Peripheral host T cells survive hematopoietic stem cell transplantation and promote graft-versus-host-disease

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Abstract

Graft-versus-host-disease (GVHD) is a major cause of morbidity and mortality in hematopoietic stem cell transplantation (HSCT). Donor T cells are key mediators in pathogenesis but a contribution from host T cells has not been explored, as conditioning regimens are believed to deplete host T cells. To evaluate a potential role for host T cells in GVHD, the origin of skin and blood T cells was assessed prospectively in patients after HSCT in the absence of GVHD. While blood contained primarily donor-derived T cells, most T cells in the skin were host-derived. We next examined patient skin, colon and blood during acute GVHD. Host T cells were present in all skin and colon acute GVHD specimens studied yet were largely absent in blood. We observed acute skin GVHD in the presence of 100% host T cells. Analysis demonstrated that a subset of host T cells in peripheral tissues were proliferating (Ki67+) and producing the pro-inflammatory cytokines IFNγ and IL-17 in situ. Comparatively, the majority of antigen presenting cells (APC) in tissue in acute GVHD were donor-derived, and donor-derived APC were observed directly adjacent to host T cells. A humanized mouse model demonstrated that host skin-resident T cells could be activated by donor monocytes to generate a GVHD-like dermatitis. Thus, host tissue-resident T cells may play a previously unappreciated pathogenic role in acute GVHD.

Authors

Sherrie J. Divito, Anders T. Aasebo, Tiago R. Matos, Pei-Chen Hsieh, Matthew Collin, Christopher P. Elco, John T. O'Malley, Espen S. Bækkevold, Henrik M. Reims, Tobias Gedde-Dahl, Michael Hagerstrom, Jude Hilaire, John W. Lian, Edgar L. Milford, Geraldine S. Pinkus, Vincent T. Ho, Robert J. Soiffer, Haesook T. Kim, Martin C. Mihm Jr, Jerome Ritz, Indira Guleria, Corey S. Cutler, Rachael Clark, Frode L. Jahnsen, Thomas S. Kupper

Inactivation of paracellular cation-selective claudin-2 channels attenuates immune-mediated experimental colitis in mice

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Abstract

The tight junction protein claudin-2 is upregulated in disease. Although many studies have linked intestinal barrier loss to local and systemic disease, these have relied on macromolecular probes. In vitro analyses show however that these probes cannot be accommodated by size- and charge-selective claudin-2 channels. We sought to define the impact of claudin-2 channels on disease. Transgenic claudin-2 overexpression or IL-13-induced claudin-2 upregulation increased intestinal small cation permeability in vivo. IL-13 did not however affect permeability in claudin-2-knockout mice. Claudin-2 is therefore necessary and sufficient to effect size- and charge-selective permeability increases in vivo. In chronic disease, T-cell transfer colitis severity was augmented or diminished in claudin-2 transgenic or knockout mice, respectively. We translated in vitro data suggesting that casein kinase-2 (CK2) inhibition blocks claudin-2 channel function and found that CK2 inhibition prevented IL-13-induced, claudin-2-mediated permeability increases in vivo. In chronic immune-mediated colitis, CK2 inhibition attenuated progression in claudin-2-sufficient, but not claudin-2-knockout, mice, i.e., the effect was claudin-2-dependent. Paracellular flux mediated by claudin-2 channels can therefore promote immune-mediated colitis progression. Although the mechanisms by which claudin-2 channels intensify disease remain to be defined, these data suggest that claudin-2 may be an accessible target in immune-mediated disorders, including inflammatory bowel disease.

Authors

Preeti Raju, Nitesh Shashikanth, Pei-Yun Tsai, Pawin Pongkorpsakol, Sandra Chanez-Parades, Peter R. Steinhagen, Wei-Ting Kuo, Gurminder Singh, Sachiko Tsukita, Jerrold R. Turner

PRICKLE3 linked to ATPase biogenesis manifested Leber’s hereditary optic neuropathy

