bluuebunny/crossref_metadata_2025_split huggingface dataset:
Virally Induced CD4+ T Cell Depletion Is Not Sufficient to Induce AIDS in a Natural Host
Authors: Milush Jeffrey M. , Reeves Jacqueline D. , Gordon Shari N. , Zhou Dejiang , Muthukumar Alagar , Kosub David A. , Chacko Elizabeth , Giavedoni Luis D. , Ibegbu Chris C. , Cole Kelly S. , Miamidian John L. , Paiardini Mirko , Barry Ashley P. , Staprans Silvija I. , Silvestri Guido , Sodora Donald L. 
Published: April 2014

Abstract
Peripheral blood CD4+ T cell counts are a key measure for assessing disease progression and need for antiretroviral therapy in HIV-infected patients. More recently, studies have demonstrated a dramatic depletion of mucosal CD4+ T cells during acute infection that is maintained during chronic pathogenic HIV as well as SIV infection. A different clinical disease course is observed during the infection of natural hosts of SIV infection, such as sooty mangabeys (Cercocebus atys), which typically do not progress to AIDS. Previous studies have determined that SIV+ mangabeys generally maintain healthy levels of CD4+ T cells despite having viral replication comparable to HIV-infected patients. In this study, we identify the emergence of a multitropic (R5/X4/R8-using) SIV infection after 43 or 71 wk postinfection in two mangabeys that is associated with an extreme, persistent (&gt;5.5 years), and generalized loss of CD4+ T cells (5–80 cells/μl of blood) in the absence of clinical signs of AIDS. This study demonstrates that generalized CD4+ T cell depletion from the blood and mucosal tissues is not sufficient to induce AIDS in this natural host species. Rather, AIDS pathogenesis appears to be the cumulative result of multiple aberrant immunologic parameters that include CD4+ T cell depletion, generalized immune activation, and depletion/dysfunction of non-CD4+ T cells. Therefore, these data provide a rationale for investigating multifaceted therapeutic strategies to prevent progression to AIDS, even following dramatic CD4 depletion, such that HIV+ humans can survive normal life spans analogous to what occurs naturally in SIV+ mangabeys.
Central Memory Vγ9Vδ2 T Lymphocytes Primed and Expanded by Bacillus Calmette-Guérin-Infected Dendritic Cells Kill Mycobacterial-Infected Monocytes
Authors: Martino Angelo , Casetti Rita , Sacchi Alessandra , Poccia Fabrizio 
Published: April 2014

Abstract
In humans, innate immune recognition of mycobacteria, including Mycobacterium tuberculosis and bacillus Calmette-Guérin (BCG), is a feature of cells as dendritic cells (DC) and γδ T cells. In this study, we show that BCG infection of human monocyte-derived DC induces a rapid activation of Vγ9Vδ2 T cells (the major subset of γδ T cell pool in human peripheral blood). Indeed, in the presence of BCG-infected DC, Vγ9Vδ2 T cells increase both their expression of CD69 and CD25 and the production of TNF-α and IFN-γ, in contrast to DC treated with Vγ9Vδ2 T cell-specific Ags. Without further exogenous stimuli, BCG-infected DC expand a functionally cytotoxic central memory Vγ9Vδ2 T cell population. This subset does not display lymph node homing receptors, but express a high amount of perforin. They are highly efficient in the killing of mycobacterial-infected primary monocytes or human monocytic THP-1 cells preserving the viability of cocultured, infected DC. This study provides further evidences about the complex relationship between important players of innate immunity and suggests an immunoregulatory role of Vγ9Vδ2 T cells in the control of mycobacterial infection.
The Paneth Cell α-Defensin Deficiency of Ileal Crohn’s Disease Is Linked to Wnt/Tcf-4
Authors: Wehkamp Jan , Wang Guoxing , Kübler Irmgard , Nuding Sabine , Gregorieff Alex , Schnabel Anke , Kays Robert J. , Fellermann Klaus , Burk Oliver , Schwab Matthias , Clevers Hans , Bevins Charles L. , Stange Eduard F. 
Published: April 2014

