Immunology
Abstract
Mendelian susceptibility to mycobacterial disease (MSMD) is characterized by a selective predisposition to clinical disease caused by the Bacille Calmette-Guérin (BCG) vaccine and environmental mycobacteria. The known genetic etiologies of MSMD are inborn errors of IFN-γ immunity due to mutations of 15 genes controlling the production of or response to IFN-γ. Since the first MSMD-causing mutations were reported in 1996, biallelic mutations in the genes encoding IFN-γ receptor 1 (IFN-γR1) and IFN-γR2 have been reported in many patients of diverse ancestries. Surprisingly, mutations of the gene encoding the IFN-γ cytokine itself have not been reported, raising the remote possibility that there might be other agonists of the IFN-γ receptor. We describe 2 Lebanese cousins with MSMD, living in Kuwait, who are both homozygous for a small deletion within the IFNG gene (c.354_357del), causing a frameshift that generates a premature stop codon (p.T119Ifs4*). The mutant allele is loss of expression and loss of function. We also show that the patients’ herpesvirus Saimiri–immortalized T lymphocytes did not produce IFN-γ, a phenotype that can be rescued by retrotransduction with WT IFNG cDNA. The blood T and NK lymphocytes from these patients also failed to produce and secrete detectable amounts of IFN-γ. Finally, we show that human IFNG has evolved under stronger negative selection than IFNGR1 or IFNGR2, suggesting that it is less tolerant to heterozygous deleterious mutations than IFNGR1 or IFNGR2. This may account for the rarity of patients with autosomal-recessive, complete IFN-γ deficiency relative to patients with complete IFN-γR1 and IFN-γR2 deficiencies.
Authors
Gaspard Kerner, Jérémie Rosain, Antoine Guérin, Ahmad Al-Khabaz, Carmen Oleaga-Quintas, Franck Rapaport, Michel J. Massaad, Jing-Ya Ding, Taushif Khan, Fatima Al Ali, Mahbuba Rahman, Caroline Deswarte, Rubén Martinez-Barricarte, Raif S. Geha, Valentine Jeanne-Julien, Diane Garcia, Chih-Yu Chi, Rui Yang, Manon Roynard, Bernhard Fleckenstein, Flore Rozenberg, Stéphanie Boisson-Dupuis, Cheng-Lung Ku, Yoann Seeleuthner, Vivien Béziat, Nico Marr, Laurent Abel, Waleed Al-Herz, Jean-Laurent Casanova, Jacinta Bustamante
Abstract
The microbiome provides resistance to infection. However, mechanisms for this are poorly understood. Here we demonstrate in a murine model that colonization with the intestinal bacterium Clostridium scindens provided protection from Entamoeba histolytica colitis via innate immunity. Introduction of C. scindens into the gut microbiota epigenetically altered and expanded bone marrow granulocyte-monocyte-progenitors (GMPs) and resulted in increased intestinal neutrophils with subsequent challenge with E. histolytica. Introduction of C. scindens alone was sufficient to expand GMPs in gnotobiotic mice. Adoptive transfer of bone-marrow from C. scindens colonized-mice into naïve-mice protected against amebic colitis and increased intestinal neutrophils. Children without E. histolytica diarrhea also had a higher abundance of Lachnoclostridia. Because of the known ability of the Lachnoclostridia C. scindens to metabolize the bile salt cholate, we measured deoxycholate and discovered that it was increased in the sera of C. scindens colonized specific pathogen free and gnotobiotic mice, as well as in children protected from amebiasis. Administration of deoxycholate alone (in the absence of C. scindens) increased GMPs and provided protection from amebiasis. We have discovered a mechanism by which C. scindens and the microbially-metabolized bile salt deoxycholic acid alter hematopoietic precursors and provide innate protection from later infection with Entamoeba histolytica.
Authors
Stacey L. Burgess, Jhansi L. Leslie, Md. Jashim Uddin, David Noah Oakland, Carol A. Gilchrist, G. Brett Moreau, Koji Watanabe, Mahmoud M. Saleh, Morgan Simpson, Brandon A. Thompson, David T. Auble, Stephen D. Turner, Natasa Giallourou, Jonathan Swann, Zhen Pu, Jennie Z. Ma, Rashidul Haque, William A. Petri, Jr.
