bluuebunny/crossref_metadata_2025 huggingface dataset:
IL-11 Receptor α in the Pathogenesis of IL-13-Induced Inflammation and Remodeling
Authors: Chen Qingsheng , Rabach Lesley , Noble Paul , Zheng Tao , Lee Chun Geun , Homer Robert J. , Elias Jack A.
Published: April 2014

IL-13 is a major stimulator of inflammation and tissue remodeling at sites of Th2 inflammation. In Th2-dominant inflammatory disorders such as asthma, IL-11 is simultaneously induced. However, the relationship(s) between IL-11 and IL-13 in these responses has not been defined, and the role(s) of IL-11 in the genesis of the tissue effects of IL-13 has not been evaluated. We hypothesized that IL-11, signaling via the IL-11Rα-gp130 receptor complex, plays a key role in IL-13-induced tissue responses. To test this hypothesis we compared the expression of IL-11, IL-11Rα, and gp130 in lungs from wild-type mice and transgenic mice in which IL-13 was overexpressed in a lung-specific fashion. We simultaneously characterized the effects of a null mutation of IL-11Rα on the tissue effects of transgenic IL-13. These studies demonstrate that IL-13 is a potent stimulator of IL-11 and IL-11Rα. They also demonstrate that IL-13 is a potent stimulator of inflammation, fibrosis, hyaluronic acid accumulation, myofibroblast accumulation, alveolar remodeling, mucus metaplasia, and respiratory failure and death in mice with wild-type IL-11Rα loci and that these alterations are ameliorated in the absence of IL-11Rα. Lastly, they provide insight into the mechanisms of these processes by demonstrating that IL-13 stimulates CC chemokines, matrix metalloproteinases, mucin genes, and gob-5 and stimulates and activates TGF-β1 via IL-11Rα-dependent pathways. When viewed in combination, these studies demonstrate that IL-11Rα plays a key role in the pathogenesis of IL-13-induced inflammation and remodeling.
In Vitro Engagement of CD3 and CD28 Corrects T Cell Defects in Chronic Lymphocytic Leukemia
Authors: Bonyhadi Mark , Frohlich Mark , Rasmussen Angela , Ferrand Christophe , Grosmaire Laura , Robinet Eric , Leis Jose , Maziarz Richard T. , Tiberghien Pierre , Berenson Ronald J.
Published: April 2014

Chronic lymphocytic leukemia (CLL) is characterized by the accumulation of leukemic B cells concomitant with immunological abnormalities and depressed immune responses. The T cell abnormalities found in CLL patients are thought to increase the risk of infection and hamper immune recognition and elimination of leukemic cells. We evaluated whether providing signals through CD3 and CD28 would correct some of these T cell defects. PBMC were incubated with anti-CD3 and anti-CD28 mAbs conjugated to superparamagnetic beads for 12–14 days. This resulted in a 1400-fold increase in T cell numbers. Activated T cells expressed high levels of CD25, CD54, CD137, and CD154, and produced IFN-γ, TNF-α, and GM-CSF. The mean T cell composition of cultures increased from ∼6% to >90% and leukemic B cells decreased from a mean of ∼85% to 0.1% or less. Leukemic B cells up-regulated expression of CD54, CD80, CD86, and CD95. Receptor up-regulation required direct cell contact with the activated T cells and could be blocked with anti-CD154 mAb, suggesting that the CD40-CD40L pathway helped mediate these effects. Poor T cell responses to allostimulation were corrected by the activation and expansion process. The skewing in the TCR repertoire returned to normal, or near normal following the culture process in eight of nine patients with abnormal TCR repertoires. Activated T cells had potent in vitro antileukemic effects in contrast to nonactivated T cells. Based upon these findings, a clinical trial has been initiated to test the potential therapeutic effects of T cells activated using this approach in patients with CLL.
Middle-Age Male Mice Have Increased Severity of Experimental Autoimmune Encephalomyelitis and Are Unresponsive to Testosterone Therapy
Authors: Matejuk Agata , Hopke Corwyn , Vandenbark Arthur A. , Hurn Patricia D. , Offner Halina
Published: April 2014

Treatment with sex hormones is known to protect against experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. However, little is known about how age affects the course of EAE or response to hormone treatment. This study demonstrates striking differences between middle-age vs young C57BL/6 male mice in the clinical course of EAE and response to both testosterone (T4) and estrogen (E2) hormone therapy. Unlike young males that developed an acute phase of EAE followed by a partial remission, middle-age males suffered severe chronic and unremitting EAE that was likely influenced by alterations in the distribution and function of splenic immunocytes and a significant reduction in suppressive activity of CD4+CD25+ regulatory T cells in the spleen and spinal cord. Middle-age males had reduced numbers of splenic CD4+ T cells that were generally hypoproliferative, but enhanced numbers of splenic macrophages and MHC class II-expressing cells, and increased secretion of the proinflammatory factors IFN-γ and MCP-1. Surprisingly, middle-age males were unresponsive to the EAE-protective effects of T4 and had only a transient benefit from E2 treatment; young males were almost completely protected by both hormone treatments. T4 treatment of young males inhibited proliferation of myelin oligodendrocyte glycoprotein 35–55-specific T cells and secretion of TNF-α and IFN-γ. The effects of T4 in vivo and in vitro were reversed by the androgen receptor antagonist, flutamide, indicating that the regulatory effects of T4 were mediated through the androgen receptor. These data are the first to define age-dependent differences in EAE expression and response to hormone therapy.
Monitoring of Anti-Vaccine CD4 T Cell Frequencies in Melanoma Patients Vaccinated with a MAGE-3 Protein
Authors: Zhang Yi , Sun Zhaojun , Nicolay Hugues , Meyer Ralf G. , Renkvist Nicolina , Stroobant Vincent , Corthals Jurgen , Carrasco Javier , Eggermont Alexander M. M. , Marchand Marie , Thielemans Kris , Wölfel Thomas , Boon Thierry , van der Bruggen Pierre
Published: April 2014