Abstract
Ileal Crohn′s disease (CD), a chronic mucosal inflammation, is characterized by two pertinent features: a specific decrease of Paneth cell-produced antimicrobial α-defensins and the presence of mucosal-adherent bacteria. A mutation in NOD2, the muramyl dipeptide recognition receptor, is found in some patients, which leads to an even more pronounced α-defensin decrease. However, the underlying mechanism remains unclear for the majority of patients. In this study, we report a reduced expression in ileal CD of the Wnt-signaling pathway transcription factor Tcf-4, a known regulator of Paneth cell differentiation and α-defensin expression. Within specimens, the levels of Tcf-4 mRNA showed a high degree of correlation with both HD5 and HD6 mRNA. The levels of Tcf-4 mRNA were decreased in patients with ileal disease irrespective of degree of inflammation, but were not decreased in colonic CD or ulcerative colitis. As a functional indicator of Tcf-4 protein, quantitative binding analysis with nuclear extracts from small intestine biopsies to a Tcf-4 high-affinity binding site in the HD-5 and HD-6 promoters showed significantly reduced activity in ileal CD. Furthermore, a causal link was shown in a murine Tcf-4 knockout model, where the comparably reduced expression of Tcf-4 in heterozygous (+/−) mice was sufficient to cause a significant decrease of both Paneth cell α-defensin levels and bacterial killing activity. Finally, the association between Paneth cell α-defensins and Tcf-4 was found to be independent of the NOD2 genotype. This new link established between a human inflammatory bowel disease and the Wnt pathway/Tcf-4 provides a novel mechanism for pathogenesis in patients with ileal CD.
Inhibition of HIV-1 Infectivity and Epithelial Cell Transfer by Human Monoclonal IgG and IgA Antibodies Carrying the b12 V Region
Authors: Mantis Nicholas J. , Palaia Jana , Hessell Ann J. , Mehta Simren , Zhu Zhiyi , Corthésy Blaise , Neutra Marian R. , Burton Dennis R. , Janoff Edward N. 
Published: April 2014

Abstract
Both IgG and secretory IgA Abs in mucosal secretions have been implicated in blocking the earliest events in HIV-1 transit across epithelial barriers, although the mechanisms by which this occurs remain largely unknown. In this study, we report the production and characterization of a human rIgA2 mAb that carries the V regions of IgG1 b12, a potent and broadly neutralizing anti-gp120 Ab which has been shown to protect macaques against vaginal simian/HIV challenge. Monomeric, dimeric, polymeric, and secretory IgA2 derivatives of b12 reacted with gp120 and neutralized CCR5- and CXCR4-tropic strains of HIV-1 in vitro. With respect to the protective effects of these Abs at mucosal surfaces, we demonstrated that IgG1 b12 and IgA2 b12 inhibited the transfer of cell-free HIV-1 from ME-180 cells, a human cervical epithelial cell line, as well as Caco-2 cells, a human colonic epithelial cell line, to human PBMCs. Inhibition of viral transfer was due to the ability of b12 to block both viral attachment to and uptake by epithelial cells. These data demonstrate that IgG and IgA MAbs directed against a highly conserved epitope on gp120 can interfere with the earliest steps in HIV-1 transmission across mucosal surfaces, and reveal a possible mechanism by which b12 protects the vaginal mucosal against viral challenge in vivo.
Codominance of TLR2-Dependent and TLR2-Independent Modulation of MHC Class II inMycobacterium tuberculosisInfection In Vivo
Authors: Kincaid Eleanor Z. , Wolf Andrea J. , Desvignes Ludovic , Mahapatra Sebabrata , Crick Dean C. , Brennan Patrick J. , Pavelka Martin S. , Ernst Joel D. 
Published: April 2014

