bluuebunny/crossref_metadata_2025 huggingface dataset:
15-Deoxy-Δ12,1412,14-prostaglandins D2 and J2 Are Potent Activators of Human Eosinophils
Authors: Monneret Guillaume , Li Hongping , Vasilescu Julian , Rokach Joshua , Powell William S.
Published: April 2014

15-Deoxy-Δ12,14-PDJ2 (15d-PGJ2) is a degradation product of PGD2 that has been proposed as an anti-inflammatory compound because of its various inhibitory effects, some of which are mediated by peroxisome proliferator-activated receptor-γ. In contrast to its reported inhibitory effects on macrophages and other cells, we found that this compound is a potent activator of eosinophils, inducing calcium mobilization, actin polymerization, and CD11b expression. It is selective for eosinophils, having little or no effect on neutrophils or monocytes. 15d-PGJ2 has an EC50 of ∼10 nM, similar to that of its precursor, PGD2. The concentrations of 15d-PGJ2 required to activate eosinophils are thus much lower than those required for its anti-inflammatory effects (usually micromolar). 15-Deoxy-Δ12,14-prostaglandin D2 (15d-PGD2) is also a potent activator of eosinophils, with an EC50 about the same as that of PGD2, whereas Δ12-PGJ2 is slightly less potent. Eosinophils pretreated with PGD2 no longer respond to 15d-PGJ2, and vice versa, but in both cases the cells still respond to another eicosanoid proinflammatory mediator, 5-oxo-6,8,11,14-eicosatetraenoic acid. This indicates that the effects of 15d-PGJ2 are mediated by the DP2/chemoattractant receptor-homologous molecule expressed on Th2 cells that has recently been identified in eosinophils. 15d-PGJ2 is selective for the DP2 receptor, in that it has no effect on DP1 receptor-mediated adenylyl cyclase activity in platelets. We conclude that 15d-PGJ2 and 15d-PGD2 are selective DP2 receptor agonists that activate human eosinophils with potencies at least 100 times greater than those for the proposed anti-inflammatory effects of 15d-PGJ2 on other cells.
Modulation of Leukotriene B4 Receptor-1 Expression by Dexamethasone: Potential Mechanism for Enhanced Neutrophil Survival
Authors: Stankova Jana , Turcotte Sylvie , Harris Jennifer , Rola-Pleszczynski Marek
Published: April 2014

Glucocorticoids can down-regulate many inflammatory and immune responses and constitute a powerful therapeutic tool in a number of diseases. However, they have a somewhat paradoxical effect on neutrophils, in that they prolong their survival. Because leukotriene B4 (LTB4) can also extend neutrophil survival, we proposed that glucocorticoids could prevent neutrophil apoptosis by up-regulating their expression of the high-affinity LTB4 receptor (BLT1). Here we show that, indeed, dexamethasone (DEX) up-regulates the steady-state levels of BLT1 mRNA in human neutrophils. The effect was time and concentration dependent, being maximal at 4 h and at 10–100 nM DEX. The effect was also dependent on transcriptional activity, whereas BLT1 mRNA stability was not affected. DEX-induced up-regulation of BLT1 expression was prevented by pretreatment with the LTB4 antagonist LY255283. Moreover, LTB4 itself up-regulated the expression of BLT1 mRNA. BLT1 protein expression on neutrophils exposed to DEX for 24 h was also up-regulated 2- to 3-fold, and DEX-treated as well as LTB4-treated cells showed enhanced responsiveness to LTB4 in terms of intracellular Ca2+ mobilization and chemotaxis. Whereas DEX and LTB4 alone decreased neutrophil apoptosis by ∼50%, neutrophils treated with both LTB4 and DEX showed >90% survival at 24 h. Moreover, BLT1 antagonists prevented the increased neutrophil survival induced by DEX as well as by LTB4. Taken together, our results suggest that DEX-induced up-regulation of BLT1 expression in neutrophils may be one mechanism through which glucocorticoids can prolong neutrophil survival, namely by enhancing cell responses to the antiapoptotic effect of LTB4.
Antibodies Against Cerebral M1 Cholinergic Muscarinic Receptor from Schizophrenic Patients: Molecular Interaction
Authors: Borda Tania , Perez Rivera Ricardo , Joensen Lilian , Gomez Ricardo M. , Sterin-Borda Leonor
Published: April 2014

We demonstrated the presence of circulating Abs from schizophrenic patients able to interact with cerebral frontal cortex-activating muscarinic acetylcholine receptors (mAChR). Sera and purified IgG from 21 paranoid schizophrenic and 25 age-matched normal subjects were studied by indirect immunofluorescence, flow cytometry, immunoblotting, dot blot, ELISA, and radioligand competition assays. Rat cerebral frontal cortex membranes and/or a synthetic peptide, with an amino acid sequence identical with that of human M1 mAChR, were used as Ags. By indirect immunofluorescence and flow cytometry procedures, we proved that serum-purified IgG fraction from schizophrenic patients reacted to neural cell surfaces from rat cerebral frontal cortex. The same Abs were able to inhibit the binding of the specific M1 mAChR radioligand [3H]pirenzepine. Immunoblotting experiments showed that IgG from schizophrenic patients revealed a band with a molecular mass coincident to that labeled by an anti-M1 mAChR Ab. Using synthetic peptide for dot blot and ELISA, we demonstrated that these Abs reacted against the second extracellular loop of human cerebral M1 mAChR. Also, the corresponding affinity-purified antipeptide Ab displayed an agonistic-like activity associated to specific receptor activation, increasing cyclic GMP production and inositol phosphate accumulation, and protein kinase C translocation. This paper gave support to the participation of an autoimmune process in schizophrenia.
Spleen Is a Primary Site for Activation of Platelet-Reactive T and B Cells in Patients with Immune Thrombocytopenic Purpura
Authors: Kuwana Masataka , Okazaki Yuka , Kaburaki Junichi , Kawakami Yutaka , Ikeda Yasuo
Published: April 2014

