bluuebunny/crossref_metadata_2025 huggingface dataset:
Skin homing of Sézary cells involves SDF-1-CXCR4 signaling and down-regulation of CD26/dipeptidylpeptidase IV
Authors: Narducci Maria Grazia , Scala Enrico , Bresin Antonella , Caprini Elisabetta , Picchio Maria Cristina , Remotti Daniele , Ragone Gianluca , Nasorri Francesca , Frontani Marina , Arcelli Diego , Volinia Stefano , Lombardo Giuseppe Alfonso , Baliva Giannandrea , Napolitano Monica , Russo Giandomenico
Published: October 2005

Sézary syndrome (SS) is a rare form of cutaneous T-cell lymphoma (CTCL) characterized by a distinct metastatic pattern mainly involving blood and skin. Chemokines and their receptors play a critical role in cellular recruitment and homing to tissues and in the metastatic process of several tumors including non-Hodgkin T-cell lymphomas (NHLs). Here we report that SS cells express a functionally active CXCR4 and that its ligand SDF-1 is abundantly produced in the skin, which represents the main destination of SS cell spreading. SDF-1 is normally inactivated by proteolytic cleavage by the CD26/dipeptidylpeptidase IV (DPPIV). The lack of CD26 from the cell surface is a hallmark of circulating SS cells. We also show that the CD26- phenotype is maintained also in skin-infiltrating neoplastic T lymphocytes and that SS-affected individuals exhibit a reduced activity of plasma soluble CD26. Finally, we observe that the addition of soluble CD26 reduces the migratory response of SS cells to SDF-1 whereas the inhibition of the CD26 peptidase activity in Hut78, a CD26+ CTCL cell line, enhances the SDF-1-induced migration of these cells. Our findings suggest that the SDF-1-CXCR4 axis could play an important role in skin homing of SS through the regulatory activity of CD26.
Influence of antigen on the development of MALT lymphoma
Authors: Lenze Dido , Berg Erika , Volkmer-Engert Rudolf , Weiser Armin A. , Greiner Axel , Knörr-Wittmann Constanze , Anagnostopoulos Ioannis , Stein Harald , Hummel Michael
Published: October 2005

Mucosa-associated lymphoid tissue (MALT) B-cell lymphomas develop in the context of autoimmune or chronic inflammations like Helicobacter pylori–induced gastritis. Remission of most gastric MALT lymphomas after eradication of H pylori links tumor cell proliferation to antigen-induced inflammation and the need for antigenic contact. Furthermore, the tumor cells correspond to antigen-activated memory B cells. To investigate the reactivity of the tumor immunoglobulins we employed in vitro–generated antibodies identical to those produced by MALT lymphoma cells. The immunoglobulin rearrangements of 7 MALT lymphomas were amplified, cloned, and expressed as single-chain fragment variable (scFv) antibodies. Antigen specificity of these 7 scFvs was analyzed by immunohistochemical staining of various normal, reactive, and malignant human tissues. Also, an expression library comprising approximately 30 000 proteins from human fetal brains (protein filter) and a peptide library were screened. One scFv stained a subpopulation of tonsillar plasma cells in immunohistochemical studies. On protein filters this scFv recognized the plasma cell–related protein Ufc1. Peptide library screening identified 9 peptides as binding partners of an additional scFv. The majority of MALT lymphoma immunoglobulins studied, however, showed no reactivity against antigens, indicating that the tumor immunoglobulins do not play a significant role in stimulation and proliferation of the MALT lymphoma tumor cells.
Increased GILZ expression in transgenic mice up-regulates Th-2 lymphokines
Authors: Cannarile Lorenza , Fallarino Francesca , Agostini Massimiliano , Cuzzocrea Salvatore , Mazzon Emanuela , Vacca Carmine , Genovese Tiziana , Migliorati Graziella , Ayroldi Emira , Riccardi Carlo
Published: October 2005

GILZ (glucocorticoid-induced leucine zipper), a gene induced by dexamethasone, is involved in control of T lymphocyte activation and apoptosis. In the present study, using Gilz transgenic mice (TG), which overexpress GILZ in the T-cell lineage, we demonstrate that Gilz is implicated in T helper-2 (Th-2) response development. After in vitro stimulation by CD3/CD28 antibodies, peripheral naive CD4+ T cells from TG mice secrete more Th-2 cytokines such as interleukin-4 (IL-4), IL-5, IL-13, and IL-10, and produce less Th-1 cytokines such as interferon-γ (IFN-γ) than wild-type mice (WT). CD4+ TG lymphocytes up-regulated Th-2 cytokine expression in the specific response to ovalbumin chicken egg (OVA) antigen immunization. Up-regulation correlated with increased expression of GATA-3 and signal transducer and activator of transcription 6 (Stat6), Th-2–specific transcription factors and decreased expression of T-bet, a transcription factor involved in Th-1 differentiation. Finally, in TG mice delayed-type hypersensitivity, a Th-1 response, was inhibited and bleomycin-induced pulmonary fibrosis, a Th-2 mediated disease, was more severe. These results indicate that Gilz contributes to CD4+ commitment toward a Th-2 phenotype and suggest this contribution may be another mechanism accounting for glucocorticoid immunomodulation.
Phospholipase C-γ2 is essential for NK cell cytotoxicity and innate immunity to malignant and virally infected cells
Authors: Caraux Anouk , Kim Nayoung , Bell Sarah E. , Zompi Simona , Ranson Thomas , Lesjean-Pottier Sarah , Garcia-Ojeda Marcos E. , Turner Martin , Colucci Francesco
Published: October 2005

