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Query: UMLS:C0038362 (
stomatitis
)
8,852
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Costimulatory signals from dendritic cells (DCs) are required for naive T cells to respond to antigenic stimulation. To what extent DCs reactivate memory T cells during recall responses is not known. Here, an in vivo depletion system has been used to analyze the role of DCs in reactivating CD8 memory T cells during recall responses to three different microbial infections. We show a profound decrease in the numbers of responding memory CD8 T cells in both
lymphoid
and nonlymphoid tissues during the recall responses to infection with vesicular
stomatitis
virus, Listeria monocytogenes (Lm), or influenza virus. These data show that interaction with DCs is a major mechanism driving T cell reactivation in vivo, even during a tissue-specific infection of the respiratory tract.
...
PMID:Dendritic cells maximize the memory CD8 T cell response to infection. 1589 74
The chemokine receptor CXCR5 and its ligand CXCL13 define the structure of B cell follicles within secondary
lymphoid
organs. Here, we examined the impact of CXCR5 on antiviral B cell responses in vivo. CXCR5-/- mice showed a normal production of IgM and IgG acutely after infection with vesicular
stomatitis
virus (VSV) and developed VSV-specific germinal centers. However, impaired Ig class switch and Ab production were observed under conditions of limited availability of Ag (i.e., after immunization with nonreplicating viral particles or soluble Ag). Adoptive transfer of CXCR5-deficient, VSV-specific B and Th cells demonstrated that CXCR5 expression on both B and Th cells is required for an efficient Ig class switch. These experiments revealed that CXCR5 is critical for the coordinated interaction of antiviral T and B cells through its impact on initial B cell expansion and the recruitment of Ag-specific B and Th cells to germinal centers.
...
PMID:CXCR5-dependent seeding of follicular niches by B and Th cells augments antiviral B cell responses. 1630 13
In practice, vaccines should induce lasting and efficacious T cell immunity without promoting deleterious pathological consequences. To accomplish this goal we immunized mice with ovalbumin peptide, polyinosinic-polycytidylic and anti-CD137. Vaccinated mice retained a massive functional CD8 T cell memory pool in
lymphoid
and non-
lymphoid
tissues for >1 year. The memory T cells clonally expanded, produced substantial amounts of IFNgamma, and responded vigorously to vesicular
stomatitis
virus infection. To understand how the vaccine might function, we showed that the antigen-specific T cells must bear CD137 in order for optimal priming to occur. Thus, anti-CD137 agonist mAb directly stimulated peptide-specific CD8 T cells and conditioned them to survive. In contrast, CD137-deficient CD8 T cells did not survive despite CD137 expression by antigen presenting cells. Taken together, the data indicate that CD137 and adjuvant combined therapy is an efficacious vaccine strategy for immunization with non-replicating inert antigen.
...
PMID:Combined CD137 (4-1BB) and adjuvant therapy generates a developing pool of peptide-specific CD8 memory T cells. 1637 63
Interaction of lymphotoxin alpha(1)beta(2) (LTalpha(1)beta(2)) with its receptor is key for the generation and maintenance of secondary
lymphoid
organ microstructure. We used mice conditionally deficient for LTbeta on different lymphocyte subsets to determine how the LTbeta-dependent
lymphoid
structure influences immune reactivity. All conditionally LTbeta-deficient mice mounted normal immune responses against vesicular
stomatitis
virus (VSV), and were protected against lymphocytic choriomeningitis virus (LCMV). In contrast, they exhibited reduced immune responses against non-replicating antigens. Completely LTbeta-deficient mice failed to retain VSV in the marginal zone and died from VSV infections, and they became virus carriers following infection with the non-cytopathic LCMV, which was correlated with defective virus replication in dendritic cells. It was ruled out that LTbeta expression on lymphocytes influenced their activation, homing capacity, or maturation. We therefore conclude that LTbeta expression influences immune reactivity at two distinct levels: (i) Expression of LTbeta on lymphocytes enhances the induction of immune responses against limiting amounts of antigen. (ii) Expression of LTbeta on non-lymphocytes governs antiviral immunity by enhancing antigen presentation on antigen-presenting cells. This prevents cytotoxic T lymphocytes exhaustion or death of the host by uncontrolled virus spread.
...