We have recently reported that in patients with chronic immune thrombocytopenic purpura (IMTP), circulating T and B cells that are responsive to gpIIb-IIIa can induce anti-platelet autoantibody production. In this study, the frequencies and activation status of gpIIb-IIIa-reactive T and B cells were evaluated in the peripheral blood and spleen obtained from nine IMTP patients undergoing splenectomy. There was no difference in gpIIb-IIIa-reactive T cell frequencies between peripheral blood and spleen (6.4 ± 2.6 vs 5.2 ± 2.4 per 105 T cells), as determined by limiting dilution analysis, but activated T cells responsive to gpIIb-IIIa showing accelerated proliferation kinetics and those expressing CD154 were more frequent in spleen than in peripheral blood. The frequencies of anti-gpIIb-IIIa Ab-producing B cells, as determined by ELISPOT assay, were also similar in peripheral blood and spleen (61.2 ± 24.0 vs 77.7 ± 45.3 per 105 B cells); however, an anti-gpIIb-IIIa Ab was spontaneously produced by splenocytes in vitro, but scarcely secreted by PBMCs. CD19−/surface Ig−/CD38+/CD138+ plasma cells secreting anti-gpIIb-IIIa Ab were exclusively detected in the spleen. In serial analysis, the frequencies of circulating gpIIb-IIIa-reactive T and B cells were markedly decreased after splenectomy in patients with a complete response, but were unchanged in nonresponders. These findings indicate that an interaction between gpIIb-IIIa-reactive T and B cells inducing anti-platelet Ab production in IMTP patients occurs primarily in the spleen and that the significant number of gpIIb-IIIa-reactive T and B cells activated in the spleen are released into the circulation as memory cells.
Cutting Edge: Role of Toll-Like Receptor 1 in Mediating Immune Response to Microbial Lipoproteins
Authors: Takeuchi Osamu , Sato Shintaro , Horiuchi Takao , Hoshino Katsuaki , Takeda Kiyoshi , Dong Zhongyun , Modlin Robert L. , Akira Shizuo
Published: April 2014

The Toll-like receptor (TLR) family acts as pattern recognition receptors for pathogen-specific molecular patterns (PAMPs). TLR2 is essential for the signaling of a variety of PAMPs, including bacterial lipoprotein/lipopeptides, peptidoglycan, and GPI anchors. TLR6 associates with TLR2 and recognizes diacylated mycoplasmal lipopeptide along with TLR2. We report here that TLR1 associates with TLR2 and recognizes the native mycobacterial 19-kDa lipoprotein along with TLR2. Macrophages from TLR1-deficient (TLR1−/−) mice showed impaired proinflammatory cytokine production in response to the 19-kDa lipoprotein and a synthetic triacylated lipopeptide. In contrast, TLR1−/− cells responded normally to diacylated lipopeptide. TLR1 interacts with TLR2 and coexpression of TLR1 and TLR2 enhanced the NF-κB activation in response to a synthetic lipopeptide. Furthermore, lipoprotein analogs whose acylation was modified were preferentially recognized by TLR1. Taken together, TLR1 interacts with TLR2 to recognize the lipid configuration of the native mycobacterial lipoprotein as well as several triacylated lipopeptides.
A Defective NF-κB/RelB Pathway in Autoimmune-Prone New Zealand Black Mice Is Associated with Inefficient Expansion of Thymocyte and Dendritic Cells
Authors: Valéro René , Baron Marie-Laurence , Guérin Sandrine , Béliard Sophie , Lelouard Hugues , Kahn-Perles Brigitte , Vialettes Bernard , Nguyen Cathy , Imbert Jean , Naquet Philippe
Published: April 2014

New Zeland Black (NZB) mice develop an autoimmune disease involving an abnormal B cell response to peripheral self Ags. This disease is associated with defects in other cell types and thymic stromal organization. We present evidence that NZB cells of various lineages, including thymocytes, fibroblasts, and dendritic precursor cells, show impaired proliferation and enhanced cell death in culture upon stimulation compared with non-autoimmune-prone mice such as C57BL/6. This phenotype explains the reduced efficiency of maturation of bone marrow-derived dendritic cells and the loss of TNF- or IL-1-dependent thymocyte costimulation. Upon TNF-induced activation of NZB thymocytes, nuclear translocation and DNA binding of RelA- and RelB-dependent NF-κB heterodimers are significantly reduced. This phenotype has a transcriptional signature, since the NZB, but not the nonobese diabetic, thymic transcriptome shows striking similarities with that of RelB-deficient thymuses. This partial NF-κB deficiency detected upon activation by proinflammatory cytokines could explain the disorganization of thymic microenvironments in NZB mice. These combined effects might reduce the efficiency of central tolerance and expose apoptotic debris generated during inflammatory processes to self recognition.
Functional Human T Lymphocyte Development from Cord Blood CD34+ Cells in Nonobese Diabetic/Shi-scid, IL-2 Receptor γ Null Mice
Authors: Yahata Takashi , Ando Kiyoshi , Nakamura Yoshihiko , Ueyama Yoshito , Shimamura Kazuo , Tamaoki Norikazu , Kato Shunichi , Hotta Tomomitsu
Published: April 2014