Phospholipase C-γ2 (PLC-γ2) is a key component of signal transduction in leukocytes. In natural killer (NK) cells, PLC-γ2 is pivotal for cellular cytotoxicity; however, it is not known which steps of the cytolytic machinery it regulates. We found that PLC-γ2-deficient NK cells formed conjugates with target cells and polarized the microtubule-organizing center, but failed to secrete cytotoxic granules, due to defective calcium mobilization. Consequently, cytotoxicity was completely abrogated in PLC-γ2-deficient cells, regardless of whether targets expressed NKG2D ligands, missed self major histocompatibility complex (MHC) class I, or whether NK cells were stimulated with IL-2 and antibodies specific for NKR-P1C, CD16, CD244, Ly49D, and Ly49H. Defective secretion was specific to cytotoxic granules because release of IFN-γ on stimulation with IL-12 was normal. Plcg2-/- mice could not reject MHC class I-deficient lymphoma cells nor could they control CMV infection, but they effectively contained Listeria monocytogenes infection. Our results suggest that exocytosis of cytotoxic granules, but not cellular polarization toward targets, depends on intracellular calcium rise during NK cell cytotoxicity. In vivo, PLC-γ2 regulates selective facets of innate immunity because it is essential for NK cell responses to malignant and virally infected cells but not to bacterial infections.
The future prospects of Lithuanian family physicians: a 10-year forecasting study
Authors: Starkiene Liudvika , Smigelskas Kastytis , Padaiga Zilvinas , Reamy Jack
Published: October 2005

Background

When health care reform was started in 1991, the physician workforce in Lithuania was dominated by specialists, and the specialty of family physician (FP) did not exist at all. During fifteen years of Lithuania's independence this specialty evolved rapidly and over 1,900 FPs were trained or retrained. Since 2003, the Lithuanian health care sector has undergone restructuring to optimize the network of health care institutions as well as the delivery of services; specific attention has been paid to the development of services provided by FPs, with more health care services shifted from the hospital level to the primary health care level. In this paper we analyze if an adequate workforce of FPs will be available in the future to take over new emerging tasks.

Methods

A computer spreadsheet simulation model was used to project the supply of FPs in 2006–2015. The supply was projected according to three scenarios, which took into account different rates of retirement, migration and drop out from training. In addition different population projections and enrolment numbers in residency programs were also considered. Three requirement scenarios were made using different approaches. In the first scenario we used the requirement estimated by a panel of experts using the Delphi technique. The second scenario was based on the number of visits to FPs in 2003 and took into account the goal to increase the number of visits. The third scenario was based on the determination that one FP should serve no more than 2,000 inhabitants. The three scenarios for the projection of supply were compared with the three requirement scenarios.

Results

The supply of family physicians will be higher in 2015 compared to 2005 according to all projection scenarios. The largest differences in the supply scenarios were caused by different migration rates, enrolment numbers to training programs and the retirement age. The second supply scenario, which took into account 1.1% annual migration rate, stable enrolment to residency programs and later retirement, appears to be the most probable. The first requirement scenario, which was based on the opinion of well-informed key experts in the field, appears to be the best reflection of FP requirements; however none of the supply scenarios considered would satisfy these requirements.

Conclusion

Despite the rapid expansion of the FP workforce during the last fifteen years, ten-year forecasts of supply and requirement indicate that the number of FPs in 2015 will not be sufficient. The annual enrolment in residency training programs should be increased by at least 20% for the next three years. Accurate year-by-year monitoring of the workforce is crucial in order to prevent future shortages and to maintain the desired family physician workforce.
Identification of moaA3 gene in patient isolates of Mycobacterium tuberculosis in Kerala, which is absent in M. tuberculosisH37Rv and H37Ra
Authors: Sarojini Suma , Soman Smitha , Radhakrishnan Indulakshmi , Mundayoor Sathish
Published: October 2005

Background

Tuberculosis is endemic to developing countries like India. Though the whole genome sequences of the type strain M. tuberculosis H37Rv and the clinical strain M. tuberculosis CDC1551 are available, the clinical isolates from India have not been studied extensively at the genome level. This study was carried out in order to have a better understanding of isolates from Kerala, a state in southern India.

Results

A PCR based strategy was followed making use of the deletion region primers to understand the genome level differences between the type strain H37Rv and the clinical isolates of M. tuberculosis from Kerala. PCR analysis of patient isolates using RD1 region primers revealed the amplification of a 386 bp region, in addition to the expected 652 bp amplicon. Southern hybridization of genomic DNA with the 386 bp amplicon confirmed the presence of this new region in a majority of the patient isolates from Kerala. Sequence comparison of this amplicon showed close homology with the moaA3 gene of M. bovis. In M. bovis this gene is present in the RvD5 region, an IS6110 mediated deletion that is absent in M. tuberculosis H37Rv.

Conclusion

This study demonstrates the presence of moaA3 gene, that is absent in M. tuberculosis H37Rv and H37Ra, in a large number of local isolates. Whether the moaA3 gene provides any specific advantage to the field isolates of the pathogen is unclear. Field strains from Kerala have fewer IS6110 sequences and therefore are likely to have fewer IS6110 dependent rearrangements. But as deletions and insertions account for much of the genomic diversity of M. tuberculosis, the mechanisms of formation of sequence polymorphisms in the local isolates should be further examined. These results suggest that studies should focus on strains from endemic areas to understand the complexities of this pathogen.
Birth outcomes in Colorado's undocumented immigrant population
Authors: Reed Mary M , Westfall John M , Bublitz Caroline , Battaglia Catherine , Fickenscher Alexandra
Published: October 2005

Background

The birth outcomes of undocumented women have not been systematically studied on a large scale. The growing number of undocumented women giving birth in the United States has important implications for clinical care and public health policy. The objective of this study was to describe birth outcomes of undocumented immigrants in Colorado.

