HLA-E–restricted HIV-1–specific CD8+ T cell responses in natural infection

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Abstract

MHC-E, a non-classical MHC molecule, restricted CD8 T-cell responses have been associated with protection in an SIV/rhesus macaque model. The biological relevance of HLA-E restricted CD8 T-cell responses in HIV infection however remains unknown. In this study, CD8 T cells responding to HIV-1 Gag peptides presented by HLA-E were analyzed. Using in-vitro assays, we observed HLA-E restricted T-cell responses to what we believe to be a newly identified subdominant Gag-KL9 as well as a well-described immuno-dominant Gag-KF11 epitope in T-cell lines derived from chronically HIV-infected patients and also primed from healthy donors. Blocking of the HLA-E/KF11 binding by the B7 signal peptide resulted in decreased CD8 T-cell responses. KF11 presented via HLA-E in HIV infected cells was recognized by antigen specific CD8 T cells. Importantly, bulk CD8 T cells obtained from HIV infected individuals recognized infected cells via HLA-E presentation. Ex-vivo analyses at the epitope level showed a higher responder frequency of HLA-E restricted responses to KF11 compared to KL9. Taken together, our findings of HLA-E restricted HIV specific immune responses offer intriguing and possibly paradigm shifting insights into factors that contribute to the immuno-dominance of CD8 T-cell responses in HIV infection.

Authors

Anju Bansal, Mika N. Gehre, Kai Qin, Sarah Sterrett, Ayub Ali, Ying Dang, Sojan Abraham, Margaret C. Costanzo, Leon A. Venegas, Jianming Tang, N. Manjunath, Mark A. Brockman, Otto O. Yang, June Kan-Mitchell, Paul A. Goepfert

DNA methylome and transcriptome landscapes of cancer-associated fibroblasts reveal a smoking-associated malignancy index

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Abstract

Unlike the better-studied aberrant epigenome in the tumor, the clinicopathologic impact of DNA methylation in the tumor microenvironment (TME), especially the contribution from cancer-associated fibroblast (CAF), remains elusive. CAFs exhibit profound patient-to-patient tumorigenic heterogeneity. We ask whether such heterogeneity may be exploited to quantify the level of TME malignancy or not. We developed a robust and efficient methylome/transcriptome co-analysis system for CAFs and paired normal fibroblasts (NFs) from non-small-cell lung cancer patients. We found 14,781 CpG sites of CAF/NF differential methylation, of which 3,707 sites showed higher methylation changes in ever-smokers than in non-smokers. Concomitant CAF/NF differential gene expression analysis pinpointed to a subset of 54 smoking-associated CpG sites with strong methylation-regulated gene expression. A methylation index that summarizes the beta-values of these CpGs was built for NF/CAF discrimination (MIND) with high sensitivity and specificity. The potential of MIND in detecting pre-malignancy across individual patients was shown. MIND succeeded in predicting tumor recurrence in multiple lung cancer cohorts without reliance on patient survival data, suggesting that the malignancy level of TME may be effectively graded by this index. Precision TME grading may provide additional pathological information to guide cancer prognosis and open up more options in personalized medicine.

Authors

Sheng-Fang Su, Hao Ho, Jia-Hua Li, Ming-Fang Wu, Hsu-Chieh Wang, Hsiang-Yuan Yeh, Shuenn-Wen Kuo, Huei-Wen Chen, Chao-Chi Ho, Ker-Chau Li

MicroRNA-26a-3p rescues depression-like behaviors in male rats via preventing hippocampal neuronal anomalies

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Abstract

Depression is a neuropsychiatric disease associated with neuronal anomalies within specific brain regions. In the present study, we screened microRNA (miRNA) expression profiles in the dentate gyrus (DG) of hippocampus and found miR-26a-3p was markedly down-regulated in the rat model of depression, whereas up-regulation of miR-26a-3p within DG regions rescued the neuronal deterioration and depression-like phenotypes resulting from stress exposure, effects which appear to be mediated by the PTEN pathway. The knock-down of miR-26a-3p in DG regions of normal control rats induced depression-like behaviors, effects which were accompanied with an activation of PTEN-PI3K/Akt signaling pathway and neuronal deterioration via suppression of autophagy, impairments in synaptic plasticity and the promotion of neuronal apoptosis. In conclusion, these results suggested that a miR-26a-3p deficits within the hippocampal DG mediated the neuronal anomalies contributing to the display of depression-like behaviors. This miRNA may serve as a potential therapeutic target for the treatment of depression.