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Abstract

Leber’s hereditary optic neuropathy (LHON) is a maternally inherited eye disease. X-linked nuclear modifiers were proposed to modify the phenotypic manifestation of LHON-associated mitochondrial DNA (mtDNA) mutations. By whole exome sequencing, we identified the X-linked LHON modifier (c.157C>T, p. Arg53Trp) in the PRICKLE3 encoding a mitochondrial protein linked to biogenesis of ATPase in three Chinese families. All affected individuals carried both ND4 11778G>A and p.Arg53Trp mutations, while subjects bearing only single mutation exhibited normal vision. The cells carrying the p.Arg53Trp mutation exhibited the defective assembly, stability and function of ATP synthase, verified by PRICKLE3 knock-down cells. Co-immunoprecipitation indicated the direct interaction of PRICKLE3 with ATP synthase via ATP8. Strikingly, mutant cells bearing both p.Arg53Trp and m.11778G>A mutations displayed greater mitochondrial dysfunctions than those carrying only single mutation. These indicated that the p.Arg53Trp mutation acted in synergy with m.11778G>A mutation and deteriorated mitochondrial dysfunctions necessary for the expression of LHON. Furthermore, we demonstrated that Prickle3 deficient mice exhibited the pronounced ATPase deficiencies. Prickle3 knock-out mice recapitulated LHON phenotypes with retina deficiencies including degeneration of retinal ganglion cells and abnormal vasculature. Our findings provided new insights into pathophysiology of LHON that were manifested by interaction between mtDNA mutation and X-linked nuclear modifier.

Authors

Jialing Yu, Xiaoyang Liang, Yanchun Ji, Cheng Ai, Junxia Liu, Ling Zhu, Zhipeng Nie, Xiaofen Jin, Chenghui Wang, Juanjuan Zhang, Fuxin Zhao, Shuang Mei, Xiaoxu Zhao, Xiangtian Zhou, Minglian Zhang, Meng Wang, Taosheng Huang, Pingping Jiang, Min-Xin Guan

Impaired hypocretin/orexin system alters responses to salient stimuli in obese male mice

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Abstract

The brain has evolved in an environment where food sources are scarce and foraging for food is one of the major challenges for survival of the individual and species. Basic and clinical studies show that obesity/overnutrition leads to overwhelming changes in the brain in animals and humans. However, the exact mechanisms underlying the consequences of excessive energy intake are not well understood. Neurons expressing the neuropeptide hypocretin/orexin (Hcrt) in the lateral/perifonical hypothalamus (LH) are critical for homeostatic regulation, reward seeking, stress response, and cognitive functions. In this study, we examined adaptations in Hcrt cells regulating behavioral responses to salient stimuli in diet-induced obese mice. Our results demonstrated changes in primary cilia, synaptic transmission and plasticity, cellular responses to neurotransmitters necessary for reward seeking and stress responses in Hcrt neurons from obese mice. Activities of neuronal networks in the LH and hippocampus were impaired as a result of decreased hypocretinergic function. The weakened Hcrt system decreased reward seeking while altering responses to acute stress (stress coping strategy), which were reversed by selectively activating Hcrt cells with chemogenetics. Taken together, our data suggest that a deficiency in the Hcrt signaling may be a common cause of behavioral changes (such as lowered arousal, weakened reward seek and altered stress response) in obese animals.

Authors

Ying Tan, Fu Hang, Zhong-Wu Liu, Milan Stoiljkovic, Mingxing Wu, Yue Tu, Wenfei Han, Angela M. Lee, Craig Kelley, Mihaly Hajos, Lingeng Lu, Luis de Lecea, Ivan de Araujo, Marina Picciotto, Tamas L. Horvath, Xiao-Bing Gao

Posttranslational modifications define course of prion strain adaptation and disease phenotype

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Abstract

Posttranslational modifications are a common feature of proteins associated with neurodegenerative diseases including prion protein (PrPC), tau and α-synuclein. Alternative self-propagating protein states or strains give rise to different disease phenotypes and display strain-specific subsets of posttranslational modifications. The relationships between strain-specific structure, posttranslational modifications and disease phenotype are poorly understood. We previously reported that among hundreds of PrPC sialoglycoforms expressed by a cell, individual prion strains recruited PrPC molecules selectively, according to the sialylation status of their N-linked glycans. Here we report that transmission of a prion strain to a new host is accompanied by a dramatic shift in the selectivity of recruitment of PrPC sialoglycoforms giving rise to PrPSc with a unique sialoglycoform signature and disease phenotype. The newly emerged strain has the shortest incubation time to disease, is characterized by a colocalization of PrPSc with microglia and a very profound proinflammatory response, features that are linked to a unique sialoglycoform composition of PrPSc. The current work provides experimental support for a hypothesis that strain-specific patterns of PrPSc sialoglycoforms formed as a result of selective recruitment dictate strain-specific disease phenotypes. This work suggests a causative relationship between a strain-specific structure, posttranslational modifications and disease phenotype.