Methods

Retrospective descriptive study of singleton births to 5961 undocumented women using birth certificate data for 1998–1999.

Results

Undocumented mothers were younger, less educated, and more likely to be single. They had higher rates of anemia, were less likely to gain enough weight, and less likely to receive early prenatal care. They were much less likely to use alcohol or tobacco. Undocumented women had a lower rate of low birth weight (5.3% v 6.5%, P < .001) or preterm infants (12.9% v 14.5%; p = .001). Undocumented women experienced higher rates of labor complications including excessive bleeding (2.3% v 0.8%, p < .001) and fetal distress (8.7% v 3.6%, p < .001).

Conclusion

Undocumented women have lower rates of preterm delivery and low birth weight infants, but higher rates of pregnancy related risk factors. Higher prevalence of some risk factors which are amenable to medical intervention reveals the need for improved prenatal care in this group.
The antihyperlipidemic activities of 4(3H) quinazolinone and two halogenated derivatives in rats
Authors: Refaie Fawzia M , Esmat Amr Y , Gawad Soad M Abdel , Ibrahim Aida M , Mohamed Mona A
Published: October 2005

In the present study, the effects of subchronic treatments (4 weeks) of hypercholesterolemic (single) and diabetic-hypercholesterolemic (combined) rats with 4 (3H) quinazolinone and 2 halogenated derivatives (6, 8-dibromo-2-methy-4 (3H) quinazolinone and 6-iodo-2-methyl-4(3H) quinazolinone) at a sublethal dose level (2 mg/Kg) on cholesterol metabolism were investigated. Bezafibrate, a hypolipidemic drug was used as a reference compound for data comparison. Treatment of rats with single and combined hypercholesterolemia with quinazolinone compounds gave rise to highly significant reductions in serum total cholesterol and cholesterol ester levels, whereas serum triacylglycerol level was significantly reduced only after treatment with halogen-substituted quinazolinones in single hyper-cholesterolemia, compared to the control group. The effects of different quinazolinones and bezafibrate on reduction of serum LDL-C level were comparable in single hypercholesterolemia but significantly different in combined hypercholesterolemia. Results obtained from this study suggest that the antihyperlipidemic effect of quinazolinone compounds was brought about by inhibition of dietary cholesterol absorption and / or intestinal ACAT activity.
12thinternational conference on human retrovirology: HTLV and related retroviruses
Authors: Lairmore Michael D , Fujii Masahiro
Published: October 2005

The 12th International Conference on Human Retrovirology: HTLV and Related Retroviruses, was held at the Half Moon Hotel in Montego Bay, Jamaica, from June 22nd to June 25th 2005. The scientific conference, sponsored by the International Retrovirology Association, is held biennially at rotating international venues around the world. The meeting brings together basic scientists, epidemiologists and clinical researchers to discuss findings to prevent HTLV infection or develop new therapies against HTLV-mediated diseases. The Association fosters the education and training of young scientists to bring new approaches to the complex problems of HTLV research, such as translational research to bring findings from the laboratory into clinical trials that benefit HTLV-infected patients. The breadth and quality of research presentations and workshops at the 12th International Conference indicate that these goals are being accomplished. As HTLV research enters its third decade a new generation of scientists face many challenges. However, HTLV scientists and clinicians displayed exciting new approaches and discoveries during plenary talks and poster sessions. The conference encouraged research in HTLV infections and disease, fostered collaborations, and stimulated new partnerships between clinicians and scientists to encourage clinical trials and novel therapeutic interventions.
Combustion of dried animal dung as biofuel results in the generation of highly redox active fine particulates
Authors: Mudway Ian S , Duggan Sean T , Venkataraman Chandra , Habib Gazala , Kelly Frank J , Grigg Jonathan
Published: October 2005

Background

The burning of biomass in the developing world for heating and cooking results in high indoor particle concentrations. Long-term exposure to airborne particulate matter (PM) has been associated with increased rates of acute respiratory infections, chronic obstructive lung disease and cancer. In this study we determined the oxidative activity of combustion particles derived from the biomass fuel dung cake by examining their capacity to deplete antioxidants from a model human respiratory tract lining fluid (RTLF). For comparison, the observed oxidative activity was compared with that of particles derived from industrial and vehicular sources.

Results

Incubation of the dung cake particle suspensions in the RTLF for 4 h resulted in a mean loss of ascorbate of 72.1 ± 0.7 and 89.7 ± 2.5% at 50 and 100 μg/ml, respectively. Reduced glutathione was depleted by 49.6 ± 4.3 and 63.5 ± 22.4% under the same conditions. The capacity of these samples to deplete ascorbate was in excess of that observed with diesel or gasoline particles, but comparable to that seen with residual oil fly ash and considerably in excess of all three control particles in terms of glutathione depletion. Co-incubation with the metal chelator diethylenetriaminepentaacetate inhibited these losses, whilst minimal inhibition was seen with superoxide dismutase and catalase treatment. The majority of the activity observed appeared to be contained within aqueous particle extracts.

