CD8+ T cell responses are necessary for immune control of simian immunodeficiency virus (SIV). However, the key parameters that dictate antiviral potency remain elusive, conceivably because most studies to date have been restricted to analyses of circulating CD8+ T cells. We conducted a detailed clonotypic, functional, and phenotypic survey of SIV-specific CD8+ T cells across multiple anatomical sites in chronically infected rhesus macaques with high (> 10,000 copies/mL plasma) or low burdens of viral RNA (< 10,000 copies/mL plasma). No significant differences in response magnitude were identified across anatomical compartments. Rhesus macaques with low viral loads (VLs) harbored higher frequencies of polyfunctional CXCR5+ SIV-specific CD8+ T cells in various lymphoid tissues and higher proportions of unique Gag-specific CD8+ T cell clonotypes in the mesenteric lymph nodes relative to rhesus macaques with high VLs. In addition, public Gag-specific CD8+ T cell clonotypes were more commonly shared across distinct anatomical sites than the corresponding private clonotypes, which tended to form tissue-specific repertoires, especially in the peripheral blood and the gastrointestinal tract. Collectively, these data suggest that functionality and tissue localization are important determinants of CD8+ T cell-mediated efficacy against SIV.
Carly E. Starke, Carol L. Vinton, Kristin Ladell, James E. McLaren, Alexandra M. Ortiz, Joseph C. Mudd, Jacob K. Flynn, Stephen H. Lai, Fan Wu, Vanessa M. Hirsch, Samuel Darko, Daniel C. Douek, David A. Price, Jason M. Brenchley
Antagonists of the type 1 cysteinyl leukotriene receptor (CysLT1R) are widely used to treat asthma and allergic rhinitis, with variable response rates. Alveolar macrophages express UDP-specific P2Y6 receptors that can be blocked by off-target effects of CysLT1R antagonists. Sensitizing intranasal doses of an extract from the house dust mite Dermatophagoides farinae (Df) sharply increased the levels of UDP detected in bronchoalveolar lavage fluid of mice. Conditional deletion of P2Y6 receptors before sensitization exacerbated eosinophilic lung inflammation and type 2 cytokine production in response to subsequent Df challenge. P2Y6 receptor signaling was necessary for dectin-2–dependent production of protective IL-12p40 and Th1 chemokines by alveolar macrophages, leading to activation of NK cells to generate IFN-γ. Administration of CysLT1R antagonists during sensitization blocked UDP-elicited potentiation of IL-12p40 production by macrophages in vitro, suppressed the Df-induced production of IL-12p40 and IFN-γ in vivo, and suppressed type 2 inflammation only in P2Y6-deficient mice. Thus, P2Y6 receptor signaling drives an innate macrophage/IL-12/NK cell/IFN-γ axis that prevents inappropriate allergic type 2 immune responses on respiratory allergen exposure and counteracts the Th2 priming effect of CysLT1R signaling at sensitization. Targeting P2Y6 signaling might prove to be a potential additional treatment strategy for allergy.
Jun Nagai, Barbara Balestrieri, Laura B. Fanning, Timothy Kyin, Haley Cirka, Junrui Lin, Marco Idzko, Andreas Zech, Edy Y. Kim, Patrick J. Brennan, Joshua A. Boyce
Tumor-associated macrophages (TAMs) usually display an antiinflammatory M2-like phenotype to facilitate tumor growth. However, what drives M2 polarization of TAMs and how TAMs suppress antitumor immunity within the tumor microenvironment (TME) remain largely undefined. Using several murine tumor models, we showed that hedgehog (Hh) signaling in myeloid cells is critical for TAM M2 polarization and tumor growth. We also found that tumor cells secrete sonic hedgehog (SHH), an Hh ligand, and that tumor-derived SHH drives TAM M2 polarization. Furthermore, Hh-induced functional polarization in TAMs suppresses CD8+ T cell recruitment to the TME through the inhibition of CXCL9 and CXCL10 production by TAMs. Last, we demonstrated that Krüppel-like factor 4 (Klf4) mediates Hh-dependent TAM M2 polarization and the immunosuppressive function. Collectively, these findings highlight a critical role for tumor-derived SHH in promoting TAM M2 polarization, a mechanism for TAM-mediated immunosuppression, and may provide insights into the design of new cancer immunotherapeutic strategies.
Amy J. Petty, Ang Li, Xinyi Wang, Rui Dai, Benjamin Heyman, David Hsu, Xiaopei Huang, Yiping Yang
Macrophages are important in mounting an innate immune response to injury as well as in repair of injury. Gene expression of Rho proteins is known to be increased in fibrotic models; however, the role of these proteins in idiopathic pulmonary fibrosis (IPF) is not known. Here, we show that BAL cells from patients with IPF have a profibrotic phenotype secondary to increased activation of the small GTPase Rac1. Rac1 activation requires a posttranslational modification, geranylgeranylation, of the C-terminal cysteine residue. We found that by supplying more substrate for geranylgeranylation, Rac1 activation was substantially increased, resulting in profibrotic polarization by increasing flux through the mevalonate pathway. The increased flux was secondary to greater levels of acetyl-CoA from metabolic reprogramming to β oxidation. The polarization mediated fibrotic repair in the absence of injury by enhancing macrophage/fibroblast signaling. These observations suggest that targeting the mevalonate pathway may abrogate the role of macrophages in dysregulated fibrotic repair.