An experimental model for human T lymphocyte development from hemopoietic stem cells is necessary to study the complex processes of T cell differentiation in vivo. In this study, we report a newly developed nonobese diabetic (NOD)/Shi-scid, IL-2Rγ null (NOD/SCID/γcnull) mouse model for human T lymphopoiesis. When these mice were transplanted with human cord blood CD34+ cells, the mice reproductively developed human T cells in their thymus and migrated into peripheral lymphoid organs. Furthermore, these T cells bear polyclonal TCR-αβ, and respond not only to mitogenic stimuli, such as PHA and IL-2, but to allogenic human cells. These results indicate that functional human T lymphocytes can be reconstituted from CD34+ cells in NOD/SCID/γcnull mice. This newly developed mouse model is expected to become a useful tool for the analysis of human T lymphopoiesis and immune response, and an animal model for studying T lymphotropic viral infections, such as HIV.
Ly-49s3 Is a Promiscuous Activating Rat NK Cell Receptor for Nonclassical MHC Class I-Encoded Target Ligands
Authors: Naper Christian , Hayashi Shigenari , Kveberg Lise , Niemi Eréne C. , Lanier Lewis L. , Vaage John T. , Ryan James C.
Published: April 2014

Previous studies of the rapid rejection of MHC-disparate lymphocytes in rats, named allogeneic lymphocyte cytotoxicity, have indicated that rat NK cells express activating receptors for nonclassical MHC class I allodeterminants from the RT1-C/E/M region. Using an expression cloning system that identifies activating receptors associated with the transmembrane adapter molecule DAP12, we have cloned a novel rat Ly-49 receptor that we have termed Ly-49 stimulatory receptor 3 (Ly-49s3). A newly generated anti-Ly-49s3 Ab, mAb DAR13, identified subpopulations of resting and IL-2-activated NK cells, but not T or B lymphocytes. Depletion of Ly-49s3-expressing NK cells drastically reduced alloreactivity in vitro, indicating that this subpopulation is responsible for a major part of the observed NK alloreactivity. DAR13-mediated blockade of Ly-49s3 inhibited killing of MHC-congenic target cells from the av1, n, lv1, and c haplotypes, but not from the u or b haplotypes. A putative ligand was mapped to the nonclassical MHC class I region (RT1-C/E/M) using intra-MHC recombinant strains. Relative numbers of Ly-49s3+ NK cells were reduced, and surface levels of Ly-49s3 were lower, in MHC congenic strains expressing the putative Ly-49s3 ligand(s). In conclusion, we have identified a novel Ly-49 receptor that triggers rat NK cell-mediated responses.
Cloning and Characterization of a Promoter Flanking the Early B Cell Factor (EBF) Gene Indicates Roles for E-Proteins and Autoregulation in the Control of EBF Expression
Authors: Smith Emma M. K. , Gisler Ramiro , Sigvardsson Mikael
Published: April 2014

The early B cell factor (EBF) is a transcription factor shown crucial for the development of B lymphocytes. The protein is expressed from the earliest stages of B cell development until the mature B cell stage, but the control elements responsible for the regulation of the gene are unknown. In this study, we report of the identification of a promoter region flanking the EBF gene. Several transcription start sites were identified by primer extension analysis in a region ∼3.1 kb from the predicted ATG. Transient transfections revealed that this region was able to stimulate transcription of a reporter gene in B lymphoid and to a lesser extent, myeloid cells, but not in a pre-T cell line. The promoter was also able to functionally interact with E47, suggesting that the EBF gene may be a direct target for activation by E-proteins. In addition, functional binding of EBF to its own promoter was confirmed by EMSA and transfection assays indicating that the EBF protein may be involved in an autoregulatory loop. Finally, a tissue-restricted factor was able to bind an upstream regulatory region in B-lineage cells, further supporting the idea that the cloned promoter participates in the regulation of stage and lineage specific expression of the EBF gene.
NKT Cell-Derived RANTES Recruits APCs and CD8+ T Cells to the Spleen During the Generation of Regulatory T Cells in Tolerance
Authors: Faunce Douglas E. , Stein-Streilein Joan
Published: April 2014

The induction of peripheral tolerance via immune privileged sites such as the eye requires splenic colocalization of NKT cells and CD1d+ tolerogenic F4/80+ APCs, both of which are needed for the generation of CD8+-regulatory T (Tr) cells. Whereas tolerogenic APCs secrete the chemokine macrophage-inflammatory protein-2 for the purpose of recruiting NKT cells, the signals responsible for recruiting potential Tr cells and additional APCs to the spleen are not known. Here we examined the ability of CD1d-stimulated NKT cells to produce chemokines that can recruit other cells needed for tolerance. Our results show that NKT cells stimulated by either CD1d-transfected fibroblasts in vitro or CD1d+ tolerogenic APCs both in vivo and ex vivo produced RANTES in a CD1d-dependent manner. The requirement for RANTES in tolerance was demonstrated by studies in which RANTES blockade in vivo prevented not only APC accumulation in the spleen but also the generation of CD8+ Tr cells that suppress Th1 immunity. Thus, CD1d-restricted NKT cells provide critical signals for orchestrating the accumulation of cells needed for tolerance induction. These data expand our current knowledge of RANTES beyond its role in Th1 immune responses to show its importance in tolerance induction and add a novel aspect to our understanding of the role of NKT cells in tolerance. Understanding the precise mechanisms involved in tolerance induction may lead to more effective therapeutic strategies for autoimmunity and graft rejection.
Contribution of IL-18 to Th1 Response and Host Defense Against Infection by Mycobacterium tuberculosis: A Comparative Study with IL-12p40
Authors: Kinjo Yuki , Kawakami Kazuyoshi , Uezu Kaori , Yara Satomi , Miyagi Kazuya , Koguchi Yoshinobu , Hoshino Tomoaki , Okamoto Masaki , Kawase Yusuke , Yokota Koichi , Yoshino Kohichiro , Takeda Kiyoshi , Akira Shizuo , Saito Atsushi
Published: April 2014

