bluuebunny/crossref_metadata_2025 huggingface dataset:
Fatty acid and triacylglycerol composition of the subcutaneous fat from iberian pigs fattened on the traditional feed: “Montanera”. effect of anatomical location and length of feeding
Authors: Narváez-Rivas Mónica , León-Camacho Manuel , Vicario Isabel M.
Published: May 2009

Fatty acid and triacylglycerol compositions of 200 samples of subcutaneous fat from two different anatomical locations (rump and adipose tissue covering the Biceps femoris muscle) of Iberian purebred pigs reared on “Montanera” were determined. Significant differences were found for the majority fatty acids and for some triacylglycerol species (PPS, PLPo + MLO, PLO, PLL + PoLO, SOS, SOL, OLL) among the two anatomical locations, being the rump location less saturated. The activity level of the key enzyme involved in lipogenesis differed (p < 0.0001) significantly between both tissues. The effect of campaign on the fatty acid and triacylglycerol composition was also explored. An increase on the ratio oleic/stearic has been found in campaigns with low resources. This indicates an increase on the activity of Stearoyl-CoA desaturase. Besides, the differences found between both subcutaneous fats during the fattening period indicates that the unsaturation of the subcutaneous fat covering a muscle with high oxidative metabolism, as Biceps femoris, increases faster than that of the subcutaneous fat covering a muscle with low oxidative metabolism, as Longissimus dorsi.
Classification of real farm conditions Iberian pigs according to the feeding regime with multivariate models developed by using fatty acids composition or NIR spectral data
Authors: García-Olmo Juan , Garrido-Varo Ana , De Pedro Emiliano
Published: May 2009

Multivariate Classification models to classify real farm conditions Iberian pigs, according to the feeding regime were developed by using fatty acids composition or NIR spectral data of liquid fat samples. A total of 121 subcutaneous fat samples were taken from Iberian pigs carcasses belonging to 5 batches reared under different feeding systems. Once the liquid sample was extracted from each subcutaneous fat sample, it was determined the percentage of 11 fatty acids (C14:0, C16:0, C16:1, C17:0, C17:1, C18:0, C18:1, C18:2, C18:3, C20:0 and C20:1). At the same time, Near Infrared (NIR) spectrum of each liquid sample was obtained. Linear Discriminant Analysis (LDA) was considered as pattern recognition method to develop the multivariate models. Classification errors of the LDA models generated by using NIR spectral data were 0.0% and 1.7% for the model generated by using fatty acids composition. Results confirm the possibility to discriminate Iberian pig liquid samples from animals reared under different feeding regimes on real farm conditions by using NIR spectral data or fatty acids composition. Classification error obtained using models generated from NIR spectral data were lower than those obtained in models based on fatty acids composition.
Lipolytic and oxidative changes during the manufacture of dry-cured lacón. Effect of the time of salting
Authors: Garrido Rubén , Gómez María , Franco Inmaculada , Carballo Javier
Published: May 2009

The acidity, peroxide and TBA values were determined, both in the subcutaneous fat and in the muscular portion fat (fat extracted from the muscular portion minced and homogenised after discarding the subcutaneous fat), or in the whole muscular portion (fat + lean tissue) in the case of the TBA values, throughout the manufacture process of drycured lacón, a traditional dry-salted and ripened meat product made in the north-west of Spain from the foreleg of the pig following a similar technological process to that of dry-cured ham. The effect of the time of salting (3, 4 or 5 days) on these parameters was also studied. Throughout the manufacture, the acidity, the peroxide and the TBA values significantly (p < 0.001) increased in all the batches studied and both in the subcutaneous fat and in the muscular portion fat or muscular portion. The increasing of the salting time, despite the fact that did not significantly increase the NaCl contents in the pieces at the end of the manufacture process, significantly (p < 0.001) increased the peroxide values throughout the manufacture process both in the subcutaneous and in the muscular portion fat. At the end of the manufacture process, the TBA values also were significantly (p < 0.001) higher in the more intensely salted batches. The increasing of the salting time seems, in general, to have a inhibitory effect on the lipolytic phenomena; however, this effect was not consistent in all the sampling times in the batches studied.
Relevance of nitrate and nitrite in dry-cured ham and their effects on aroma development
Authors: Toldrá Fidel , Aristoy M-Concepción , Flores Mónica
Published: May 2009

Potassium and sodium salts of nitrite (E 249 and E 250) and nitrate (E 251 and E 252) are authorised for use under certain levels in several foodstuffs such as non-heat-treated, cured and dried meat products, other cured meat products, canned meat products and bacon. The key point in the use of nitrate and nitrite as preservatives is to find a balance between ensuring the microbiological safety of the ham and keeping as low as possible the level of nitrosamines in the final product. Nitrites and nitrates are authorised as additives for dry-cured ham in the Directive 2006/52/EC of 5 July 2006 that modifies previous Council Directive 95/2/EC on food additives other than colours and sweeteners. The effect of nitrate and its reduction to nitrite in controlling the lipid oxidation process during the ham ripening is very important for the development of the characteristic cured flavour. The main benefits and drawbacks of the use of nitrites and nitrates in dry-cured ham and how these levels may affect its flavour are discussed in this manuscript.
Contributing to interpret sensory attributes qualifying Iberian hams from the volatile profile
Authors: García-González Diego L. , Tena Noelia , Aparicio Ramón
Published: May 2009

