Gut Microbiota Regulation of T Cells During Inflammation and Autoimmunity.

The intestinal microbiota plays a crucial role in influencing the development of host immunity, and in turn the immune system also acts to regulate the microbiota through intestinal barrier maintenance and immune exclusion. Normally, these interactions are homeostatic, tightly controlled, and organized by both innate and adaptive immune responses. However, a combination of environmental exposures and genetic defects can result in a break in tolerance and intestinal homeostasis. The outcomes of these interactions at the mucosal interface have broad, systemic effects on host immunity and the development of chronic inflammatory or autoimmune disease. The underlying mechanisms and pathways the microbiota can utilize to regulate these diseases are just starting to emerge. Here, we discuss the recent evidence in this area describing the impact of microbiota-immune interactions during inflammation and autoimmunity, with a focus on barrier function and CD4+ T cell regulation.

Structural Mimicry in Microbial and Antimicrobial Amyloids.

The remarkable variety of microbial species of human pathogens and microbiomes generates significant quantities of secreted amyloids, which are structured protein fibrils that serve diverse functions related to virulence and interactions with the host. Human amyloids are associated largely with fatal neurodegenerative and systemic aggregation diseases, and current research has put forward the hypothesis that the interspecies amyloid interactome has physiological and pathological significance. Moreover, functional and molecular-level connections between antimicrobial activity and amyloid structures suggest a neuroimmune role for amyloids that are otherwise known to be pathological. Compared to the extensive structural information that has been accumulated for human amyloids, high-resolution structures of microbial and antimicrobial amyloids are only emerging. These recent structures reveal both similarities and surprising departures from the typical amyloid motif, in accordance with their diverse activities, and advance the discovery of novel antivirulence and antimicrobial agents. In addition, the structural information has led researchers to postulate that amyloidogenic sequences are natural targets for structural mimicry, for instance in host-microbe interactions. Microbial amyloid research could ultimately be used to fight aggressive infections and possibly processes leading to autoimmune and neurodegenerative diseases.

The evolution and diversification of oakleaf butterflies.

Oakleaf butterflies in the genus Kallima have a polymorphic wing phenotype, enabling these insects to masquerade as dead leaves. This iconic example of protective resemblance provides an interesting evolutionary paradigm that can be employed to study biodiversity. We integrated multi-omic data analyses and functional validation to infer the evolutionary history of Kallima species and investigate the genetic basis of their variable leaf wing patterns. We find that Kallima butterflies diversified in the eastern Himalayas and dispersed to East and Southeast Asia. Moreover, we find that leaf wing polymorphism is controlled by the wing patterning gene cortex, which has been maintained in Kallima by long-term balancing selection. Our results provide macroevolutionary and microevolutionary insights into a model species originating from a mountain ecosystem.

Spliceosome-targeted therapies trigger an antiviral immune response in triple-negative breast cancer.

Many oncogenic insults deregulate RNA splicing, often leading to hypersensitivity of tumors to spliceosome-targeted therapies (STTs). However, the mechanisms by which STTs selectively kill cancers remain largely unknown. Herein, we discover that mis-spliced RNA itself is a molecular trigger for tumor killing through viral mimicry. In MYC-driven triple-negative breast cancer, STTs cause widespread cytoplasmic accumulation of mis-spliced mRNAs, many of which form double-stranded structures. Double-stranded RNA (dsRNA)-binding proteins recognize these endogenous dsRNAs, triggering antiviral signaling and extrinsic apoptosis. In immune-competent models of breast cancer, STTs cause tumor cell-intrinsic antiviral signaling, downstream adaptive immune signaling, and tumor cell death. Furthermore, RNA mis-splicing in human breast cancers correlates with innate and adaptive immune signatures, especially in MYC-amplified tumors that are typically immune cold. These findings indicate that dsRNA-sensing pathways respond to global aberrations of RNA splicing in cancer and provoke the hypothesis that STTs may provide unexplored strategies to activate anti-tumor immune pathways.

Ca2+ sensor-mediated ROS scavenging suppresses rice immunity and is exploited by a fungal effector.

