TNFR1 and TNFR2 have received prominent attention because of their dominance in the pathogenesis of inflammation and autoimmunity. TNFR1 has been extensively studied and primarily mediates inflammation. TNFR2 remains far less studied, although emerging evidences demonstrate that TNFR2 plays an anti-inflammatory and immunoregulatory role in various conditions and diseases. Herein, we report that TNFR2 regulates macrophage polarization, a highly dynamic process controlled by largely unidentified intracellular regulators. Using biochemical co-purification and mass spectrometry approaches, we isolated the signaling molecule 14-3-3ε as a component of TNFR2 complexes in response to progranulin stimulation in macrophages. In addition, 14-3-3ε was essential for TNFR2 signaling-mediated regulation of macrophage polarization and switch. Both global and myeloid-specific deletion of 14-3-3ε resulted in exacerbated inflammatory arthritis and counteracted the protective effects of progranulin-mediated TNFR2 activation against inflammation and autoimmunity. TNFR2/14-3-3ε signaled through PI3K/Akt/mTOR to restrict NF-κB activation while simultaneously stimulating C/EBPβ activation, thereby instructing macrophage plasticity. Collectively, this study identifies 14-3-3ε as a previously-unrecognized vital component of the TNFR2 receptor complex and provides new insights into the TNFR2 signaling, particularly its role in macrophage polarization with therapeutic implications for various inflammatory and autoimmune diseases with activation of the TNFR2/14-3-3ε anti-inflammatory pathway.
Wenyu Fu, Wenhuo Hu, Young-Su Yi, Aubryanna Hettinghouse, Guodong Sun, Yufei Bi, Wenjun He, Lei Zhang, Guanmin Gao, Jody Liu, Kazuhito Toyo-oka, Guozhi Xiao, David B. Solit, Png Loke, Chuan-ju Liu
SLIT2 is a secreted polypeptide that guides migration of cells expressing ROBO1&2 receptors. Herein, we investigated SLIT2/ROBO signaling effects in gliomas. In patients with glioblastoma (GBM), SLIT2 expression increased with malignant progression and correlated with poor survival and immunosuppression. Knockdown of SLIT2 in mouse glioma cells and patient derived GBM xenografts reduced tumor growth and rendered tumors sensitive to immunotherapy. Tumor cell SLIT2 knockdown inhibited macrophage invasion and promoted a cytotoxic gene expression profile, which improved tumor vessel function and enhanced efficacy of chemotherapy and immunotherapy. Mechanistically, SLIT2 promoted microglia/macrophage chemotaxis and tumor-supportive polarization via ROBO1&2-mediated PI3Kgamma activation. Macrophage Robo1&2 deletion and systemic SLIT2 trap delivery mimicked SLIT2 knockdown effects on tumor growth and the tumor microenvironment (TME), revealing SLIT2 signaling through macrophage ROBOs as a potentially novel regulator of the GBM microenvironment and immunotherapeutic target for brain tumors.
Luiz H. Geraldo, Yunling Xu, Laurent Jacob, Laurence Pibouin-Fragner, Rohit Rao, Nawal Maïssa, Maite Verreault, Nolwenn Lemaire, Camille Knosp, Corinne Lesaffre, Thomas Daubon, Joost Dejaegher, Lien Solie, Justine Rudewicz, Thomas Viel, Bertrand Tavitian, Steven De Vleeschouwer, Marc Sanson, Andreas Bikfalvi, Ahmed Idbaih, Qing Richard Lu, Flavia R.S. Lima, Jean-Leon Thomas., Anne Eichmann, Thomas Mathivet
Without CFTR-mediated HCO3- secretion, airway epithelia of newborns with cystic fibrosis (CF) produce an abnormally acidic airway surface liquid (ASL), and the decreased pH impairs respiratory host defenses. However, within a few months of birth, ASL pH increases to match that in non-CF airways. Although the physiological basis for the increase is unknown, this time-course matches the development of inflammation in CF airways. To learn whether inflammation alters CF ASL pH, we treated CF epithelia with TNFα and IL-17, two inflammatory cytokines that are elevated in CF airways. TNFα+IL-17 markedly increased ASL pH by upregulating pendrin, an apical Cl-/HCO3- exchanger. Moreover, when CF epithelia were exposed to TNFα+IL-17, clinically approved CFTR modulators further alkalinized ASL pH. As predicted by these results, in vivo data revealed a positive correlation between airway inflammation and CFTR modulator-induced improvement in lung function. These findings suggest that inflammation is a key regulator of HCO3- secretion in CF airways. Thus, they explain earlier observations that ASL pH increases after birth and indicate that for similar levels of inflammation, the pH of CF ASL is abnormally acidic. These results also suggest that a non-cell-autonomous mechanism, airway inflammation, is an important determinant of the response to CFTR modulators.