The study involved the sensory assessment of 8 Iberian hams from the main producer zones and the analysis of their volatile composition by SPME-GC. The latter analysis was carried out independently on 4 well defined locations of the ham (subcutaneous fat, and biceps femoris, semitendinosus, and semimembranosus muscles) in order to know their possible partial contribution to the whole ham aroma. The relation between volatile compounds and sensory attributes was established by the procedure of statistical sensory wheel (SSW), generating 4 different plots, each one of them referring to one of the ham locations. The volatile compounds explain similar information of the sensory attributes independently of the part of the ham from which they are produced although the volatiles quantified in semitendinosus muscle and subcutaneous fat seem to contribute slightly more than the other parts to the sensory profile determined by the panellists.Volatiles compounds with significance in the ham aroma were 3-methylbutanol, hexanal, octanol, nonanol, 2- heptanol, among many others, although their contribution to the aroma varies depending on the location.
Dry cured ham quality as related to lipid quality of raw material and lipid changes during processing: a review.
Authors: Gilles Gandemer
Published: May 2009

Lipids play a key role in sensory traits of dry cured hams. Both the quantity and the composition of lipids in raw material affect dry-cured hams quality. The lipid characteristics strongly depend on rearing systems developed in different area in Europe. During processing, lipids undergo lipolysis and oxidation. Phospholipids are the main substrates of both lipolysis and oxidation. Lipolysis forms free fatty acids rich in polyunsaturated fatty acids all along the process. Lipids are also subjected to oxidation which forms many volatile compounds. These volatiles affect in the aroma of dry-cured hams and are associated with aroma notes such as rancid, aged meat or dry-cured. According to the genotype and the rearing conditions of pigs and the parameters of processing, dry-cured hams have specific sensory profiles. This paper reviews the present knowledge on lipids and dry-cured ham quality.
RANK-RANKL Signaling Pathway Is Critically Involved in the Function of CD4+CD25+ Regulatory T Cells in Chronic Colitis
Authors: Totsuka Teruji , Kanai Takanori , Nemoto Yasuhiro , Tomita Takayuki , Okamoto Ryuichi , Tsuchiya Kiichiro , Nakamura Tetsuya , Sakamoto Naoya , Akiba Hisaya , Okumura Ko , Yagita Hideo , Watanabe Mamoru
Published: May 2009

It is now clear that functional CD4+CD25+ regulatory T (TR) cells exist as part of the normal immune population and prevent the development of intestinal inflammation. We have recently shown that CD4+CD25+ TR cells reside in the intestine and control intestinal homeostasis in humans and mice. In this study, we demonstrate that the TNF family molecule RANKL and its receptor RANK are critically involved in controlling the function of CD4+CD25+ TR cells in the intestine. We first found that RANKL was preferentially expressed on both CD4+CD25+ TR cells and colitogenic CD4+ T cells, whereas RANK was expressed on dendritic cells. Although neutralizing anti-RANKL mAb did not affect TR activity of CD4+CD25+ TR cells to suppress the proliferation of CD4+ responder cells in vitro, in vivo administration of anti-RANKL mAb abrogated CD4+CD25+ TR cell-mediated suppression of colitis induced by adoptive transfer of CD4+CD45RBhigh T cells into SCID mice. Interestingly, an adoptive transfer experiment using Ly5.1+CD4+CD45RBhigh cells and Ly5.2+CD4+CD25+ TR cells revealed that the ratio of CD4+CD25+ TR cells in total CD4+ T cells in inflamed mucosa was significantly decreased by anti-RANKL mAb treatment. Consistent with this, the expression of RANK on lamina propria CD11c+ cells from colitic mice was significantly increased as compared with that from normal mice, and in vitro treatment with anti-RANKL mAb suppressed the expansion of CD4+Foxp3+ TR cells in culture with colitic lamina propria CD11c+ cells. Together, these results suggest that the RANK-RANKL signaling pathway is critically involved in regulating the function of CD4+CD25+ TR cells in colitis.
Protein Kinase Cθ Focusing at the cSMAC Is a Consequence rather than Cause of TCR Signaling and Is Dependent on the MEK/ERK Pathway
Authors: Praveen Kesavannair , Zheng Yan , Rivas Fabiola , Gajewski Thomas F.
Published: May 2009

Correlation between protein kinase Cθ focusing within the central supramolecular activation cluster (cSMAC) of the immunological synapse and optimal TCR/costimulatory receptor ligation was interpreted to imply that PKCθ focusing is required for productive signaling. However, this notion has been called into question and competing data suggest that the cSMAC contributes to receptor down-modulation. The observation that PKCθ focusing at the cSMAC is promoted by CD28 coligation, and also that it occurs late after proximal tyrosine phosphorylation events have been initiated, has led us to investigate an alternative possibility that PKCθ focusing might be a consequence rather than a cause of productive integrated signaling. Indeed, we found that inhibition of the downstream signaling molecules MEK and PI3K (but not of calcineurin, NF-κB, JNK, or p38 MAPK) significantly prevented the focusing of PKCθ at the cSMAC. It recently has been suggested that the cSMAC may be associated with TCR degradation and signal termination. Using MEK inhibition as a tool, we observed that absence of detectable PKCθ focusing had no significant effect on TCR down-modulation or duration of CD3ζ phosphorylation. Our results suggest that PKCθ focusing at the cSMAC occurs as a consequence of productive integrated downstream signaling at least at the level of MEK. If PKCθ focusing accurately reflects the cSMAC as a whole, then our data also argue against the cSMAC as being required for proximal TCR signal termination.
Proteasome Regulation of ULBP1 Transcription
Authors: Butler James E. , Moore Mikel B. , Presnell Steven R. , Chan Huei-Wei , Chalupny N. Jan , Lutz Charles T.
Published: May 2009

