1,135 research outputs found
A globalised practice of local peace agreements
In recent years, the difficulties and failures of national level peace processes have prompted increased attention on ‘the local’ as a space of conflict resolution.
The papers presented here suggest both the existence of local peacemaking, and the impossibility of delimiting what is merely ‘local’ about it. This in turn points to a need for a new political imaginary for peace processes, which would go beyond the idea that it is about brokering elite pacts reached in a comprehensive peace agreement.
The contributions to this Collection all conclude that local agreements deserve greater attention as a peacemaking tool. They also demonstrate variation in how local agreements are used within and across contexts, and indicate significant involvement of international actors in many contexts
CCL2 Expression in Tumor Cells and Tumor-Infiltrating Immune Cells Shows Divergent Prognostic Potential for Bladder Cancer Patients Depending on Lymph Node Stage
Bladder cancer (BCa) is the ninth most commonly diagnosed cancer worldwide. Although there are several well-established molecular and immunological classifications, markers for tumor cells and immune cells that are associated with prognosis are still needed. The chemokine CC motif ligand 2 (CCL2) could be such a marker. We analyzed the expression of CCL2 by immunohistochemistry (IHC) in 168 muscle invasive BCa samples using a tissue microarray. Application of a single cut-off for the staining status of tumor cells (TCs; positive vs. negative) and immune cells (ICs; ≤6% of ICs vs. >6% of ICs) revealed 57 cases (33.9%) and 70 cases (41.7%) with CCL2-positive TCs or ICs, respectively. IHC results were correlated with clinicopathological and survival data. Positive CCL2 staining in TCs was associated with shorter overall survival (OS), disease-specific survival (DSS), and relapse-free survival (RFS) (p = 0.004, p = 0.036, and p = 0.047; log rank test) and appeared to be an independent prognostic factor for OS (RR = 1.70; p = 0.007; multivariate Cox’s regression analysis). In contrast, positive CCL2 staining in the ICs was associated with longer OS, DSS, and RFS (p = 0.032, p = 0.001, and p = 0.001; log rank test) and appeared to be an independent prognostic factor for DSS (RR = 1.77; p = 0.031; multivariate Cox’s regression analysis). Most interestingly, after separating the patients according to their lymph node status (N0 vs. N1+2), CCL2 staining in the ICs was differentially associated with prognosis. In the N0 group, CCL2 positivity in the ICs was a positive independent prognostic factor for OS (RR = 1.99; p = 0.014), DSS (RR = 3.17; p = 0.002), and RFS (RR = 3.10; p = 0.002), whereas in the N1+2 group, CCL2 positivity was a negative independent factor for OS (RR = 3.44; p = 0.019)) and RFS (RR = 4.47; p = 0.010; all multivariate Cox’s regression analyses). In summary, CCL2 positivity in TCs is a negative prognostic factor for OS, and CCL2 can mark ICs that are differentially associated with prognosis depending on the nodal stage of BCa patients. Therefore, CCL2 staining of TCs and ICs is suggested as a prognostic biomarker for BCa patients
Intestinal helminth infection drives carcinogenesis in colitis-associated colon cancer
Inflammatory bowel diseases (IBD) are chronic inflammatory disorders of the
gastrointestinal tract, strongly associated with an increased risk of
colorectal cancer development. Parasitic infections caused by helminths have
been shown to modulate the host’s immune response by releasing
immunomodulatory molecules and inducing regulatory T cells (Tregs). This
immunosuppressive state provoked in the host has been considered as a novel
and promising approach to treat IBD patients and alleviate acute intestinal
inflammation. On the contrary, specific parasite infections are well known to
be directly linked to carcinogenesis. Whether a helminth infection interferes
with the development of colitis-associated colon cancer (CAC) is not yet
known. In the present study, we demonstrate that the treatment of mice with
the intestinal helminth Heligmosomoides polygyrus at the onset of tumor
progression in a mouse model of CAC does not alter tumor growth and
distribution. In contrast, H. polygyrus infection in the early inflammatory
phase of CAC strengthens the inflammatory response and significantly boosts
tumor development. Here, H. polygyrus infection was accompanied by long-
lasting alterations in the colonic immune cell compartment, with reduced
frequencies of colonic CD8+ effector T cells. Moreover, H. polygyrus infection
in the course of dextran sulfate sodium (DSS) mediated colitis significantly
exacerbates intestinal inflammation by amplifying the release of colonic IL-6
and CXCL1. Thus, our findings indicate that the therapeutic application of
helminths during CAC might have tumor-promoting effects and therefore should
be well-considered
SDHA gain-of-function engages inflammatory mitochondrial retrograde signaling via KEAP1-Nrf2.