The present study was conducted to critically determine the protective role of IL-18 in host response to Mycobacterium tuberculosis infection. IL-18-deficient (knockout (KO)) mice were slightly more prone to this infection than wild-type (WT) mice. Sensitivity of IL-12p40KO mice was lower than that of IL-12p40/IL-18 double KO mice. IFN-γ production caused by the infection was significantly attenuated in IL-18KO mice compared with WT mice, as indicated by reduction in the levels of this cytokine in sera, spleen, lung, and liver, and its synthesis by spleen cells restimulated with purified protein derivatives. Serum IL-12p40 level postinfection and its production by peritoneal exudate cells stimulated with live bacilli were also significantly lower in IL-18KO mice than WT mice, suggesting that attenuated production of IFN-γ was secondary to reduction of IL-12 synthesis. However, this was not likely the case, because administration of excess IL-12 did not restore the reduced IFN-γ production in IL-18KO mice. In further studies, IL-18 transgenic mice were more resistant to the infection than control littermate mice, and serum IFN-γ level and its production by restimulated spleen cells were increased in the former mice. Taken together, our results indicate that IL-18 plays an important role in Th1 response and host defense against M. tuberculosis infection although the contribution was not as profound as that of IL-12p40.
The Role of Proinflammatory Cytokines in Wasting Disease During Lymphocytic Choriomeningitis Virus Infection
Authors: Kamperschroer Cris , Quinn Daniel G.
Published: April 2014

Infection with pathogens often leads to loss of body weight, but the cause of weight loss during infection is poorly understood. We used the infection of mice with lymphocytic choriomeningitis virus (LCMV) as a model to study how pathogens induce weight loss. If LCMV is introduced into the CNS of CTL-deficient mice, the immune response against the virus leads to a severe weight loss called wasting disease. We planned to determine what components of this antiviral immune response mediate wasting disease. By adoptive transfer, we show that CD4 T cells activated by LCMV infection are sufficient to cause wasting disease. We examined the role of cytokines in LCMV-induced wasting disease using mice lacking specific cytokines or cytokine receptors. Results of adoptive transfer experiments suggest that TNF-α is not involved in LCMV-induced wasting disease and show that IFN-γ contributes to the disease. Consistent with a role for IFN-γ in wasting, we find that IFN-γ is necessary for LCMV-specific CD4 T cell responses in the CNS, most likely because it is required to induce MHC class II expression. Our data also indicate that IL-1 is required for LCMV-induced wasting and that IL-6 contributes to the wasting disease. Additionally, our results identify α-melanocyte-stimulating hormone as a potential mediator of the disease. Overall, this work defines the critical role of virus-primed CD4 T cells and of proinflammatory cytokines in the pathogenesis of wasting disease induced by LCMV infection.
Type I IFN as a Natural Adjuvant for a Protective Immune Response: Lessons from the Influenza Vaccine Model
Authors: Proietti Enrico , Bracci Laura , Puzelli Simona , Di Pucchio Tiziana , Sestili Paola , De Vincenzi Enrico , Venditti Massimo , Capone Imerio , Seif Isabelle , De Maeyer Edward , Tough David , Donatelli Isabella , Belardelli Filippo
Published: April 2014

The identification of natural adjuvants capable of selectively promoting an efficient immune response against infectious agents would represent an important advance in immunology, with direct implications for vaccine development, whose progress is generally hampered by the difficulties in defining powerful synthetic adjuvants suitable for clinical use. Here, we demonstrate that endogenous type I IFN is necessary for the Th1 type of immune response induced by typical adjuvants in mice and that IFN itself is an unexpectedly powerful adjuvant when administered with the human influenza vaccine, for inducing IgG2a and IgA production and conferring protection from virus challenge. The finding that these cytokines, currently used in patients, are necessary for full expression of adjuvant activity and are sufficient for the generation of a protective immune response opens new perspectives in understanding the basis of immunity and in vaccine development.
The Epistatic Interrelationships of IL-1, IL-1 Receptor Antagonist, and the Type I IL-1 Receptor
Authors: Irikura Vera M. , Lagraoui Mouna , Hirsh David
Published: April 2014

Mice lacking the gene for the IL-1R antagonist (IL-1ra) show abnormal development and homeostasis as well as altered responses to infectious and inflammatory stimuli. A reduction in the level of IL-1 signaling, either by deletion of the receptor or increased expression of IL-1ra, does not affect development or homeostasis, but does alter immune responses. In this study we use genetic epistasis to investigate the interdependence of selected genes in the IL-1 family in the regulation of these developmental and immunological processes. Deletion of the gene encoding the type I IL-1R (IL-1RI) is epistatic to deletion of the IL-1ra gene. Therefore, all functions of IL-1ra depend upon the presence of a functional receptor; there is no other target. Similarly, overexpression of the mRNA encoding the secreted form of IL-1ra is epistatic to deletion of the receptor antagonist, leaving the role of the intracellular splice variants of IL-1ra unknown. The abnormal development of IL-1ra-deficient mice is probably due to chronic overstimulation of the proinflammatory pathway via IL-1, but a clear single pathological defect is not apparent. These results support the model that the only essential function of IL-1ra in both health and disease is competitive inhibition of the IL-1RI.
Differential Glucocorticoid Enhancement of the Cytokine-Driven Transcriptional Activation of the Human Acute Phase Serum Amyloid A Genes, SAA1 and SAA2
Authors: Thorn Caroline F. , Whitehead Alexander S.
Published: April 2014