Killer lymphocytes recognize stress-activated NKG2D ligands on tumors. We examined NKG2D ligand expression in head and neck squamous cell carcinoma (HNSCC) cells and other cell lines. HNSCC cells typically expressed MHC class I chain-related gene A (MICA), MICB, UL16-binding protein (ULBP)2, and ULBP3, but they were uniformly negative for cell surface ULBP1 and ULBP4. We then studied how cancer treatments affected NKG2D ligand expression. NKG2D ligand expression was not changed by most cancer-relevant treatments. However, bortezomib and other proteasome inhibitor drugs with distinct mechanisms of action dramatically and specifically up-regulated HNSCC ULBP1 mRNA and cell surface protein. Proteasome inhibition also increased RNA for ULBP1 and other NKG2D ligands in nontransformed human keratinocytes. Proteasome inhibitor drugs increased ULBP1 transcription by acting at a site in the 522-bp ULBP1 promoter. Although the DNA damage response pathways mediated by ATM (ataxia-telangiectasia, mutated) and ATR (ATM and Rad3-related) signaling had been reported to up-regulate NKG2D ligand expression, we found that ULBP1 up-regulation was not inhibited by caffeine and wortmannin, inhibitors of ATM/ATR signaling. ULBP1 expression in HNSCC cells was not increased by several ATM/ATR activating treatments, including bleomycin, cisplatin, aphidicolin, and hydroxyurea. Ionizing radiation caused ATM activation in HNSCC cells, but high-level ULBP1 expression was not induced by gamma radiation or UV radiation. Thus, ATM/ATR signaling was neither necessary nor sufficient for high-level ULBP1 expression in human HNSCC cell lines and could not account for the proteasome effect. The selective induction of ULBP1 expression by proteasome inhibitor drugs, along with variable NKG2D ligand expression by human tumor cells, indicates that NKG2D ligand genes are independently regulated.
IgE-FcεRI Interactions Determine HIV Coreceptor Usage and Susceptibility to Infection during Ontogeny of Mast Cells
Authors: Sundstrom J. Bruce , Hair Gregory A. , Ansari Aftab A. , Secor W. Evan , Gilfillan Alasdair M. , Metcalfe Dean D. , Kirshenbaum Arnold S.
Published: May 2009

Progenitor mast cells (prMCs), derived from CD34+ precursors are CD4+/CCR5+/CXCR4+ and susceptible to CCR5(R5)-tropic virus but only marginally susceptible to CXCR4(X4)-tropic HIV. As infected prMCs mature within extravascular compartments, they become both latently infected and HIV-infection resistant, and thus capable of establishing an inducible reservoir of CCR5-tropic infectious clones. In this report we provide the first evidence that IgE-FcεRI interactions, occurring during a unique period of mast cell (MC) ontogeny, enhance prMC susceptibility to X4 and R5X4 virus. IgE-FcεRI interactions significantly increased expression of CXCR4 mRNA (∼400- to 1800-fold), enhanced prMC susceptibility to X4 and R5X4 virus (∼3000- to 16,000-fold), but had no significant effect on CD4, CCR3, or CCR5 expression, susceptibility to R5 virus, or degranulation. Enhanced susceptibility to infection with X4 virus occurred during the first 3–5 wk of MC ontogeny and was completely inhibited by CXCR4-specific peptide antagonists and omalizumab, a drug that inhibits IgE-FcεRI interactions. IgE-FcεRI coaggregation mediated by HIVgp120 or Schistosoma mansoni soluble egg Ag accelerated maximal CXCR4 expression and susceptibility to X4 virus by prMCs. Our findings suggest that for HIV-positive individuals with atopic or helminthic diseases, elevated IgE levels could potentially influence the composition of CXCR4-tropic and R5X4-tropic variants archived within the long-lived tissue MC reservoir created during infection.
Novel Human Transitional B Cell Populations Revealed by B Cell Depletion Therapy
Authors: Palanichamy Arumugam , Barnard Jennifer , Zheng Bo , Owen Teresa , Quach Tam , Wei Chungwen , Looney R. John , Sanz Iñaki , Anolik Jennifer H.
Published: May 2009

Transitional cells represent a crucial step in the differentiation and selection of the mature B cell compartment. Human transitional B cells have previously been variably identified based on the high level of expression of CD10, CD24, and CD38 relative to mature B cell populations and are expanded in the peripheral blood following rituximab-induced B cell-depletion at reconstitution. In this study, we take advantage of the gradual acquisition of the ABCB1 transporter during B cell maturation to delineate refined subsets of transitional B cells, including a late transitional B cell subset with a phenotype intermediate between T2 and mature naive. This late transitional subset appears temporally following the T1 and T2 populations in the peripheral compartment after rituximab-induced B cell reconstitution (and is thus termed T3) and is more abundant in normal peripheral blood than T1 and T2 cells. The identity of this subset as a developmental intermediate between early transitional and mature naive B cells was further supported by its ability to differentiate to naive during in vitro culture. Later transitional B cells, including T2 and T3, are found at comparatively increased frequencies in cord blood and spleen but were relatively rare in bone marrow. Additional studies demonstrate that transitional B cells mature across a developmental continuum with gradual up-regulation of mature markers, concomitant loss of immature markers, and increased responsiveness to BCR cross-linking in terms of proliferation, calcium flux, and survival. The characterization of multiple transitional B cell subpopulations provides important insights into human B cell development.
A Programmed Switch from IL-15- to IL-2-Dependent Activation in Human NK Cells
Authors: Pillet Anne-Hélène , Bugault Florence , Thèze Jacques , Chakrabarti Lisa A. , Rose Thierry
Published: May 2009