Abstract
Hepatocellular carcinoma (HCC) is difficult to detect, carries a poor prognosis, and is one of few cancers with an increasing yearly incidence. Molecular defects in complement factor H (CFH), a critical regulatory protein of the complement alternative pathway (AP), are typically associated with inflammatory diseases of the eye and kidney. Little is known regarding the role of CFH in controlling complement activation with the liver. While studying aging CFH-deficient (fH–/–) mice, we observed spontaneous hepatic tumor formation in more than 50% of aged fH–/– males. Examination of fH–/– livers (3–24 months) for evidence of complement-mediated inflammation revealed widespread deposition of complement activation fragments throughout the sinusoids, elevated transminase levels, increased hepatic CD8+ and F4/80+ cells, overexpress of hepatic mRNA associated with inflammatory signaling pathways, steatosis and increased collagen deposition. Immunostaining of human HCC biopsies revealed extensive deposition of complement fragments within the tumors. Interrogation of the Cancer Genome Atlas also revealed that increased CFH mRNA expression is associated with improved survival in HCC patients, whereas mutations are associated with worse survival. These results indicate that CFH is critical for controlling complement activation in the liver, and in its absence, AP activation leads to chronic inflammation and promotes hepatic carcinogenesis.
Authors
Jennifer Laskowski, Brandon Renner, Matthew C. Pickering, Natalie J. Serkova, Peter M. Smith-Jones, Eric T. Clambey, Raphael A. Nemenoff, Joshua M. Thurman
Abstract
Patients with respiratory syncytial virus (RSV) infection exhibit enhanced susceptibility to subsequent pneumococcal infections. However, the underlying mechanisms involved in this increased susceptibility remain unclear. Here, we identified potentially novel cellular and molecular cascades triggered by RSV infection to exacerbate secondary pneumococcal pneumonia. RSV infection stimulated the local production of growth arrest–specific 6 (Gas6). The Gas6 receptor Axl was crucial for attenuating pneumococcal immunity in that the Gas6/Axl blockade fully restored antibacterial immunity. Mechanistically, Gas6/Axl interaction regulated the conversion of alveolar macrophages from an antibacterial phenotype to an M2-like phenotype that did not exhibit antibacterial activity, and the attenuation of caspase-1 activation and IL-18 production in response to pneumococcal infection. The attenuated IL-18 production failed to drive both NK cell–mediated IFN-γ production and local NO and TNF-α production, which impair the control of bacterial infection. Hence, the RSV-mediated Gas6/Axl activity attenuates the macrophage-mediated protection against pneumococcal infection. The Gas6/Axl axis could be a potentially novel therapeutic target for RSV-associated secondary bacterial infection.
Authors
Takehiko Shibata, Airi Makino, Ruiko Ogata, Shigeki Nakamura, Toshihiro Ito, Kisaburo Nagata, Yoshihiko Terauchi, Taku Oishi, Mikiya Fujieda, Yoshimasa Takahashi, Manabu Ato
Abstract
Myeloid cells comprise a major component of the tumor-microenvironment (TME) promoting tumor growth and immune evasion. By employing a novel small molecule inhibitor of glutamine metabolism, not only were we able to inhibit tumor growth, but we markedly inhibited the generation and recruitment of myeloid-derived suppressor cells (MDSCs). Targeting tumor glutamine metabolism led to a decrease in CSF3 and hence recruitment of MDSCs as well immunogenic cell death leading to an increase in inflammatory tumor-associated macrophages (TAMs). Alternatively, inhibiting glutamine metabolism of the MDSCs themselves led to activation induced cell death and conversion of MDSCs to inflammatory macrophages. Surprisingly, blocking glutamine metabolism also inhibited IDO expression of both the tumor and myeloid derived cells leading to a marked decrease in kynurenine levels. This in turn inhibited the development of metastasis and further enhanced anti-tumor immunity. Indeed, targeting glutamine metabolism rendered checkpoint blockade-resistant tumors susceptible to immunotherapy. Overall, our studies define an intimate interplay between the unique metabolism of tumors and the metabolism of suppressive immune cells.
