Mutations in the isocitrate dehydrogenase genes
Gary Kohanbash, Diego A. Carrera, Shruti Shrivastav, Brian J. Ahn, Naznin Jahan, Tali Mazor, Zinal S. Chheda, Kira M. Downey, Payal B. Watchmaker, Casey Beppler, Rolf Warta, Nduka A. Amankulor, Christel Herold-Mende, Joseph F. Costello, Hideho Okada
Moesin is a member of the ezrin-radixin-moesin (ERM) family of proteins that are important for organizing membrane domains and receptor signaling and regulating the migration of effector T cells. Whether moesin plays any role during the generation of TGF-β–induced Tregs (iTregs) is unknown. Here, we have discovered that moesin is translationally regulated by TGF-β and is also required for optimal TGF-β signaling that promotes efficient development of iTregs. Loss of moesin impaired the development and function of both peripherally derived iTregs and in vitro–induced Tregs. Mechanistically, we identified an interaction between moesin and TGF-β receptor II (TβRII) that allows moesin to control the surface abundance and stability of TβRI and TβRII. We also found that moesin is required for iTreg conversion in the tumor microenvironment, and the deletion of moesin from recipient mice supported the rapid expansion of adoptively transferred CD8+ T cells against melanoma. Our study establishes moesin as an important regulator of the surface abundance and stability of TβRII and identifies moesin’s role in facilitating the efficient generation of iTregs. It also provides an advancement to our understanding about the role of the ERM proteins in regulating signal transduction pathways and suggests that modulation of moesin is a potential therapeutic target for Treg-related immune disorders.
Ephraim A. Ansa-Addo, Yongliang Zhang, Yi Yang, George S. Hussey, Breege V. Howley, Mohammad Salem, Brian Riesenberg, Shaoli Sun, Don C. Rockey, Serhan Karvar, Philip H. Howe, Bei Liu, Zihai Li
Vaccines targeting glycan structures at the surface of pathogenic microbes must overcome the inherent T cell–independent nature of immune responses against glycans. Carbohydrate conjugate vaccines achieve this by coupling bacterial polysaccharides to a carrier protein that recruits heterologous CD4 T cells to help B cell maturation. Yet they most often produce low- to medium-affinity immune responses of limited duration in immunologically fit individuals and disappointing results in the elderly and immunocompromised patients. Here, we hypothesized that these limitations result from suboptimal T cell help. To produce the next generation of more efficacious conjugate vaccines, we have explored a synthetic design aimed at focusing both B cell and T cell recognition to a single short glycan displayed at the surface of a virus-like particle. We tested and established the proof of concept of this approach for 2 serotypes of
Zinaida Polonskaya, Shenglou Deng, Anita Sarkar, Lisa Kain, Marta Comellas-Aragones, Craig S. McKay, Katarzyna Kaczanowska, Marie Holt, Ryan McBride, Valle Palomo, Kevin M. Self, Seth Taylor, Adriana Irimia, Sanjay R. Mehta, Jennifer M. Dan, Matthew Brigger, Shane Crotty, Stephen P. Schoenberger, James C. Paulson, Ian A. Wilson, Paul B. Savage, M.G. Finn, Luc Teyton
The antiviral restriction factor IFN-induced transmembrane protein 3 (IFITM3) inhibits cell entry of a number of viruses, and genetic diversity within
Maria A. Stacey, Simon Clare, Mathew Clement, Morgan Marsden, Juneid Abdul-Karim, Leanne Kane, Katherine Harcourt, Cordelia Brandt, Ceri A. Fielding, Sarah E. Smith, Rachael S. Wash, Silvia Gimeno Brias, Gabrielle Stack, George Notley, Emma L. Cambridge, Christopher Isherwood, Anneliese O. Speak, Zoë Johnson, Walter Ferlin, Simon A. Jones, Paul Kellam, Ian R. Humphreys
B cells contribute to multiple aspects of autoimmune disorders and may play a role in triggering disease. Thus, targeting B cells may be a promising strategy for treating autoimmune disorders. Better understanding of the B cell subsets that are responsible for the development of autoimmunity will be critical for developing efficient therapies. Here we have reported that B cells expressing the transcription factor T-bet promote the rapid appearance of autoantibodies and germinal centers in spontaneous murine models of systemic lupus erythematosus (SLE). Conditional deletion of T-bet from B cells impaired the formation of germinal centers and mitigated the development of kidney damage and rapid mortality in SLE mice. B cell–specific deletion of T-bet was also associated with lower activation of both B cells and T cells. Taken together, our results suggest that targeting T-bet–expressing B cells may be a potential target for therapy for autoimmune diseases.
