The aorta and the large conductive arteries are immunoprivileged tissues and are protected against inflammatory attack. A breakdown of the immunoprivilege leads to autoimmune vasculitis, such as giant cell arteritis (GCA), in which CD8+ T regulatory (Treg) cells fail to contain CD4+ T cells and macrophages, resulting in the formation of tissue-destructive granulomatous lesions. Here, we report that the molecular defect of malfunctioning CD8+ Treg cells lies in aberrant NOTCH4 signaling that deviates endosomal trafficking and minimizes exosome production. By transcriptionally controlling the profile of RAB GTPases, NOTCH4 signaling restricted membrane translocation and vesicular secretion of the enzyme NADPH oxidase 2 (NOX2). Specifically, NOTCH4hiCD8+ Treg cells increased RAB5A and RAB11A expression and suppressed RAB7A, culminating in the accumulation of early and recycling endosomes and trapping of NOX2 in an intracellular, non-secretory compartment. RAB7AloCD8+ Treg cells failed in the surface translocation and the exosomal release of NOX2. NOTCH4hi RAB5Ahi RAB7Alo RAB11Ahi CD8+ Treg cells left adaptive immunity unopposed, enabling a breakdown in tissue tolerance and aggressive vessel wall inflammation. Inhibiting NOTCH4 signaling corrected the defect and protected arteries from inflammatory insult. The study implicates NOTCH4-dependent transcriptional control of RAB proteins and intracellular vesicle trafficking in autoimmune disease and in vascular inflammation.
Ke Jin, Zhenke Wen, Bowen Wu, Hui Zhang, Jingtao Qiu, Yanan Wang, Kenneth J. Warrington, Gerald Berry, Jörg J. Goronzy, Cornelia M. Weyand
Macrophages are main effectors of heme metabolism, increasing transiently in the liver during heightened disposal of damaged or senescent red blood cells (sRBC). Macrophages are also essential in defense against microbial threats, but pathologic states of heme excess may be immunosuppressive. Herein, we uncovered a mechanism whereby an acute rise in sRBC disposal by macrophages led to an immunosuppressive phenotype following intrapulmonary Klebsiella pneumoniae infection characterized by increased extrapulmonary bacterial proliferation and reduced survival from sepsis in mice. The impaired immunity to K. pneumoniae during heightened sRBC disposal was independent of iron acquisition by bacterial siderophores, as K. pneumoniae mutant lacking siderophore function recapitulated findings observed with wildtype strain. Rather, sRBC disposal induced a liver transcriptomic profile notable for suppression of Stat1 and interferon-related responses during K. pneumoniae sepsis. Excess heme handling by macrophages recapitulated STAT1 suppression during infection that required synergistic NRF1 and NRF2 activation but was independent of heme oxygenase-1 induction. Whereas iron was dispensable, the porphyrin moiety of heme was sufficient to mediate suppression of STAT1-dependent responses in human and mouse macrophages and promoted liver dissemination of K. pneumoniae in vivo. Thus, cellular heme metabolism dysfunction negatively regulates the STAT1 pathway with implications in severe infection.
Tolani F. Olonisakin, Tomeka L. Suber, Shekina Gonzalez-Ferrer, Zeyu Xiong, Hernán F. Peñaloza, Rick van der Geest, Yuting Xiong, David O. Osei-Hwedieh, Jesus Tejero, Matthew R. Rosengart, Wendy M. Mars, Daria Van Tyne, Andreas Perlegas, Samuel Brashears, Daniel B. Kim-Shapiro, Mark T. Gladwin, Michael A. Bachman, Eldad A. Hod, Claudette St. Croix, Yulia Y. Tyurina, Valerian E. Kagan, Rama K. Mallampalli, Anuradha Ray, Prabir Ray, Janet S. Lee
Therapeutic strategies designed to target TP53-deficient cancer cells remain elusive. Here, we showed that TP53 loss initiated a pharmacologically actionable secretory process that drove lung adenocarcinoma (LUAD) progression. Molecular, biochemical, and cell biological studies showed that TP53 loss increased the expression of Golgi reassembly and stacking protein 55 kD (G55), a Golgi stacking protein that maintains Golgi organelle integrity and is part of a GOLGIN45/myosin IIA-containing protein complex that activates secretory vesicle biogenesis in the Golgi. TP53 loss activated G55-dependent secretion by relieving G55 and myosin IIA from miR-34a-dependent silencing. G55-dependent secreted proteins enhanced the proliferative and invasive activities of TP53-deficient LUAD cells and promoted angiogenesis and CD8+ T cell exhaustion in the tumor microenvironment. A small molecule that blocks G55/G45 interactions impaired secretion and reduced TP53-deficient LUAD growth and metastasis. These results identified a targetable secretory vulnerability in TP53-deficient LUAD cells.