Plant immunity is activated upon pathogen perception and often affects growth and yield when it is constitutively active. How plants fine-tune immune homeostasis in their natural habitats remains elusive. Here, we discover a conserved immune suppression network in cereals that orchestrates immune homeostasis, centering on a Ca2+-sensor, RESISTANCE OF RICE TO DISEASES1 (ROD1). ROD1 promotes reactive oxygen species (ROS) scavenging by stimulating catalase activity, and its protein stability is regulated by ubiquitination. ROD1 disruption confers resistance to multiple pathogens, whereas a natural ROD1 allele prevalent in indica rice with agroecology-specific distribution enhances resistance without yield penalty. The fungal effector AvrPiz-t structurally mimics ROD1 and activates the same ROS-scavenging cascade to suppress host immunity and promote virulence. We thus reveal a molecular framework adopted by both host and pathogen that integrates Ca2+ sensing and ROS homeostasis to suppress plant immunity, suggesting a principle for breeding disease-resistant, high-yield crops.

A Gut Microbial Mimic that Hijacks Diabetogenic Autoreactivity to Suppress Colitis.

The gut microbiota contributes to the development of normal immunity but, when dysregulated, can promote autoimmunity through various non-antigen-specific effects on pathogenic and regulatory lymphocytes. Here, we show that an integrase expressed by several species of the gut microbial genus Bacteroides encodes a low-avidity mimotope of the pancreatic ß cell autoantigen islet-specific glucose-6-phosphatase-catalytic-subunit-related protein (IGRP206-214). Studies in germ-free mice monocolonized with integrase-competent, integrase-deficient, and integrase-transgenic Bacteroides demonstrate that the microbial epitope promotes the recruitment of diabetogenic CD8+ T cells to the gut. There, these effectors suppress colitis by targeting microbial antigen-loaded, antigen-presenting cells in an integrin ß7-, perforin-, and major histocompatibility complex class I-dependent manner. Like their murine counterparts, human peripheral blood T cells also recognize Bacteroides integrase. These data suggest that gut microbial antigen-specific cytotoxic T cells may have therapeutic value in inflammatory bowel disease and unearth molecular mimicry as a novel mechanism by which the gut microbiota can regulate normal immune homeostasis. PAPERCLIP.

Non-canonical substrate recognition by the human WDR26-CTLH E3 ligase regulates prodrug metabolism.

The yeast glucose-induced degradation-deficient (GID) E3 ubiquitin ligase forms a suite of complexes with interchangeable receptors that selectively recruit N-terminal degron motifs of metabolic enzyme substrates. The orthologous higher eukaryotic C-terminal to LisH (CTLH) E3 complex has been proposed to also recognize substrates through an alternative subunit, WDR26, which promotes the formation of supramolecular CTLH E3 assemblies. Here, we discover that human WDR26 binds the metabolic enzyme nicotinamide/nicotinic-acid-mononucleotide-adenylyltransferase 1 (NMNAT1) and mediates its CTLH E3-dependent ubiquitylation independently of canonical GID/CTLH E3-family substrate receptors. The CTLH subunit YPEL5 inhibits NMNAT1 ubiquitylation and cellular turnover by WDR26-CTLH E3, thereby affecting NMNAT1-mediated metabolic activation and cytotoxicity of the prodrug tiazofurin. Cryoelectron microscopy (cryo-EM) structures of NMNAT1- and YPEL5-bound WDR26-CTLH E3 complexes reveal an internal basic degron motif of NMNAT1 essential for targeting by WDR26-CTLH E3 and degron mimicry by YPEL5's N terminus antagonizing substrate binding. Thus, our data provide a mechanistic understanding of how YPEL5-WDR26-CTLH E3 acts as a modulator of NMNAT1-dependent metabolism.

Analysis of a Therapeutic Antibody Cocktail Reveals Determinants for Cooperative and Broad Ebolavirus Neutralization.

Structural principles underlying the composition of protective antiviral monoclonal antibody (mAb) cocktails are poorly defined. Here, we exploited antibody cooperativity to develop a therapeutic mAb cocktail against Ebola virus. We systematically analyzed the antibody repertoire in human survivors and identified a pair of potently neutralizing mAbs that cooperatively bound to the ebolavirus glycoprotein (GP). High-resolution structures revealed that in a two-antibody cocktail, molecular mimicry was a major feature of mAb-GP interactions. Broadly neutralizing mAb rEBOV-520 targeted a conserved epitope on the GP base region. mAb rEBOV-548 bound to a glycan cap epitope, possessed neutralizing and Fc-mediated effector function activities, and potentiated neutralization by rEBOV-520. Remodeling of the glycan cap structures by the cocktail enabled enhanced GP binding and virus neutralization. The cocktail demonstrated resistance to virus escape and protected non-human primates (NHPs) against Ebola virus disease. These data illuminate structural principles of antibody cooperativity with implications for development of antiviral immunotherapeutics.