Quantitative evaluation of T cell responses of patients receiving antitumoral vaccination with a protein is difficult because of the large number of possible HLA-peptide combinations that could be targeted by the response. To evaluate the responses of patients vaccinated with protein MAGE-3, we have developed an approach that involves overnight stimulation of blood T cells with autologous dendritic cells loaded with the protein, sorting by flow cytometry of the T cells that produce IFN-γ, cloning of these cells, and evaluation of the number of T cell clones that secrete IFN-γ upon stimulation with the Ag. An important criterion is that T cell clones must recognize not only stimulator cells loaded with the protein, but also stimulator cells transduced with the MAGE-3 gene, so as to exclude the T cells that recognize contaminants generated by the protein production system. Using this approach it is possible to measure T cell frequencies as low as 10−6. We analyzed the frequencies of anti-vaccine CD4 T cells in five metastatic melanoma patients who had been injected with a MAGE-3 protein without adjuvant and showed evidence of tumor regression. Anti-MAGE-3 CD4 T cells were detected in one of the five patients. The frequency of the anti-MAGE-3 CD4 T cells was estimated at 1/60,000 of the CD4 T cells in postvaccination blood samples, representing at least an 80-fold increase in the frequency found before immunization. The frequencies of one anti-MAGE-3 CD4 T cell clonotype were confirmed by PCR analysis on blood lymphocytes. The 13 anti-MAGE-3 clones, which corresponded to five different TCR clonotypes, recognized the same peptide presented by HLA-DR1.
Activation of Marginal Zone B Cells from Lupus Mice with Type A(D) CpG-Oligodeoxynucleotides
Authors: Brummel Rachel , Lenert Petar
Published: April 2014

Several types of CpG-oligodeoxynucleotides (ODN) have been recently characterized. In mice, type A(D) CpG-ODNs primarily stimulate macrophages and dendritic cells, but fail to stimulate B cells. On the contrary, type B(K) CpG-ODNs are excellent B cell activators. Type C CpG-ODNs combine features of both types A(D) and B(K) CpG-ODNs. Despite cell type preferences, all CpG-ODNs require the presence of TLR9 for activation. In this study, we show that a subset of B cells from lupus mice responds to type A(D) CpG-ODN stimulation vigorously and directly with increased CD25 and CD86 expression and IL-10 secretion. Furthermore, these CpG-ODNs induce high surface IgM expression and promote 50- to 100-fold higher IgM and IgG3 secretion in lupus B cells than in controls. This response is similar to that seen with bacterial DNA stimulation of B cells. Type A(D)-responsive cells are enriched within lupus B cells with the marginal zone (MZ) phenotype. These cells are at least twice more numerous in lupus mice than in controls. The ability of lupus B cells to respond to type A(D) CpG-ODN stimulation is not due to differential TLR9 expression. Therefore, type A(D) CpG-ODNs may contribute to the lupus pathogenesis by inducing MZ-B cell activation, costimulatory molecule expression, and polyclonal Ig secretion. Through increased IL-10 secretion, MZ-B cells may also modify the activity of other cell types, particularly dendritic cells and macrophages.
Cutting Edge: Fas Ligand (CD178) Cytoplasmic Tail Is a Positive Regulator of Fas Ligand-Mediated Cytotoxicity
Authors: Jodo Satoshi , Pidiyar Vyankatesh J. , Xiao Sheng , Furusaki Akira , Sharma Rahul , Koike Takao , Ju Shyr-Te
Published: April 2014

The cytotoxic function of CD178 (Fas ligand (FasL)) is critical to the maintenance of peripheral tolerance and immune-mediated tissue pathology. The active site of FasL resides at the FasL extracellular region (FasLExt) and it functions through binding/cross-linking Fas receptor on target cells. In this study, we report that FasLExt-mediated cytotoxicity is regulated by the FasL cytoplasmic tail (FasLCyt). Deleting the N-terminal 2–70 aa (Δ70) or N-terminal 2–33 aa (Δ33) reduced the cytotoxic strength as much as 30- to 100-fold. By contrast, change in the cytotoxic strength was not observed with FasL deleted of the proline-rich domains (45–74 aa, ΔPRD) in the FasLCyt. Our study identifies a novel function of FasLCyt and demonstrates that FasL2–33, a sequence unique to FasL, is critically required for the optimal expression of FasLExt-mediated cytotoxicity.
Cutting Edge: Itk Is Not Essential for CD28 Signaling in Naive T Cells
Authors: Li Cheng-Rui , Berg Leslie J.
Published: April 2014

Itk, a member of the Tec family of tyrosine kinases, is critical for TCR signaling, leading to the activation of phospholipase Cγ1. Early biochemical studies performed in tumor cell lines also implicated Itk in CD28 signaling. These data were complemented by functional studies on primary Itk−/− T cells that suggested a negative role for Itk in CD28 signaling. In this report, we describe a thorough analysis of CD28-mediated responses in T cells lacking Itk. Using purified naive CD4+ T cells from Itk−/− mice, we examine a range of responses dependent on CD28 costimulation. We also analyze Akt and glycogen synthase kinase-3β phosphorylation in response to stimulation of CD28 alone. Overall, these experiments demonstrate that CD28 signaling, as well as CD28-mediated costimulation of TCR signaling, function efficiently in the absence of Itk. These findings indicate that Itk is not essential for CD28 signaling in primary naive CD4+ T cells.
Antinuclear Antigen B Cells That Down-Regulate Surface B Cell Receptor during Development to Mature, Follicular Phenotype Do Not Display Features of Anergy In Vitro
Authors: Liu Xiaohe , Manser Tim
Published: April 2014

