 587 positions, the following primers were used to amplify a 242 base pair (bp) product: 5'-TTCTGGAGTTGGCTGCGTGT-3' and ACTCTCCTATCCTGCCTGCT-3'. PCR products of TNFR2 digested with 2U enzymes of NLA III. RESULTS: The current study found a strong correlation between two polymorphisms in different loci of TNF-α gene including 857 C/C (85; 56.2%) and TNF 238 A/A 127 (84.1%). However, there were no associations between polymorphisms of the TNF-α gene and its receptor, that is, TNFR2. CONCLUSION: Concerning our current study, screening assessments for TNF-α-857 and A238GSNPs in Iran would be important in order to make future decisions for preventive treatments before getting the disease among individuals who are at high risk considering their genotyping.