Authors
Min-Hee Oh, Im-Hong Sun, Liang Zhao, Robert D. Leone, Im-Meng Sun, Wei Xu, Samuel L. Collins, Ada J. Tam, Richard L. Blosser, Chirag H. Patel, Judson M. Englert, Matthew L. Arwood, Jiayu Wen, Yee Chan-Li, Lukáš Tenora, Pavel Majer, Rana Rais, Barbara S. Slusher, Maureen R. Horton, Jonathan D. Powell
Abstract
Backgroun NK cells are activated by innate cytokines and viral ligands to kill virus-infected cells; these functions are enhanced during secondary immune responses and after vaccination by synergy with effector T cells and virus-specific antibodies. In human Ebola virus infection, clinical outcome is strongly associated with the initial innate cytokine response, but the role of NK cells has not been thoroughly examined. Methods The novel 2-dose heterologous Adenovirus type 26.ZEBOV (Ad26.ZEBOV) and modified vaccinia Ankara-BN-Filo (MVA-BN-Filo) vaccine regimen is safe and provides specific immunity against Ebola glycoprotein, and is currently in phase 2 and 3 studies. Here, we analysed NK cell phenotype and function in response to Ad26.ZEBOV, MVA-BN-Filo vaccination regimen, and in response to in vitro Ebola glycoprotein stimulation of PBMC isolated before and after vaccination. Results We show enhanced NK cell proliferation and activation after vaccination compared with baseline. Ebola glycoprotein-induced activation of NK cells was dependent on accessory cells and TLR-4-dependent innate cytokine secretion (predominantly from CD14+ monocytes) and enriched within less differentiated NK cell subsets. Optimal NK cell responses were dependent on IL-18 and IL-12, whilst IFN-γ secretion was restricted by high concentrations of IL-10. Conclusion This study demonstrates the induction of NK cell effector functions early after Ad26.ZEBOV, MVA-BN-Filo vaccination and provides a mechanism for the activation and regulation of NK cells by Ebola GP. Trial registration ClinicalTrials.gov Identifier: NCT02313077 Funding U.K. Medical Research Council Studentship in Vaccine Research, Innovative Medicines Initiative 2 Joint Undertaking, EBOVAC (Grant 115861) and Crucell Holland (now Janssen Vaccines & Prevention B.V.), European Union’s Horizon 2020 research and innovation programme and European Federation of Pharmaceutical Industries and Associations (EFPIA).
Authors
Helen R. Wagstaffe, Elizabeth A. Clutterbuck, Viki Bockstal, Jeroen N. Stoop, Kerstin Luhn, Macaya J. Douoguih, Georgi Shukarev, Matthew D. Snape, Andrew J. Pollard, Eleanor M. Riley, Martin Goodier
Abstract
Tumor-associated peptide–human leukocyte antigen complexes (pHLAs) represent the largest pool of cell surface–expressed cancer-specific epitopes, making them attractive targets for cancer therapies. Soluble bispecific molecules that incorporate an anti-CD3 effector function are being developed to redirect T cells against these targets using 2 different approaches. The first achieves pHLA recognition via affinity-enhanced versions of natural TCRs (e.g., immune-mobilizing monoclonal T cell receptors against cancer [ImmTAC] molecules), whereas the second harnesses an antibody-based format (TCR-mimic antibodies). For both classes of reagent, target specificity is vital, considering the vast universe of potential pHLA molecules that can be presented on healthy cells. Here, we made use of structural, biochemical, and computational approaches to investigate the molecular rules underpinning the reactivity patterns of pHLA-targeting bispecifics. We demonstrate that affinity-enhanced TCRs engage pHLA using a comparatively broad and balanced energetic footprint, with interactions distributed over several HLA and peptide side chains. As ImmTAC molecules, these TCRs also retained a greater degree of pHLA selectivity, with less off-target activity in cellular assays. Conversely, TCR-mimic antibodies tended to exhibit binding modes focused more toward hot spots on the HLA surface and exhibited a greater degree of crossreactivity. Our findings extend our understanding of the basic principles that underpin pHLA selectivity and exemplify a number of molecular approaches that can be used to probe the specificity of pHLA-targeting molecules, aiding the development of future reagents.