PMID:Expression of lymphotoxin beta governs immunity at two distinct levels. 1684 Dec 97
Whether memory CD8 T cells can be reactivated in nonlymphoid tissues is unclear. Using mice lacking the spleen, lymph nodes, or both, we show that the secondary T cell response, but not homeostatic maintenance of memory cells, required
lymphoid
tissue. Whereas primary and secondary CD8 T cell responses to vesicular
stomatitis
virus infection were lymph node dependent, responses to Listeria monocytogenes infection were driven primarily in the spleen. Memory cell subset reactivation was also regulated by location of the responding population and the pathogen. Thus, CD62Llow effector memory T cells (TEM) cells responded nearly as well as CD62Lhigh central memory T cells (TCM) and TCM cells after L. monocytogenes infection, and both subsets generated equivalent populations of secondary memory cells. In contrast, TCM cells, but not TEM cells, mounted a robust response to vesicular
stomatitis
virus infection. TCM and TEM cells also required
lymphoid
tissue to mount recall responses, and the bone marrow did not contribute significantly to the response of either subset. Our findings indicated that characteristics of the infectious agent and the migratory preferences of memory cells dictated the secondary
lymphoid
tissue requirement for the recall response to infection.
...
PMID:CD8 T cell recall responses are regulated by the tissue tropism of the memory cell and pathogen. 1708 87
The present study describes pathologic and virologic findings in 15 sheep and 6 goats that died of natural peste des petits ruminants virus infection in Turkey. Pathologic findings included erosive-ulcerative
stomatitis
, fibrino-necrotic tracheitis, bronchointerstitial pneumonia, multifocal coagulation necroses in the liver, and severe lymphocytolysis in
lymphoid
tissues. Syncytial cells were conspicuous, especially in the oral mucosa, pulmonary alveoli, liver, and
lymphoid
tissues. In addition to the typical tissue distribution, eosinophilic intracytoplasmic and/or intranuclear inclusions were observed in epithelial cells lining the renal pelvis and abomasal mucosa. Immunolabeling of the viral antigen was observed in the kidney, brain, rumen, abomasum, heart, and myocytes of the tongue besides its more typical locations. In this study, we report and describe in detail the first peste des petits ruminants endemic in Kirikkale Province, Central Anatolia of Turkey. In conclusion, these previously unreported pathologic findings in natural peste des petits ruminants virus infection establish a basis for resemblance to other morbillivirus infections, such as canine distemper and distemper of sea mammals. Reverse transcriptase-polymerase chain reaction analyses indicated that the 448-bp genome fragment was amplified in 18 cases (18/21, 85.7 %). Phylogenetic analysis showed that viruses belong to lineage 4 in the peste des petits ruminants virus common phylogenetic tree.
...
PMID:Natural peste des petits ruminants virus infection: novel pathologic findings resembling other morbillivirus infections. 1760 9
Type I interferon (IFN) is critical for resistance of mice to infection with vesicular
stomatitis
virus (VSV). Wild type (wt) VSV infection did not induce type I IFN production in vitro or in the central nervous system (CNS) of mice; however IFN-beta was detected in lungs, spleen, and serum within 24 h. The M protein mutant VSV, T1026R1 (also referred to as M51R), induced type I IFN production in vitro and in the CNS, with poor expression in spleens. In addition, VSV T1026R1 was not pathogenic to mice after intranasal infection, illustrating the importance of IFN in controlling VSV replication in the CNS. Experiments with chemical sympathectomy, sRAGE, and neutralizing antibody to VSV were performed to investigate the mechanism(s) utilized for induction of peripheral IFN; neither sRAGE infusion nor chemical sympathectomy had an effect on peripheral IFN production. In contrast, administration of neutralizing antibody (Ab) readily blocked the response. Infectious VSV was transiently present in lungs and spleens at 24 h post infection. The results are consistent with VSV traffic from the olfactory neuroepithelium to peripheral
lymphoid
organs hematogenously or via lymphatic circulation. These results suggest that VSV replicates to high titers in the brains of mice because of the lack of IFN production in the CNS after intranasal VSV infection. In contrast, replication of VSV in peripheral organs is controlled by the production of large amounts of IFN.
...
