Project description:TNF superfamily ligands play a critical role in the regulation of adaptive immune responses, including the costimulation of dendritic cells, T cells, and B cells. This costimulation could potentially be exploited for the development of prophylactic vaccines and immunotherapy. Despite this, there have been only a limited number of reports on the use of this family of molecules as gene-based adjuvants to enhance DNA and/or viral vector vaccines. In addition, the molecule latent membrane protein 1 (LMP1), a viral mimic of the TNF superfamily receptor CD40, provides an alternative approach for the design of novel molecular adjuvants. Here, we discuss advances in the development of recombinant TNF superfamily ligands as adjuvants for HIV vaccines and as cancer immunotherapy, including the use of LMP1 and LMP1-CD40 chimeric fusion proteins to mimic constitutive CD40 signaling.
Project description:This study characterizes the evolution of the tumor necrosis factor superfamily (TNFSF) across vertebrate lineages, both cyclostomes and gnathostomes, by combining sequence similarity and synteny data for the genes from 23 model species. The available evidence supports a simple model in which most of the diversity found in living species can be attributed to the expansion of four genes found in an ancestor of all vertebrates before the first of the genome duplications that occurred in the vertebrate lineages. It is inferred that the ancestor of all cyclostomes possessed only six TNFSF genes. A cyclostome-specific genome triplication had little effect on the total number of these genes. The ancestor of all gnathostomes, due to the effect of a second genome duplication plus additional single-gene duplications, already had 21 TNFSF genes. In several gnathostome lineages, particularly in some tetrapods, the TNF superfamily has significantly contracted due to numerous gene losses. This evolutionary model provides a framework for exploring functional data, showing that the descendants of different ancestral genes have acquired distinct roles, most prominently in the innate and adaptive immune systems, which led to a species-specific refinement of which TNFSF genes were conserved or lost. Several data hitherto difficult to interpret (the interactions of very different TNFSF ligands with the same receptors; the ability of the same ligands to bind alternative receptors, with or without death domains; and the cooperation of different ligands in specific functions) can be explained as consequences of the evolutionary history of the TNF superfamily.
Project description:The tumor necrosis factor (TNF) ligand family has nine ligands that show promiscuity in binding multiple receptors. As different receptors transduce into diverse pathways, the study on the functional role of natural ligands is very complex. In this review, we discuss the TNF ligands engineering for receptor specificity and summarize the performance of the ligand variants in vivo and in vitro. Those variants have an increased binding affinity to specific receptors to enhance the cell signal conduction and have reduced side effects due to a lowered binding to untargeted receptors. Refining receptor specificity is a promising research strategy for improving the application of multi-receptor ligands. Further, the settled variants also provide experimental guidance for engineering receptor specificity on other proteins with multiple receptors.
Project description:Cancer is a complex disease with apoptosis evasion as one of its hallmarks; therefore, apoptosis induction in transformed cells seems a promising approach as a cancer treatment. TNF apoptosis-inducing ligands, which are naturally present in the body and possess tumoricidal activity, are attractive candidates. The most studied proteins are TNF-α, FasL, and TNF-related apoptosis-inducing ligand (TRAIL). Over the years, different recombinant TNF family-derived apoptosis-inducing ligands and agonists have been designed. Their stability, specificity, and half-life have been improved because most of the TNF ligands have the disadvantages of having a short half-life and affinity to more than one receptor. Here, we review the outlook on apoptosis-inducing ligands as cancer treatments in diverse preclinical and clinical stages and summarize strategies of overcoming their natural limitations to improve their effectiveness.
Project description:Fibrosis is the result of extracellular matrix protein deposition and remains a leading cause of death in USA. Despite major advances in recent years, there remains an unmet need to develop therapeutic options that can effectively degrade or reverse fibrosis. The tumor necrosis super family (TNFSF) members, previously studied for their roles in inflammation and cell death, now represent attractive therapeutic targets for fibrotic diseases. In this review, we will summarize select TNFSF and their involvement in fibrosis of the lungs, the heart, the skin, the gastrointestinal tract, the kidney, and the liver. We will emphasize their direct activity on epithelial cells, fibroblasts, and smooth muscle cells. We will further report on major clinical trials targeting these ligands. Whether in isolation or in combination with other anti-TNFSF member or treatment, targeting this superfamily remains key to improve efficacy and selectivity of currently available therapies for fibrosis.