Tayyab Rehman, Philip H. Karp, Ping Tan, Brian J. Goodell, Alejandro A. Pezzulo, Andrew L. Thurman, Ian M. Thornell, Samantha L. Durfey, Michael E. Duffey, David A. Stoltz, Edward F. McKone, Pradeep K. Singh, Michael J. Welsh
Genetic alterations in the RUNX1 gene are associated with benign and malignant blood disorders, particularly of megakaryocyte and myeloid lineages. The role of RUNX1 in acute lymphoblastic leukemia (ALL) is less clear, particularly how germline genetic variation influences the predisposition to this type of leukemia. Sequencing 4,836 children with B-ALL and 1,354 cases of T-ALL, we identified 31 and 18 germline RUNX1 variants, respectively. RUNX1 variants in B-ALL consistently showed minimal damaging effects. By contrast, 6 T-ALL-related variants result in drastic loss of RUNX1 activity as a transcription activator in vitro. Ectopic expression of dominant-negative RUNX1 variants in human CD34+ cells repressed differentiation into erythroid, megakaryocytes, and T cells, while promoting myeloid cell development. Chromatin immunoprecipitation sequencing of T-ALL models showed distinctive patterns of RUNX1 binding by variant proteins. Further whole genome sequencing identified JAK3 mutation as the most frequent somatic genomic abnormality in T-ALL with germline RUNX1 variants. Co-introduction of RUNX1 variant and JAK3 mutation in hematopoietic stem and progenitor cells in mice gave rise to T-ALL with early T-cell precursor phenotype. Taken together, these results indicated that RUNX1 is an important predisposition gene for T-ALL and pointed to novel biology of RUNX1-mediated leukemogenesis in the lymphoid lineages.
Yizhen Li, Wentao Yang, Meenakshi Devidas, Stuart S. Winter, Chimene Kesserwan, Wenjian Yang, Kimberly P. Dunsmore, Colton Smith, Maoxiang Qian, Xujie Zhao, Ranran Zhang, Julie M. Gastier-Foster, Elizabeth A. Raetz, William L. Carroll, Chunliang Li, Paul P. Liu, Karen R. Rabin, Takaomi Sanda, Charles G. Mullighan, Kim E. Nichols, William E. Evans, Ching-Hon Pui, Stephen P. Hunger, David T. Teachey, Mary V. Relling, Mignon L. Loh, Jun J. Yang
BACKGROUND. VRC01, a potent, broadly-neutralizing monoclonal antibody, inhibits simian-HIV infection in animal models. HVTN 104 assessed VRC01 safety and pharmacokinetics in humans. We extend the clinical evaluation to determine intravenous-infused VRC01 distribution and protective function at mucosal sites of HIV-1 entry. METHODS. Healthy, HIV-1-uninfected men (n=7) and women (n=5) receiving VRC01 every two months provided mucosal and serum samples once, 4-13 days post-infusion. Eleven male and 8 female HIV-seronegative volunteers provided untreated control samples. VRC01 levels were measured in serum, secretions and tissue, and HIV-1 inhibition was determined in tissue explants. RESULTS. Median VRC01 levels were quantifiable in serum (96.2 µg/ml or 1.3 pg/ng protein), rectal tissue (0.11 pg/ng protein), rectal secretions (0.13 pg/ng protein), vaginal tissue (0.1 pg/ng protein) and cervical secretions (0.44 pg/ng protein) from all recipients. VRC01/IgG ratios in male serum correlated with those in paired rectal tissue (r=0.893, P=0.012) and rectal secretions (r=0.9643, P=0.003). Ex vivo HIV-1Bal26 challenge infected 4/21 rectal explants from VRC01-infused versus 20/22 from controls (P=0.005); HIV-1 Du422.1 infected 20/21 rectal explants of VRC01 recipients and 12/12 from controls (P=0.639). HIV-1Bal26 infected 0/14 vaginal explants of VRC01 recipients compared to 23/28 control explants (P=0.003). CONCLUSION. Intravenous VRC01 distributes into the female genital and male rectal mucosa and retains anti-HIV-1 functionality, inhibiting a highly neutralization-sensitive but not a highly-resistant HIV-1 strain in mucosal tissue. These findings lend insight into VRC01 mucosal infiltration and provide perspective to in vivo protective efficacy. FUNDING. National Institute of Allergy and Infectious Diseases and Bill & Melinda Gates Foundation.