Kira Rubtsova, Anatoly V. Rubtsov, Joshua M. Thurman, Johanna M. Mennona, John W. Kappler, Philippa Marrack
Autoimmune responses to meiotic germ cell antigens (MGCA) that are expressed on sperm and testis occur in human infertility and after vasectomy. Many MGCA are also expressed as cancer/testis antigens (CTA) in human cancers, but the tolerance status of MGCA has not been investigated. MGCA are considered to be uniformly immunogenic and nontolerogenic, and the prevailing view posits that MGCA are sequestered behind the Sertoli cell barrier in seminiferous tubules. Here, we have shown that only some murine MGCA are sequestered. Nonsequestered MCGA (NS-MGCA) egressed from normal tubules, as evidenced by their ability to interact with systemically injected antibodies and form localized immune complexes outside the Sertoli cell barrier. NS-MGCA derived from cell fragments that were discarded by spermatids during spermiation. They egressed as cargo in residual bodies and maintained Treg-dependent physiological tolerance. In contrast, sequestered MGCA (S-MGCA) were undetectable in residual bodies and were nontolerogenic. Unlike postvasectomy autoantibodies, which have been shown to mainly target S-MGCA, autoantibodies produced by normal mice with transient Treg depletion that developed autoimmune orchitis exclusively targeted NS-MGCA. We conclude that spermiation, a physiological checkpoint in spermatogenesis, determines the egress and tolerogenicity of MGCA. Our findings will affect target antigen selection in testis and sperm autoimmunity and the immune responses to CTA in male cancer patients.
Kenneth S.K. Tung, Jessica Harakal, Hui Qiao, Claudia Rival, Jonathan C.H. Li, Alberta G.A. Paul, Karen Wheeler, Patcharin Pramoonjago, Constance M. Grafer, Wei Sun, Robert D. Sampson, Elissa W.P. Wong, Prabhakara P. Reddi, Umesh S. Deshmukh, Daniel M. Hardy, Huanghui Tang, C. Yan Cheng, Erwin Goldberg
Defective apoptotic death of activated macrophages has been implicated in the pathogenesis of rheumatoid arthritis (RA). However, the molecular signatures defining apoptotic resistance of RA macrophages are not fully understood. Here, global transcriptome profiling of RA macrophages revealed that the osmoprotective transcription factor nuclear factor of activated T cells 5 (NFAT5) critically regulates diverse pathologic processes in synovial macrophages including the cell cycle, apoptosis, and proliferation. Transcriptomic analysis of NFAT5-deficient macrophages revealed the molecular networks defining cell survival and proliferation. Proinflammatory M1-polarizing stimuli and hypoxic conditions were responsible for enhanced NFAT5 expression in RA macrophages. An in vitro functional study demonstrated that NFAT5-deficient macrophages were more susceptible to apoptotic death. Specifically, CCL2 secretion in an NFAT5-dependent fashion bestowed apoptotic resistance to RA macrophages in vitro. Injection of recombinant CCL2 into one of the affected joints of
Susanna Choi, Sungyong You, Donghyun Kim, Soo Youn Choi, H. Moo Kwon, Hyun-Sook Kim, Daehee Hwang, Yune-Jung Park, Chul-Soo Cho, Wan-Uk Kim
An intracellular complement system (ICS) has recently been described in immune and nonimmune human cells. This system can be activated in a convertase-independent manner from intracellular stores of the complement component C3. The source of these stores has not been rigorously investigated. In the present study, Western blotting identified a band corresponding to C3 in freshly isolated human peripheral blood cells that was absent in corresponding cell lines. One difference between native cells and cell lines was the time absent from a fluid-phase complement source; therefore, we hypothesized that loading C3 from plasma was a route of establishing intracellular C3 stores. We found that many types of human cells specifically internalized C3(H2O), the hydrolytic product of C3, and not native C3, from the extracellular milieu. Uptake was rapid, saturable, and sensitive to competition with unlabeled C3(H2O), indicating a specific mechanism of loading. Under steady-state conditions, approximately 80% of incorporated C3(H2O) was returned to the extracellular space. These studies identify an ICS recycling pathway for C3(H2O). The loaded C3(H2O) represents a source of C3a, and its uptake altered the cytokine profile of activated CD4+ T cells. Importantly, these results indicate that the impact of soluble plasma factors should be considered when performing in vitro studies assessing cellular immune function.