We previously demonstrated that B cells expressing a transgenic BCR with “dual reactivity” for the hapten arsonate and nuclear autoantigens efficiently complete development to follicular phenotype and stably reside in follicles in vivo. These B cells express very low levels of surface IgM and IgD, suggesting that they avoid central deletion and peripheral anergy by reducing their avidity for autoantigen via surface BCR (sBCR) down-regulation. Since a variety of states of B cell anergy have been previously described, a thorough examination of the functional capabilities of these B cells was required to test this hypothesis. In this study, we show that surface Ig cross-linking induces amounts of proximal BCR signaling in these B cells commensurate with their reduced sBCR levels. Functionally, however, they are comparable to nonautoreactive B cells in cell cycle progression, up-regulation of activation and costimulatory molecules, and Ab-forming cell differentiation when treated with a variety of stimuli in vitro. In addition, these B cells can efficiently process and present Ag and are capable of undergoing cognate interaction with naive TCR-transgenic T cells, resulting in robust IL-2 production. Together, these data reveal a lack of intrinsic anergy involving any known mechanism, supporting the idea that this type of antinuclear Ag B cell becomes indifferent to cognate autoantigen by down-regulating sBCR.
Microtubule Disruption Suppresses Allergic Response through the Inhibition of Calcium Influx in the Mast Cell Degranulation Pathway
Authors: Oka Tatsuya , Hori Masatoshi , Ozaki Hiroshi
Published: April 2014

Mast cells are secretory cells that release their granules, which contain inflammatory mediators. Some recent data suggested that cytoskeletons play a role in this process. However, the role of microtubules in Ca2+ signaling has not yet been well defined. In this study, we demonstrate that the microtubule cytoskeleton is important to maintain Ca2+ influx in the degranulation pathway of mast cells, using the microtubule depolymerizers nocodazole and colchicine. The microtubule depolymerizers inhibited Ag-induced degranulation in RBL-2H3 cells and bone marrow-derived mast cells. When the cells were stimulated with Ag in the presence of the microtubule depolymerizers, the Ca2+ influx was decreased without affecting Ca2+ release from the endoplasmic reticulum (ER). Capacitative Ca2+ entry, which was induced by inhibitors of Ca2+-ATPase in the ER membrane, thapsigargin and cyclopiazonic acid, was also decreased by nocodazole. Fluorescent probe analysis demonstrated that nocodazole disrupted microtubule formation and changed the cytoplasmic distribution of the ER. The microtubule depolymerizers attenuated the passive cutaneous anaphylaxis reaction in back skin of Sprague Dawley rats. These results suggest that the microtubule cytoskeleton in mast cells is important to maintain Ag-induced capacitative Ca2+ entry, which is responsible for degranulation and the allergic response.
Does the Frequency and Avidity Spectrum of the Neuroantigen-Specific T Cells in the Blood Mirror the Autoimmune Process in the Central Nervous System of Mice Undergoing Experimental Allergic Encephalomyelitis?
Authors: Hofstetter Harald H. , Targoni Oleg S. , Karulin Alexey Y. , Forsthuber Thomas G. , Tary-Lehmann Magdalena , Lehmann Paul V.
Published: April 2014

In humans, studies of autoreactive T cells that mediate multiple sclerosis have been largely confined to testing peripheral blood lymphocytes. Little is known how such measurements reflect the disease-mediating autoreactive T cells in the CNS. This information is also not available for murine experimental allergic encephalomyelitis (EAE); the low number of T cells that can be obtained from the blood or the brain of mice prevented such comparisons. We used single-cell resolution IFN-γ ELISPOT assays to measure the frequencies and functional avidities of myelin basic protein (MBP:87–99)-specific CD4 cells in SJL mice immunized with this peptide. Functional MBP:87–99-specific IFN-γ-producing cells were present in the CNS during clinical signs of EAE, but not during phases of recovery. In contrast, MBP:87–99-specific T cells persisted in the blood during all stages of the disease, and were also present in mice that did not develop EAE. Therefore, the increased frequency of MBP:87–99-reactive T cells in the blood reliably reflected the primed state, but not the inflammatory activity of these cells in the brain. The functional avidity of the MBP:87–99-reactive T cells was identical in the brain and blood and did not change over 2 mo as the mice progressed from acute to chronic EAE. Therefore, high-affinity T cells did not become selectively enriched in the target organ, and avidity maturation of the MBP:87–99-specific T cell repertoire did not occur in the observation period. The data may help the interpretation of measurements made with peripheral blood lymphocytes of multiple sclerosis patients.
Rac2 Regulates Neutrophil Chemotaxis, Superoxide Production, and Myeloid Colony Formation through Multiple Distinct Effector Pathways
Authors: Carstanjen Dirk , Yamauchi Akira , Koornneef Annemart , Zang Heesuk , Filippi Marie-Dominique , Harris Chad , Towe Jason , Atkinson Simon , Zheng Yi , Dinauer Mary C. , Williams David A.
Published: April 2014

Polymorphonuclear neutrophils (PMN) are an important component of the innate immune system. We have shown previously that migration and superoxide (O⨪2) production, as well as some kinase signaling pathways are compromised in mice deficient in the Ras-related Rho GTPase Rac2. In this study, we demonstrate that Rac2 controls chemotaxis and superoxide production via distinct pathways and is critical for development of myeloid colonies in vitro. The Rac2 mutants V36A, F37A, and N39A all bind to both Pak1 and p67phox, yet are unable to rescue superoxide production and chemotaxis when expressed in Rac2−/− PMN. In contrast, the N43A mutant, which binds to Por1 (Arfaptin 2), p67phox, and Pak1, is able to rescue superoxide production but not chemotaxis. The F37A mutant, demonstrated to have reduced binding to Por1, shows reduced rescue of fMLP-induced chemotaxis. Finally, the Rac2Y40C mutant that is defective in binding to all three potential downstream effectors (Pak1, p67phox, and Por1) is unable to rescue chemotaxis, motility, or superoxide production, but is able to rescue defective growth of myeloid colonies in vitro. These findings suggest that binding to any single effector is not sufficient to rescue the distinct cellular phenotypes of Rac2−/− PMN, implicating multiple, distinct, and potentially parallel effector pathways.
Suppressive Effect of IL-4 on IL-13-Induced Genes in Mouse Lung
Authors: Finkelman Fred D. , Yang Mingyan , Perkins Charles , Schleifer Kathleen , Sproles Alyssa , Santeliz JoAnna , Bernstein Jonathan A. , Rothenberg Marc E. , Morris Suzanne C. , Wills-Karp Marsha
Published: April 2014