Jennifer L. Larson-Casey, Mudit Vaid, Linlin Gu, Chao He, Guo-Qiang Cai, Qiang Ding, Dana Davis, Taylor F. Berryhill, Landon S. Wilson, Stephen Barnes, Jeffrey D. Neighbors, Raymond J. Hohl, Kurt A. Zimmerman, Bradley K. Yoder, Ana Leda F. Longhini, Vidya Sagar Hanumanthu, Ranu Surolia, Veena B. Antony, A. Brent Carter
Tumor-resident lymphocytes can mount a response against neoantigens expressed in microsatellite-stable gastrointestinal (GI) cancers, and adoptive transfer of neoantigen-specific lymphocytes has demonstrated antitumor activity in selected patients. However, whether peripheral blood could be used as an alternative minimally invasive source to identify lymphocytes targeting neoantigens in patients with GI cancer with relatively low mutation burden is unclear. We used a personalized high-throughput screening strategy to investigate whether PD-1 expression in peripheral blood could be used to identify CD8+ or CD4+ lymphocytes recognizing neoantigens identified by whole-exome sequencing in 7 patients with GI cancer. We found that neoantigen-specific lymphocytes were preferentially enriched in the CD8+PD-1+/hi or CD4+PD-1+/hi subsets, but not in the corresponding bulk or PD-1– fractions. In 6 of 7 individuals analyzed we identified circulating CD8+ and CD4+ lymphocytes targeting 6 and 4 neoantigens, respectively. Moreover, neoantigen-reactive T cells and a T cell receptor (TCR) isolated from the CD8+PD-1+ subsets recognized autologous tumor, albeit at reduced levels, in 2 patients with available cell lines. These data demonstrate the existence of circulating T cells targeting neoantigens in GI cancer patients and provide an approach to generate enriched populations of personalized neoantigen-specific lymphocytes and isolate TCRs that could be exploited therapeutically to treat cancer.
Alena Gros, Eric Tran, Maria R. Parkhurst, Sadia Ilyas, Anna Pasetto, Eric M. Groh, Paul F. Robbins, Rami Yossef, Andrea Garcia-Garijo, Carlos A. Fajardo, Todd D. Prickett, Li Jia, Jared J. Gartner, Satyajit Ray, Lien Ngo, John R. Wunderllich, James C. Yang, Steven A. Rosenberg
Polymorphonuclear neutrophils (PMNs) are increasingly recognized to influence solid tumor development, but why their effects are so context-dependent and even frequently divergent remains poorly understood. Using an autochthonous mouse model of uterine cancer and the administration of respiratory hyperoxia as a means to improve tumor oxygenation, we provide in vivo evidence that hypoxia is a potent determinant of tumor-associated PMN phenotypes and direct PMN-tumor cell interactions. Upon relief of tumor hypoxia, PMNs were recruited less intensely to the tumor-bearing uterus but the recruited cells much more effectively killed tumor cells, an activity our data moreover suggested was mediated via their production of NADPH oxidase-derived reactive oxygen species and MMP-9. Simultaneously, their ability to promote tumor cell proliferation, which appeared mediated via their production of neutrophil elastase, was rendered less effective. Relieving tumor hypoxia thus greatly improved net PMN-dependent tumor control, leading to a massive reduction in tumor burden. Remarkably, this outcome was T cell-independent. Together, these findings identify key hypoxia-regulated molecular mechanisms through which PMNs directly induce tumor cell death and proliferation in vivo and suggest that the contrasting properties of PMNs in different tumor settings may in part reflect the effects of hypoxia on direct PMN-tumor cell interactions.
Karim Mahiddine, Adam Blaisdell, Stephany Ma, Amandine Créquer-Grandhomme, Clifford A. Lowell, Adrian Erlebacher
A number of highly potent and broadly neutralizing antibodies (bNAbs) against the human immunodeficiency virus (HIV) have recently been shown to prevent transmission of the virus, suppress viral replication, and delay plasma viral rebound following discontinuation of antiretroviral therapy in animal models and infected humans. However, the degree and extent to which such bNAbs interact with primary lymphocytes have not been fully delineated. Here, we show that certain glycan-dependent bNAbs, such as PGT121 and PGT151, bind to B, activated T, and natural killer (NK) cells of HIV-infected and -uninfected individuals. Binding of these bNAbs, particularly PGT121 and PGT151, to activated CD4+ and CD8+ T cells was mediated by complex-type glycans and was abrogated by enzymatic inhibition of N-linked glycosylation. In addition, a short-term incubation of PGT151 and primary NK cells led to degranulation and cellular death. Our data suggest that the propensity of certain bNAbs to bind uninfected/bystander cells has the potential for unexpected outcomes in passive-transfer studies and underscore the importance of antibody screening against primary lymphocytes.