The human acute phase serum amyloid A (A-SAA) genes, SAA1 and SAA2, have a high degree of sequence identity that extends ∼450 bp upstream of their transcription start sites. Each promoter contains analogously positioned functional binding sites for the transcription factors NF-κB and NF-IL6. In human HepG2 hepatoma cells transfected with SAA promoter luciferase reporter constructs, administration of IL-1 and IL-6, singly or in combination, induced SAA1 and SAA2 transcriptional readouts that were qualitatively indistinguishable. However, under induced conditions, the SAA2 promoter had a significant quantitative transcriptional advantage over the SAA1 promoter. The application of the synthetic glucocorticoid dexamethasone in the context of cytokine stimulation enhanced the transcriptional activity of the SAA1, but not the SAA2, promoter such that readout from the former became equivalent to that from the latter. A putative glucocorticoid response element (GRE) is present (between residues −208 and −194) only in the SAA1 gene; a similar sequence in the corresponding region of the SAA2 gene is disrupted by a nine-residue insertion. The SAA1 GRE was shown to be functionally active and the SAA2 disrupted GRE was shown to be functionally inactive in experiments using reporter constructs carrying SAA1 and SAA2 promoters that had been modified by site-specific mutagenesis. Quantitative analysis of transcript-specific RT-PCR products, derived from SAA1 and SAA2 mRNAs after treatment of HepG2 cells with cytokines in the presence or absence of dexamethasone, confirmed that the endogenous SAA1 gene has a cytokine-driven transcriptional disadvantage that is superseded by a marginal transcriptional advantage when glucocorticoids are present.
Cooperative Effects of Th2 Cytokines and Allergen on Normal and Asthmatic Bronchial Epithelial Cells
Authors: Lordan James L. , Bucchieri Fabio , Richter Audrey , Konstantinidis Athanassias , Holloway John W. , Thornber Matthew , Puddicombe Sarah M. , Buchanan Diana , Wilson Susan J. , Djukanović Ratko , Holgate Stephen T. , Davies Donna E.
Published: April 2014

In sensitized individuals, exposure to allergens such as Dermatophagoides pteronyssinus (Der p) causes Th2 polarization and release of cytokines, including IL-4 and IL-13. Because Der p extracts also have direct effects on epithelial cells, we hypothesized that allergen augments the effects of Th2 cytokines by promoting mediator release from the bronchial epithelium in allergic asthma. To test our hypothesis, primary bronchial epithelial cultures were grown from bronchial brushings of normal and atopic asthmatic subjects. RT-PCR showed that each culture expressed IL-4Rα, common γ-chain, and IL-13Rα1, as well as IL-13Rα2, which negatively regulates IL-13 signaling; FACS analysis confirmed IL-13Rα2 protein expression. Exposure of epithelial cultures to either Der p extracts, TNF-α, IL-4, or IL-13 enhanced GM-CSF and IL-8 release, and this was partially suppressible by corticosteroids. Simultaneous exposure of the epithelial cultures to IL-4 or IL-13 together with Der p resulted in a further increase in cytokine release, which was at least additive. Release of TGF-α was also increased by TNF-α and combinations of IL-4, IL-13, and Der p; however, this stimulation was only significant in the asthma-derived cultures. These data suggest that, in an allergic environment, Th2 cytokines and allergen have the potential to sustain airway inflammation through a cooperative effect on cytokine release by the bronchial epithelium. Our novel finding that IL-4, IL-13, and allergen enhance release of TGF-α, a ligand for the epidermal growth factor receptor that stimulates fibroblast proliferation and goblet cell differentiation, provides a potential link between allergen exposure, Th2 cytokines, and airway remodelling in asthma.
Impaired IFN-γ-Dependent Inflammatory Responses in Human Keratinocytes Overexpressing the Suppressor of Cytokine Signaling 1
Authors: Federici Monica , Giustizieri Maria Laura , Scarponi Claudia , Girolomoni Giampiero , Albanesi Cristina
Published: April 2014

Keratinocytes contribute relevantly to the pathogenesis of inflammatory skin diseases by expressing a variety of proinflammatory molecules, with T cell-derived IFN-γ being the most potent keratinocyte activator. Suppressor of cytokine signaling (SOCS)1 and SOCS3 are negative regulators of IFN-γ signaling and are induced in many cell types by IFN-γ itself or by other cytokines. We show in this work that SOCS1, SOCS2, SOCS3, and cytokine-inducible SH2-containing protein mRNA were up-regulated by IFN-γ in normal human keratinocytes, whereas only SOCS1 or SOCS1 and cytokine-inducible SH2-containing protein were induced by TNF-α or IL-4, respectively. SOCS1, SOCS2, and SOCS3 proteins were undetectable in healthy skin and highly expressed in the epidermis of psoriasis and allergic contact dermatitis, but were only weakly expressed in atopic dermatitis skin. In keratinocytes transiently transfected with SOCS1 or SOCS3 the IFN-γ-induced transactivation of an IFN-γ-responsive reporter gene was markedly inhibited. SOCS1 and SOCS3 overexpression in keratinocyte stable clones inhibited IFN-γ-induced phosphorylation of IFN-γRα and activation of STAT1 and STAT3. Furthermore, SOCS1 and, to a lesser extent, SOCS3 reduced membrane expression of ICAM-1 and HLA-DR, and release of IFN-γ-inducible protein-10, monokine induced by IFN-γ, and monocyte chemoattractant protein-1 by keratinocyte clones promoted by IFN-γ. SOCS1-expressing keratinocytes showed constitutively higher, but not IFN-γ-inducible, IL-8 levels compared with SOCS2 and SOCS3 clones, and were resistant to IFN-γ-mediated growth inhibition. Targeting keratinocyte SOCS1 may represent a novel therapeutic approach to IFN-γ-dependent skin diseases.
Proinflammatory Cytokine IL-1β Promotes Tumor Growth of Lewis Lung Carcinoma by Induction of Angiogenic Factors: In Vivo Analysis of Tumor-Stromal Interaction
Authors: Saijo Yasuo , Tanaka Masashi , Miki Makoto , Usui Kazuhiro , Suzuki Takuji , Maemondo Makoto , Hong Xin , Tazawa Ryushi , Kikuchi Toshiaki , Matsushima Kouji , Nukiwa Toshihiro
Published: April 2014