Authors

Ye Li, Cuiqin Fan, Liyan Wang, Tian Lan, Rui Gao, Wenjing Wang, Shu Yan Yu

Perineuronal net degradation rescues CA2 plasticity in Rett syndrome model mice

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Abstract

Perineuronal nets (PNNs), a specialized form of extracellular matrix, are abnormal in the human brain of Rett syndrome (RTT). We previously reported that PNNs function to restrict synaptic plasticity in hippocampal area CA2, which is unusually resistant to long-term potentiation (LTP) and has been linked to social learning in mice. Here we reported that PNNs appear elevated in area CA2 of a human RTT hippocampus and that PNNs develop precociously and remain elevated in area CA2 of a mouse model of RTT (Mecp2-null). Further, we provided evidence that LTP could be induced at CA2 synapses prior to PNN maturation (postnatal day 8-11) in wildtype mice and that this window of plasticity was prematurely restricted at CA2 synapses in Mecp2-null mice. Degrading PNNs in Mecp2-null hippocampus was sufficient to rescue the premature disruption of CA2 plasticity. We identified several molecular targets that were altered in the developing Mecp2-null hippocampus that may explain aberrant PNNs and CA2 plasticity, and we discovered that CA2 PNNs are negatively regulated by neuronal activity. Collectively, our findings demonstrated that CA2 PNN development is regulated by Mecp2 and identified a novel window of hippocampal plasticity that is disrupted in a mouse model of RTT.

Authors

Kelly E. Carstens, Daniel J. Lustberg, Emma Shaughnessy, Katharine E. McCann, Georgia M. Alexander, Serena M. Dudek

Distinct mechanisms govern populations of myeloid-derived suppressor cells in chronic viral infection and cancer

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Abstract

Myeloid-derived suppressor cells (MDSC) are major negative regulators of immune responses in cancer and chronic infections. It remains unclear if regulation of MDSC activity at different conditions is controlled by similar mechanisms. We compared MDSC in mice with cancer and lymphocytic choriomeningitis virus (LCMV) infection. Chronic LCMV infection caused the development of monocytic - M-MDSC but did not induce polymorphonuclear - PMN-MDSC. In contrast, both MDSC populations were present in cancer models. An acquisition of immune suppressive activity by PMN-MDSC in cancer was controlled by IRE1α and ATF6 pathways of the endoplasmic reticulum (ER) stress response. Abrogation of PMN-MDSC activity by blockade of the ER stress response resulted in increase in tumor-specific immune response and reduced tumor progression. In contrast, the ER stress response was dispensable for suppressive activity of M-MDSC in cancer and LCMV infection. Acquisition of immune suppressive activity by M-MDSC in spleens was mediated by IFN-γ signaling. However, it was dispensable for suppressive activity of M-MDSC in tumor tissues. Suppressive activity of M-MDSC in tumors was retained due to the effect of IL-6 present at high concentrations in tumor site. These results demonstrate disease and population-specific mechanisms of MDSC accumulation and need for targeting of different pathways to achieve inactivation of these cells.

Authors

Evgenii N. Tcyganov, Shino Hanabuchi, Ayumi Hashimoto, David Campbell, Gozde Kar, Timothy W.F. Slidel, Corinne Cayatte, Aimee Landry, Fernanda Pilataxi, Susana Hayes, Brian Dougherty, Kristin C. Hicks, Kathy Mulgrew, Chih-Hang A. Tang, Chih-Chi A. Hu, Wei Guo, Sergei Grivennikov, Mohammed-Alkhatim A. Ali, Jean-Christophe Beltra, E. John Wherry, Yulia Nefedova, Dmitry I. Gabrilovich

Calcium phosphate microcrystals in the renal tubular fluid accelerate chronic kidney disease progression

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Abstract

The western pattern diet is rich not only in fat and calorie but also in phosphate. Negative impacts of excessive fat and calorie intake on health are widely accepted, whereas potential harms of excessive phosphate intake are poorly recognized. Here we show the mechanism by which dietary phosphate damages the kidney. When phosphate intake was excessive relative to the functioning nephron number, circulating fibroblast growth factor-23 (FGF23), a hormone that increases phosphate excretion per nephron, was increased to maintain phosphate homeostasis. FGF23 suppressed phosphate reabsorption in renal tubules and thus raised the phosphate concentration in the tubular fluid. Once it exceeded a threshold, microscopic particles containing calcium phosphate crystals appeared in the tubular lumen, which damaged tubular cells through binding to Toll-like receptor-4 expressed on them. Persistent tubular damage induced interstitial fibrosis, reduced the nephron number, and further boosted FGF23 to trigger a deterioration spiral leading to progressive nephron loss. In humans, progression of chronic kidney disease (CKD) ensued when the serum FGF23 level exceeded 53 pg/mL. The present study identified the calcium phosphate particles in the renal tubular fluid as an effective therapeutic target to decelerate nephron loss during the course of aging and CKD progression.