AbstractMycobacterium tuberculosis is an exceptionally successful human pathogen. A major component of this success is the ability of the bacteria to infect immunocompetent individuals and to evade eradication by an adaptive immune response that includes production of the macrophage-activating cytokine, IFN-γ. Although IFN-γ is essential for arrest of progressive tuberculosis, it is insufficient for efficacious macrophage killing of the bacteria, which may be due to the ability of M. tuberculosis to inhibit selected macrophage responses to IFN-γ. In vitro studies have determined that mycobacterial lipoproteins and other components of the M. tuberculosis cell envelope, acting as agonists for TLR2, inhibit IFN-γ induction of MHC class II. In addition, M. tuberculosis peptidoglycan and IL-6 secreted by infected macrophages inhibit IFN-γ induction of MHC class II in a TLR2-independent manner. To determine whether TLR2-dependent inhibition of macrophage responses to IFN-γ is quantitatively dominant over the TLR2-independent mechanisms in vivo, we prepared mixed bone marrow chimeric mice in which the hemopoietic compartment was reconstituted with a mixture of TLR+/+ and TLR2−/− cells. When the chimeric mice were infected with M. tuberculosis, the expression of MHC class II on TLR2+/+ and TLR2−/− macrophages from the lungs of individual infected chimeric mice was indistinguishable. These results indicate that TLR2-dependent and -independent mechanisms of inhibition of responses to IFN-γ are equivalent in vivo, and that M. tuberculosis uses multiple pathways to abrogate the action of an important effector of adaptive immunity.
Individual Variation of Scavenger Receptor Expression in Human Macrophages with Oxidized Low-Density Lipoprotein Is Associated with a Differential Inflammatory Response
Authors: Martín-Fuentes Paula , Civeira Fernando , Recalde Delia , García-Otín Angel Luis , Jarauta Estíbaliz , Marzo Isabel , Cenarro Ana 
Published: April 2014

Abstract
Atherosclerosis is an inflammatory disease in which oxidized low-density lipoprotein (oxLDL) plays important roles. Scavenger receptors (SR) CD36, SR-A, and LOX-1 uptake over 90% of the oxLDL leading to foam cell formation and secretion of inflammatory cytokines. To investigate whether the interindividual differences in macrophage SR gene expression could determine the inflammatory variability in response to oxLDL, we quantified the gene and protein expression of SR and inflammatory molecules from macrophages isolated from 18 volunteer subjects and incubated with oxLDL for 1, 3, 6, and 18 h. The individual gene expression profile of the studied SR at 1 h of incubation was highly variable, showing a wide fold-change range: CD36: −3.57–4.22, SR-A: −5.0–4.43, and LOX-1: −1.56–75.32. We identified subjects as high and low responders depending on whether their SR gene expression was above or below the median, showing a different inflammation response pattern. CD36 and LOX-1 gene expression correlated positively with IL-1β; SR-A correlated negatively with IL-8 and positively with PPARγ and NF-κBΙA. These results were confirmed in the same subjects 3 mo after the first sampling. Furthermore, a negative correlation existed between CD36 and SR-A at protein level after 18 h of oxLDL incubation (R = −0.926, p = 0.024). These data would suggest that the type of SR could determine the macrophage activation: more proinflammatory when associated to CD36 and LOX-1 than when associated with SR-A.
Th2 Differentiation in Distinct Lymph Nodes Influences the Site of Mucosal Th2 Immune-Inflammatory Responses
Authors: Alvarez David , Arkinson Janine L. , Sun Jiangfeng , Fattouh Ramzi , Walker Tina , Jordana Manel 
Published: April 2014