Inflammatory conditions are associated with tumor development. IL-1β is a multifunctional and proinflammatory cytokine that affects nearly all types of cells. To investigate the role of IL-1β in tumor growth in vivo, we transduced the retroviral vector coding human IL-1β gene into mouse Lewis lung carcinoma (LLC) cells and subsequently inoculated the transformant (LLC/IL-1β) to syngeneic C57BL/6 mice. Tumors derived from LLC/IL-1β grew faster (240%, day 18, vs null-vector control LLC/neo; p < 0.01) and showed more abundant vasculature (250%, vs LLC/neo; p < 0.05), whereas LLC/IL-1β cells, LLC/neo cells, and wild-type LLC cells did not show any significant difference in the growth rate in vitro. As compared with LLC/neo cells, LLC/IL-1β cells secreted 2-fold the amount of vascular endothelial growth factor and >10-fold the amount of macrophage-inflammatory protein-2 (CXCL2), one of whose main functions is angiogenesis. Although LLC/IL-1β itself did not secrete hepatocyte growth factor (HGF), the tumor derived from LLC/IL-1β cells also contained a >4-fold higher concentration of HGF, another angiogenic factor. In situ hybridization of HGF mRNA in LLC/IL-1β tumor sections demonstrated that stromal fibroblasts and infiltrating cells overexpressed HGF mRNA. Moreover, when cultured in the presence of HGF in vitro, LLC/IL-1β cells secreted even larger amounts of vascular endothelial growth factor and macrophage-inflammatory protein-2. The antiangiogenic agent TNP-470 and anti-CXCR2 Ab inhibited the tumor growth of LLC/IL-1β cells in vivo. These results indicated that secreting IL-1β into the tumor milieu induces several angiogenic factors from tumor and stromal cells and thus promotes tumor growth through hyperneovascularization.
Cutting Edge: Molecular Portrait of Human Autoimmune Disease
Authors: Maas Kevin , Chan Sanny , Parker Joel , Slater Angela , Moore Jason , Olsen Nancy , Aune Thomas M.
Published: April 2014

Autoimmune diseases affect 3–5% of the population, are mediated by the immune response to self-Ags, and are characterized by the site of tissue destruction. We compared expression levels of >4,000 genes in PBMC of control individuals before and after immunization to those of individuals with four distinct autoimmune diseases. The gene expression profile of the normal immune response exhibits coordinate changes in expression of genes with related functions over time. In contrast, each individual from all autoimmune diseases displays a similar gene expression profile unrelated to the pattern of the immunized group. To our surprise, genes with a distinct expression pattern in autoimmunity are not necessarily “immune response” genes, but are genes that encode proteins involved in apoptosis, cell cycle progression, cell differentiation, and cell migration.
Analysis of the Innate and Adaptive Phases of Allograft Rejection by Cluster Analysis of Transcriptional Profiles
Authors: Christopher Kenneth , Mueller Thomas F. , Ma Chunyan , Liang Yurong , Perkins David L.
Published: April 2014

Both clinical and experimental observations suggest that allograft rejection is a complex process with multiple components that are, at least partially, functionally redundant. Studies using graft recipients deficient in various genes including chemokines, cytokines, and other immune-associated genes frequently produce a phenotype of delayed, but not indefinitely prevented, rejection. Only a small subset of genetic deletions (for example, TCRα or β, MHC I and II, B7-1 and B7-2, and recombinase-activating gene) permit permanent graft acceptance suggesting that rejection is orchestrated by a complex network of interrelated inflammatory and immune responses. To investigate this complex process, we have used oligonucleotide microarrays to generate quantitative mRNA expression profiles following transplantation. Patterns of gene expression were confirmed with real-time PCR data. Hierarchical clustering algorithms clearly differentiated the early and late phases of rejection. Self-organizing maps identified clusters of coordinately regulated genes. Genes up-regulated during the early phase included genes with prior biological functions associated with ischemia, injury, and Ag-independent innate immunity, whereas genes up-regulated in the late phase were enriched for genes associated with adaptive immunity.
Identification of HLA-A*0201-Restricted T Cell Epitopes Derived from the Novel Overexpressed Tumor Antigen Calcium-Activated Chloride Channel 2
Authors: Konopitzky Renate , König Ulrich , Meyer Ralf G. , Sommergruber Wolfgang , Wölfel Thomas , Schweighoffer Tamás
Published: April 2014

Vaccination against tumor Ags may become a promising treatment modality especially in cancer types where other therapeutic approaches fail. However, diversity of tumors requires that a multitude of Ags become available. Differential expression in normal vs cancerous tissues, both at the mRNA and the protein level, may identify Ag candidates. We have previously compared transcripts from squamous cell lung cancer and normal lung tissue using differential display analysis, and found a transcript that was overexpressed in malignant cells and was identical with the calcium-activated chloride channel 2 (CLCA2) gene. We have now selected HLA-A2-restricted peptides from CLCA2, and have generated T cell lines against the CLCA2-derived KLLGNCLPTV, LLGNCLPTV, and SLQALKVTV peptides using in vitro priming. Specificity of T cells was ascertained in ELISPOT assays. The primed T cells also recognized allogeneic tumor cells in an Ag-specific and HLA-restricted fashion. Moreover, peptide LLGNCLPTV was also independently recognized by CD8+ T cells expanded from pancreatic carcinoma/T cell cocultures. CLCA2-specific CD8+ T cells were absent from the peripheral blood of healthy donors. These data indicate that an immune response can be induced against CLCA2, which thus may become an important Ag for anti-tumor vaccination approaches.
2B4 Is Constitutively Associated with Linker for the Activation of T Cells in Glycolipid-Enriched Microdomains: Properties Required for 2B4 Lytic Function
Authors: Klem Jennifer , Verrett Pamela C. , Kumar Vinay , Schatzle John D.
Published: April 2014