Michelle Elvington, M. Kathryn Liszewski, Paula Bertram, Hrishikesh S. Kulkarni, John P. Atkinson
Tissue inflammation is a key component of obesity-induced insulin resistance, with a variety of immune cell types accumulating in adipose tissue. Here, we have demonstrated increased numbers of B2 lymphocytes in obese adipose tissue and have shown that high-fat diet–induced (HFD-induced) insulin resistance is mitigated in B cell-deficient (Bnull) mice. Adoptive transfer of adipose tissue B2 cells (ATB2) from wild-type HFD donor mice into HFD Bnull recipients completely restored the effect of HFD to induce insulin resistance. Recruitment and activation of ATB2 cells was mediated by signaling through the chemokine leukotriene B4 (LTB4) and its receptor LTB4R1. Furthermore, the adverse effects of ATB2 cells on glucose homeostasis were partially dependent upon T cells and macrophages. These results demonstrate the importance of ATB2 cells in obesity-induced insulin resistance and suggest that inhibition of the LTB4/LTB4R1 axis might be a useful approach for developing insulin-sensitizing therapeutics.
Wei Ying, Joshua Wollam, Jachelle M. Ofrecio, Gautam Bandyopadhyay, Dalila El Ouarrat, Yun Sok Lee, Da Young Oh, Pingping Li, Olivia Osborn, Jerrold M. Olefsky
Chimeric antigen receptor (CAR) T cells have been highly successful in treating hematological malignancies, including acute and chronic lymphoblastic leukemia. However, treatment of solid tumors using CAR T cells has been largely unsuccessful to date, partly because of tumor-induced immunosuppressive mechanisms, including adenosine production. Previous studies have shown that adenosine generated by tumor cells potently inhibits endogenous antitumor T cell responses through activation of adenosine 2A receptors (A2ARs). Herein, we have observed that CAR activation resulted in increased A2AR expression and suppression of both murine and human CAR T cells. This was reversible using either A2AR antagonists or genetic targeting of A2AR using shRNA. In 2 syngeneic HER2+ self-antigen tumor models, we found that either genetic or pharmacological targeting of the A2AR profoundly increased CAR T cell efficacy, particularly when combined with PD-1 blockade. Mechanistically, this was associated with increased cytokine production of CD8+ CAR T cells and increased activation of both CD8+ and CD4+ CAR T cells. Given the known clinical relevance of the CD73/adenosine pathway in several solid tumor types, and the initiation of phase I trials for A2AR antagonists in oncology, this approach has high translational potential to enhance CAR T cell efficacy in several cancer types.
Paul A. Beavis, Melissa A. Henderson, Lauren Giuffrida, Jane K. Mills, Kevin Sek, Ryan S. Cross, Alexander J. Davenport, Liza B. John, Sherly Mardiana, Clare Y. Slaney, Ricky W. Johnstone, Joseph A. Trapani, John Stagg, Sherene Loi, Lev Kats, David Gyorki, Michael H. Kershaw, Phillip K. Darcy