Although IL-4 signals through two receptors, IL-4Rα/common γ-chain (γc) and IL-4Rα/IL-13Rα1, and only the latter is also activated by IL-13, IL-13 contributes more than IL-4 to goblet cell hyperplasia and airway hyperresponsiveness in murine asthma. To determine whether unique gene induction by IL-13 might contribute to its greater proasthmatic effects, mice were inoculated intratracheally with IL-4 or IL-13, and pulmonary gene induction was compared by gene microarray and real-time PCR. Only the collagen α2 type VI (Ca2T6) gene and three small proline-rich protein (SPRR) genes were reproducibly induced >4-fold more by IL-13 than by IL-4. Preferential IL-13 gene induction was not attributable to B cells, T cells, or differences in cytokine potency. IL-4 signaling through IL-4Rα/γc suppresses Ca2T6 and SPRR gene expression in normal mice and induces these genes in RAG2/γc-deficient mice. Although IL-4, but not IL-13, induces IL-12 and IFN-γ, which suppress many effects of IL-4, IL-12 suppresses only the Ca2T6 gene, and IL-4-induced IFN-γ production does not suppress the Ca2T6 or SPRR genes. Thus, IL-4 induces genes in addition to IL-12 that suppress STAT6-mediated SPRR gene induction. These results provide a potential explanation for the dominant role of IL-13 in induction of goblet cell hyperplasia and airway hyperresponsiveness in asthma.
Tumor Vaccine Based on Cell Surface Expression of DcR3/TR6
Authors: Shi Guixiu , Mao Jianning , Yu Guang , Zhang Jun , Wu Jiangping
Published: April 2014

DcR3/TR6, a secreted protein belonging to the TNF receptor superfamily, interacts with lymphotoxin-like, exhibits inducible expression, and competes with herpes simplex virus glycoprotein D for herpes virus entrance mediator (LIGHT), Fas ligand (FasL), and TL1A, all members of the TNF superfamily. Solid-phase TR6 can trigger reverse signaling of LIGHT and FasL expressed on T cells, and lead to T cell costimulation. In this study, we engineered tumor cells to express cell surface TR6 and used these cells as a tumor vaccine. We demonstrated that mastocytoma P815 cells expressing surface TR6 (TR6-P815) effectively augmented the T cells response in vitro and ex vivo in terms of proliferation, as well as IL-2 and IFN-γ secretion. TR6-P815 cells had reduced tumorigenicity compared with parental P815 cells. When inactivated TR6-P815 cells were employed as a vaccine, they protected the mice from challenge with live parental P815 cells, and eliminated established P815 tumors. The cell surface TR6-based tumor vaccine was also effective against low antigenicity tumors, such as B16 melanoma; co-administration of bacillus Calmette-Guérin further enhanced the vaccine’s efficacy. Thus, cell surface TR6 expression is a useful addition to our tumor vaccine arsenal.
Surfactant Protein-D Regulates Soluble CD14 through Matrix Metalloproteinase-12
Authors: Senft Albert P. , Korfhagen Thomas R. , Whitsett Jeffrey A. , Shapiro Steven D. , LeVine Ann Marie
Published: April 2014

Surfactant protein D (SP-D) and CD14 are important innate immune defense molecules that mediate clearance of pathogens and apoptotic cells from the lung. To test whether CD14 expression and function were influenced by SP-D, the surface expression of CD14 was assessed on alveolar macrophages from SP-D−/− mice. CD14 was reduced on alveolar macrophages from SP-D−/− mice and was associated with reduced uptake of LPS and decreased production of TNF-α after LPS stimulation. CD14 is proteolytically cleaved from the cell surface to form a soluble peptide. Soluble CD14 (sCD14) was increased in the bronchoalveolar lavage fluid from SP-D−/− mice. Because matrix metalloproteinase (MMP)-9 and -12 activities were increased in the lungs of SP-D−/− mice, the role of these metalloproteases in the production of sCD14 was assessed. sCD14 was decreased in both MMP9−/−/SP-D−/− and MMP12−/−/SP-D−/− mice demonstrating MMP-9 and MMP-12 contribute to proteolytic shedding of CD14. The increased sCD14 seen in SP-D−/− mice was dependent upon the activation of MMP-12 via an MMP-9-dependent mechanism. Supporting this observation, MMP-12 caused the release of sCD14 from RAW 264.7 cells in vitro. In conclusion, SP-D influences innate host defense, in part, by regulating sCD14 in a process mediated by MMP-9 and MMP-12.
Early Establishment of γ-Herpesvirus Latency: Implications for Immune Control
Authors: Flaño Emilio , Jia Qingmei , Moore John , Woodland David L. , Sun Ren , Blackman Marcia A.
Published: April 2014

The human γ-herpesviruses, EBV and Kaposi’s sarcoma-associated herpesvirus, infect >90% of the population worldwide, and latent infection is associated with numerous malignancies. Rational vaccination and therapeutic strategies require an understanding of virus-host interactions during the initial asymptomatic infection. Primary EBV infection is associated with virus replication at epithelial sites and entry into the circulating B lymphocyte pool. The virus exploits the life cycle of the B cell and latency is maintained long term in resting memory B cells. In this study, using a murine γ-herpesvirus model, we demonstrate an early dominance of latent virus at the site of infection, with lung B cells harboring virus almost immediately after infection. These data reinforce the central role of the B cell not only in the later phase of infection, but early in the initial infection. Early inhibition of lytic replication does not impact the progression of the latent infection, and latency is established in lymphoid tissues following infection with a replication-deficient mutant virus. These data demonstrate that lytic viral replication is not a requirement for γ-herpesvirus latency in vivo and suggest that viral latency can be disseminated by cellular proliferation. These observations emphasize that prophylactic vaccination strategies must target latent γ-herpesvirus at the site of infection.
Leukotriene B4 Receptor-1 Is Essential for Allergen-Mediated Recruitment of CD8+ T Cells and Airway Hyperresponsiveness
Authors: Miyahara Nobuaki , Takeda Katsuyuki , Miyahara Satoko , Taube Christian , Joetham Anthony , Koya Toshiyuki , Matsubara Shigeki , Dakhama Azzeddine , Tager Andrew M. , Luster Andrew D. , Gelfand Erwin W.
Published: April 2014