Project description:The T-cell functions of a proliferation-inducing ligand (APRIL, also known as TNFSF13) remain largely undefined. We previously showed that APRIL suppressed Th2 cytokine production in cultured CD4(+) T cells and Th2 antibody responses. Here we show that APRIL suppresses allergic lung inflammation, which is associated with diminished expression of the transcription factor c-maf. Mice deficient in the April gene (April(-/-) mice) had significantly aggravated lung inflammation compared with WT mice in the ovalbumin-induced allergic lung inflammation model. Likewise, blockade of APRIL in WT mice by the APRIL-receptor fusion protein, transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI)-Ig, enhanced lung inflammation. Transfer of APRIL-sufficient, ovalbumin-specific, TCR-transgenic CD4(+) T (OT-II) cells to April(-/-) mice restored the suppressive effect of APRIL on lung inflammation. Mechanistically, the expression of the Th2 cytokine transcription factor c-maf, but not GATA-3, was markedly enhanced in April(-/-) CD4(+) T cells at the RNA and protein level and under non-polarizing (Th neutral, ThN) and Th2-polarizing conditions. Since c-maf transactivates the IL-4 gene, the increased c-maf expression in April(-/-) mice readily explains increased Th2 cytokine production. Independent of its effect on IL-4, APRIL suppressed IL-13 expression. APRIL thus may regulate lung inflammation in a dual way, by acting on c-maf expression and by directly controlling IL-13 production.
Project description:One of the key features of tumor cells is the acquisition of resistance to apoptosis. Thus, novel therapeutic strategies that circumvent apoptotic resistance and result in tumor elimination are needed. One strategy to induce apoptosis is to activate death receptor signaling pathways. In the tumor microenvironment, stimulation of Fas, Death receptor 4 (DR4) and tumor necrosis factor receptor 1 (TNFR1) can initiate multiple signaling pathways driving either tumor promotion or elimination. Nitric oxide (NO) is an important signaling molecule now understood to play a dual role in cancer biology. More and more attention is directed toward the role displayed by S-nitrosylation, the incorporation of an NO moiety to a cysteine thiol group, in promoting cell death in tumor cells. Protein post-translation modification by S-nitrosylation has decisive roles in regulating signal-transduction pathways. In this review, we summarize several examples of protein modification by S-nitrosylation that regulate signaling pathways engaged by members of the TNF superfamily (Fas ligand (FasL), Tumor-necrosis-factor-related apoptosis inducing ligand (TRAIL) and TNFalpha (TNFα)) and the way it influences cell fate decisions.
Project description:The tumor necrosis factor (TNF) superfamily (TNFSF) contains about thirty structurally related receptors (TNFSFRs) and about twenty protein ligands that bind to one or more of these receptors. Almost all of these cell surface protein-protein interactions (PPIs) represent high-value therapeutic targets for inflammatory or immune modulation in autoimmune diseases, transplant recipients, or cancers, and there are several biologics including antibodies and fusion proteins targeting them that are in various phases of clinical development. Small-molecule inhibitors or activators could represent possible alternatives if the difficulties related to the targeting of protein-protein interactions by small molecules can be addressed. Compounds proving the feasibility of such approaches have been identified through different drug discovery approaches for a number of these TNFSFR-TNFSF type PPIs including CD40-CD40L, BAFFR-BAFF, TRAIL-DR5, and OX40-OX40L. Corresponding structural, signaling, and medicinal chemistry aspects are briefly reviewed here. While none of these small-molecule modulators identified so far seems promising enough to be pursued for clinical development, they provide proof-of-principle evidence that these interactions are susceptible to small-molecule modulation and can serve as starting points toward the identification of more potent and selective candidates.
Project description:Members of the tumor necrosis factor receptor superfamily play key roles in innate and adaptive immunity. Here, we review recent structural studies in the intracellular signal transduction of these receptors. A central theme revealed from these structural studies is that upon ligand binding, multiple intracellular proteins form higher-order signaling machines to transduce and amplify receptor activation information to different cellular fates, including NF-κB activation, apoptosis, and programmed necrosis. These studies open a new vista for understanding the biophysical principles in these signaling cascades.
Project description:The clinical approval of immune checkpoint inhibitors is an important advancement in the field of cancer immunotherapy. However, the percentage of beneficiaries is still limited and it is becoming clear that combination therapies are required to further enhance the treatment efficacy. The potential of strategies targeting the immunoregulatory network by "hitting the gas pedal" as opposed to "blocking the brakes" is being recognized and intensively investigated. Hence, next to immune checkpoint inhibitors, agonists of co-stimulatory receptors of the tumor necrosis factor superfamily (TNF-SF) are emerging as promising options to expand the immunomodulatory toolbox. In this review the development of different categories of recombinant antibody and ligand-based agonists of 4-1BB, OX40, and GITR is summarized and discussed in the context of the challenges presented by the structural and mechanistical features of the TNFR-SF. An overview of current formats, trends, and clinical studies is provided.