Abstract
Allergic individuals rarely present with concurrent multiple-organ disease but, rather, with manifestations that privilege a specific site such as the lung, skin, or gastrointestinal tract. Whether the site of allergic sensitization influences the localization of Th2 immune-inflammatory responses and, ultimately, the organ-specific expression of disease, remains to be determined. In this study, we investigated whether both the site of initial Ag exposure and concomitant Th2 differentiation in specific lymph nodes (LNs) privileges Th2 memory responses to mucosal and nonmucosal sites, and whether this restriction is associated with a differential expression in tissue-specific homing molecules. In mice exposed to Ag (OVA) via the peritoneum, lung, or skin, we examined several local and distal LNs to determine the site of Ag-specific proliferation and Th2 differentiation. Whereas respiratory and cutaneous Ag exposure led to Ag-specific proliferation and Th2 differentiation exclusively in lung- and skin-draining LNs, respectively, Ag delivery to the peritoneum evoked responses in gut-associated, as well as distal thoracic, LNs. Importantly, only mice that underwent Th2 differentiation in thoracic- or gut-associated LNs mounted Th2 immune-inflammatory responses upon respiratory or gastric Ag challenge, respectively, whereas cutaneous Th2 recall responses were evoked irrespective of the site of initial sensitization. In addition, we observed the differential expression of gut homing molecules (CCR9, α4, β7) in gut-associated LNs and, unexpectedly, a universal induction of skin-related homing molecules (CCR4, CCR10) in all LNs. These data suggest that the site of initial Th2 differentiation and differential homing molecule expression restricts Th2 immune-inflammatory responses to mucosal, but not cutaneous, tissues.
CD4+ T Cells Generated De Novo from Donor Hemopoietic Stem Cells Mediate the Evolution from Acute to Chronic Graft-versus-Host Disease
Authors: Zhang Yi , Hexner Elizabeth , Frank Dale , Emerson Stephen G. 
Published: April 2014

AbstractAcute and chronic graft-versus-host disease (GVHD) remain the major complications limiting the efficacy of allogeneic hemopoietic stem cell transplantation. Chronic GVHD can evolve from acute GVHD, or in some cases may overlap with acute GVHD, but how acute GVHD evolves to chronic GVHD is unknown. In this study, in a classical CD8+ T cell-dependent mouse model, we found that pathogenic donor CD4+ T cells developed from engrafted hemopoietic stem cells (HSCs) in C57BL/6SJL(B6/SJL, H-2b) mice suffering from acute GVHD after receiving donor CD8+ T cells and HSCs from C3H.SW mice (H-2b). These CD4+ T cells were activated, infiltrated into GVHD target tissues, and produced high levels of IFN-γ. These in vivo-generated CD4+ T cells caused lesions characteristic of chronic GVHD when adoptively transferred into secondary allogeneic recipients and also caused GVHD when administered into autologous C3H.SW recipients. The in vivo generation of pathogenic CD4+ T cells from engrafted donor HSCs was thymopoiesis dependent. Keratinocyte growth factor treatment improved the reconstitution of recipient thymic dendritic cells in CD8+ T cell-repleted allogeneic hemopoietic stem cell transplantation and prevented the development of pathogenic donor CD4+ T cells. These results suggest that de novo-generated donor CD4+ T cells, arising during acute graft-versus-host reactions, are key contributors to the evolution from acute to chronic GVHD. Preventing or limiting thymic damage may directly ameliorate chronic GVHD.
Peripheral Tolerance and the Qualitative Characteristics of Autoreactive T Cell Clones in Primary Biliary Cirrhosis
Authors: Kawano Akira , Shimoda Shinji , Kamihira Takashi , Ishikawa Fumihiko , Niiro Hiroaki , Soejima Yuji , Taketomi Akinobu , Maehara Yoshihiko , Nakamura Minoru , Komori Atsumasa , Migita Kiyoshi , Ishibashi Hiromi , Azuma Miyuki , Gershwin M. Eric , Harada Mine 
Published: April 2014

