Julika NeumannErika Van NieuwenhoveLara E.TerryFrederik Staels...
11-25页
查看更多>>摘要：Calcium signaling is essential for lymphocyte activation,with genetic disruptions of store-operated calcium(Ca2+)entry resulting in severe immunodeficiency.The inositol 1,4,5-trisphosphate receptor(IP3R),a homo-or heterotetramer of the IP3R1-3 isoforms,amplifies lymphocyte signaling by releasing Ca2+ from endoplasmic reticulum stores following antigen stimulation.Although knockout of all IP3R isoforms in mice causes immunodeficiency,the seeming redundancy of the isoforms is thought to explain the absence of variants in human immunodeficiency.In this study,we identified compound heterozygous variants of ITPR3(a gene encoding IP3R subtype 3)in two unrelated Caucasian patients presenting with immunodeficiency.To determine whether ITPR3 variants act in a nonredundant manner and disrupt human immune responses,we characterized the Ca2+ signaling capacity,the lymphocyte response,and the clinical phenotype of these patients.We observed disrupted Ca2+ signaling in patient-derived fibroblasts and immune cells,with abnormal proliferation and activation responses following T-cell receptor stimulation.Reconstitution of IP3R3 in IP3R knockout cell lines led to the identification of variants as functional hypomorphs that showed reduced ability to discriminate between homeostatic and induced states,validating a genotype-phenotype link.These results demonstrate a functional link between defective endoplasmic reticulum Ca2+channels and immunodeficiency and identify IP3Rs as diagnostic targets for patients with specific inborn errors of immunity.These results also extend the known cause of Ca2+-associated immunodeficiency from store-operated entry to impaired Ca2+mobilization from the endoplasmic reticulum,revealing a broad sensitivity of lymphocytes to genetic defects in Ca2+ signaling.
Kelly A.DingessMax HoekDanique M.H.van RijswijkSem Tamara...
26-37页
查看更多>>摘要：The most abundant immunoglobulin present in the human body is IgA.It has the highest concentrations at the mucosal lining and in biofluids such as milk and is the second most abundant class of antibodies in serum.We assessed the structural diversity and clonal repertoire of IgA1-containing molecular assemblies longitudinally in human serum and milk from three donors using a mass spectrometry-based approach.IgA-containing molecules purified from serum or milk were assessed by the release and subsequent analysis of their Fab fragments.Our data revealed that serum IgA1 consists of two distinct structural populations,namely monomeric IgA1(∼80%)and dimeric joining(J-)chain coupled IgA1(∼20%).Also,we confirmed that IgA1 in milk is present solely as secretory(S)IgA,consisting of two(∼50%),three(∼33%)or four(∼17%)IgA1 molecules assembled with a J-chain and secretory component(SC).Interestingly,the serum and milk IgA1-Fab repertoires were distinct between monomeric,and J-chain coupled dimeric IgA1.The serum dimeric J-chain coupled IgA1 repertoire contained several abundant clones also observed in the milk IgA1 repertoire.The latter repertoire had little to no overlap with the serum monomeric IgA1 repertoire.This suggests that human IgA1s have(at least)two distinct origins;one of these produces dimeric J-chain coupled IgA1 molecules,shared in human serum and milk,and another produces monomeric IgA1 ending up exclusively in serum.
查看更多>>摘要：Increased levels of surfactant protein D(SP-D)and lipid-laden foamy macrophages(FMs)are frequently found under oxidative stress conditions and/or in patients with chronic obstructive pulmonary disease(COPD)who are also chronically exposed to cigarette smoke(CS).However,the roles and molecular mechanisms of SP-D and FMs in COPD have not yet been determined.In this study,increased levels of SP-D were found in the bronchoalveolar lavage fluid(BALF)and sera of ozone-and CS-exposed mice.Furthermore,SP-D-knockout mice showed increased lipid-laden FMs and airway inflammation caused by ozone and CS exposure,similar to that exhibited by our study cohort of chronic smokers and COPD patients.We also showed that an exogenous recombinant fragment of human SP-D(rfhSP-D)prevented the formation of oxidized low-density lipoprotein(oxLDL)-induced FMs in vitro and reversed the airway inflammation and emphysematous changes caused by oxidative stress and CS exposure in vivo.SP-D upregulated bone marrow-derived macrophage(BMDM)expression of genes involved in countering the oxidative stress and lipid metabolism perturbations induced by CS and oxLDL.Our study demonstrates the crucial roles of SP-D in the lipid homeostasis of dysfunctional alveolar macrophages caused by ozone and CS exposure in experimental mouse emphysema,which may provide a novel opportunity for the clinical application of SP-D in patients with COPD.