Pervasive mimicry in flight behavior among aposematic butterflies.

Flight was a key innovation in the adaptive radiation of insects. However, it is a complex trait influenced by a large number of interacting biotic and abiotic factors, making it difficult to unravel the evolutionary drivers. We investigate flight patterns in neotropical heliconiine butterflies, well known for mimicry of their aposematic wing color patterns. We quantify the flight patterns (wing beat frequency and wing angles) of 351 individuals representing 29 heliconiine and 9 ithomiine species belonging to ten color pattern mimicry groupings. For wing beat frequency and up wing angles, we show that heliconiine species group by color pattern mimicry affiliation. Convergence of down wing angles to mimicry groupings is less pronounced, indicating that distinct components of flight are under different selection pressures and constraints. The flight characteristics of the Tiger mimicry group are particularly divergent due to convergence with distantly related ithomiine species. Predator-driven selection for mimicry also explained variation in flight among subspecies, indicating that this convergence can occur over relatively short evolutionary timescales. Our results suggest that the flight convergence is driven by aposematic signaling rather than shared habitat between comimics. We demonstrate that behavioral mimicry can occur between lineages that have separated over evolutionary timescales ranging from <0.5 to 70 My.

Diversity and modularity of tyrosine-accepting tRNA-like structures.

Certain positive-sense single-stranded RNA viruses contain elements at their 3' termini that structurally mimic tRNAs. These tRNA-like structures (TLSs) are classified based on which amino acid is covalently added to the 3' end by host aminoacyl-tRNA synthetase. Recently, a cryoEM reconstruction of a representative tyrosine-accepting tRNA-like structure (TLSTyr) from brome mosaic virus (BMV) revealed a unique mode of recognition of the viral anticodon-mimicking domain by tyrosyl-tRNA synthetase. Some viruses in the hordeivirus genus of Virgaviridae are also selectively aminoacylated with tyrosine, yet these TLS RNAs have a different architecture in the 5' domain that comprises the atypical anticodon loop mimic. Herein, we present bioinformatic and biochemical data supporting a distinct secondary structure for the 5' domain of the hordeivirus TLSTyr compared to those in Bromoviridae Despite forming a different secondary structure, the 5' domain is necessary to achieve robust in vitro aminoacylation. Furthermore, a chimeric RNA containing the 5' domain from the BMV TLSTyr and the 3' domain from a hordeivirus TLSTyr are aminoacylated, illustrating modularity in these structured RNA elements. We propose that the structurally distinct 5' domain of the hordeivirus TLSTyrs performs the same role in mimicking the anticodon loop as its counterpart in the BMV TLSTyr Finally, these structurally and phylogenetically divergent types of TLSTyr provide insight into the evolutionary connections between all classes of viral tRNA-like structures.

Structure of CC Chemokine Receptor 5 with a Potent Chemokine Antagonist Reveals Mechanisms of Chemokine Recognition and Molecular Mimicry by HIV.

CCR5 is the primary chemokine receptor utilized by HIV to infect leukocytes, whereas CCR5 ligands inhibit infection by blocking CCR5 engagement with HIV gp120. To guide the design of improved therapeutics, we solved the structure of CCR5 in complex with chemokine antagonist [5P7]CCL5. Several structural features appeared to contribute to the anti-HIV potency of [5P7]CCL5, including the distinct chemokine orientation relative to the receptor, the near-complete occupancy of the receptor binding pocket, the dense network of intermolecular hydrogen bonds, and the similarity of binding determinants with the FDA-approved HIV inhibitor Maraviroc. Molecular modeling indicated that HIV gp120 mimicked the chemokine interaction with CCR5, providing an explanation for the ability of CCR5 to recognize diverse ligands and gp120 variants. Our findings reveal that structural plasticity facilitates receptor-chemokine specificity and enables exploitation by HIV, and provide insight into the design of small molecule and protein inhibitors for HIV and other CCR5-mediated diseases.

Galectin-4 Antimicrobial Activity Primarily Occurs Through its C-Terminal Domain.