Authors

Kazuhiro Shiizaki, Asako Tsubouchi, Yutaka Miura, Kinya Seo, Takahiro Kuchimaru, Hirosaka Hayashi, Yoshitaka Iwazu, Marina Miura, Batpurev Battulga, Nobuhiko Ohno, Toru Hara, Rina Kunishige, Mamiko Masutani, Keita Negishi, Kazuomi Kario, Kazuhiko Kotani, Toshiyuki Yamada, Daisuke Nagata, Issei Komuro, Hiroshi Itoh, Hiroshi Kurosu, Masayuki Murata, Makoto Kuro-o

TNFR2/14-3-3ε signaling complex instructs macrophage plasticity in inflammation and autoimmunity

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Abstract

TNFR1 and TNFR2 have received prominent attention because of their dominance in the pathogenesis of inflammation and autoimmunity. TNFR1 has been extensively studied and primarily mediates inflammation. TNFR2 remains far less studied, although emerging evidences demonstrate that TNFR2 plays an anti-inflammatory and immunoregulatory role in various conditions and diseases. Herein, we report that TNFR2 regulates macrophage polarization, a highly dynamic process controlled by largely unidentified intracellular regulators. Using biochemical co-purification and mass spectrometry approaches, we isolated the signaling molecule 14-3-3ε as a component of TNFR2 complexes in response to progranulin stimulation in macrophages. In addition, 14-3-3ε was essential for TNFR2 signaling-mediated regulation of macrophage polarization and switch. Both global and myeloid-specific deletion of 14-3-3ε resulted in exacerbated inflammatory arthritis and counteracted the protective effects of progranulin-mediated TNFR2 activation against inflammation and autoimmunity. TNFR2/14-3-3ε signaled through PI3K/Akt/mTOR to restrict NF-κB activation while simultaneously stimulating C/EBPβ activation, thereby instructing macrophage plasticity. Collectively, this study identifies 14-3-3ε as a previously-unrecognized vital component of the TNFR2 receptor complex and provides new insights into the TNFR2 signaling, particularly its role in macrophage polarization with therapeutic implications for various inflammatory and autoimmune diseases with activation of the TNFR2/14-3-3ε anti-inflammatory pathway.

Authors

Wenyu Fu, Wenhuo Hu, Young-Su Yi, Aubryanna Hettinghouse, Guodong Sun, Yufei Bi, Wenjun He, Lei Zhang, Guanmin Gao, Jody Liu, Kazuhito Toyo-oka, Guozhi Xiao, David B. Solit, Png Loke, Chuan-ju Liu

SLIT2/ROBO signaling in tumor-associated microglia/macrophages drives glioblastoma immunosuppression and vascular dysmorphia

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Abstract

SLIT2 is a secreted polypeptide that guides migration of cells expressing ROBO1&2 receptors. Herein, we investigated SLIT2/ROBO signaling effects in gliomas. In patients with glioblastoma (GBM), SLIT2 expression increased with malignant progression and correlated with poor survival and immunosuppression. Knockdown of SLIT2 in mouse glioma cells and patient derived GBM xenografts reduced tumor growth and rendered tumors sensitive to immunotherapy. Tumor cell SLIT2 knockdown inhibited macrophage invasion and promoted a cytotoxic gene expression profile, which improved tumor vessel function and enhanced efficacy of chemotherapy and immunotherapy. Mechanistically, SLIT2 promoted microglia/macrophage chemotaxis and tumor-supportive polarization via ROBO1&2-mediated PI3Kgamma activation. Macrophage Robo1&2 deletion and systemic SLIT2 trap delivery mimicked SLIT2 knockdown effects on tumor growth and the tumor microenvironment (TME), revealing SLIT2 signaling through macrophage ROBOs as a potentially novel regulator of the GBM microenvironment and immunotherapeutic target for brain tumors.