Abstract
Primary biliary cirrhosis is characterized by autoreactive T cells specific for the mitochondrial Ag PDC-E2163–176. We studied the ability of eight T cell clones (TCC) specific for PDC-E2163–176 to proliferate or become anergic in the presence of costimulation signals. TCC were stimulated with either human PDC-E2163–176, an Escherichia coli 2-oxoglutarate dehydrogenase mimic (OGDC-E234–47), or analogs with amino acid substitutions using HLA-matched allogeneic PBMC or mouse L-DR53 fibroblasts as APC. Based on their differential responses to these peptides (human PDC-E2163–176, E. coli OGDC-E234–47) in the different APC systems, TCC were classified as costimulation dependent or independent. Only costimulation-dependent TCC could become anergic. TCC with costimulation-dependent responses to OGDC-E2 become anergic to PDC-E2 when preincubated with mimic, even if costimulation is independent for PDC-E2163–176. Anergic TCC produced IL-10. One selected TCC could not become anergic after preincubation with PDC-E2163–176-pulsed L-DR53 but became anergic using L-DR53 pulsed with PDC-E2 peptide analogs with a substitution at a critical TCR binding site. TCC that only respond to peptide-pulsed PBMC, but not L-DR53, proliferate with peptide-pulsed CD80/CD86-transfected L-DR53; however, anergy was not induced with peptide-pulsed L-DR53 transfected with only CD80 or CD86. These data highlight that costimulation plays a dominant role in maintaining peripheral tolerance to PBC-specific Ags. They further suggest that, under specific circumstances, molecular mimicry of an autoantigen may restore rather than break peripheral tolerance.
Tumor-Derived Chemokine MCP-1/CCL2 Is Sufficient for Mediating Tumor Tropism of Adoptively Transferred T Cells
Authors: Brown Christine E. , Vishwanath Reena P. , Aguilar Brenda , Starr Renate , Najbauer Joseph , Aboody Karen S. , Jensen Michael C. 
Published: April 2014

Abstract
To exert a therapeutic effect, adoptively transferred tumor-specific CTLs must traffic to sites of tumor burden, exit the circulation, and infiltrate the tumor microenvironment. In this study, we examine the ability of adoptively transferred human CTL to traffic to tumors with disparate chemokine secretion profiles independent of tumor Ag recognition. Using a combination of in vivo tumor tropism studies and in vitro biophotonic chemotaxis assays, we observed that cell lines derived from glioma, medulloblastoma, and renal cell carcinoma efficiently chemoattracted ex vivo-expanded primary human T cells. We compared the chemokines secreted by tumor cell lines with high chemotactic activity with those that failed to elicit T cell chemotaxis (Daudi lymphoma, 10HTB neuroblastoma, and A2058 melanoma cells) and found a correlation between tumor-derived production of MCP-1/CCL2 (≥10 ng/ml) and T cell chemotaxis. Chemokine immunodepletion studies confirmed that tumor-derived MCP-1 elicits effector T cell chemotaxis. Moreover, MCP-1 is sufficient for in vivo T cell tumor tropism as evidenced by the selective accumulation of i.v. administered firefly luciferase-expressing T cells in intracerebral xenografts of tumor transfectants secreting MCP-1. These studies suggest that the capacity of adoptively transferred T cells to home to tumors may be, in part, dictated by the species and amounts of tumor-derived chemokines, in particular MCP-1.
B Subunit of Shiga Toxin-Based Vaccines Synergize with α-Galactosylceramide to Break Tolerance against Self Antigen and Elicit Antiviral Immunity
Authors: Adotevi Olivier , Vingert Benoit , Freyburger Ludovic , Shrikant Protul , Lone Yu-Chun , Quintin-Colonna Françoise , Haicheur Nacilla , Amessou Mohamed , Herbelin André , Langlade-Demoyen Pierre , Fridman Wolf H. , Lemonnier François , Johannes Ludger , Tartour Eric 
Published: April 2014