Although immune tolerance evolved to reduce reactivity with self, it creates a gap in the adaptive immune response against microbes that decorate themselves in self-like antigens. This is particularly apparent with carbohydrate-based blood group antigens, wherein microbes can envelope themselves in blood group structures similar to human cells. In this study, we demonstrate that the innate immune lectin, galectin-4 (Gal-4), exhibits strain-specific binding and killing behavior towards microbes that display blood group-like antigens. Examination of binding preferences using a combination of microarrays populated with ABO(H) glycans and a variety of microbial strains, including those that express blood group-like antigens, demonstrated that Gal-4 binds mammalian and microbial antigens that have features of blood group and mammalian-like structures. Although Gal-4 was thought to exist as a monomer that achieves functional bivalency through its two linked carbohydrate recognition domains, our data demonstrate that Gal-4 forms dimers and that differences in the intrinsic ability of each domain to dimerize likely influences binding affinity. While each Gal-4 domain exhibited blood group-binding activity, the C-terminal domain (Gal-4C) exhibited dimeric properties, while the N-terminal domain (Gal-4N) failed to similarly display dimeric activity. Gal-4C not only exhibited the ability to dimerize but also possessed higher affinity toward ABO(H) blood group antigens and microbes expressing glycans with blood group-like features. Furthermore, when compared to Gal-4N, Gal-4C exhibited more potent antimicrobial activity. Even in the context of the full-length protein, where Gal-4N is functionally bivalent by virtue of Gal-4C dimerization, Gal-4C continued to display higher antimicrobial activity. These results demonstrate that Gal-4 exists as a dimer and exhibits its antimicrobial activity primarily through its C-terminal domain. In doing so, these data provide important insight into key features of Gal-4 responsible for its innate immune activity against molecular mimicry.

Bivalent molecular mimicry by ADP protects metal redox state and promotes coenzyme B12 repair.

Control over transition metal redox state is essential for metalloprotein function and can be achieved via coordination chemistry and/or sequestration from bulk solvent. Human methylmalonyl-Coenzyme A (CoA) mutase (MCM) catalyzes the isomerization of methylmalonyl-CoA to succinyl-CoA using 5'-deoxyadenosylcobalamin (AdoCbl) as a metallocofactor. During catalysis, the occasional escape of the 5'-deoxyadenosine (dAdo) moiety leaves the cob(II)alamin intermediate stranded and prone to hyperoxidation to hydroxocobalamin, which is recalcitrant to repair. In this study, we have identified the use of bivalent molecular mimicry by ADP, coopting the 5'-deoxyadenosine and diphosphate moieties in the cofactor and substrate, respectively, to protect against cob(II)alamin overoxidation on MCM. Crystallographic and electron paramagnetic resonance (EPR) data reveal that ADP exerts control over the metal oxidation state by inducing a conformational change that seals off solvent access, rather than by switching five-coordinate cob(II)alamin to the more air stable four-coordinate state. Subsequent binding of methylmalonyl-CoA (or CoA) promotes cob(II)alamin off-loading from MCM to adenosyltransferase for repair. This study identifies an unconventional strategy for controlling metal redox state by an abundant metabolite to plug active site access, which is key to preserving and recycling a rare, but essential, metal cofactor.

Convergence in sympatric swallowtail butterflies reveals ecological interactions as a key driver of worldwide trait diversification.

Ecological interactions can promote phenotypic diversification in sympatric species. While competition can enhance trait divergence, other ecological interactions may promote convergence in sympatric species. Within butterflies, evolutionary convergences in wing color patterns have been reported between distantly related species, especially in females of palatable species, where mimetic color patterns are promoted by predator communities shared with defended species living in sympatry. Wing color patterns are also often involved in species recognition in butterflies, and divergence in this trait has been reported in closely related species living in sympatry as a result of reproductive character displacement. Here, we investigate the effect of sympatry between species on the convergence vs. divergence of their wing color patterns in relation to phylogenetic distance, focusing on the iconic swallowtail butterflies (family Papilionidae). We developed an unsupervised machine learning-based method to estimate phenotypic distances among wing color patterns of 337 species, enabling us to finely quantify morphological diversity at the global scale among species and allowing us to compute pairwise phenotypic distances between sympatric and allopatric species pairs. We found phenotypic convergence in sympatry, stronger among distantly related species, while divergence was weaker and restricted to closely related males. The convergence was stronger among females than males, suggesting that differential selective pressures acting on the two sexes drove sexual dimorphism. Our results highlight the significant effect of ecological interactions driven by predation pressures on trait diversification in Papilionidae and provide evidence for the interaction between phylogenetic proximity and ecological interactions in sympatry, acting on macroevolutionary patterns of phenotypic diversification.