IL-2 and IL-15 differentially control the development, activation and proliferation of human NK cells, although they share common signal-transducing receptor chains CD122 and common γ. To explore this issue, we analyzed in detail the kinetics of cytokine receptor expression, cytokine binding, and signaling responses in human NK cells treated with common γ-chain family cytokines. We provide evidence for the sequential expression of IL-15Rα and IL-2Rα at the surface of cytokine-stimulated human NK cells, independent of the cytokine used for stimulation (IL-2, IL-15, or IL-7). Binding experiments confirmed the switch of high-affinity receptor from IL-15R to IL-2R between 18 and 48 h after stimulation. Consequently, phospho-STAT5 signaling responses to IL-15 were efficient in human NK cells pretreated with cytokines for 18 h, but were abolished at 48 h. Functional NK cell responses to IL-15, including IFN-γ secretion and CD107a expression, followed a similar pattern, indicating the physiological relevance of the cytokine receptor switch. Importantly, IL-15 complexed to soluble IL-15Rα preserved the capacity to activate cytokine-stimulated human NK cells at 48 h, suggesting that human NK cells remained competent for IL-15 trans-presentation, while they had become refractory to free diffusible IL-15. These findings define a common cytokine receptor expression program, which increases human NK cell sensitivity to free IL-15 in early activation and redirects responses toward IL-2 and trans-presented IL-15 at later stages. Such a program may prevent excessive human NK cell activation by effectors of innate immunity and regulate the transition between the innate and adaptive stages of immune responses.
Central Memory CD8+ T Cells Induce Graft-versus-Host Disease and Mediate Graft-versus-Leukemia
Authors: Zheng Hong , Matte-Martone Catherine , Jain Dhanpat , McNiff Jennifer , Shlomchik Warren D.
Published: May 2009

In allogeneic hemopoietic stem cell transplantation, mature donor αβ T cells in the allograft promote T cell reconstitution in the recipient and mediate the graft-vs-leukemia (GVL) effect. Unfortunately, donor T cells can attack nonmalignant host tissues and cause graft-vs-host disease (GVHD). It has previously been shown that effector memory T cells not primed to alloantigen do not cause GVHD yet transfer functional T cell memory and mediate GVL. Recently, central memory T cells (TCM) have also been reported to not cause GVHD. In contrast, in this study, we demonstrate that purified CD8+ TCM not specifically primed to alloantigens mediate GVHD in the MHC-mismatched C57BL/6 (B6)→BALB/c and the MHC-matched, multiple minor histocompatibility Ag-mismatched C3H.SW→B6 strain pairings. CD8+ TCM and naive T cells (TN) caused similar histological disease in liver, skin, and bowel. B6 CD8+ TCM and TN similarly expanded in BALB/c recipients, and the majority of their progeny produced IFN-γ upon restimulation. However, in both models, CD8+ TCM induced milder clinical GVHD than did CD8+ TN. Nonetheless, CD8+ TCM and TN were similarly potent mediators of GVL against a mouse model of chronic-phase chronic myelogenous leukemia. Thus, in contrast to what was previously thought, CD8+ TCM are capable of inducing GVHD and are substantially different from TEM but only subtly so from TN.
Role of Marginal Zone B Lymphocytes in Invariant NKT Cell Activation
Authors: Bialecki Emilie , Paget Christophe , Fontaine Josette , Capron Monique , Trottein François , Faveeuw Christelle
Published: May 2009

Splenic marginal zone B (MZB) lymphocytes represent, along with dendritic cells (DC) a first line of defense against blood-borne pathogens. MZB cells express high levels of MHC class II and CD1d molecules but so far their ability to activate and orientate conventional and innate-like T lymphocytes, such as invariant NKT (iNKT) cells, is still elusive. In the present study, we show that murine MZB cells proliferate, mature phenotypically, and secrete cytokines in response to TLR (except TLR3) agonists. When pulsed with OVA peptide (but not whole OVA), MZB cells promote the release of IFN-γ and IL-4 by Ag-specific CD4+ T lymphocytes and their stimulation with the TLR9 agonist CpG oligodeoxynucleotide (ODN), a potent MZB cell activator, biases them toward more Th1 inducers. Unlike DC, CpG ODN-stimulated MZB cells fail to stimulate iNKT cells. Although able to activate iNKT hybridomas, MZB cells sensitized with free α-galactosylceramide (α-GalCer), a CD1d-restricted glycolipid Ag, do not directly activate ex vivo sorted iNKT cells unless DC are added to the culture system. Interestingly, MZB cells amplify the DC-mediated activation of iNKT cells and depletion of MZB cells from total splenocytes strongly reduces iNKT cell activation (cytokine production) in response to α-GalCer. Thus, DC and MZB cells provide help to each other to optimize iNKT cell stimulation. Finally, in vivo transfer of α-GalCer-loaded MZB cells potently activates iNKT and NK cells. This study confirms and extends the concept that MZB cells are important players in immune responses, a property that might be exploited.
Neonatal Exposure to Low-Dose 2,3,7,8-Tetrachlorodibenzo-p-Dioxin Causes Autoimmunity Due to the Disruption of T Cell Tolerance
Authors: Ishimaru Naozumi , Takagi Atsuya , Kohashi Masayuki , Yamada Akiko , Arakaki Rieko , Kanno Jun , Hayashi Yoshio
Published: May 2009