2B4 is a receptor belonging to the Ig superfamily and is found on all murine NK cells as well as a small subset of T cells. Previous studies have found that cross-linking of the 2B4 receptor results in both increased cytotoxicity and IFN-γ secretion. We have discovered that 2B4 from transfected NK and T cell lines, as well as from primary murine cells, coimmunoprecipitates with the phosphoprotein linker for the activation of T cells (LAT), which is essential for TCR-mediated signaling. This association is independent of both 2B4 phosphorylation and the cytoplasmic tail of 2B4. We have found that, along with LAT, 2B4 is constitutively located in glycolipid-enriched microdomains of the plasma membrane. In fact, 2B4 appears to associate with LAT only when it localizes to glycolipid-enriched microdomains. This localization of 2B4 occurs due to a CxC cysteine motif found in the transmembrane region, as determined by mutagenesis studies. 2B4-mediated cytotoxicity is defective in the absence of LAT, indicating that LAT is a required intermediate for 2B4 signal transduction. However, we have also shown that LAT association alone is not sufficient for maximal 2B4 activation.
Identification of Naturally Processed CD4 T Cell Epitopes from the Prostate-Specific Antigen Kallikrein 4 Using Peptide-Based In Vitro Stimulation
Authors: Hural John A. , Friedman Rachel S. , McNabb Andria , Steen Sean S. , Henderson Robert A. , Kalos Michael
Published: April 2014

Kallikrein (KLK)4 is a recently described member of the tissue kallikrein gene family that is specifically expressed in normal and prostate tumor tissues. The tissue-specific expression profile of this molecule suggests that it might be useful as a vaccine candidate against prostate cancer. To examine the presence of CD4 T cells specific for KLK4 in PBMC of normal individuals, a peptide-based in vitro stimulation protocol was developed that uses overlapping KLK4-derived peptides spanning the majority of the KLK4 protein. Using this methodology, three naturally processed CD4 epitopes derived from the KLK4 sequence are identified. These epitopes are restricted by HLA-DRB1*0404, HLA-DRB1*0701, and HLA-DPB1*0401 class II alleles. CD4 T cell clones specific for these epitopes are shown to efficiently and specifically recognize both recombinant KLK4 protein and lysates from prostate tumor cell lines virally infected to express KLK4. CD4 T cells specific for these KLK4 epitopes are shown to exist in PBMC from multiple male donors that express the relevant class II alleles, indicating that a CD4 T cell repertoire specific for KLK4 is present and potentially expandable in prostate cancer patients. The demonstration that KLK4-specific CD4 T cells exist in the peripheral circulation of normal male donors and the identification of naturally processed KLK4-derived CD4 T cell epitopes support the use of KLK4 in whole gene-, protein-, or peptide-based vaccine strategies against prostate cancer. Furthermore, the identification of naturally processed KLK4-derived epitopes provides valuable tools for monitoring preexisting and vaccine-induced responses to this molecule.
Efficient Isolation of Novel Human Monoclonal Antibodies with Neutralizing Activity Against HIV-1 from Transgenic Mice Expressing Human Ig Loci
Authors: He Yuxian , Honnen William J. , Krachmarov Chavdar P. , Burkhart Michael , Kayman Samuel C. , Corvalan Jose , Pinter Abraham
Published: April 2014

Despite considerable interest in the isolation of mAbs with potent neutralization activity against primary HIV-1 isolates, both for identifying useful targets for vaccine development and for the development of therapeutically useful reagents against HIV-1 infection, a relatively limited number of such reagents have been isolated to date. Human mAbs (hu-mAbs) are preferable to rodent mAbs for treatment of humans, but isolation of hu-mAbs from HIV-infected subjects by standard methods of EBV transformation of B cells or phage display of Ig libraries is inefficient and limited by the inability to control or define the original immunogen. An alternative approach for the isolation of hu-mAbs has been provided by the development of transgenic mice that produce fully hu-mAbs. In this report, we show that immunizing the XenoMouse G2 strain with native recombinant gp120 derived from HIVSF162 resulted in robust humoral Ab responses against gp120 and allowed the efficient isolation of hybridomas producing specific hu-mAbs directed against multiple regions and epitopes of gp120. hu-mAbs possessing strong neutralizing activity against the autologous HIVSF162 strain were obtained. The epitopes recognized were located in three previously described neutralization domains, the V2-, V3- and CD4-binding domains, and in a novel neutralization domain, the highly variable C-terminal region of the V1 loop. This is the first report of neutralizing mAbs directed at targets in the V1 region. Furthermore, the V2 and V3 epitopes recognized by neutralizing hu-mAbs were distinct from those of previously described human and rodent mAbs and included an epitope requiring a full length V3 loop peptide for effective presentation. These results further our understanding of neutralization targets for primary, R5 HIV-1 viruses and demonstrate the utility of the XenoMouse system for identifying new and interesting epitopes on HIV-1.
Src-Dependent Syk Activation Controls CD69-Mediated Signaling and Function on Human NK Cells
Authors: Pisegna Simona , Zingoni Alessandra , Pirozzi Gianluca , Cinque Benedetta , Cifone Maria Grazia , Morrone Stefania , Piccoli Mario , Frati Luigi , Palmieri Gabriella , Santoni Angela
Published: April 2014