Authors

Natallia Makarava, Jennifer Chen-Yu Chang, Kara Molesworth, Ilia V. Baskakov

FTY720 reactivates cryptococcal granulomas in mice through S1P receptor 3 on macrophages

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Abstract

FTY720 (Gilenya, Novartis), is a treatment for relapsing remitting multiple sclerosis (MS). It is an analog of sphingosine-1-phosphate (S1P) and targets S1P receptors 1,3,4, and 5. Recent reports indicate an association between long term exposure to FTY720 and cases of cryptococcal infection. Here, we studied the effect of FTY720 and its derivative, BAF312 (Mayzent, Novartis), which only target S1P receptors 1 and 5, in a mouse model of cryptococcal infection. We found that treatment with FTY720, but not with BAF312, lead to decreased survival and increased organ burden in mouse cryptococcal granulomas. Both FTY720 and BAF312 caused a profound CD4+ and CD8+ T cell depletion in blood and lungs but only treatment with FTY720 lead to cryptococcal reactivation. Treatment with FTY720, but not with BAF312, was associated with disorganization of macrophages and with a M2 polarization at the granuloma site. In a cell system, FTY720 decreased phagocytosis and production of reactive oxygen species by macrophages, a phenotype recapitulated in the S1pr3-/- knockout macrophages. Our results suggest that FTY720 reactivates cryptococcosis from the granuloma through a S1P receptor 3-mediated mechanism and support the rationale for development of more specific receptor modulators for therapeutic use of MS.

Authors

Arielle M. Bryan, Jeehyun Karen You, Travis McQuiston, Cristina Lazzarini, Zhijuan Qiu, Brian S. Sheridan, Barbara Nuesslein-Hildesheim, Maurizio Del Poeta

Salt generates anti-inflammatory Th17 cells but amplifies their pathogenicity in pro-inflammatory cytokine microenvironments

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Abstract

T helper cells integrate signals from their microenvironment to acquire distinct specialization programs for efficient clearance of diverse pathogens or for immunotolerance. Ionic signals have recently been demonstrated to affect T cell polarization and function. Sodium chloride (NaCl) was proposed to accumulate in peripheral tissues upon dietary intake and to promote autoimmunity via the Th17 cell axis. Here we demonstrate that high NaCl conditions induced a stable, pathogen-specific, anti-inflammatory Th17 cell fate in human T cells in vitro. The p38/MAPK pathway, involving NFAT5 and SGK1, regulated FoxP3 and interleukin (IL)-17A-expression in high-NaCl conditions. The NaCl-induced acquisition of an anti-inflammatory Th17 cell fate was confirmed in vivo in an experimental autoimmune encephalomyelitis (EAE) mouse model, which demonstrated strongly reduced disease symptoms upon transfer of T cells polarized in high NaCl conditions. However, NaCl was coopted to promote murine and human Th17 cell pathogenicity, if T cell stimulation occurred in a pro-inflammatory and TGF-β-low cytokine microenvironment. Taken together, our findings reveal a context-dependent, dichotomous role for NaCl in shaping Th17 cell pathogenicity. NaCl might therefore prove beneficial for the treatment of chronic inflammatory diseases in combination with cytokine-blocking drugs.

Authors

Julia Matthias, Sylvia Heink, Felix S.R. Picard, Julia Zeiträg, Anna Kolz, Ying-Yin Chao, Dominik Soll, Gustavo P. de Almeida, Elke Glasmacher, Ilse D. Jacobsen, Thomas Riedel, Anneli Peters, Stefan Floess, Jochen Huehn, Dirk Baumjohann, Magdalena Huber, Thomas Korn, Christina E. Zielinski

BET bromodomain inhibition attenuates cardiac phenotype in myocyte-specific Lamin A/C-deficient mice