Although 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been shown to influence immune responses, the effects of low-dose TCDD on the development of autoimmunity are unclear. In this study, using NFS/sld mice as a model for human Sjögren’s syndrome, in which the lesions are induced by the thymectomy on day 3 after birth, the autoimmune lesions in the salivary glands, and in later phase, inflammatory cell infiltrations in the other organs were developed by neonatal exposure to nonapoptotic dosage of TCDD without thymectomy on day 3 after birth. We found disruption of thymic selection, but not thymic atrophy, in TCDD-administered mice. The endogenous expression of aryl hydrocarbon receptor in the neonatal thymus was significantly higher than that in the adult thymus, suggesting that the neonatal thymus may be much more sensitive to TCDD compared with the adult thymus. In addition, the production of TH1 cytokines such as IL-2 and IFN-γ from splenic CD4+ T cells and the autoantibodies relevant for Sjögren’s syndrome in the sera from TCDD-exposed mice were significantly increased compared with those in control mice. These results suggest that TCDD/aryl hydrocarbon receptor signaling in the neonatal thymus plays an important role in the early thymic differentiation related to autoimmunity.
Hypoxia-Inducible Factor (HIF) 1α Accumulation and HIF Target Gene Expression Are Impaired after Induction of Endotoxin Tolerance
Authors: Frede Stilla , Stockmann Christian , Winning Sandra , Freitag Patricia , Fandrey Joachim
Published: May 2009

The oxygen-sensitive transcription factor hypoxia-inducible factor 1 (HIF-1) is known as the key regulator of hypoxia-induced gene expression. In addition to hypoxia, endotoxins such as bacterial LPS as well as proinflammatory cytokines have been shown to induce HIF-1, suggesting an integrative role for HIF-1 in conditions of hypoxia and inflammation. Cells can become tolerant to endotoxins by repetitive exposure to LPS. Herein, we studied the effect of endotoxin tolerance on HIF-1α accumulation and expression of HIF target genes in human monocytic cells and primary mouse peritoneal macrophages. Tolerant cells had reduced levels of HIF-1α under hypoxia, which was due to lowered levels of HIF-1α mRNA. HIF-1α expression is under control of NF-κB and increased DNA binding of the p52 subunit of NF-κB was found in tolerant cells. Knock down of p52 abolished the effects of endotoxin tolerance on HIF-1α expression, which suggest a negative regulatory role of p52 on HIF-1α transcription during endotoxin tolerance. Endotoxin tolerant cells showed diminished expression of the HIF target genes phosphoglycerate kinase 1 and adrenomedullin and reduced viability under hypoxic conditions, as well as a significantly reduced invasion. Peritoneal macrophages from endotoxin-tolerant mice made showed significantly reduced HIF-1α protein accumulation and subsequent HIF target gene expression. We conclude that endotoxin tolerance impairs HIF-1α induction which reduces the ability of monocytic cells to survive and function under hypoxic conditions.
Withdrawal of Sex Steroids Reverses Age- and Chemotherapy-Related Defects in Bone Marrow Lymphopoiesis
Authors: Dudakov Jarrod A. , Goldberg Gabrielle L. , Reiseger Jessica J. , Chidgey Ann P. , Boyd Richard L.
Published: May 2009

A significant decline in immune function is characteristic of aging. Along with the involution of the thymus and associated impaired architecture, which contributes to profound loss of naive T cell production, there are also significant declines in B cell development and the progenitors that support lymphopoiesis. These collectively lead to a reduced peripheral immune repertoire, increase in opportunistic infections, and limited recovery following cytoablation through chemo- or radiotherapy. We have previously shown that sex steroid ablation (SSA) causes a major reversal of age-related thymic atrophy and improves recovery from hematopoietic stem cell transplant. This study focused on the impact of SSA on the B cell compartment and their progenitors in middle-aged and cyclophosphamide-treated mice. In both models, SSA enhanced the number of lymphoid progenitors and developing B cells in the bone marrow (BM) as well as reversing age-related defects in the cycling kinetics of these cells. Enhanced BM lymphopoiesis was reflected in the periphery by an increase in recent BM emigrants as well as immature and mature plasma cells, leading to an enhanced humoral response to challenge by hepatitis B vaccine. In conclusion, SSA improves lymphoid progenitor and B cell recovery from age- and chemotherapy-induced immunodepletion, complimenting the effects on T cells. Since SSA has been achieved clinically for over 25 years, this provides a novel, rational basis for approaching the need for immune recovery in many clinical conditions.
Histone Deacetylases Inhibit IFN-γ-Inducible Gene Expression in Mouse Trophoblast Cells
Authors: Choi Jason C. , Holtz Renae , Murphy Shawn P.
Published: May 2009

Trophoblast cells are the first cells to differentiate from the developing mammalian embryo, and they subsequently form the blastocyst-derived component of the placenta. IFN-γ plays critical roles in activating innate and adaptive immunity, as well as apoptosis. In mice, IFN-γ is produced in the pregnant uterus, and is essential for formation of the decidual layer of the placenta and remodeling of the uterine vasculature. Responses of mouse trophoblast cells to IFN-γ appear to be selective, for IFN-γ activates MHC class I expression and enhances phagocytosis, but fails to activate either MHC class II expression or apoptosis in these cells. To investigate the molecular basis for the selective IFN-γ responsiveness of mouse trophoblast cells, IFN-γ-inducible gene expression was examined in the trophoblast cell lines SM9 and M-11, trophoblast stem cells, and trophoblast stem cell-derived giant cells. IFN-γ-inducible expression of multiple genes, including IFN regulatory factor-1 (IRF-1), was significantly reduced in trophoblast cells compared with fibroblast cells. Decreased IRF-1 mRNA expression in trophoblast cells was due to a reduced rate of IRF-1 transcription relative to fibroblast cells. However, no impairment of STAT-1 tyrosine phosphorylation or DNA-binding capacity was observed in IFN-γ-treated mouse trophoblast cells. Importantly, histone deacetylase (HDAC) inhibitors significantly enhanced IFN-γ-inducible gene expression in trophoblast cells, but not fibroblasts. Our collective studies demonstrate that IFN-γ-inducible gene expression is repressed in mouse trophoblast cells by HDACs. We propose that HDAC-mediated inhibition of IFN-γ-inducible gene expression in mouse trophoblast cells may contribute to successful pregnancy by preventing activation of IFN-γ responses that might otherwise facilitate the destruction of the placenta.
IL-31-IL-31R Interactions Limit the Magnitude of Th2 Cytokine-Dependent Immunity and Inflammation following Intestinal Helminth Infection
Authors: Perrigoue Jacqueline G. , Zaph Colby , Guild Katherine , Du Yurong , Artis David
Published: May 2009