Authors
Christopher J. Holland, Rory M. Crean, Johanne M. Pentier, Ben de Wet, Angharad Lloyd, Velupillai Srikannathasan, Nikolai Lissin, Katy A. Lloyd, Thomas H. Blicher, Paul J. Conroy, Miriam Hock, Robert J. Pengelly, Thomas E. Spinner, Brian Cameron, Elizabeth A. Potter, Anitha Jeyanthan, Peter E. Molloy, Malkit Sami, Milos Aleksic, Nathaniel Liddy, Ross A. Robinson, Stephen Harper, Marco Lepore, Chris R. Pudney, Marc W. van der Kamp, Pierre J. Rizkallah, Bent K. Jakobsen, Annelise Vuidepot, David K. Cole
Abstract
Microbial ingestion by a macrophage results in the formation of an acidic phagolysosome but the host cell has no information on the pH susceptibility of the ingested organism. This poses a problem for the macrophage and raises the fundamental question of how the phagocytic cell optimizes the acidification process to prevail. We analyzed the dynamical distribution of phagolysosomal pH in murine and human macrophages that had ingested live or dead Cryptococcus neoformans cells, or inert beads. Phagolysosomal acidification produced a range of pH values that approximated normal distributions, but these differed from normality depending on ingested particle type. Analysis of the increments of pH reduction revealed no forbidden ordinal patterns, implying that phagosomal acidification process was a stochastic dynamical system. Using simulation modeling, we determined that by stochastically acidifying a phagolysosome to a pH within the observed distribution, macrophages sacrificed a small amount of overall fitness to reduce their overall variation in fitness. Hence, chance in the final phagosomal pH introduces unpredictability to the outcome of the macrophage-microbe, which implies a bet-hedging strategy that benefits the macrophage. While bet hedging is common in biological systems at the organism level, our results show its use at the organelle and cellular level.
Authors
Quigly Dragotakes, Kaitlin M. Stouffer, Man Shun Fu, Yehonatan Sella, Christine Youn, Olivia Insun Yoon, Carlos M. De Leon-Rodriguez, Joudeh Freij, Aviv Bergman, Arturo Casadevall
Abstract
IL-17–producing RORγt+ γδ T cells (γδT17 cells) are innate lymphocytes that participate in type 3 immune responses during infection and inflammation. Herein, we show that γδT17 cells rapidly proliferate within neonatal lymph nodes and gut, where, upon entry, they upregulate T-bet and coexpress IL-17, IL-22, and IFN-γ in a STAT3- and retinoic acid–dependent manner. Neonatal expansion was halted in mice conditionally deficient in STAT5, and its loss resulted in γδT17 cell depletion from all adult organs. Hyperactive STAT5 mutant mice showed that the STAT5A homolog had a dominant role over STAT5B in promoting γδT17 cell expansion and downregulating gut-associated T-bet. In contrast, STAT5B preferentially expanded IFN-γ–producing γδ populations, implying a previously unknown differential role of STAT5 gene products in lymphocyte lineage regulation. Importantly, mice lacking γδT17 cells as a result of STAT5 deficiency displayed a profound resistance to experimental autoimmune encephalomyelitis. Our data identify that the neonatal microenvironment in combination with STAT5 is critical for post-thymic γδT17 development and tissue-specific imprinting, which is essential for infection and autoimmunity.
Authors
Darshana Kadekar, Rasmus Agerholm, John Rizk, Heidi A. Neubauer, Tobias Suske, Barbara Maurer, Monica Torrellas Viñals, Elena M. Comelli, Amel Taibi, Richard Moriggl, Vasileios Bekiaris
Abstract
Food allergies are a major clinical problem and are driven by IgE antibodies specific for food antigens. T follicular regulatory (TFR) cells are a specialized subset of Foxp3+ T cells that modulate antibody responses. Here we analyzed the role of TFR cells in regulating antigen-specific IgE using a peanut-based food allergy model in mice. Peanut-specific IgE titers and anaphylaxis responses were significantly blunted in TFR cell-deficient Foxp3-cre Bcl6-fl/fl mice. Loss of TFR cells led to greatly increased non-specific IgE levels, showing that TFR cells have both helper and suppressor functions on IgE production in the GC that work together to facilitate the production of antigen-specific IgE. Foxp3-cre Pten-fl/fl mice with augmented TFR cell responses had markedly higher levels of peanut-specific IgE, revealing an active helper function by TFR cells on antigen-specific IgE. The helper function of TFR cells for IgE production involves IL-10, and the loss of IL-10 signaling by B cells led to a severely curtailed peanut-specific IgE response, decreased GC B cell survival and loss of GC dark zone B cells after peanut sensitization. We thus reveal that TFR cells have an unexpected helper role in promoting food allergy and are a novel target for drug development.
Authors
Markus M. Xie, Qiang Chen, Hong Liu, Kai Yang, Byunghee Koh, Hao Wu, Soheila J. Maleki, Barry K. Hurlburt, Joan Cook-Mills, Mark H. Kaplan, Alexander L. Dent
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)