PMID:Peripheral, but not central nervous system, type I interferon expression in mice in response to intranasal vesicular stomatitis virus infection. 1799 28
Chronic immune activation is a major cause for progressive immunodeficiency in human immunodeficiency virus type-1 (HIV) infection. The underlying trigger, however, remains largely unknown. HIV single-stranded RNA is a potent immune activator by triggering Toll-like receptor (TLR) 7/8. Thus, we hypothesized that sustained TLR7 triggering induces chronic immune activation and thereby contributes to progressive immunodeficiency. We used the synthetic compound R848 or a mixture of uridine-rich HIV single-stranded (ss) RNA oligonucleotides--both are potent TLR7/8 agonists--to explore the effects of sustained TLR7 triggering on the murine
lymphoid
system. Sustained TLR7 triggering induced an immunopathology reminiscent of progressive
lymphoid
destruction in HIV disease; we observed lymphopenia, elevated proinflammatory cytokines, splenomegaly, contracted
lymphoid
subsets, and
lymphoid
microarchitecture alteration with reduced marginal zone B-lymphocytes. Upon exposure to inactivated vesiculo-
stomatitis
virus, antibody production was abolished, although splenic lymphocytes were activated and total IgG was elevated. Our data imply that HIV itself may directly contribute to immune activation and dysfunction by stimulating TLR7. Thus, manipulation of TLR7 signaling may be a potential strategy to reduce chronic hyper-immune activation and, thereby, disease progression in HIV infection.
...
PMID:Triggering TLR7 in mice induces immune activation and lymphoid system disruption, resembling HIV-mediated pathology. 1913 56
Epstein-Barr virus (EBV) is a herpesvirus that is associated with development of malignancies of
lymphoid
tissue. EBV infections are life-long and occur in >90% of the population. Herpesviruses enter host cells in a process that involves fusion of viral and cellular membranes. The fusion apparatus is comprised of envelope glycoprotein B (gB) and a heterodimeric complex made of glycoproteins H and L. Glycoprotein B is the most conserved envelope glycoprotein in human herpesviruses, and the structure of gB from Herpes simplex virus 1 (HSV-1) is available. Here, we report the crystal structure of the secreted EBV gB ectodomain, which forms 16-nm long spike-like trimers, structurally homologous to the postfusion trimers of the fusion protein G of vesicular
stomatitis
virus (VSV). Comparative structural analyses of EBV gB and VSV G, which has been solved in its pre and postfusion states, shed light on gB residues that may be involved in conformational changes and membrane fusion. Also, the EBV gB structure reveals that, despite the high sequence conservation of gB in herpesviruses, the relative orientations of individual domains, the surface charge distributions, and the structural details of EBV gB differ from the HSV-1 protein, indicating regions and residues that may have important roles in virus-specific entry.
...
PMID:Structure of a trimeric variant of the Epstein-Barr virus glycoprotein B. 1919 55
In a previously developed infant macaque model mimicking HIV infection by breast-feeding, we demonstrated that intramuscular immunization with recombinant poxvirus vaccines expressing simian immunodeficiency virus (SIV) structural proteins provided partial protection against infection following oral inoculation with virulent SIV. In an attempt to further increase systemic but also local antiviral immune responses at the site of viral entry, we tested the immunogenicity of different orally administered, replicating vaccines. One group of newborn macaques received an oral prime immunization with a recombinant vesicular
stomatitis
virus expressing SIVmac239 gag, pol and env (VSV-SIVgpe), followed 2 weeks later by an intramuscular boost immunization with MVA-SIV. Another group received two immunizations with live-attenuated SIVmac1A11, administered each time both orally and intravenously. Control animals received mock immunizations or non-SIV VSV and MVA control vectors. Analysis of SIV-specific immune responses in blood and
lymphoid
tissues at 4 weeks of age demonstrated that both vaccine regimens induced systemic antibody responses and both systemic and local cell-mediated immune responses. The safety and immunogenicity of the VSV-SIVgpe+MVA-SIV immunization regimen described in this report provide the scientific incentive to explore the efficacy of this vaccine regimen against virulent SIV exposure in the infant macaque model.
...
PMID:Immunogenicity of viral vector, prime-boost SIV vaccine regimens in infant rhesus macaques: attenuated vesicular stomatitis virus (VSV) and modified vaccinia Ankara (MVA) recombinant SIV vaccines compared to live-attenuated SIV. 1999 39
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