IL-31 is a recently identified cytokine made predominantly by CD4+ Th2 cells and its receptor, IL-31R, is expressed by a number of cell types including monocytes, epithelial cells, and T cells. Originally identified as a potential mediator of inflammation in the skin, we recently reported a novel function for endogenous IL-31R interactions in limiting type 2 inflammation in the lung. However, whether IL-31-IL-31R interactions regulate immunity or inflammation at other mucosal sites, such as the gut, is unknown. In this study, we report a regulatory role for IL-31-IL-31R interactions in the intestine following infection with the gastrointestinal helminth Trichuris muris, immunity to which is critically dependent on CD4+ Th2 cells that produce IL-4 and IL-13. IL-31Rα was constitutively expressed in the colon and exposure to Trichuris induced the expression of IL-31 in CD4+ T cells. In response to Trichuris infection, IL-31Rα−/− mice exhibited increased Th2 cytokine responses in the mesenteric lymph nodes and elevated serum IgE and IgG1 levels compared with wild type mice. IL-31Rα−/− mice also displayed enhanced goblet cell hyperplasia and a marked increase in secretion of goblet cell-derived resistin-like molecule β into the intestinal lumen. Consistent with their exacerbated type 2 inflammatory responses, IL-31Rα−/− mice exhibited accelerated expulsion of Trichuris with significantly decreased worm burdens compared with their wild type counterparts early following infection. Collectively, these data provide the first evidence of a function for IL-31-IL-31R interactions in limiting the magnitude of type 2 inflammatory responses within the intestine.
Impaired Priming and Activation of the Neutrophil NADPH Oxidase in Patients with IRAK4 or NEMO Deficiency
Authors: Singh Anjali , Zarember Kol A. , Kuhns Douglas B. , Gallin John I.
Published: May 2009

The NADPH oxidase (NOX), an oligomeric enzyme, plays a key role in polymorphonuclear neutrophil (PMN)-mediated host defense by producing cytotoxic superoxide anion (O2). Whereas in vitro and biochemical studies have examined the assembly and activation of this important host immune defense system, few studies have examined the function of NOX in human patients with primary immunodeficiency other than chronic granulomatous disease. We studied the activation of NOX in PMN from patients with two distinct immunodeficiencies, IL-1R-associated kinase (IRAK)4 deficiency and NF-κB essential modulator (NEMO or IκB kinase γ) deficiency. We observed impaired O2 generation by LPS-treated and fMLP-activated IRAK4-deficient PMN that correlated with decreased phosphorylation of p47phox and subnormal translocation of p47phox, p67phox, Rac2, and gp91phox/Nox2 to the membranes indicating that TLR4 signaling to the NOX activation pathway requires IRAK4. NEMO-deficient PMN generated significantly less O2 in response to LPS-primed fMLP and translocated less p67phox than normal PMN, although p47phox and Rac2 translocation were normal. Generally, responses of NEMO-deficient cells were intermediate between IRAK4-deficient cells and normal cells. Decreased LPS- and fMLP-induced phosphorylation of p38 MAPK in both IRAK4- and NEMO-deficient PMN implicates additional signal transduction pathways in regulating PMN activation by LPS and fMLP. Decreased activation of NOX may contribute to the increased risk of infection seen in patients with IRAK4 and NEMO deficiency.
Lack of Functional P-Selectin Ligand Exacerbates Salmonella Serovar Typhimurium Infection
Authors: Kum Winnie W. S. , Lee Sansan , Grassl Guntram A. , Bidshahri Roza , Hsu Kimberly , Ziltener Hermann J. , Finlay B. Brett
Published: May 2009

The selectin family of adhesion molecules mediates the recruitment of immune cells to the site of inflammation, which is critical for host survival of infection. To characterize the role of selectins in host defense against Salmonella Typhimurium infection, wild-type (WT) mice and mice lacking P-selectin glycoprotein ligand-1 (PSGL-1), P-, E-, or L-selectin, or the glycosyltransferase C2GlcNAcT-I (core 2) were infected using a Salmonella acute gastroenteritis model. Mice were monitored for survival and assessed for intestinal inflammation at 1 and 4 days postinfection. Infected mice lacking core 2, PSGL-1, or P-selectin showed a more pronounced morbidity and a significantly higher mortality rate associated with higher bacterial load and proinflammatory cytokine production, including that of TNF-α, MCP-1, and IL-6, from the colons at 4 days postinfection as compared with WT control. Surprisingly, at 1 day postinfection, more severe inflammation and higher neutrophil infiltration were observed in the ceca of mice lacking core 2, PSGL-1, or P-selectin compared with WT control. Enhanced levels of α4β7+ and MAdCAM-1+ cells were observed in the ceca of infected mice lacking core 2, PSGL-1, or P-selectin. Neutrophil recruitment, cecal inflammation, and mortality rates were dramatically reduced in infected P-selectin knockout mice receiving blocking mAb to α4β7 integrin, indicating that this alternative adhesion molecule may attempt to compensate for the loss of selectins in neutrophil recruitment. These results demonstrate a definitive phenotypic abnormality in mice lacking core 2, PSGL-1, or P-selectin, suggesting that the interaction of functional PSGL-1 with P-selectin is an important process in host defense against Salmonella infection.
Tumor Regulatory T Cells Potently Abrogate Antitumor Immunity
Authors: Liu Zuqiang , Kim Jin H. , Falo Louis D. , You Zhaoyang
Published: May 2009