Recent studies in both human and rodents have indicated that in addition to CD4+ T cells, CD8+ T cells play an important role in allergic inflammation. We previously demonstrated that allergen-sensitized and -challenged CD8-deficient (CD8−/−) mice develop significantly lower airway hyperresponsiveness (AHR), eosinophilic inflammation, and IL-13 levels in bronchoalveolar lavage fluid compared with wild-type mice, and that all these responses were restored by adoptive transfer of in vivo-primed CD8+ T cells or in vitro-generated effector CD8+ T cells (TEFF). Recently, leukotriene B4 and its high affinity receptor, BLT1, have been shown to mediate in vitro-generated TEFF recruitment into inflamed tissues. In this study we investigated whether BLT1 is essential for the development of CD8+ T cell-mediated allergic AHR and inflammation. Adoptive transfer of in vivo-primed BLT1+/+, but not BLT1−/−, CD8+ T cells into sensitized and challenged CD8−/− mice restored AHR, eosinophilic inflammation, and IL-13 levels. Moreover, when adoptively transferred into sensitized CD8−/− mice, in vitro-generated BLT1+/+, but not BLT1−/−, TEFF accumulated in the lung and mediated these altered airway responses to allergen challenge. These data are the first to show both a functional and an essential role for BLT1 in allergen-mediated CD8+ TEFF recruitment into the lung and development of AHR and airway inflammation.
Composition of the Lectin Pathway of Complement inGallus gallus: Absence of Mannan-Binding Lectin-Associated Serine Protease-1 in Birds
Authors: Lynch Nicholas J. , Khan Saeed-ul-Hassan , Stover Cordula M. , Sandrini Sara M. , Marston Denise , Presanis Julia S. , Schwaeble Wilhelm J.
Published: April 2014

The lectin pathway of complement is activated by multimolecular complexes that recognize and bind to microbial polysaccharides. These complexes comprise a multimeric carbohydrate recognition subunit (either mannan-binding lectin (MBL) or a ficolin), three MBL-associated serine proteases (MASP-1, -2, and -3), and MAp19 (a truncated product of the MASP-2 gene). In this study we report the cloning of chicken MASP-2, MASP-3, and MAp19 and the organization of their genes and those for chicken MBL and a novel ficolin. Mammals usually possess two MBL genes and two or three ficolin genes, but chickens have only one of each, both of which represent the undiversified ancestors of the mammalian genes. The primary structure of chicken MASP-2 is 54% identical with those of the human and mouse MASP-2, and the organization of its gene is the same as in mammals. MASP-3 is even more conserved; chicken MASP-3 shares ∼75% of its residues with human and Xenopus MASP-3. It is more widely expressed than other lectin pathway components, suggesting a possible function of MASP-3 different from those of the other components. In mammals, MASP-1 and MASP-3 are alternatively spliced products of a single structural gene. We demonstrate the absence of MASP-1 in birds, possibly caused by the loss of MASP-1-specific exons during phylogeny. Despite the lack of MASP-1-like enzymatic activity in sera of chicken and other birds, avian lectin pathway complexes efficiently activate C4.
Autoimmune Alterations Induced by the New Zealand BlackLbw2Locus in BWF1 Mice
Authors: Haraldsson Maria K. , dela Paz Nathanial G. , Kuan Jason G. , Gilkeson Gary S. , Theofilopoulos Argyrios N. , Kono Dwight H.
Published: April 2014

The New Zealand Black (NZB) Lbw2 locus (lupus NZB × New Zealand White (NZW) 2 locus) was previously linked to mortality and glomerulonephritis, but not to IgG autoantibodies, suggesting that it played a role in a later disease stage. To define its contribution, (NZB × NZW)F1 hybrids (BWF1) containing two, one, or no copies of this locus were generated. Lack of the NZB Lbw2 indeed reduced mortality and glomerulonephritis, but not serum levels of total and anti-DNA IgG Abs. There were, however, significant reductions in the B cell response to LPS, total and anti-DNA IgM and IgG Ab-forming cells, IgM Ab levels, and glomerular Ig deposits. Furthermore, although serum IgG autoantibody levels correlated poorly with kidney IgG deposits, the number of spontaneous IgG Ab-forming cells had a significant correlation. Genome-wide mapping of IgM anti-chromatin levels identified only Lbw2, and analysis of subinterval congenics tentatively reduced Lbw2 to ∼5 Mb. Because no known genes associated with B cell activation and lupus are in this interval, Lbw2 probably represents a novel B cell activation gene. These findings establish the importance of Lbw2 in the BWF1 hybrid and indicate that Lbw2, by enhancing B cell hyperactivity, promotes the early polyclonal activation of B cells and subsequent production of autoantibodies.
Bone Marrow Clonogenic Capability, Cytokine Production, and Thymic Output in Patients with Common Variable Immunodeficiency
Authors: Isgrò Antonella , Marziali Marco , Mezzaroma Ivano , Luzi Giuseppe , Mazzone Anna Maria , Guazzi Vanessa , Andolfi Grazia , Cassani Barbara , Aiuti Alessandro , Aiuti Fernando
Published: April 2014