Whether screening the metabolic activity of immune cells facilitates discovery of molecular pathology remains unknown. Here we prospectively screened the extracellular acidification rate as a measure of glycolysis and the oxygen consumption rate as a measure of mitochondrial respiration in B cells from patients with primary antibody deficiency. The highest oxygen consumption rate values were detected in three study participants with persistent polyclonal B cell lymphocytosis (PPBL). Exome sequencing identified germline mutations in SDHA, which encodes succinate dehydrogenase subunit A, in all three patients with PPBL. SDHA gain-of-function led to an accumulation of fumarate in PPBL B cells, which engaged the KEAP1-Nrf2 system to drive the transcription of genes encoding inflammatory cytokines. In a single patient trial, blocking the activity of the cytokine interleukin-6 in vivo prevented systemic inflammation and ameliorated clinical disease. Overall, our study has identified pathological mitochondrial retrograde signaling as a disease modifier in primary antibody deficiency
HIV Infection and Gut Mucosal Immune Function: Updates on Pathogenesis with Implications for Management and Intervention
HIV is primarily a sexually transmitted infection. However, given that the gastrointestinal tract (GIT) houses most of the body’s lymphocytes, including activated memory CD4+ T cells that are preferential targets for HIV, recent research has focused on the role of the GIT in transmission and pathogenesis. In health, the GIT maintains a balance between immune tolerance and rapid responsiveness. A complex network of innate and adaptive responses maintains this balance, which is severely perturbed in HIV infection. Recent studies have focused on mechanisms of GIT CD4+ T-cell depletion and epithelial disruption in HIV infection, the role of inflammation in accelerating viral dissemination, the kinetics of the adaptive response following transmission, and the extent of T-cell reconstitution following antiretroviral therapy. This review summarizes the results of recent investigations that may have important implications for the development of vaccines, microbicides, and therapeutic interventions for HIV and other mucosal pathogens
Two-Component Elements Mediate Interactions between Cytokinin and Salicylic Acid in Plant Immunity
Recent studies have revealed an important role for hormones in plant immunity. We are now beginning to understand the contribution of crosstalk among different hormone signaling networks to the outcome of plant–pathogen interactions. Cytokinins are plant hormones that regulate development and responses to the environment. Cytokinin signaling involves a phosphorelay circuitry similar to two-component systems used by bacteria and fungi to perceive and react to various environmental stimuli. In this study, we asked whether cytokinin and components of cytokinin signaling contribute to plant immunity. We demonstrate that cytokinin levels in Arabidopsis are important in determining the amplitude of immune responses, ultimately influencing the outcome of plant–pathogen interactions. We show that high concentrations of cytokinin lead to increased defense responses to a virulent oomycete pathogen, through a process that is dependent on salicylic acid (SA) accumulation and activation of defense gene expression. Surprisingly, treatment with lower concentrations of cytokinin results in increased susceptibility. These functions for cytokinin in plant immunity require a host phosphorelay system and are mediated in part by type-A response regulators, which act as negative regulators of basal and pathogen-induced SA–dependent gene expression. Our results support a model in which cytokinin up-regulates plant immunity via an elevation of SA–dependent defense responses and in which SA in turn feedback-inhibits cytokinin signaling. The crosstalk between cytokinin and SA signaling networks may help plants fine-tune defense responses against pathogens
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Overcoming EGFR T790M and C797S resistance with mutant-selective allosteric inhibitors
EGFR tyrosine kinase inhibitors (TKIs) gefitinib, erlotinib and afatinib are approved treatments for non-small cell lung cancers harboring activating mutations in the EGFR kinase1,2, but resistance arises rapidly, most frequently due to the secondary T790M mutation within the ATP-site of the receptor.3,4 Recently developed mutant-selective irreversible inhibitors are highly active against the T790M mutant5,6, but their efficacy can be compromised by acquired mutation of C797, the cysteine residue with which they form a key covalent bond7. All current EGFR TKIs target the ATP-site of the kinase, highlighting the need for therapeutic agents with alternate mechanisms of action. Here we describe rational discovery of EAI045, an allosteric inhibitor that targets selected drug-resistant EGFR mutants but spares the wild type receptor. A crystal structure shows that the compound binds an allosteric site created by the displacement of the regulatory C-helix in an inactive conformation of the kinase. The compound inhibits L858R/T790M-mutant EGFR with low-nanomolar potency in biochemical assays, but as a single agent is not effective in blocking EGFR-driven proliferation in cells due to differential potency on the two subunits of the dimeric receptor, which interact in an asymmetric manner in the active state8. We observe dramatic synergy of EAI045 with cetuximab, an antibody therapeutic that blocks EGFR dimerization9,10, rendering the kinase uniformly susceptible to the allosteric agent. EAI045 in combination with cetuximab is effective in mouse models of lung cancer driven by L858R/T790M EGFR and by L858R/T790M/C797S EGFR, a mutant that is resistant to all currently available EGFR TKIs. More generally, our findings illustrate the utility of purposefully targeting allosteric sites to obtain mutant-selective inhibitors
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