Xiaochao Tan, Lei Shi, Priyam Banerjee, Xin Liu, Hou-Fu Guo, Jiang Yu, Neus Bota-Rabassedas, B. Leticia Rodriguez, Don L. Gibbons, William K. Russell, Chad J. Creighton, Jonathan M. Kurie
BACKGROUND. The ABO histo-blood group is defined by carbohydrate modifications and is associated with risk for multiple diseases including Acute Respiratory Distress Syndrome (ARDS). We hypothesized that genetically determined blood subtype A1 is associated with increased risk of ARDS and markers of microvascular dysfunction and coagulation. METHODS. We conducted analyses in three cohorts of critically ill trauma and sepsis patients (n = 3,710) genotyped on genome-wide platforms to determine the association of the A1 blood type genotype with ARDS risk. We subsequently determined if associations were present in FUT2 defined non-secretors who lack ABO antigens on epithelium, but not endothelium. In a patient subgroup, we determined the associations of blood type with plasma levels of endothelial glycoproteins and disseminated intravascular coagulation (DIC). Lastly, we tested if blood type A was associated with less donor lung injury recovery during human ex vivo lung perfusion (EVLP). RESULTS. The A1 genotype was associated with a higher risk of moderate to severe ARDS relative to type O in all three populations. In sepsis, this relationship was strongest in non-pulmonary infections. The association persisted in non-secretors, suggesting a vascular mechanism. The A1 genotype was also associated with higher DIC risk as well as concentrations of thrombomodulin and von Willebrand Factor, which in turn were associated with ARDS risk. Blood type A was also associated with less lung injury recovery during EVLP. CONCLUSIONS. We identified a replicable association between ABO blood type A1 and risk of ARDS among the critically ill possibly mediated through microvascular dysfunction and coagulation.
John P. Reilly, Nuala J. Meyer, Michael G.S. Shashaty, Brian J. Anderson, Caroline Ittner, Thomas G. Dunn, Brian Lim, Caitlin Forker, Michael P. Bonk, Ethan D. Kotloff, Rui Feng, Edward Cantu, Nilam S. Mangalmurti, Carolyn S. Calfee, Michael A. Matthay, Carmen Mikacenic, Keith R. Walley, James A. Russell, David C. Christiani, Mark M. Wurfel, Paul N. Lanken, Muredach P. Reilly, Jason D. Christie
CD4+ T cells interactions with B cells play a critical role in the pathogenesis of systemic autoimmune diseases such as systemic lupus and chronic graft-versus-host disease (cGVHD). Extrafollicular CD44hiCD62LloPSGL1loCD4+ (PSGL1loCD4+) T cells are associated with the pathogenesis of lupus and cGVHD, but their causal role has not been established. With murine and humanized MHC–/–HLA-A2+DR4+ murine models of cGVHD, we show that both murine and human PSGL1loCD4+ T cells from GVHD target tissues have features of B cell helpers with upregulated-expression of PD1 and ICOS and production of IL-21. They reside in non-lymphoid tissues without circulating in the blood and have features of tissue-resident memory T cells with upregulated-expression of CD69. Murine PSGL1loCD4+ T cells from GVHD target tissues augmented B cell differentiation into plasma cells and production of autoantibodies via their PD1 interaction with PD-L2 on B cells. Human PSGL1loCD4+ T cells were apposed with memory B cells in the liver tissues of humanized mice and cGVHD patients. Human PSGL1loCD4+ T cells from humanized GVHD target tissues also augmented autologous memory B cell differentiation into plasma cells and antibody production in PD1/PD-L2-dependent manner. Further preclinical studies targeting tissue-resident T cells to treat antibody-mediated features of autoimmune diseases are warranted.
Xiaohui Kong, Deye Zeng, Xiwei Wu, Bixin Wang, Shijie Yang, Qingxiao Song, Yongping Zhu, Martha Salas, Hanjun Qin, Ubaydah Nasri, Karen M. Haas, Arthur D. Riggs, Ryotaro Nakamura, Paul J. Martin, Aimin Huang, Defu Zeng