Authors

Luiz H. Geraldo, Yunling Xu, Laurent Jacob, Laurence Pibouin-Fragner, Rohit Rao, Nawal Maïssa, Maite Verreault, Nolwenn Lemaire, Camille Knosp, Corinne Lesaffre, Thomas Daubon, Joost Dejaegher, Lien Solie, Justine Rudewicz, Thomas Viel, Bertrand Tavitian, Steven De Vleeschouwer, Marc Sanson, Andreas Bikfalvi, Ahmed Idbaih, Qing Richard Lu, Flavia R.S. Lima, Jean-Leon Thomas., Anne Eichmann, Thomas Mathivet

Inflammatory cytokines TNFα and IL-17 enhance the efficacy of cystic fibrosis transmembrane conductance regulator modulators

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Abstract

Without CFTR-mediated HCO3- secretion, airway epithelia of newborns with cystic fibrosis (CF) produce an abnormally acidic airway surface liquid (ASL), and the decreased pH impairs respiratory host defenses. However, within a few months of birth, ASL pH increases to match that in non-CF airways. Although the physiological basis for the increase is unknown, this time-course matches the development of inflammation in CF airways. To learn whether inflammation alters CF ASL pH, we treated CF epithelia with TNFα and IL-17, two inflammatory cytokines that are elevated in CF airways. TNFα+IL-17 markedly increased ASL pH by upregulating pendrin, an apical Cl-/HCO3- exchanger. Moreover, when CF epithelia were exposed to TNFα+IL-17, clinically approved CFTR modulators further alkalinized ASL pH. As predicted by these results, in vivo data revealed a positive correlation between airway inflammation and CFTR modulator-induced improvement in lung function. These findings suggest that inflammation is a key regulator of HCO3- secretion in CF airways. Thus, they explain earlier observations that ASL pH increases after birth and indicate that for similar levels of inflammation, the pH of CF ASL is abnormally acidic. These results also suggest that a non-cell-autonomous mechanism, airway inflammation, is an important determinant of the response to CFTR modulators.

Authors

Tayyab Rehman, Philip H. Karp, Ping Tan, Brian J. Goodell, Alejandro A. Pezzulo, Andrew L. Thurman, Ian M. Thornell, Samantha L. Durfey, Michael E. Duffey, David A. Stoltz, Edward F. McKone, Pradeep K. Singh, Michael J. Welsh

Germline RUNX1 variation and predisposition to childhood acute lymphoblastic leukemia

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Abstract

Genetic alterations in the RUNX1 gene are associated with benign and malignant blood disorders, particularly of megakaryocyte and myeloid lineages. The role of RUNX1 in acute lymphoblastic leukemia (ALL) is less clear, particularly how germline genetic variation influences the predisposition to this type of leukemia. Sequencing 4,836 children with B-ALL and 1,354 cases of T-ALL, we identified 31 and 18 germline RUNX1 variants, respectively. RUNX1 variants in B-ALL consistently showed minimal damaging effects. By contrast, 6 T-ALL-related variants result in drastic loss of RUNX1 activity as a transcription activator in vitro. Ectopic expression of dominant-negative RUNX1 variants in human CD34+ cells repressed differentiation into erythroid, megakaryocytes, and T cells, while promoting myeloid cell development. Chromatin immunoprecipitation sequencing of T-ALL models showed distinctive patterns of RUNX1 binding by variant proteins. Further whole genome sequencing identified JAK3 mutation as the most frequent somatic genomic abnormality in T-ALL with germline RUNX1 variants. Co-introduction of RUNX1 variant and JAK3 mutation in hematopoietic stem and progenitor cells in mice gave rise to T-ALL with early T-cell precursor phenotype. Taken together, these results indicated that RUNX1 is an important predisposition gene for T-ALL and pointed to novel biology of RUNX1-mediated leukemogenesis in the lymphoid lineages.

Authors

Yizhen Li, Wentao Yang, Meenakshi Devidas, Stuart S. Winter, Chimene Kesserwan, Wenjian Yang, Kimberly P. Dunsmore, Colton Smith, Maoxiang Qian, Xujie Zhao, Ranran Zhang, Julie M. Gastier-Foster, Elizabeth A. Raetz, William L. Carroll, Chunliang Li, Paul P. Liu, Karen R. Rabin, Takaomi Sanda, Charles G. Mullighan, Kim E. Nichols, William E. Evans, Ching-Hon Pui, Stephen P. Hunger, David T. Teachey, Mary V. Relling, Mignon L. Loh, Jun J. Yang