Rena D. Astronomo, Maria P. Lemos, Sandeep R. Narpala, Julie Czartoski, Lamar Ballweber Fleming, Kelly E. Seaton, Madhu Prabhakaran, Yunda Huang, Yiwen Lu, Katharine Westerberg, Lily Zhang, Mary K. Gross, John Hural, Hong-Van Tieu, Lindsey R. Baden, Scott Hammer, Ian Frank, Christina Ochsenbauer, Nicole Grunenberg, Julie E. Ledgerwood, Kenneth Mayer, Georgia Tomaras, Adrian B. McDermott, M. Juliana McElrath
The 12q13-q14 chromosomal region is recurrently amplified in 25% of fusion-positive (FP) rhabdomyosarcoma (RMS) cases and is associated with a poor prognosis. To identify amplified oncogenes in FP RMS, we compared the size, gene composition and expression of 12q13-q14 amplicons in FP RMS with other cancer categories (glioblastoma multiforme, lung adenocarcinoma and liposarcoma) in which 12q13-q14 amplification frequently occurs. We uncovered a 0.2 Mb region that is commonly amplified across these cancers and includes CDK4 and six other genes that are overexpressed in amplicon-positive samples. Additionally, we identified a 0.5 Mb segment that is only recurrently amplified in FP RMS and includes four genes that are overexpressed in amplicon-positive RMS. Among these genes, only SHMT2 was overexpressed at the protein level in an amplicon-positive RMS cell line. SHMT2 knockdown in amplicon- positive RMS cells suppressed growth, transformation and tumorigenesis, whereas overexpression in amplicon-negative RMS cells promoted these phenotypes. High SHMT2 expression reduced sensitivity of FP RMS cells to SHIN1, a direct SHMT2 inhibitor, but sensitized cells to pemetrexed, an inhibitor of the folate cycle. In conclusion, our study demonstrated that SHMT2 contributes to tumorigenesis in FP RMS and that SHMT2 amplification predicts differential response to drugs targeting this metabolic pathway.
Thanh H. Nguyen, Prasantha L. Vemu, Gregory E. Hoy, Salah Boudjadi, Bishwanath Chatterjee, Jack F. Shern, Javed Khan, Wenyue Sun, Frederic G. Barr
Multisystem inflammatory syndrome in children (MIS-C) occurs during, or recently following SARS-CoV-2 infection and is characterized by persistent fever, inflammation and severe illness requiring hospitalization. The majority of MIS-C cases also present with gastrointestinal (GI) symptoms, including abdominal pain, vomiting and diarrhea. In a recent issue of the JCI, Yonker and Gilboa et al., identify zonulin as a biomarker of GI permeability in children with MIS-C, and present the results of an intriguing proof-of-concept study which suggests that zonulin may represent a potential therapeutic target for MIS-C treatment and prevention. Together, these findings suggest that intestinal mucosal dysfunction and epithelial barrier breakdown may represent a biological mechanism underlying the development of MIS-C in SARS-CoV-2-infected children.
Tiffany R. Hensley-McBain, Jennifer A. Manuzak
Broadly reactive antibodies targeting the influenza A virus hemagglutinin (HA) head domain are thought to be rare and to require extensive somatic mutations or unusual structural features to achieve breadth against divergent HA subtypes. Here we describe common genetic and structural features of protective human antibodies from several individuals recognizing the trimer interface (TI) of the influenza A HA head, a recently identified site of vulnerability. We examined the sequence of TI-reactive antibodies, determined crystal structures for TI antibody-antigen complexes, and analyzed the contact residues of the antibodies on HA to discover common genetic and structural features of TI antibodies. Our data reveal that many TI antibodies are encoded by a light chain variable gene segment incorporating a shared somatic mutation. In addition, these antibodies have a shared acidic residue in the heavy chain despite originating from diverse heavy chain variable gene segments. These studies show that the TI region of influenza A HA is a major antigenic site with conserved structural features that are recognized by a common human B cell public clonotype. The canonical nature of this antibody-antigen interaction suggests that the TI epitope might serve as an important new target for structure-based vaccine design.
Seth J. Zost, Jinhui Dong, Iuliia M. Gilchuk, Pavlo Gilchuk, Natalie J. Thornburg, Sandhya Bangaru, Nurgun Kose, Jessica A. Finn, Robin Bombardi, Cinque Soto, Elaine C. Chen, Rachel S. Nargi, Rachel E. Sutton, Ryan P. Irving, Naveenchandra Suryadevara, Jonna B. Westover, Robert H. Carnahan, Hannah L. Turner, Sheng Li, Andrew B. Ward, James E. Crowe Jr.