Conclusion

These data demonstrate that biomass derived particles have considerable oxidative activity, largely attributable to their transition metal content.
MHC II molecules and invariant chain reside in membranes distinct from conventional lipid rafts
Authors: Karacsonyi Claudia , Bedke Tanja , Hinrichsen Nils , Schwinzer Reinhard , Lindner Robert
Published: October 2005

Major histocompatibility complex class II (MHC II) peptide complexes can associate with lipid rafts, and this is a prerequisite for their recruitment to the immunological synapse and for efficient T cell stimulation. One of the most often used criterion for raft association is the resistance to extraction by the detergent Triton X-100 (TX-100) at low temperature. For MHC II, a variety of detergents have been used under different conditions, leading to variable and often conflicting conclusions about the association of MHC II with detergent-resistant membranes (DRMs). To clarify whether these inconsistencies were caused by variations in the isolation protocols or reflect different biochemical properties of MHC II lipid complexes, we used two standardized procedures for the isolation of membranes resistant to TX-100, 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS), or Brij 98. Our results suggest that some of the reported variations in the association of MHC II with DRMs are caused by differences in the methods. We also show that in our hands, specific and efficient flotation of MHC II and the MHC II-associated invariant chain from mouse B-lymphoma cells was only achieved with Brij 98, but not with TX-100 and CHAPS. We furthermore used DRMs prepared from hen egg lysozyme-fed B-lymphoma cells to activate the T cell hybridoma 3A9. In agreement with our biochemical data, T cell activation could only be achieved with Brij 98- but not with TX-100-resistant membranes. Thus, MHC II and also the invariant chain belong to a set of proteins comprising the T cell receptor, prominin, and the prion protein, which reside in membrane environments distinct from conventional lipid rafts.
Leukocyte-versus microparticle-mediated tissue factor transfer during arteriolar thrombus development
Authors: Gross Peter L , Furie Barbara C , Merrill-Skoloff Glenn , Chou Janet , Furie Bruce
Published: October 2005

Circulating tissue factor accumulates in the developing thrombus and contributes to fibrin clot formation. To determine whether tissue factor derived from hematopoietic cells is delivered to the thrombus via tissue factor-bearing microparticles or circulating leukocytes expressing tissue factor on the plasma membrane, we compared the kinetics of tissue factor accumulation in the developing arteriolar thrombus with the time course of leukocyte-thrombus interaction and microparticle-thrombus interaction in the microcirculation of a living mouse using intravital high-speed widefield and confocal microscopy. Tissue factor rapidly accumulated in the developing thrombus, appearing immediately following vessel wall injury, reaching a first peak in ∼100 s. In contrast, leukocyte-thrombus interaction was not observed until after 2–3 min following vessel wall injury. Maximal leukocyte rolling and firm leukocyte adherence on thrombi in wild-type mice were observed after ∼8 min and were dependent on P-selectin and P-selectin glycoprotein ligand-1. This delay in P-selectin-dependent leukocyte rolling is a result of time-dependent platelet activation and P-selectin expression on the luminal surface of the thrombus. In contrast, microparticle accumulation in the developing arteriolar thrombus was rapid, and peak accumulation was within 60 s. The accumulation of hematopoietic cell-derived tissue factor in the developing thrombus correlates to the kinetics of microparticle accumulation and does not correlate temporally with leukocyte-thrombus interaction. These results indicate that tissue factor derived from hematopoietic cells is delivered by microparticles during the initial phase of thrombus development in vivo.
Identification of novel mediators of NF-κB through genome-wide survey of monocyte adherence-induced genes
Authors: Diatchenko Luda , Romanov Sergei , Malinina Inga , Clarke Julie , Tchivilev Igor , Li Xiangli , Makarov Sergei S
Published: October 2005

The transcription factor nuclear factor (NF)-κB controls the expression of genes involved in inflammation, cell proliferation, apoptosis, and differentiation. Impaired regulation of NF-κB has been associated with many diseases; thus, there is significant interest in therapeutic approaches based on modulation of this transcription factor. NF-κB activity is controlled by numerous signaling molecules, many of which are potentially to be identified. Monocytes are principal effectors of the immune system, and monocyte adherence is the first step leading to their activation and differentiation. Adherence induces activation of NF-κB, resulting in the induction of proinflammatory genes as well as anti-inflammatory genes, which counterbalance and limit the intensity and duration of NF-κB activation. Here, to identify novel mediators of NF-κB signaling, we used the model of monocyte adherence to perform a systematic, genome-wide survey of adherence-induced genes. Having isolated mRNAs from nonadherent and adherent primary human monocytes, we constructed suppressive subtraction hybridization libraries containing cDNAs, which were differentially regulated by adherence. Of 366 identified differentially expressed genes, most were found to be up-regulated by adherence. Having analyzed a subset of these genes, we found that the library was enriched with inhibitors of NF-κB. Three of those (an orphan nuclear receptor NUR77, a guanosine 5′-diphosphate/guanosine 5′-triphosphate exchange factor RABEX5, and a PRK1-associated protein AWP1) were particularly potent inhibitors of NF-κB activation. Thus, the collection of monocyte adherence-regulated genes represents a rich source for the identification of novel components of the machinery that controls NF-κB activation.
Cocaine and σ-1 receptors modulate HIV infection, chemokine receptors, and the HPA axis in the huPBL-SCID model
Authors: Roth Michael D , Whittaker Katherine M , Choi Ruth , Tashkin Donald P , Baldwin Gayle Cocita
Published: October 2005