In patients with primary Ab deficiencies, hematological and immunological abnormalities are frequently observed. A regenerative failure of hemopoietic stem/progenitor cells has been hypothesized. We evaluated in the bone marrow (BM) of 11 patients with common variable immunodeficiency, the phenotype of BM progenitors and their in vitro growth by colony-forming cell (CFC) and long-term culture (LTC) assays. A significant decrease in erythroid and mixed CFC and, to a greater extent, in primitive LTC-CFC progenitors was observed in patients compared with healthy controls. The frequency of BM pre-B and pro-B cells correlated directly with the absolute number of CD19+ lymphocytes. BM cells cultured in vitro produced spontaneously lower amounts of IL-2 and elevated levels of TNF-α compared with controls, indicating a skewing toward a proapoptotic cytokine pattern. In addition, stromal cells generated after BM LTC secreted less IL-7 and displayed by immunohistochemistry an altered phenotype. These findings were associated with a significant decrease in naive Th cells coexpressing CD31 in the peripheral blood. These results indicate an impaired growth and differentiation capacity of progenitor cells in patients with common variable immunodeficiency.
CCL1-CCR8 Interactions: An Axis Mediating the Recruitment of T Cells and Langerhans-Type Dendritic Cells to Sites of Atopic Skin Inflammation
Authors: Gombert Michael , Dieu-Nosjean Marie-Caroline , Winterberg Franziska , Bünemann Erich , Kubitza Robert C. , Da Cunha Ludivine , Haahtela Anna , Lehtimäki Sari , Müller Anja , Rieker Juliane , Meller Stephan , Pivarcsi Andor , Koreck Andrea , Fridman Wolf-Herman , Zentgraf Hans-Walter , Pavenstädt Hermann , Amara Ali , Caux Christophe , Kemeny Lajos , Alenius Harri , Lauerma Antti , Ruzicka Thomas , Zlotnik Albert , Homey Bernhard
Published: April 2014

Atopic dermatitis represents a chronically relapsing skin disease with a steadily increasing prevalence of 10–20% in children. Skin-infiltrating T cells, dendritic cells (DC), and mast cells are thought to play a crucial role in its pathogenesis. We report that the expression of the CC chemokine CCL1 (I-309) is significantly and selectively up-regulated in atopic dermatitis in comparison to psoriasis, cutaneous lupus erythematosus, or normal skin. CCL1 serum levels of atopic dermatitis patients are significantly higher than levels in healthy individuals. DC, mast cells, and dermal endothelial cells are abundant sources of CCL1 during atopic skin inflammation and allergen challenge, and Staphylococcus aureus-derived products induce its production. In vitro, binding and cross-linking of IgE on mast cells resulted in a significant up-regulation of this inflammatory chemokine. Its specific receptor, CCR8, is expressed on a small subset of circulating T cells and is abundantly expressed on interstitial DC, Langerhans cells generated in vitro, and their monocytic precursors. Although DC maintain their CCR8+ status during maturation, brief activation of circulating T cells recruits CCR8 from intracytoplamic stores to the cell surface. Moreover, the inflammatory and atopy-associated chemokine CCL1 synergizes with the homeostatic chemokine CXCL12 (SDF-1α) resulting in the recruitment of T cell and Langerhans cell-like DC. Taken together, these findings suggest that the axis CCL1-CCR8 links adaptive and innate immune functions that play a role in the initiation and amplification of atopic skin inflammation.
CD8α+ Dendritic Cells Selectively Present MHC Class I-Restricted Noncytolytic Viral and Intracellular Bacterial Antigens In Vivo
Authors: Belz Gabrielle T. , Shortman Ken , Bevan Michael J. , Heath William R.
Published: April 2014

CD8α+ dendritic cells (DCs) have been shown to be the principal DC subset involved in priming MHC class I-restricted CTL immunity to a variety of cytolytic viruses, including HSV type 1, influenza, and vaccinia virus. Whether priming of CTLs by CD8α+ DCs is limited to cytolytic viruses, which may provide dead cellular material for this DC subset, or whether these DCs selectively present intracellular Ags, is unknown. To address this question, we examined Ag presentation to a noncytolytic virus, lymphocytic choriomeningitis virus, and to an intracellular bacterium, Listeria monocytogenes. We show that regardless of the type of intracellular infection, CD8α+ DCs are the principal DC subset that initiate CD8+ T cell immunity.
Cutting Edge: B-1 Cells Are Deficient in Lck: Defective B Cell Receptor Signal Transduction in B-1 Cells Occurs in the Absence of Elevated Lck Expression
Authors: Francés Rubén , Tumang Joseph R. , Rothstein Thomas L.
Published: April 2014

B-1 cells constitute a unique B cell subset that is primarily responsible for producing nonimmune Ig. This natural Ig acts as a principal line of defense against infection. A key feature of B-1 cells is the failure of BCR-triggered signal transduction. Recently, defective BCR signaling in B-1 cells has been attributed to elevated expression of the canonical T cell src kinase, Lck. In the present study, we re-examined Lck expression in normal B-1 cells. We found that B-1 cells expressed less Lck at both the protein and RNA levels than did B-2 cells. The same B-1 cells manifested defective BCR-mediated induction of IKKβ phosphorylation, IκBα degradation, and intracellular Ca2+ mobilization. Thus, the failure of BCR signaling in B-1 cells does not relate to subset-specific elevation of Lck.
The CD3ε Proline-Rich Sequence, and Its Interaction with Nck, Is Not Required for T Cell Development and Function
Authors: Szymczak Andrea L. , Workman Creg J. , Gil Diana , Dilioglou Smaroula , Vignali Kate M. , Palmer Ed , Vignali Dario A. A.
Published: April 2014