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Abstract

Mutation in the LMNA gene, encoding Lamin A/C, cause a diverse group of diseases called laminopathies. Cardiac involvement is the major cause of death and manifests as dilated cardiomyopathy (DCM), heart failure, arrhythmias, and sudden death. There is no specific therapy for LMNA-associated cardiomyopathy. We report that deletion of Lmna in cardiac myocytes in mice leads to severe cardiac dysfunction, conduction defect, ventricular arrhythmias, fibrosis, apoptosis, and premature death within 4 weeks. The phenotype is similar to LMNA-associated cardiomyopathy in humans. RNA sequencing, performed prior to the onset of cardiac dysfunction, led to identification of 2,338 differentially expressed genes (DEGs) in Lmna-deleted cardiac myocytes. DEGs predicted activation of bromodomain-containing protein 4 (BRD4), a regulator of chromatin-associated proteins and transcription factors, which was confirmed by complementary approaches, including chromatin immunoprecipitation-sequencing. Daily injection of JQ1, a specific BET bromodomain inhibitor partially reversed the DEGs, including those encoding secretome, improved cardiac function, abrogated cardiac arrhythmias, fibrosis, and apoptosis, and prolonged the median survival time by 2-fold in the myocyte-specific Lmna-deleted mice. The findings highlight the important role of LMNA in cardiac myocyte and identify BET bromodomain inhibition as a potential therapeutic target in LMNA-associated cardiomyopathy, for which there is no specific effective therapy.

Authors

Gaelle Auguste, Leila Rouhi, Scot J. Matkovich, Cristian Coarfa, Matthew J. Robertson, Grazyna Czernuszewicz, Priyatansh Gurha, Ali J. Marian

Bruton’s tyrosine kinase inhibition effectively protects against human IgE-mediated anaphylaxis

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Abstract

No known therapies can prevent anaphylaxis. Bruton’s tyrosine kinase (BTK) is an enzyme thought to be essential for high-affinity IgE receptor (FcεRI) signaling in human cells. We tested the hypothesis that FDA-approved BTK inhibitors (BTKi’s) would prevent IgE-mediated responses including anaphylaxis. We showed that irreversible BTKi’s broadly prevented IgE-mediated degranulation and cytokine production in primary human mast cells and blocked allergen-induced contraction of isolated human bronchi. To address their efficacy in vivo, we created and utilized what we believe to be a novel humanized mouse model of anaphylaxis that does not require marrow ablation or human tissue implantation. After a single intravenous injection of human CD34+ cells, NSG-SGM3 mice supported the population of mature human tissue-resident mast cells and basophils. These mice showed excellent responses during passive systemic anaphylaxis using human IgE to selectively evoke human mast cell and basophil activation, and response severity was controllable by altering the amount of allergen used for challenge. Remarkably, pretreatment with just two oral doses of the BTKi acalabrutinib completely prevented moderate IgE-mediated anaphylaxis in these mice and also significantly protected against death during severe anaphylaxis. Our data suggest that BTKi’s may be able to prevent anaphylaxis in humans by inhibiting FcεRI-mediated signaling.

Authors

Melanie C. Dispenza, Rebecca A. Krier-Burris, Krishan D. Chhiba, Bradley J. Undem, Piper A. Robida, Bruce S. Bochner

γ9δ2T cell diversity and the receptor interface with tumor cells

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Abstract

γ9δ2T cells play a major role in cancer immune surveillance, yet the clinical translation of their in vitro promise remains challenging. To address limitations of previous clinical attempts utilizing expanded γ9δ2T cells, we explored the clonal diversity of γ9δ2T cell repertoires and characterized their target. We demonstrated that only a fraction of expanded γ9δ2T cells is active against cancer cells, and that activity of the parental clone, or functional avidity of selected γ9δ2TCRs does not associate with clonal frequency. We also analyzed the target-receptor-interface and provided a two-receptor, three-ligand model. Activation is initiated by binding of the γ9δ2TCR to BTN2A1 through the regions between CDR2 and CDR3 of the TCR γ chain, and modulated by the affinity of the CDR3 region of the TCR δ chain, which is phosphoantigen (pAg)-independent and does not depend on CD277. CD277 is secondary, serving as mandatory co-activating ligand. Binding of CD277 to its putative ligand does not depend on the presence of γ9δ2TCR, does depend on usage of the intracellular CD277, creates pAg-dependent proximity to BTN2A1, enhances cell-cell conjugate formation and stabilizes the immunological synapse. This process critically depends on the affinity of the γ9δ2TCR and requires membrane flexibility of the γ9δ2TCR and CD277, facilitating their polarization and high-density recruitment during immunological synapse formation.

Authors

Anna Vyborova, Dennis X. Beringer, Domenico Fasci, Froso Karaiskaki, Eline van Diest, Lovro Kramer, Aram de Haas, Jasper Sanders, Anke Janssen, Trudy Straetemans, Daniel Olive, Jeanette H.W. Leusen, Lola Boutin, Steven Nedellec, Samantha L. Schwartz, Michael J. Wester, Keith A. Lidke, Emmanuel Scotet, Diane Lidke, Albert J.R. Heck, Zsolt Sebestyen, Jurgen Kuball