Regulatory T cell (Treg) from mice bearing a breast tumor were elevated (tumor Treg). In vitro, whereas tumor Treg ability to inhibit tumor-primed CD4+ T cell activity is comparable to Treg from naive mice (naive Treg), only tumor Treg suppress naive CD8+ T cell activation and DC function. Neither tumor Treg nor naive Treg can suppress antitumor immunity at the effector phase of the immune response induced by adoptively transferred tumor-primed CD4+ T cells. This is consistent with the observation that, in this model, neither tumor Treg nor naive Treg can inhibit effectors in vitro or in vivo. However, tumor Treg abrogate tumor-specific CD8+ T cell responses in tumor-draining lymph nodes and antitumor immunity at the early stage of the immune response induced by adoptively transferred tumor-primed CD4+ T cells. These data indicate that, in this model, tumor Treg potently abrogate tumor-specific CD8+ T cell responses in tumor-draining lymph nodes, thereby suppressing antitumor immunity at the early stage of the immune response induced by adoptively transferred tumor-primed CD4+ T cells.
Neisseria gonorrhoeae Activates the Proteinase Cathepsin B to Mediate the Signaling Activities of the NLRP3 and ASC-Containing Inflammasome
Authors: Duncan Joseph A. , Gao Xi , Huang Max Tze-Han , O'Connor Brian P. , Thomas Christopher E. , Willingham Stephen B. , Bergstralh Daniel T. , Jarvis Gary A. , Sparling P. Frederick , Ting Jenny P.-Y.
Published: May 2009

Neisseria gonorrhoeae is a common sexually transmitted pathogen that significantly impacts female fertility, neonatal health, and transmission of HIV worldwide. N. gonorrhoeae usually causes localized inflammation of the urethra and cervix by inducing production of IL-1β and other inflammatory cytokines. Several NLR (nucleotide-binding domain, leucine-rich repeat) proteins are implicated in the formation of pro-IL-1β-processing complexes called inflammasomes in response to pathogens. We demonstrate that NLRP3 (cryopyrin, NALP3) is the primary NLR required for IL-1β/IL-18 secretion in response to N. gonorrhoeae in monocytes. We also show that N. gonorrhoeae infection promotes NLRP3-dependent monocytic cell death via pyronecrosis, a recently described pathway with morphological features of necrosis, including release of the strong inflammatory mediator HMBG1. Additionally, N. gonorrhoeae activates the cysteine protease cathepsin B as measured by the breakdown of a cathepsin B substrate. Inhibition of cathepsin B shows that this protease is an apical controlling step in the downstream activities of NLRP3 including IL-1β production, pyronecrosis, and HMGB1 release. Nonpathogenic Neisseria strains (Neisseria cinerea and Neisseria flavescens) do not activate NLRP3 as robustly as N. gonorrhoeae. Conditioned medium from N. gonorrhoeae contains factors capable of initiating the NLRP3-mediated signaling events. Isolated N. gonorrhoeae lipooligosaccharide, a known virulence factor from this bacterium that is elaborated from the bacterium in the form of outer membrane blebs, activates both NLRP3-induced IL-1β secretion and pyronecrosis. Our findings indicate that activation of NLRP3-mediated inflammatory response pathways is an important venue associated with host response and pathogenesis of N. gonorrhoeae.
Tetraspanin CD9 Negatively Regulates Lipopolysaccharide-Induced Macrophage Activation and Lung Inflammation
Authors: Suzuki Mayumi , Tachibana Isao , Takeda Yoshito , He Ping , Minami Seigo , Iwasaki Takeo , Kida Hiroshi , Goya Sho , Kijima Takashi , Yoshida Mitsuhiro , Kumagai Toru , Osaki Tadashi , Kawase Ichiro
Published: May 2009

Tetraspanins facilitate the formation of multiple molecular complexes at specialized membrane microdomains and regulate cell activation and motility. In the present study, the role of tetraspanin CD9 in LPS-induced macrophage activation and lung inflammation was investigated in vitro and in vivo. When CD9 function was ablated with mAb treatment, small interfering RNA transfection, or gene knockout in RAW264.7 cells or bone marrow-derived macrophages, these macrophages produced larger amounts of TNF-α, matrix metalloproteinase-2, and -9 upon stimulation with LPS in vitro, when compared with control cells. Sucrose gradient analysis revealed that CD9 partly colocalized with the LPS-induced signaling mediator, CD14, at low-density light membrane fractions. In CD9 knockout macrophages, CD14 expression, CD14 and TLR4 localization into the lipid raft, and their complex formation were increased whereas IκBα expression was decreased when compared with wild-type cells, suggesting that CD9 prevents the formation of LPS receptor complex. Finally, deletion of CD9 in mice enhanced macrophage infiltration and TNF-α production in the lung after intranasal administration of LPS in vivo, when compared with wild-type mice. These results suggest that macrophage CD9 negatively regulates LPS response at lipid-enriched membrane microdomains.
CD8 T Cells Producing IL-17 and IFN-γ Initiate the Innate Immune Response Required for Responses to Antigen Skin Challenge
Authors: Kish Danielle D. , Li Xiaoxia , Fairchild Robert L.
Published: May 2009