查看更多>>摘要：Boosting tumor immunosurveillance with vaccines has been proven to be a feasible and cost-effective strategy to fight cancer.Although major breakthroughs have been achieved in preventative tumor vaccines targeting oncogenic viruses,limited advances have been made in curative vaccines for virus-irrelevant malignancies.Accumulating evidence suggests that preconditioning tumor cells with certain cytotoxic drugs can generate whole-cell tumor vaccines with strong prophylactic activities.However,the immunogenicity of these vaccines is not sufficient to restrain the outgrowth of existing tumors.In this study,we identified arsenic trioxide(ATO)as a wide-spectrum cytotoxic and highly immunogenic drug through multiparameter screening.ATO preconditioning could generate whole-cell tumor vaccines with potent antineoplastic effects in both prophylactic and therapeutic settings.The tumor-preventive or tumor-suppressive benefits of these vaccines relied on CD8+ T cells and type I and II interferon signaling and could be linked to the release of immunostimulatory danger molecules.Unexpectedly,following ATO-induced oxidative stress,multiple cell death pathways were activated,including autophagy,apoptosis,necroptosis,and ferroptosis.CRISPR‒Cas9-mediated knockout of cell death executors revealed that the absence of Rip3,Mlkl,or Acsl4 largely abolished the efficacy of ATO-based prophylactic and therapeutic cancer vaccines.This therapeutic failure could be rescued by coadministration of danger molecule analogs.In addition,PD-1 blockade synergistically improved the therapeutic efficacy of ATO-based cancer vaccines by augmenting local IFN-γ production.
查看更多>>摘要：The cytokine granulocyte-macrophage-colony stimulating factor(GM-CSF)possesses the capacity to differentiate monocytes into macrophages(MØs)with opposing functions,namely,proinflammatory M1-like MØs and immunosuppressive M2-like MØs.Despite the importance of these opposing biological outcomes,the intrinsic mechanism that regulates the functional polarization of MØs under GM-CSF signaling remains elusive.Here,we showed that GM-CSF-induced MØ polarization resulted in the expression of cytokine-inducible SH2-containing protein(CIS)and that CIS deficiency skewed the differentiation of monocytes toward immunosuppressive M2-like MØs.CIS deficiency resulted in hyperactivation of the JAK-STAT5 signaling pathway,consequently promoting downregulation of the transcription factor Interferon Regulatory Factor 8(IRF8).Loss-and gain-of-function approaches highlighted IRF8 as a critical regulator of the M1-like polarization program.In vivo,CIS deficiency induced the differentiation of M2-like macrophages,which promoted strong Th2 immune responses characterized by the development of severe experimental asthma.Collectively,our results reveal a CIS-modulated mechanism that clarifies the opposing actions of GM-CSF in MØ differentiation and uncovers the role of GM-CSF in controlling allergic inflammation.
查看更多>>摘要：In sepsis,macrophage bacterial phagocytosis is impaired,but the mechanism is not well elucidated.Extracellular cold-inducible RNA-binding protein(eCIRP)is a damage-associated molecular pattern that causes inflammation.However,whether eCIRP regulates macrophage bacterial phagocytosis is unknown.Here,we reported that the bacterial loads in the blood and peritoneal fluid were decreased in CIRP-/-mice and anti-eCIRP Ab-treated mice after sepsis.Increased eCIRP levels were correlated with decreased bacterial clearance in septic mice.CIRP-/-mice showed a marked increase in survival after sepsis.Recombinant murine CIRP(rmCIRP)significantly decreased the phagocytosis of bacteria by macrophages in vivo and in vitro.rmCIRP decreased the protein expression of actin-binding proteins,ARP2,and p-cofilin in macrophages.rmCIRP significantly downregulated the protein expression of βPIX,a Rac1 activator.We further demonstrated that STAT3 and βPIX formed a complex following rmCIRP treatment,preventing βPIX from activating Rac1.We also found that eCIRP-induced STAT3 phosphorylation was required for eCIRP's action in actin remodeling.Inhibition of STAT3 phosphorylation prevented the formation of the STAT3-βPIX complex,restoring ARP2 and p-cofilin expression and membrane protrusion in rmCIRP-treated macrophages.The STAT3 inhibitor stattic rescued the macrophage phagocytic dysfunction induced by rmCIRP.Thus,we identified a novel mechanism of macrophage phagocytic dysfunction caused by eCIRP,which provides a new therapeutic target to ameliorate sepsis.
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