SARS-CoV-2 accessory proteins ORF7a and ORF3a use distinct mechanisms to down-regulate MHC-I surface expression.

Major histocompatibility complex class I (MHC-I) molecules, which are dimers of a glycosylated polymorphic transmembrane heavy chain and the small-protein ß2-microglobulin (ß2m), bind peptides in the endoplasmic reticulum that are generated by the cytosolic turnover of cellular proteins. In virus-infected cells, these peptides may include those derived from viral proteins. Peptide-MHC-I complexes then traffic through the secretory pathway and are displayed at the cell surface where those containing viral peptides can be detected by CD8+ T lymphocytes that kill infected cells. Many viruses enhance their in vivo survival by encoding genes that down-regulate MHC-I expression to avoid CD8+ T cell recognition. Here, we report that two accessory proteins encoded by SARS-CoV-2, the causative agent of the ongoing COVID-19 pandemic, down-regulate MHC-I expression using distinct mechanisms. First, ORF3a, a viroporin, reduces the global trafficking of proteins, including MHC-I, through the secretory pathway. The second, ORF7a, interacts specifically with the MHC-I heavy chain, acting as a molecular mimic of ß2m to inhibit its association. This slows the exit of properly assembled MHC-I molecules from the endoplasmic reticulum. We demonstrate that ORF7a reduces antigen presentation by the human MHC-I allele HLA-A*02:01. Thus, both ORF3a and ORF7a act post-translationally in the secretory pathway to lower surface MHC-I expression, with ORF7a exhibiting a specific mechanism that allows immune evasion by SARS-CoV-2.

The tempo and mode of character evolution in the assembly of mimetic communities.

Multitrait adaptive evolution is shaped by factors such as phylogenetic and functional constraints as well as the intensity and direction of selection. The tempo and mode of such multitrait evolution can differentially impact the assembly of biological communities. Batesian mimicry, in which undefended prey gain a fitness advantage by evolving a resemblance to aposematic models, involves adaptive evolution of multiple traits such as color patterns and flight morphology. To elucidate the evolutionary mechanisms of such multitrait adaptations, we evaluated the tempo and mode of adaptive convergence in flight morphology and color patterns in mimetic butterfly communities. We found that compared with Batesian mimics or nonmimetic sister species, models showed significantly faster rates of aposematic trait evolution, creating adaptive peaks for mimicry. At the community level, the degree of mimetic resemblance between mimics and models was positively correlated with the rate of character evolution, but independent of phylogenetic relatedness. Monomorphic mimics and female-limited mimics converged on the color patterns of models to a similar degree, showing that there were no constraints on mimetic trait evolution with respect to sex-specific selections. Convergence was driven by the greater lability of color patterns, which evolved at significantly faster rates than the phylogenetically conserved flight morphological traits, indicating that the two traits evolve under differential selection pressures and/or functional and genetic constraints. These community-wide patterns show that during the assembly of a community, the tempo of adaptive evolution is nonlinear, and specific to the underlying functional relationships and key traits that define the community.

T cell deletional tolerance restricts AQP4 but not MOG CNS autoimmunity.

Aquaporin-4 (AQP4)-specific Th17 cells are thought to have a central role in neuromyelitis optica (NMO) pathogenesis. When modeling NMO, only AQP4-reactive Th17 cells from AQP4-deficient (AQP4-/-), but not wild-type (WT) mice, caused CNS autoimmunity in recipient WT mice, indicating that a tightly regulated mechanism normally ensures tolerance to AQP4. Here, we found that pathogenic AQP4 T cell epitopes bind MHC II with exceptionally high affinity. Examination of T cell receptor (TCR) α/ß usage revealed that AQP4-specific T cells from AQP4-/- mice employed a distinct TCR repertoire and exhibited clonal expansion. Selective thymic AQP4 deficiency did not fully restore AQP4-reactive T cells, demonstrating that thymic negative selection alone did not account for AQP4-specific tolerance in WT mice. Indeed, AQP4-specific Th17 cells caused paralysis in recipient WT or B cell-deficient mice, which was followed by complete recovery that was associated with apoptosis of donor T cells. However, donor AQP4-reactive T cells survived and caused persistent paralysis in recipient mice deficient in both T and B cells or mice lacking T cells only. Thus, AQP4 CNS autoimmunity was limited by T cell-dependent deletion of AQP4-reactive T cells. In contrast, myelin oligodendrocyte glycoprotein (MOG)-specific T cells survived and caused sustained disease in WT mice. These findings underscore the importance of peripheral T cell deletional tolerance to AQP4, which may be relevant to understanding the balance of AQP4-reactive T cells in health and in NMO. T cell tolerance to AQP4, expressed in multiple tissues, is distinct from tolerance to MOG, an autoantigen restricted in its expression.