Cocaine is associated with an increased risk for, and progression of, clinical disease associated with human immunodeficiency virus (HIV) infection. A human xenograft model, in which human peripheral blood mononuclear cells were implanted into severe combined immunodeficiency mice (huPBL-SCID) and infected with a HIV reporter virus, was used to investigate the biological interactions between cocaine and HIV infection. Systemic administration of cocaine (5 mg/kg/d) significantly increased the percentage of HIV-infected PBL (two- to threefold) and viral load (100- to 300-fold) in huPBL-SCID mice. Despite the capacity for cocaine to increase corticosterone and adrenocorticotropic hormone levels in control mice, the hypothalamic-pituitary-adrenal axis was suppressed in HIV-infected animals, and corticosterone levels were further decreased when animals were exposed to HIV and cocaine. Activating huPBL in vitro in the presence of 10−8 M cocaine increased expression of CC chemokine receptor 5 (CCR5) and CXC chemokine receptor 4 (CXCR4) coreceptors. Expression of CCR5 was also increased at early time-points in the huPBL-SCID model following systemic exposure to cocaine (54.1±9.4% increase over control, P<0.01). This effect preceded the boost in viral infection and waned as HIV infection progressed. Cocaine has been shown to mediate immunosuppressive effects by activating σ-1 receptors in immune cells in vitro and in vivo. Consistent with these reports, a selective σ-1 antagonist, BD1047, blocked the effects of cocaine on HIV replication in the huPBL-SCID mouse. Our results suggest that systemic exposure to cocaine can enhance HIV infection in vivo by activating σ-1 receptors and by modulating the expression of HIV coreceptors.
Are chemokines the third major system in the brain?
Authors: Adler Martin W , Rogers Thomas J
Published: October 2005

Chemokines are a family of small proteins involved in cellular migration and intercellular communication. Although the chemokines and their receptors are located throughout the brain, they are not distributed uniformly. Among the chemokines and their receptors that are arrayed disproportionately in glia and neurons are monocyte chemotactic protein-1/CC chemokine ligand 2 (CCL2), stromal cell-derived factor-1/CXC chemokine ligand 12 (CXCL12), fractalkine/CX3C chemokine ligand 1, interferon-γ-inducible-protein-10/CXCL10, macrophage inflammatory protein-1α/CCL3, and regulated on activation, normal T cell expressed and secreted/CCL5. In the brain, they are found in the hypothalamus, nucleus accumbens, limbic system, hippocampus, thalamus, cortex, and cerebellum. The uneven distribution suggests that there may be functional roles for the chemokine “system,” comprised of chemokine ligands and their receptors. In addition to anatomical, immunohistochemical, and in vitro studies establishing the expression of the chemokine ligands and receptors, there is an increasing body of research that suggests that the chemokine system plays a crucial role in brain development and function. Our data indicate that the chemokine system can alter the actions of neuronally active pharmacological agents including the opioids and cannabinoids. Combined with evidence that the chemokine system in the brain interacts with neurotransmitter systems, we propose the following hypothesis: The endogenous chemokine system in the brain acts in concert with the neurotransmitter and neuropeptide systems to govern brain function. The chemokine system can thus be thought of as the third major transmitter system in the brain.
Leukocytes in the regulation of pain and analgesia
Authors: Rittner H L , Machelska H , Stein C
Published: October 2005

When tissue is destroyed or invaded by leukocytes in inflammation, numerous mediators are delivered by the circulation and/or liberated from resident and immigrated cells at the site. Proalgesic mediators include proinflammatory cytokines, chemokines, protons, nerve growth factor, and prostaglandins, which are produced by invading leukocytes or by resident cells. Less well known is that analgesic mediators, which counteract pain, are also produced in inflamed tissues. These include anti-inflammatory cytokines and opioid peptides. Interactions between leukocyte-derived opioid peptides and opioid receptors can lead to potent, clinically relevant inhibition of pain (analgesia). Opioid receptors are present on peripheral endings of sensory neurons. Opioid peptides are synthesized in circulating leukocytes, which migrate to inflamed tissues directed by chemokines and adhesion molecules. Under stressful conditions or in response to releasing agents (e.g., corticotropin-releasing factor, cytokines, noradrenaline), leukocytes can secrete opioids. They activate peripheral opioid receptors and produce analgesia by inhibiting the excitability of sensory nerves and/or the release of excitatory neuropeptides. This review presents discoveries that led to the concepts of pain generation by mediators secreted from leukocytes and of analgesia by immune-derived opioids.
Aberrant expression of neutrophil and macrophage-related genes in a murine model for human neutrophil-specific granule deficiency
Authors: Gombart Adrian F , Krug Utz , O'Kelly James , An Eun , Vegesna Vijaya , Koeffler H Phillip
Published: October 2005