To the Editor: Povysil G. et al. report that “rare loss-of-function (LOF) variants in type I interferon (IFN) immunity genes are not associated with severe COVID-19” (1). We disagree with the authors’ interpretation of our data and their own (2), for six reasons: 1) Only predicted LOF (pLOF) variants are relevant for comparison between the two studies, because, unlike us, these authors did not test variants experimentally. The relevant proportion in our data is therefore not 24/659=3.5%, but 9/659= 1.36%, whereas theirs is 1/713=0.14%. 2) Our definitions of ‘severe/critical’ patients are different: we defined critical disease as severity grades 6-10 of the WHO scale (3), whereas they restricted their recruitment to grades 7-10 (i.e., excluding patients on high-flow oxygen, considered in our study). Their cohort of ‘mild’ cases may therefore include ‘severe’ COVID-19 cases (grade 6), such as perhaps their ‘mild’ TLR3 pLOF carrier. 3) Their ‘controls’ are subjects from the general population, without depletion of COVID-19 genetic risk factors, whereas we used pauci-/asymptomatic infected subjects (grades 1-3) as ‘controls’. Consequently their power computation in Figure 1 is based on an incorrect hypothesis about the odds ratio, which would be expected to be lower when using general population controls (as they did), than when using pauci- and asymptomatic infected individuals (as we did). 4) The ethnic origin of the patients differs between the two studies: 58% of our 659 patients (and 8 of our 9 pLOF carriers) were European, versus only 10% of their 713 patients with severe disease (and their pLOF carrier is East Asian). 5) Age is a key factor neglected in their comparison: our sample was much younger (mean age: 51.8 years) than theirs (mean: 65.9 years), and seven of our nine pLOF carriers were < 60 years old. We performed a comparison stratified by age (<60/≥60 years), and no significant difference in pLOF proportion was found between the two studies, even ignoring the only patient carrying a pLOF they found (of unknown age): 7/458 in our sample vs. 0/192 in their sample (p=0.11, Fisher’s exact test) for patients <60 years old, and 2/201 vs. 0/521 (p=0.07) for patients ≥60 years old. 6) Finally, and crucially, the authors did not exclude patients with autoantibodies against type I IFN, which account for at least 10% of critical cases and are much more frequent in patients > 60 years of age, particularly men (4).
Qian Zhang, Aurélie Cobat, Paul Bastard, Luigi D. Notarangelo, Helen C. Su, Laurent Abel, Jean-Laurent Casanova
The authors reply: We appreciate the interest of Dr. Zhang and colleagues in our manuscript. The main difference between our publication and that of Zhang et al. (1), was that we assessed all rare predicted loss-of-function variants (pLOFs) meeting the same criteria in cases and controls, which is a well-established paradigm in the field (2). On the other hand, Zhang et al. included specific variants which were experimentally confirmed only in cases, but not controls, precluding a valid case-control comparison. We matched patients as closely as possible to the previous study, and the inclusion of more severe cases (WHO grades 7-10) should only strengthen the signal against population controls. The use of population controls is standard in such settings and has minimal impact on power, because only a small proportion of individuals exposed to SARS-Cov-2 develop severe disease (3). Additionally, for the pLOF model we report adequate power even for an odds ratio of 5.5, which is considerably lower than the one reported by Zhang et al. We tested the same dominant model as Zhang et al., even though LOF variants in these genes have only been reported to cause disease under recessive inheritance (4). We have serious concerns about confounding by ancestry in the analysis by Zhang et al. in which the pLOF carriers were mostly European, but functionally validated missense variants were found in various nationalities from Asia, Europe, Latin America, and the Middle East. Because the rates of pLOFs vary considerably across populations, adjusting for only 3 principal components of ancestry in rare-variant association tests of multi-ethnic cohorts does not provide adequate control for population structure. While we noted that age differences may contribute to the discrepancies between the two studies, Zhang et al. do not discuss the role of age in the interpretation of their results stating: “Inborn errors of TLR3- and IRF7-dependent type I IFN immunity at eight loci were found in as many as 23 patients (3.5%) of various ages (17 to 77 years) and ancestries (various nationalities from Asia, Europe, Latin America, and the Middle East) and in patients of both sexes.” We also note that the patients with autoantibodies were not excluded from the primary analysis by Zhang et al., but this was done only in the post-hoc analysis. Most importantly, our negative findings are in full agreement with the recently published independent study of 586,157 individuals, including 20,952 cases of COVID-19 (4,928 hospitalized and 1,304 requiring ventilation or resulting in death) (5). There were no significant associations with any of the 13 candidate genes examined either individually or in aggregate, or when comparisons included all hospitalized cases or only the most severe cases. Indeed, none of the associations displayed even marginal significance. Therefore, consistent with our study, these findings do not support substantial contributions of inborn errors in type I IFN immunity to COVID-19 severity. These negative results underscore the importance of proper study design, selection of appropriate genetic models, adequate control for genetic ancestry, and adherence to unbiased methods for genetic discovery rather than focusing only on a candidate biological pathway.
Gundula Povysil, Guillaume Butler-Laporte, Ali G. Gharavi, J. Brent Richards, David B. Goldstein, Krzysztof Kiryluk
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