Abstract
The nontoxic B subunit of Shiga toxin (STxB) targets in vivo Ag to dendritic cells that preferentially express the glycolipid Gb3 receptor. After administration of STxB chemically coupled to OVA (STxB-OVA) or E7, a polypeptide derived from HPV, in mice, we showed that the addition of α-galactosylceramide (α-GalCer) resulted in a dramatic improvement of the STxB Ag delivery system, as reflected by the more powerful and longer lasting CD8+ T cell response observed even at very low dose of immunogen (50 ng). This synergy was not found with other adjuvants (CpG, poly(I:C), IFN-α) also known to promote dendritic cell maturation. With respect to the possible mechanism explaining this synergy, mice immunized with α-GalCer presented in vivo the OVA257–264/Kb complex more significantly and for longer period than mice vaccinated with STxB alone or mixed with other adjuvants. To test whether this vaccine could break tolerance against self Ag, OVA transgenic mice were immunized with STxB-OVA alone or mixed with α-GalCer. Although no CTL induction was observed after immunization of OVA transgenic mice with STxB-OVA, tetramer assay clearly detected specific anti-OVA CD8+ T cells in 8 of 11 mice immunized with STxB-OVA combined with α-GalCer. In addition, vaccination with STxB-OVA and α-GalCer conferred strong protection against a challenge with vaccinia virus encoding OVA with virus titers in the ovaries reduced by 5 log compared with nonimmunized mice. STxB combined with α-GalCer therefore appears as a promising vaccine strategy to more successfully establish protective CD8+ T cell memory against intracellular pathogens and tumors.
Cutting Edge: Selective Tyrosine Dephosphorylation of Interferon-Activated Nuclear STAT5 by the VHR Phosphatase
Authors: Hoyt Richard , Zhu Wei , Cerignoli Fabio , Alonso Andres , Mustelin Tomas , David Michael 
Published: April 2014

Abstract
Cytokine-induced tyrosine phosphorylation of the transcription factor STAT5 is required for its transcriptional activity. In this article we show that the small dual-specificity phosphatase VHR selectively dephosphorylates IFN-α- and β-activated, tyrosine-phosphorylated STAT5, leading to the subsequent inhibition of STAT5 function. Phosphorylation of VHR at Tyr138 was required for its phosphatase activity toward STAT5. In addition, the Src homology 2 domain of STAT5 was required for the effective dephosphorylation of STAT5 by VHR. The tyrosine kinase Tyk2, which mediates the phosphorylation of STAT5, was also responsible for the phosphorylation of VHR at Tyr138.
Histamine Improves Antigen Uptake and Cross-Presentation by Dendritic Cells
Authors: Amaral Maria Marta , Davio Carlos , Ceballos Ana , Salamone Gabriela , Cañones Cristian , Geffner Jorge , Vermeulen Mónica 
Published: April 2014

AbstractPrevious studies have shown that histamine is able to modulate the function of dendritic cells (DCs). Histamine seems to be required for the normal differentiation of DCs. Moreover, it is capable of stimulating the chemotaxis of immature DCs and of promoting the differentiation of T CD4+ cells into a Th2 profile. In this study, we analyzed whether histamine was able to modulate endocytosis and cross-presentation mediated by immature DCs. Our results show that both functions are stimulated by histamine. Endocytosis of soluble HRP and FITC-OVA and cross-presentation of soluble OVA were markedly increased by histamine. Interestingly, stimulation of endocytosis and cross-presentation appeared to be mediated through different histamine receptors. In fact, the enhancement of endocytosis was prevented by the histamine2 receptor (H2R) antagonist cimetidine, whereas the stimulation of cross-presentation was prevented by the H3R/H4R antagonist thioperamide. Of note, contrasting with the observations made with soluble Ags, we found that histamine did not increase either the uptake of OVA-attached to latex beads, or the cross-presentation of OVA immobilized on latex beads. This suggests that the ability of histamine to increase endocytosis and cross-presentation is dependent on the Ag form and/or the mechanisms through which the Ag is internalized by DCs. Our results support that histamine may favor cross-presentation of soluble allergens by DCs enabling the activation of allergen-specific T CD8+ cells, which appears to play an important role in the development of allergic responses in the airway.