Neutrophil-specific granule deficiency involves inheritance of germline mutations in the CCAAT/enhancer-binding protein ε (C/EBPE) gene. Humans and mice lacking active C/EBPε suffer frequent bacterial infections as a result of functionally defective neutrophils and macrophages. We hypothesized that these defects reflected dysregulation of important immune response genes. To test this, gene expression differences of peritoneally derived neutrophils and macrophages from C/EBPε−/− and wild-type mice were determined with DNA microarrays. Of 283 genes, 146 known genes and 21 expressed sequence tags (ESTs) were down-regulated, and 85 known genes and 31 ESTs were up-regulated in the C/EBP−/− mice. These included genes involved in cell adhesion/chemotaxis, cytoskeletal organization, signal transduction, and immune/inflammatory responses. The cytokines CC chemokine ligand 4, CXC chemokine ligand 2, and interleukin (IL)-6, as well as cytokine receptors IL-8RB and granulocyte-colony stimulating factor, were down-regulated. Chromatin immunoprecipitation analysis identified binding of C/EBPε to their promoter regions. Increased expression for lipid metabolism genes apolipoprotein E (APOE), scavenger receptor class B-1, sorting protein-related receptor containing low-density lipoprotein receptor class A repeat 1, and APOC2 in the C/EBPε−/− mice correlated with reduced total cholesterol levels in these mice before and after maintenance on a high-fat diet. Also, C/EBPε-deficient macrophages showed a reduced capacity to accumulate lipids. In summary, dysregulation of numerous, novel C/EBPε target genes impairs innate immune response and possibly other important biological processes mediated by neutrophils and macrophages.
Distribution and leukocyte contacts of γδ T cells in the lung
Authors: Wands J M , Roark Christina L , Aydintug M Kemal , Jin Niyun , Hahn Youn-Soo , Cook Laura , Yin Xiang , Dal Porto Joseph , Lahn Michael , Hyde Dallas M , Gelfand Erwin W , Mason Robert J , O'Brien Rebecca L , Born Willi K
Published: October 2005

Pulmonary γδ T cells protect the lung and its functions, but little is known about their distribution in this organ and their relationship to other pulmonary cells. We now show that γδ and αβ T cells are distributed differently in the normal mouse lung. The γδ T cells have a bias for nonalveolar locations, with the exception of the airway mucosa. Subsets of γδ T cells exhibit further variation in their tissue localization. γδ and αβ T cells frequently contact other leukocytes, but they favor different cell-types. The γδ T cells show an intrinsic preference for F4/80+ and major histocompatibility complex class II+ leukocytes. Leukocytes expressing these markers include macrophages and dendritic cells, known to function as sentinels of airways and lung tissues. The continuous interaction of γδ T cells with these sentinels likely is related to their protective role.
Spontaneous neutrophil apoptosis and regulation of cell survival by granulocyte macrophage-colony stimulating factor
Authors: Kobayashi Scott D , Voyich Jovanka M , Whitney Adeline R , DeLeo Frank R
Published: October 2005

Polymorphonuclear leukocytes (PMNs or neutrophils) are the most prominent cellular component of the innate immune system in humans and produce an array of potent cytotoxic molecules. It is important that neutrophils undergo constitutive (spontaneous) apoptosis as a mechanism to facilitate normal cell turnover and immune system homeostasis. Conversely, several proinflammatory cytokines, including granulocyte macrophage-colony stimulating factor (GM-CSF), prolong neutrophil survival. The molecular mechanisms that regulate PMN apoptosis or survival remain incompletely defined. To that end, we compared global gene expression in human neutrophils during spontaneous apoptosis with that in cells cultured with human GM-CSF. Genes encoding proteins that inhibit apoptosis, such as myeloid cell leukemia sequence 1, caspase 8 and Fas-associated via death domain-like apoptosis regulator (CFLAR), B cell chronic lymphocytic leukemia/lymphoma 2 (BCL2)/adenovirus E1B 19 kDa-interacting protein 2 (BNIP2), and serum/glucocorticoid-regulated kinase (SGK), were down-regulated coincident with neutrophil apoptosis. In contrast, those encoding apoptosis inhibitor 5, BCL2-like 1, BNIP2, CFLAR, SGK, and tumor necrosis factor α-induced protein 8 were up-regulated in PMNs cultured with GM-CSF. Correspondingly, GM-CSF delayed PMN apoptosis (P<0.03), increased cell viability (P<0.03), and prolonged neutrophil phagocytic capacity (P<0.05). Prolonged functional capacity was paralleled by striking up-regulation of proinflammatory genes and proteins, including CD14, CD24, CD66, and human leukocyte antigen-DR. In addition, expression of SGK protein diminished during PMN apoptosis but was restored by culture with GM-CSF, suggesting SGK is involved in leukocyte survival. These studies provide a global view of the molecular events that regulate neutrophil survival and apoptosis.
Vasoactive intestinal peptide generates CD4+CD25+ regulatory T cells in vivo
Authors: Delgado Mario , Chorny Alejo , Gonzalez-Rey Elena , Ganea Doina
Published: October 2005

CD4+CD25+ regulatory T (Treg) cells control the immune response to a variety of antigens, including self-antigens, and several models support the idea of the peripheral expansion of CD4+CD25+ Treg cells. Although hormones such as estrogen and α-melanocyte-stimulating hormone have been recently reported to expand the CD4+CD25+ Foxp3-expressing Treg cell compartment, little is known about the endogenous factors and mechanisms controlling the peripheral expansion of CD4+CD25+ Treg cells. In this study, we report on the capacity of the vasoactive intestinal peptide (VIP), an immunosuppressive neuropeptide, to induce functional Treg cells in vivo. The administration of VIP together with specific antigen to T cell receptor (TCR)-transgenic (Tg) mice results in the expansion of the CD4+CD25+, Foxp-3/neuropilin 1-expressing T cells, which inhibit responder T cell proliferation through direct cellular contact. In addition to the increase in the number of CD4+CD25+ Treg cells, VIP induces more efficient suppressors on a per-cell basis. The VIP-generated CD4+CD25+ Treg cells transfer suppression, inhibit delayed-type hypersensitivity in TCR-Tg hosts, and prevent graft-versus-host disease in irradiated hosts reconstituted with allogeneic bone marrow.
Alcohol-induced oxidative stress in brain endothelial cells causes blood-brain barrier dysfunction
Authors: Haorah J , Knipe B , Leibhart J , Ghorpade A , Persidsky Y
Published: October 2005