Effector CD8 T cell recruitment into the skin in response to Ag challenge requires prior CXCL1/KC-directed neutrophil infiltration. Mechanisms inducing CXCL1 production and the dynamics of neutrophil-CD8 T cell interactions during elicitation of Ag-specific responses in the skin were investigated. CXCL1 and CXCL2/MIP-2 were produced within 3–6 h of Ag challenge at 10-fold higher levels in skin challenge sites of Ag-sensitized vs nonsensitized mice. In the challenge sites of sensitized mice this production decreased at 6–9 h postchallenge to near the levels observed in skin challenge sites of nonsensitized mice but rose to a second peak 12 h after challenge. The elevated early neutrophil chemoattractant production at 3–6 h after skin challenge of sensitized animals required both IFN-γ and IL-17, produced by distinct populations of Ag-primed CD8 T cells in response to Ag challenge. Although induced by the Ag-primed CD8 T cells, the early CXCL1 and CXCL2 production was accompanied by neutrophil but not CD8 T cell infiltration into the skin Ag challenge site. Infiltration of the CD8 T cells into the challenge site was not observed until 18–24 h after challenge. These results demonstrate an intricate series of early interactions between Ag-specific and innate immune components that regulate the sequential infiltration of neutrophils and then effector T cells into the skin to mediate an immune response.
Impaired Mast Cell-Driven Immune Responses in Mice Lacking the Transcription Factor NFATc2
Authors: Becker Marc , Heib Valeska , Klein Matthias , Doener Fatma , Bopp Tobias , Taube Christian , Radsak Markus , Schild Hansjörg , Schmitt Edgar , Stassen Michael
Published: May 2009

The three calcium-dependent factors NFATc1, c2, and c3 are expressed in cells of the immune system and play pivotal roles in modulating cellular activation. With regard to NFATc2, it was reported that NFATc2-deficient mice display increased immune responses in several models for infection and allergy in vivo. This led to the assumption that NFATc2 is involved in the maintenance of immune homeostasis. Using the synthetic TLR7 agonist imiquimod as an adjuvant in epicutaneous peptide immunization, we observed that both the inflammatory reaction and the peptide-specific CTL response are severely impaired in NFATc2-deficient mice. Detailed analyses revealed that early production of proinflammatory cytokines, lymph node hypertrophy, and migration of Langerhans cells are strongly reduced in NFATc2-deficient animals. With the aid of mast cell-deficient mice and reconstitution experiments using mast cells derived from either NFATc2-deficient mice or wild-type controls, we were able to show that NFATc2 expressed in mast cells is critical for the initiation of inflammation, migration of Langerhans cells, and the development of full-blown CTL responses following epicutaneous immunization. Thus, NFATc2 is an important factor controlling mast cell accessory function at the interface of innate and adaptive immunity.
Differentiation of Central Memory CD8 T Cells Is Independent of CD62L-Mediated Trafficking to Lymph Nodes
Authors: Wirth Thomas C. , Badovinac Vladimir P. , Zhao Lichao , Dailey Morris O. , Harty John T.
Published: May 2009

CD62L (L-selectin) is a key regulator of T cell trafficking, and its surface expression on activated T cells is modulated to control T cell access to lymph nodes after acute infections. In memory T cells, CD62L is the most frequently used marker to define central memory T cells, a population that provides enhanced protection against most, but not all, pathogens. Early access of CD62Lpos effector T cells to lymph nodes has been proposed to result in preferential central memory T cell differentiation, but direct proof for the involvement of lymph node homing in memory T cell differentiation is lacking. In this study, we show that central memory lineage commitment in CD8 T cells is unaltered by enhanced entry into lymph nodes as a result of constitutive CD62L expression, and that equal numbers of effector and central memory CD8 T cells develop in the absence of CD62L-mediated lymph node trafficking. Our results suggest that CD62L is not a deterministic marker of central memory T cell differentiation, thus providing new insight into the process of memory CD8 T cell generation.
M1 and M2a Polarization of Human Monocyte-Derived Macrophages Inhibits HIV-1 Replication by Distinct Mechanisms
Authors: Cassol Edana , Cassetta Luca , Rizzi Chiara , Alfano Massimo , Poli Guido
Published: May 2009

The capacity of macrophages to support productive HIV-1 infection is known to be modulated by cytokines and other extracellular stimuli. In this study, we demonstrate that cytokine-induced polarization of human monocyte-derived macrophage (MDM) into either classical (M1) or alternatively activated (M2a) MDM is associated with a reduced capacity to support productive CCR5-dependent (R5) HIV-1 infection. M1 polarization was associated with a significant down-regulation of CD4 receptors, increased secretion of CCR5-binding chemokines (CCL3, CCL4, and CCL5), and a >90% decrease in HIV-1 DNA levels 48-h postinfection, suggesting that the inhibition occurred at an early preintegration step in the viral life cycle. In contrast, M2a polarization had no effect on either HIV-1 DNA or protein expression levels, indicating that inhibition occurred at a late/postintegration level in the viral life cycle. M2a inhibition was sustained for up to 72-h postinfection, whereas M1-effects were more short-lived. Most phenotypic and functional changes were fully reversible 7 days after removal of the polarizing stimulus, and a reciprocal down-regulation of M1-related chemokines and cytokines was observed in M2a MDM and vice versa. Since reversion to a nonpolarized MDM state was associated with a renewed capacity to support HIV replication to control levels, M1/M2a polarization may represent a mechanism that allows macrophages to cycle between latent and productive HIV-1 infection.