CD69 C-type lectin receptor represents a functional triggering molecule on activated NK cells, capable of directing their natural killing function. The receptor-proximal signaling pathways activated by CD69 cross-linking and involved in CD69-mediated cytotoxic activity are still poorly understood. Here we show that CD69 engagement leads to the rapid and selective activation of the tyrosine kinase Syk, but not of the closely related member of the same family, ZAP70, in IL-2-activated human NK cells. Our results indicate the requirement for Src family kinases in the CD69-triggered activation of Syk and suggest a role for Lck in this event. We also demonstrate that Syk and Src family tyrosine kinases control the CD69-triggered tyrosine phosphorylation and activation of phospholipase Cγ2 and the Rho family-specific exchange factor Vav1 and are responsible for CD69-triggered cytotoxicity of activated NK cells. The same CD69-activated signaling pathways are also observed in an RBL transfectant clone, constitutively expressing the receptor. These data demonstrate for the first time that the CD69 receptor functionally couples to the activation of Src family tyrosine kinases, which, by inducing Syk activation, initiate downstream signaling pathways and regulate CD69-triggered functions on human NK cells.
Dynamics of Memory T Cell Proliferation Under Conditions of Heterologous Immunity and Bystander Stimulation
Authors: Kim Sung-Kwon , Brehm Michael A. , Welsh Raymond M. , Selin Liisa K.
Published: April 2014

By examining adoptively transferred CSFE-labeled lymphocytic choriomeningitis virus (LCMV)-immune donor T cells in Thy-1 congenic hosts inoculated with viruses or with the cytokine inducer poly(I:C), strikingly different responses of bona fide memory T cells were found in response to different stimuli. Poly(I:C) (cytokine) stimulation caused a limited synchronized division of memory CD8 T cells specific to each of five LCMV epitopes, with no increase and sometimes a loss in number, and no change in their epitope hierarchy. Homologous LCMV infection caused more than seven divisions of T cells specific for each epitope, with dramatic increases in number and minor changes in hierarchy. Infections with the heterologous viruses Pichinde and vaccinia (VV) caused more than seven divisions and increases in number of T cells specific to some putatively cross-reactive but not other epitopes and resulted in substantial changes in the hierarchy of the LCMV-specific T cells. Hence, there can be memory T cell division without proliferation (i.e., increase in cell number) in the absence of Ag and division with proliferation in the presence of Ag from homologous or heterologous viruses. Heterologous protective immunity between viruses is not necessarily reciprocal, given that LCMV protects against VV but VV does not protect against LCMV. VV elicited proliferation of LCMV-induced CD8 and CD4 T cells, whereas LCMV did not elicit proliferation of VV-induced T cells. Thus, depending on the pathogen and the sequence of infection, a heterologous agent may selectively stimulate the memory pool in patterns consistent with heterologous immunity.
Cutting Edge: CD94/NKG2 Is Expressed on Th1 But Not Th2 Cells and Costimulates Th1 Effector Functions
Authors: Meyers Jennifer Hartt , Ryu Akemi , Monney Laurent , Nguyen Khuong , Greenfield Edward A. , Freeman Gordon J. , Kuchroo Vijay K.
Published: April 2014

Th1 and Th2 cells can be phenotypically distinguished by very few cell surface markers. To identify cell surface molecules that are specifically expressed on Th1 cells, we have generated a panel of mAbs that specifically bind the surfaces of murine Th1 but not Th2 cells. One of these Abs identified the NK cell receptor CD94 as a molecule also specifically expressed on the surface of Th1 cells. As in NK cells, CD94 is expressed on Th1 cells together with members of the NKG2 family of molecules, including NKG2A, C, and E. Cross-linking these receptors on differentiated Th1 cells in vitro costimulates proliferation and cytokine production with a potency similar to that obtained by cross-linking CD28. We propose that CD94/NKG2 heterodimers may costimulate effector functions of differentiated Th1 cells.
Cutting Edge: Molecular Analysis of the Negative Regulatory Function of Lymphocyte Activation Gene-3
Authors: Workman Creg J. , Dugger Kari J. , Vignali Dario A. A.
Published: April 2014

Lymphocyte activation gene (LAG)-3 (CD223) is a CD4-related activation-induced cell surface molecule that binds to MHC class II molecules with high affinity and negatively regulates T cell expansion and homeostasis. In this study, we show that LAG-3 inhibits CD4-dependent, but not CD4-independent, T cell function via its cytoplasmic domain. Although high affinity interaction with MHC class II molecules is essential for LAG-3 function, tailless LAG-3 does not compete with CD4 for ligand binding. A single lysine residue (K468) within a conserved “KIEELE” motif is essential for interaction with downstream signaling molecules. These data provide insight into the mechanism of action of this important T cell regulatory molecule.
Cutting Edge: Inhibiting Measles Virus Infection but Promoting Reproduction: An Explanation for Splicing and Tissue-Specific Expression of CD46
Authors: Riley Rebecca C. , Tannenbaum Pamela L. , Abbott David H. , Atkinson John P.
Published: April 2014

Membrane cofactor protein (MCP; CD46) regulates the complement cascade by inhibiting C3b and C4b deposited on self tissue. This function resides in the complement control protein repeats (CCPs), with CCPs 2–4 essential for regulation. MCP is expressed on the inner acrosomal membrane of human sperm, and Abs to CCP1 inhibit sperm-egg interactions. In somatic tissues, New World monkeys express an alternatively spliced form of MCP lacking CCP1. Although retaining complement-regulatory activity, this form is postulated to render these species less susceptible to strains of the measles virus whose hemagglutinin requires CCP1 and CCP2 for attachment. Using PCR, sequencing, Western blotting, and immunohistochemistry, we characterized MCP expression in the testes and sperm of two New World monkeys. In these species, sperm express MCP bearing CCP1. The germ cell-specific expression pattern of this domain strongly suggests an evolutionarily conserved role for MCP in fertilization.