Brain microvascular endothelial cells (BMVEC) connected by tight junctions (TJ) form a tight monolayer at the blood-brain barrier (BBB). We investigated the idea that BBB dysfunction seen in alcohol abuse is associated with oxidative stress stemming from ethanol (EtOH) metabolism in BMVEC. Exposure to EtOH induced catalytic activity/expression of EtOH-metabolizing enzymes, which paralleled enhanced generation of reactive oxygen species (ROS). EtOH-mediated oxidative stress led to activation of myosin light chain (MLC) kinase, phosphorylation of MLC and TJ proteins, decreased BBB integrity, and enhanced monocyte migration across BBB. Acetaldehyde or ROS donors mimicked changes induced by EtOH in BMVEC. Thus, oxidative stress resulting from alcohol metabolism in BMVEC can lead to BBB breakdown in alcohol abuse, serving as an aggravating factor in neuroinflammatory disorders.
Viral strategies for evading antiviral cellular immune responses of the host
Authors: Iannello Alexandre , Debbeche Olfa , Martin Elodie , Attalah Lynda Habiba , Samarani Suzanne , Ahmad Ali
Published: October 2005

The host invariably responds to infecting viruses by activating its innate immune system and mounting virus-specific humoral and cellular immune responses. These responses are aimed at conrolling viral replication and eliminating the infecting virus from the host. However, viruses have evolved numerous strategies to counter and evade host's antiviral responses. Providing specific examples from the published literature, we discuss in this review article various strategies that viruses have developed to evade antiviral cellular responses of the host. Unraveling these viral strategies allows a better understanding of the host-pathogen interactions and their coevolution. This knowledge is important for identifying novel molecular targets for developing antiviral reagents. Finally, it may also help devise new knowledge-based strategies for developing antiviral vaccines.
Structural organization of the neutrophil NADPH oxidase: phosphorylation and translocation during priming and activation
Authors: Sheppard Forest R , Kelher Marguerite R , Moore Ernest E , McLaughlin Nathan J D , Banerjee Anirban , Silliman Christopher C
Published: October 2005

The reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is part of the microbicidal arsenal used by human polymorphonuclear neutrophils (PMNs) to eradicate invading pathogens. The production of a superoxide anion (O2–) into the phagolysosome is the precursor for the generation of more potent products, such as hydrogen peroxide and hypochlorite. However, this production of O2– is dependent on translocation of the oxidase subunits, including gp91phox, p22phox, p47phox, p67phox, p40phox, and Rac2 from the cytosol or specific granules to the plasma membrane. In response to an external stimuli, PMNs change from a resting, nonadhesive state to a primed, adherent phenotype, which allows for margination from the vasculature into the tissue and chemotaxis to the site of infection upon activation. Depending on the stimuli, primed PMNs display altered structural organization of the NADPH oxidase, in that there is phosphorylation of the oxidase subunits and/or translocation from the cytosol to the plasma or granular membrane, but there is not the complete assembly required for O2– generation. Activation of PMNs is the complete assembly of the membrane-linked and cytosolic NADPH oxidase components on a PMN membrane, the plasma or granular membrane. This review will discuss the individual components associated with the NADPH oxidase complex and the function of each of these units in each physiologic stage of the PMN: rested, primed, and activated.
Toll-like receptor 2 mediates inflammatory cytokine induction but not sensitization for liver injury byPropioni- bacterium acnes
Authors: Romics Laszlo , Dolganiuc Angela , Velayudham Arumugam , Kodys Karen , Mandrekar Pranoti , Golenbock Douglas , Kurt-Jones Evelyn , Szabo Gyongyi
Published: October 2005

Recognition of Gram-positive bacteria by Toll-like receptor 2 (TLR2) induces activation of proinflammatory pathways. In mice, sensitization with the Gram-positive Propionibacterium acnes followed by a challenge with the TLR4 ligand, lipopolysaccharide (LPS), results in fulminant hepatic failure. Here, we investigated the role of TLR2 in liver sensitization to LPS-induced injury. Stimulation of Chinese hamster ovary cells and peritoneal macrophages with heat-killed P. acnes required expression of TLR2 but not of TLR4, suggesting that P. acnes was a TLR2 ligand. Cell activation by P. acnes was myeloid differentiation primary-response protein 88 (MyD88)-dependent, and it was augmented by coexpression of CD14 in mouse peritoneal macrophages. In vitro, P. acnes behaved as a TLR2 ligand and induced TLR4 hetero- and TLR2 homotolerance in peritoneal macrophages. In vivo priming of wild-type mice with P. acnes, but not with the selective TLR2 ligands peptidoglycan and lipotheicoic acid, resulted in hepatocyte necrosis, hyperelevated serum levels of tumor necrosis factor α (TNF-α), interleukin (IL)-6, interferon-γ (IFN-γ), and IL-12 (p40/p70), and increased RNA expression of proinflammatory cytokines (IL-12p40, IL-1α, IL-6, IL-1β, IL-18, IFN-γ) in the liver after a LPS challenge. Furthermore, P. acnes priming sensitized TLR2-deficient (TLR2−/−) but not MyD88−/− mice to LPS-induced injury, evidenced by hepatocyte necrosis, increased levels of serum TNF-α, IFN-γ, IL-6, and liver proinflammatory cytokine mRNA expression. IFN-γ, a cytokine sensitizing to endotoxin, was induced by P. acnes in splenocytes of TLR2−/− and TLR9−/− but not MyD88−/− mice. These results suggest that although P. acnes triggers TLR2-mediated cell activation, TLR2-independent but MyD88-dependent mechanisms mediate in vivo sensitization by P. acnes for LPS-induced liver injury.
Different signaling pathways inhibit DNA methylation activity and up-regulate IFN-γ in human lymphocytes
Authors: Bonilla-Henao Victoria , Martínez Raquel , Sobrino Francisco , Pintado Elizabeth
Published: October 2005