The CD3ε proline-rich sequence (PRS) binds to the cytosolic adaptor molecule Nck after TCR ligation. It has been proposed that this interaction is essential for immunological synapse formation and T cell activation. To assess the physiological importance of the CD3ε PRS, we have generated mice that lack this motif (CD3ε.PRSM). Pull-down experiments demonstrated the inability of Nck to bind to the CD3ε PRS in thymocytes from mutant mice after TCR ligation. Surprisingly, no differences were observed in the number and percentage of T cell subsets in the thymus and spleen, and there was no apparent defect in positive or negative selection. Furthermore, the proliferative response of CD3ε.PRSM T cells to staphylococcal enterotoxin B and anti-CD3 Ab was normal. TCR surface expression, constitutive internalization, and Ag-induced down-modulation were also normal. These data suggest that the interaction between the CD3ε PRS and Nck, or any other Src homology 3 domain-containing molecule, is not essential for T cell development and function.
The Unique Region of Surrogate Light Chain Component λ5 Is a Heavy Chain-Specific Regulator of Precursor B Cell Receptor Signaling
Authors: Guloglu F. Betul , Bajor Ewa , Smith Brendan P. , Roman Christopher A. J.
Published: April 2014

Signals transduced by precursor-BCRs (pre-BCRs) composed of Ig μ heavy chains (HCs) and the surrogate L chain components λ5 and VpreB are critical for B cell development. A conserved unique region (UR) of λ5 was shown to activate pre-BCR complexes in transformed cells and to engage putative ligands, but its contribution to pre-B cell development is not known. It is also not clear why the λ-like sequences in λ5 are used to select HCs that will associate mainly with κ L chains. In this study, we show that, in transformed and primary mouse B cell progenitors, receptors containing full-length HCs and lacking the λ5UR were expressed at higher surface levels, but exhibited reduced activity compared with normal pre-BCRs in supporting developmental changes that accompany the progenitor to pre-B cell transition in primary cell culture systems and in the bone marrow in vivo. In contrast, deletion of the λ5UR did not change net signaling output by the Dμ-pre-BCR, a developmentally defective receptor that exhibited impaired activity in the primary cell culture system. Moreover, the λ-like sequences in λ5 were more accommodating than κ in supporting surface expression and signaling by the different HCs. These results show that the λ5UR is important, although not essential, for surrogate L chain-dependent receptor signaling in primary cells, and furthermore may help allow discrimination of signaling competency between normal and Dμ-pre-BCRs. That the λ-like portion of λ5 in the absence of the UR was nondiscriminatory suggests that the λ5UR focuses pre-BCR-dependent selection on the HC V region.
Cutting Edge: Low-Affinity, Smith Antigen-Specific B Cells Are Tolerized by Dendritic Cells and Macrophages
Authors: Kilmon Michelle A. , Rutan Jennifer A. , Clarke Stephen H. , Vilen Barbara J.
Published: April 2014

Polyclonal B cell activation promotes immunity without the loss of tolerance. Our data show that during activation of the innate immune system, B cell tolerance to Smith Ag Sm is maintained by dendritic cells (DCs) and macrophages (MΦ). TLR4-activated myeloid DCs and MΦ, but not plasmacytoid or lymphoid DCs, repressed autoreactive B cells through the secretion of soluble mediators, including IL-6. Although IL-6 promotes plasma cell differentiation of B cells acutely stimulated by Ag, we show that it repressed cells that were chronically exposed to self-Ag. This mechanism of tolerance was not limited to Smith Ag-specific B cells as hen egg lysozyme- and p-azophenylarsonate-specific B cells were similarly affected. Our data define a tolerogenic role for MΦ and DCs in regulating autoreactive B cells during activation of the innate immune system.
Mannose-Binding Lectin Is a Regulator of Inflammation That Accompanies Myocardial Ischemia and Reperfusion Injury
Authors: Walsh Mary C. , Bourcier Todd , Takahashi Kazue , Shi Lei , Busche Marc N. , Rother Russell P. , Solomon Scott D. , Ezekowitz R. Alan B. , Stahl Gregory L.
Published: April 2014

The mannose-binding lectin (MBL), a circulating pattern recognition molecule, recognizes a wide range of infectious agents with resultant initiation of the complement cascade in an Ab-independent manner. MBL recognizes infectious non-self and altered self in the guise of apoptotic and necrotic cells. In this study, we demonstrate that mice lacking MBL, and hence are devoid of MBL-dependent lectin pathway activation but have fully active alternative and classical complement pathways, are protected from cardiac reperfusion injury with resultant preservation of cardiac function. Significantly, mice that lack a major component of the classical complement pathway initiation complex (C1q) but have an intact MBL complement pathway, are not protected from injury. These results suggest that the MBL-dependent pathway of complement activation is a key regulator of myocardial reperfusion ischemic injury. MBL is an example of a pattern recognition molecule that plays a dual role in modifying inflammatory responses to sterile and infectious injury.
The Clinical Benefit of Adjunctive Dexamethasone in Tuberculous Meningitis Is Not Associated with Measurable Attenuation of Peripheral or Local Immune Responses
Authors: Simmons Cameron P. , Thwaites Guy E. , Quyen Nguyen Than Ha , Chau Tran Thi Hong , Mai Pham Phuong , Dung Nguyen Thi , Stepniewska Kasia , White Nicholas J. , Hien Tran Tinh , Farrar Jeremy
Published: April 2014

Outcome from tuberculous meningitis (TBM) is believed to be dependent on the severity of the intracerebral inflammatory response. We have recently shown that dexamethasone improved survival in adults with TBM and postulated that the clinical effect would be associated with a measurable systemic and intracerebral impact on immunological markers of inflammation. Prolonged inflammatory responses were detected in all TBM patients irrespective of treatment assignment (placebo or dexamethasone). The inflammatory response in the cerebrospinal fluid was characterized by a leukocytosis (predominantly CD3+CD4+ T lymphocytes, phenotypically distinct from those in the peripheral blood), elevated concentrations of inflammatory and anti-inflammatory cytokines, chemokines, and evidence of prolonged blood-brain barrier dysfunction. Dexamethasone significantly modulated acute cerebrospinal fluid protein concentrations and marginally reduced IFN-γ concentrations; other immunological and routine biochemical indices of inflammation were unaffected. Peripheral blood monocyte and T cell responses to Mycobacterium tuberculosis Ags were also unaffected. Dexamethasone does not appear to improve survival from TBM by attenuating immunological mediators of inflammation in the subarachnoid space or by suppressing peripheral T cell responses to mycobacterial Ags. These findings challenge previously held theories of corticosteroid action in this disease. An understanding of how dexamethasone acts in TBM may suggest novel and more effective treatment strategies.
Novel Protein and Poxvirus-Based Vaccine Combinations for Simultaneous Induction of Humoral and Cell-Mediated Immunity
Authors: Hutchings Claire L. , Gilbert Sarah C. , Hill Adrian V. S. , Moore Anne C.
Published: April 2014