Trophoblast PR-SET7 dysfunction induces viral mimicry response and necroptosis associated with recurrent miscarriage.

Recurrent miscarriage (RM) is a distressing pregnancy complication. While the etiology of RM remains unclear, growing evidence has indicated the relevance of trophoblast impairment to the pathogenesis of RM. PR-SET7 is the sole enzyme catalyzing monomethylation of H4K20 (H4K20me1) and has been implicated in many pathophysiological processes. However, how PR-SET7 functions in trophoblasts and its relevance to RM remain unknown. Here, we found that trophoblast-specific loss of Pr-set7 in mice led to defective trophoblasts, resulting in early embryonic loss. Mechanistic analysis revealed that PR-SET7 deficiency in trophoblasts derepressed endogenous retroviruses (ERVs), leading to double-stranded RNA stress and subsequent viral mimicry, which drove overwhelming interferon response and necroptosis. Further examination discovered that H4K20me1 and H4K20me3 mediated the inhibition of cell-intrinsic expression of ERVs. Importantly, dysregulation of PR-SET7 expression and the corresponding aberrant epigenetic modifications were observed in the placentas of RM. Collectively, our results demonstrate that PR-SET7 acts as an epigenetic transcriptional modulator essential for repressing ERVs in trophoblasts, ensuring normal pregnancy and fetal survival, which sheds new light on potential epigenetic causes contributing to RM.

Origins and evolving functionalities of tRNA-derived small RNAs.

Transfer RNA (tRNA)-derived small RNAs (tsRNAs) are among the most ancient small RNAs in all domains of life and are generated by the cleavage of tRNAs. Emerging studies have begun to reveal the versatile roles of tsRNAs in fundamental biological processes, including gene silencing, ribosome biogenesis, retrotransposition, and epigenetic inheritance, which are rooted in tsRNA sequence conservation, RNA modifications, and protein-binding abilities. We summarize the mechanisms of tsRNA biogenesis and the impact of RNA modifications, and propose how thinking of tsRNA functionality from an evolutionary perspective urges the expansion of tsRNA research into a wider spectrum, including cross-tissue/cross-species regulation and harnessing of the 'tsRNA code' for precision medicine.

LncRNA-SERB promotes vasculogenic mimicry (VM) formation and tumor metastasis in renal cell carcinoma.

A growing body of evidence shows that vasculogenic mimicry (VM) is closely related to the invasion and metastasis of many tumor cells. Although the estrogen receptor (ER) can promote initiation and progression of renal cell carcinoma (RCC), how the downstream biomolecules are involved, and the detailed mechanisms of how ER expression is elevated in RCC remain to be further elucidated. Here, we discovered that long noncoding RNA (LncRNA)-SERB is highly expressed in tumor cells of RCC patients. We used multiple RCC cells and an in vivo mouse model for our study, and results indicated that LncRNA-SERB could boost RCC VM formation and cell invasion in vitro and in vivo. Although a previous report showed that ERß can affect the VM formation in RCC, it is unclear which factor could upregulate ERß. This is the first study to show LncRNA-SERB can be the upstream regulator of ERß to control RCC progression. Mechanistically, LncRNA-SERB may increase ERß via binding to the promoter area, and ERß functions through transcriptional regulation of zinc finger E-box binding homeobox 1 (ZEB1) to regulate VM formation. These results suggest that LncRNA-SERB promotes RCC cell VM formation and invasion by upregulating the ERß/ZEB1 axis and that therapeutic targeting of this newly identified pathway may better inhibit RCC progression.