DNA methylation is recognized increasingly for its prominent role in controlling diverse immune processes. In this study, we show that in Jurkat T cells and fresh peripheral lymphocytes, short-time incubation with protein kinase C activators or phosphatase inhibitors down-regulate DNA methylation activity in a dose-dependent manner. This inhibition correlates with the induction of the interferon-γ (IFN-γ) gene, which contains several CG sequences in its promoter. The expression of mRNA and protein of the different DNA methyltransferases did not decrease after the treatment. In addition, sulfydryl reagents have a strong inhibitory effect on DNA methylation activity and also induce IFN-γ gene expression, thus suggesting a link between both effects.
Effects of Short-Term Experimental Insulin Resistance and Family History of Diabetes on Pancreatic β-Cell Function in Nondiabetic Individuals
Authors: Rasouli Neda , Hale Terri , Kahn Steven E. , Spencer Horace J. , Elbein Steven C.
Published: October 2005

Context: Normal glucose homeostasis is maintained despite reductions in insulin sensitivity by increasing insulin secretion. This ability to compensate for reduced insulin sensitivity is highly heritable, but the mechanisms for this compensation or its failure in type 2 diabetes (T2DM) are unknown.

Objective: The objective of this study was to test whether individuals with a family history of T2DM have a fixed decrease in β-cell mass or function that would be revealed as an impaired insulin secretory response to short-term insulin resistance.

Design: Glucose tolerance, insulin sensitivity (SI), and insulin response to iv glucose (AIRG) were compared in nondiabetic individuals with and without a family history of diabetes before and after nicotinic acid (NA) treatment.

Setting: This study was performed at the Ambulatory General Clinical Research Center.

Subjects: Healthy, nonobese, nondiabetic individuals with or without a family history of T2DM were studied.

Interventions: Oral NA was given, with a final dose of 2 g/d, for at least 7 d.

Main Outcome Measure: The main outcome measure was the disposition index (insulin sensitivity × insulin response) in response to NA.

Results: Postchallenge plasma glucose levels rose during NA therapy regardless of family history. Neither group adequately increased their AIRG to maintain the disposition index. Family members did not differ from controls at baseline or after NA treatment for any outcome measure, but only 28 of 52 subjects experienced a 25% or greater fall in SI with NA treatment.

Conclusions: Short-term β-cell compensation to NA-induced insulin resistance was incomplete and did not differ by genetic predisposition. A genetic defect controlling β-cell growth in response to chronic insulin resistance better explains differences in the ability to compensate for insulin resistance than an inherited, fixed defect in β-cell mass.
Hypothalamus-Pituitary-Adrenal Hyperactivity in Human Aging Is Partially Refractory to Stimulation by Mineralocorticoid Receptor Blockade
Authors: Giordano Roberta , Bo Mario , Pellegrino Micaela , Vezzari Marco , Baldi Matteo , Picu Andreea , Balbo Marcella , Bonelli Lorenza , Migliaretti Giuseppe , Ghigo Ezio , Arvat Emanuela
Published: October 2005

Context: The hypothalamus-pituitary-adrenal (HPA) axis is mainly regulated by CRH, arginine vasopressin, and glucocorticoid feedback. Hippocampal mineralocorticoid receptors mediate proactive glucocorticoid feedback and mineralocorticoid antagonists, accordingly, stimulate HPA axis. Age-related HPA hyperactivity reflects impaired glucocorticoid feedback at the suprapituitary level.

Design: ACTH, cortisol, and dehydroepiandrosterone (DHEA) secretion were studied in eight healthy elderly (75.1 ± 3.2 yr) and eight young (25.0 ± 4.6 yr) subjects during placebo or canrenoate (CAN) administration (200 mg iv bolus followed by 200 mg infused over 4 h).

Results: During placebo administration, ACTH and cortisol areas under the curve (AUCs) in elderly subjects were higher than in young subjects (P ≤ 0.01); conversely, DHEA AUCs in elderly subjects were lower than in young subjects (P = 0.002). CAN increased ACTH, cortisol, and DHEA levels in both groups. In young subjects, ACTH, cortisol, and DHEA levels at the end of CAN infusion were higher (P ≤ 0.05) than after placebo. In elderly subjects, at the end of CAN infusion, ACTH, cortisol, and DHEA levels were higher (P = 0.01) than after placebo. Under CAN, ACTH and cortisol AUCs were persistently higher (P ≤ 0.01) and DHEA AUCs lower (P = 0.006) in elderly than in young subjects. Cortisol AUCs after CAN in young subjects did not become significantly different from those in elderly subjects after placebo.

Conclusions: 1) Evening-time ACTH and cortisol secretion in elderly subjects is higher than in young subjects; 2) ACTH and cortisol secretion in elderly subjects is enhanced by CAN but less than that in young subjects; and 3) DHEA hyposecretion in elderly subjects is partially restored by mineralocorticoid antagonism. Age-related variations of HPA activity may be determined by some derangement in mineralocorticoid receptors function at the hippocampal level.