Jana Blazkova, Eric W. Refsland, Katherine E. Clarridge, Victoria Shi, J. Shawn Justement, Erin D. Huiting, Kathleen R. Gittens, Xuejun Chen, Stephen D. Schmidt, Cuiping Liu, Nicole Doria-Rose, John R. Mascola, Alonso Heredia, Susan Moir, Tae-Wook Chun
We report on 2 patients with compound heterozygous mutations in forkhead box N1 (FOXN1), a transcription factor essential for thymic epithelial cell (TEC) differentiation. TECs are critical for T cell development. Both patients had a presentation consistent with T–/loB+NK+ SCID, with normal hair and nails, distinct from the classic nude/SCID phenotype in individuals with autosomal-recessive FOXN1 mutations. To understand the basis of this phenotype and the effects of the mutations on FOXN1, we generated mice using CRISPR-Cas9 technology to genocopy mutations in 1 of the patients. The mice with the Foxn1 compound heterozygous mutations had thymic hypoplasia, causing a T–B+NK+ SCID phenotype, whereas the hair and nails of these mice were normal. Characterization of the functional changes due to the Foxn1 mutations revealed a 5–amino acid segment at the end of the DNA-binding domain essential for the development of TECs but not keratinocytes. The transcriptional activity of this Foxn1 mutant was partly retained, indicating a region that specifies TEC functions. Analysis of an additional 9 FOXN1 mutations identified in multiple unrelated patients revealed distinct functional consequences contingent on the impact of the mutation on the DNA-binding and transactivation domains of FOXN1.
Qiumei Du, Larry K. Huynh, Fatma Coskun, Erika Molina, Matthew A. King, Prithvi Raj, Shaheen Khan, Igor Dozmorov, Christine M. Seroogy, Christian A. Wysocki, Grace T. Padron, Tyler R. Yates, M. Louise Markert, M. Teresa de la Morena, Nicolai S.C. van Oers
Multiple sclerosis (MS) is a disabling disease of the CNS. Inflammatory features of MS include lymphocyte accumulations in the CNS and cerebrospinal fluid (CSF). The preclinical events leading to established MS are still enigmatic. Here we compared gene expression patterns of CSF cells from MS-discordant monozygotic twin pairs. Six “healthy” co-twins, who carry a maximal familial risk for developing MS, showed subclinical neuroinflammation (SCNI) with small MRI lesions. Four of these subjects had oligoclonal bands (OCBs). By single-cell RNA sequencing of 2752 CSF cells, we identified clonally expanded CD8+ T cells, plasmablasts, and, to a lesser extent, CD4+ T cells not only from MS patients but also from subjects with SCNI. In contrast to nonexpanded T cells, clonally expanded T cells showed characteristics of activated tissue-resident memory T (TRM) cells. The TRM-like phenotype was detectable already in cells from SCNI subjects but more pronounced in cells from patients with definite MS. Expanded plasmablast clones were detected only in MS and SCNI subjects with OCBs. Our data provide evidence for very early concomitant activation of 3 components of the adaptive immune system in MS, with a notable contribution of clonally expanded TRM-like CD8+ cells.
Eduardo Beltrán, Lisa Ann Gerdes, Julia Hansen, Andrea Flierl-Hecht, Stefan Krebs, Helmut Blum, Birgit Ertl-Wagner, Frederik Barkhof, Tania Kümpfel, Reinhard Hohlfeld, Klaus Dornmair
Catecholamines released by sympathetic nerves can activate adrenergic receptors present on nearly every cell type, including myeloid derived suppressor cells (MDSCs). Using in vitro systems and murine tumor models, in wild-type mice and genetically modified (β2-AR–/–) mice, as well adoptive transfer approaches, we found that the degree of β2-AR signaling significantly influences MDSC frequency and survival in tumors and other tissues, modulates their expression of immunosuppressive molecules such as arginase-I and PDL-1 and alters their ability to suppress the proliferation of T cells. The regulatory functions of β-AR signaling in MDSCs were found to be dependent upon STAT3 phosphorylation. Moreover, we observed that the β2-AR-mediated increase in survival of MDSCs is dependent upon Fas-FasL interactions, and this is consistent with gene expression analyses which reveal a greater expression of apoptosis-related genes in β2-AR–/– MDSCs. Our data reveals the potential of β2-AR signaling to increase the generation of MDSCs from both murine and human peripheral blood cells and that the immunosuppressive function of MDSCs could be mitigated by treatment with β-AR antagonists, or enhanced by β-AR agonists, strongly supporting the possibility that reducing stress-induced activation of β2-ARs could help to overcome immune suppression and enhance the efficacy of immunotherapy and other cancer therapies.
Hemn Mohammadpour, Cameron R. MacDonald, Guanxi Qiao, Minhui Chen, Bowen Dong, Bonnie L. Hylander, Philip L. McCarthy, Scott I. Abrams, Elizabeth A. Repasky