The presence of both cell-mediated and humoral immunity is important in protection from and clearance of a number of infectious pathogens. We describe novel vaccine regimens using combinations of plasmid DNA, poxvirus and protein to induce strong Ag-specific T cell and Ab responses simultaneously in a murine model. Intramuscular (i.m.) immunization with plasmid DNA encoding the middle Ag of hepatitis B (DNA) concurrently with a commercial hepatitis B virus (HBV) vaccine (Engerix-B) followed by boosting immunizations with both modified vaccinia virus Ankara (MVA) encoding the middle Ag of HBV and Engerix-B induced high levels of CD4+ and CD8+ T cells and high titer Ab responses to hepatitis B surface Ag (HbsAg). Substitution of Engerix-B with adjuvant-free rHBsAg induced similar T cell responses and greatly enhanced Ab levels. Repeated immunizations with recombinant or nonrecombinant MVA mixed with Ag induced higher titers of Abs compared with immunization with either Ag or Engerix-B further demonstrating this novel adjuvant effect of MVA. The poxviruses NYVAC, fowlpox (FP9) and ALVAC, and to a lesser extent, adenovirus, also displayed similar adjuvant properties when used in combination with rHBsAg. The use of poxviruses as an adjuvant for protein to concurrently induce Ag-specific T cells and Abs could be applied to the development of vaccines for many diseases, including HIV and malaria, where both cell mediated and humoral immunity may be important for protection.
Treatment of Mice with 2,3,7,8-Tetrachlorodibenzo-p-Dioxin Leads to Aryl Hydrocarbon Receptor-Dependent Nuclear Translocation of NF-κB and Expression of Fas Ligand in Thymic Stromal Cells and Consequent Apoptosis in T Cells
Authors: Camacho Iris A. , Singh Narendra , Hegde Venkatesh L. , Nagarkatti Mitzi , Nagarkatti Prakash S.
Published: April 2014

We investigated the role of aryl hydrocarbon receptor (AhR) in the regulation of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced apoptosis in thymic T cells. AhR knockout (KO) mice were resistant to TCDD-induced thymic atrophy and apoptosis when compared with the AhR wild-type mice. TCDD triggered the expression of several apoptotic genes, including FasL in AhR wild-type but not AhRKO mice. TCDD-induced increase in FasL was seen only in thymic stromal but not thymic T cells. When TCDD-exposed stromal cells were mixed with untreated thymic T cells, increased apoptosis was detected in T cells that involved Fas-FasL interactions. Thus, apoptosis in T cells was not detected when TCDD-treated stromal cells from FasL-defective or AhRKO mice were mixed with wild-type T cells or when TCDD-exposed wild-type stromal cells were mixed with Fas-deficient T cells. TCDD treatment, in vivo and in vitro, led to colocalization and translocation of NF-κB subunits (p50, p65) to the nucleus in stromal but not T cells from AhR wild-type mice. NF-κB activation was not observed in stromal cells isolated from TCDD-treated AhRKO mice. Mutations in NF-κB-binding sites on the FasL promoter showed that TCDD regulates FasL promoter activity through NF-κB. TCDD treatment in vivo caused activation of the death receptor and mitochondrial pathways of apoptosis. Cross-talk between the two pathways was not necessary for apoptosis inasmuch as TCDD-treated Bid KO mice showed thymic atrophy and increased apoptosis, similar to the wild-type mice. These findings demonstrate that AhR regulates FasL and NF-κB in stromal cells, which in turn plays a critical role in initiating apoptosis in thymic T cells.
Essential Role of the MyD88 Pathway, but Nonessential Roles of TLRs 2, 4, and 9, in the Adjuvant Effect Promoting Th1-Mediated Autoimmunity
Authors: Su Shao Bo , Silver Phyllis B. , Grajewski Rafael S. , Agarwal Rajeev K. , Tang Jun , Chan Chi-Chao , Caspi Rachel R.
Published: April 2014

Induction of tissue-specific experimental autoimmune diseases involves an obligatory adjuvant effect to trigger an innate response of a type that will drive a Th1-biased adaptive response. This is achieved by use of CFA containing mycobacteria (Mycobacterium tuberculosis), whose recognition by cells of the innate immune system depends on TLRs that signal through the adaptor molecule MyD88. We examined the role of selected components of the MyD88 pathway in promoting experimental autoimmune uveitis (EAU). Mice deficient in MyD88, TLR2, TLR4, or TLR9 were immunized with the retinal Ag interphotoreceptor retinoid-binding protein in CFA, and their EAU scores and associated immunological responses were examined. MyD88−/− mice were completely resistant to EAU and had a profound defect in Th1, but not Th2, responses to autoantigen challenge. Surprisingly, TLR2−/−, TLR4−/−, and TLR9−/− mice were fully susceptible to EAU and had unaltered adaptive responses to interphotoreceptor retinoid-binding protein. Examination of IL-1R family members, which share the common adaptor MyD88 with the TLR family, revealed that IL-1R-deficient mice, but not IL-18-deficient mice, are resistant to EAU and have profoundly reduced Th1 and Th2 responses. These data are compatible with the interpretation that TLR9, TLR4, and TLR2 signaling is either not needed, or, more likely, redundant in the adjuvant effect needed to induce EAU. In contrast, signaling through the IL-1R plays a necessary and nonredundant role in EAU and can by itself account for the lack of EAU development in MyD88 mice.