RESUMO
Translation of drug candidates into clinical settings requires demonstration of preclinical efficacy and formal toxicology analysis for filling an Investigational New Drug (IND) application with the US Food and Drug Administration (FDA). Here, we investigate the membrane-associated glucose response protein 78 (GRP78) as a therapeutic target in leukemia and lymphoma. We evaluated the efficacy of the GRP78-targeted proapoptotic drug bone metastasis targeting peptidomimetic 78 (BMTP-78), a member of the D(KLAKLAK)2-containing class of agents. BMTP-78 was validated in cells from patients with acute myeloid leukemia and in a panel of human leukemia and lymphoma cell lines, where it induced dose-dependent cytotoxicity in all samples tested. Based on the in vitro efficacy of BMTP-78, we performed formal good laboratory practice toxicology studies in both rodents (mice and rats) and nonhuman primates (cynomolgus and rhesus monkeys). These analyses represent required steps towards an IND application of BMTP-78 for theranostic first-in-human clinical trials.
Assuntos
Avaliação Pré-Clínica de Medicamentos , Proteínas de Choque Térmico/genética , Leucemia/tratamento farmacológico , Linfoma/tratamento farmacológico , Peptidomiméticos/administração & dosagem , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Chaperona BiP do Retículo Endoplasmático , Proteínas de Choque Térmico/antagonistas & inibidores , Humanos , Leucemia/patologia , Linfoma/patologia , Macaca fascicularis , Macaca mulatta , Camundongos , Terapia de Alvo Molecular , Peptidomiméticos/efeitos adversos , Primatas , Ratos , Estados Unidos , United States Food and Drug AdministrationRESUMO
BACKGROUND: The aim of the present study was to evaluate the subjective outcome of primary repair of obstetric anal sphincter injury (OASIS) at 6 months, the factors associated with the symptoms of anal incontinence (AI), and the role of a simple survey consisting in one question with three answer choices, combined with the Wexner incontinence score for the assessment of this patient population. METHODS: A retrospective cohort study was conducted on patients with third- or fourth-degree OASIS operated on between January 2007 and December 2013 inclusive at Tampere University Hospital, Finland. At 6 months, the patients were asked to report their Wexner's score as well as the three-choice assessment regarding AI symptoms. Based on this assessment, the patients were divided into three groups: those, asymptomatic, those with mild symptoms who did not want further treatment and those with severe symptoms who were willing to undergo further evaluation and treatment. RESULTS: There were 325 patients (median age 30 years). A total of 310 patients answered the questionnaire. Of which, one hundred and ninety-eight (63.9%) patients were asymptomatic, 85 (27.4%) had mild AI, and 27 (8.7%) experienced severe symptoms. There was no statistical difference in the results between the two techniques used (overlapping vs. end-to-end), or the stage of specialization of the operating physician. Persistent symptoms were associated with instrumental vaginal delivery (OR 2.12, 95% CI 1.32-3.41), severity of the injury (OR 1.64, 95% CI 1.20-2.25), and increased maternal age (OR 1.07, 95% CI 1.02-1.13). The correlation between the three-choice symptom evaluation and the Wexner score was good (Spearman's rho 0.82). CONCLUSIONS: After 6 months, severe symptoms after OASIS repair were present in 9% of women and were more frequent in older women, women with high-degree tears and after instrumental vaginal delivery. A three-choice assessment of AI symptoms correlated well with the Wexner score and might be useful to triage patients who need further evaluation.
Assuntos
Canal Anal/lesões , Canal Anal/cirurgia , Parto Obstétrico/efeitos adversos , Incontinência Fecal/etiologia , Índice de Gravidade de Doença , Inquéritos e Questionários , Adulto , Parto Obstétrico/métodos , Extração Obstétrica/efeitos adversos , Feminino , Humanos , Manometria , Idade Materna , Gravidez , Estudos Retrospectivos , Avaliação de Sintomas , Índices de Gravidade do TraumaRESUMO
Activation studies performed with transfected T cell hybridomas and tumors revealed that chimeric molecules containing the CD3 epsilon or zeta chain intracytoplasmic portions can induce the complete effector functions normally seen only when the complete T cell receptor (TCR)/CD3 complexes of T lymphocytes are triggered. Therefore, the zeta chain, with its three antigen recognition activation motives, is thought to connect the antigen-binding Ti chains with the intracellular signaling machinery of the T cell. Here we demonstrate that the cytoplasmic portion of the TCR-zeta chain is not sufficient to activate resting T lymphocytes when cells from transgenic mice expressing a chimeric zeta receptor are used. However, after (in vivo and in vitro) activation through their endogenous TCR/CD3 complexes, the preactivated T lymphocytes could be triggered through the zeta chimera to the same extent as when they were activated through their endogenous TCR/CD3 complexes. They were able to proliferate and elicit cytotoxic functions when triggered through their zeta chimeras. These results suggest that the triggering requirements for effector functions seem to be different in resting than in activated T cells.
Assuntos
Ativação Linfocitária , Proteínas de Membrana/fisiologia , Receptores de Antígenos de Linfócitos T/fisiologia , Linfócitos T/imunologia , Animais , Sequência de Bases , Cálcio/metabolismo , Citotoxicidade Imunológica , Hibridomas , Camundongos , Camundongos Transgênicos , Dados de Sequência Molecular , Complexo Receptor-CD3 de Antígeno de Linfócitos T/fisiologia , Células Tumorais CultivadasRESUMO
It is well established that lymphoid dendritic cells (DC) play an important role in the immune system. Beside their role as potent inducers of primary T cell responses, DC seem to play a crucial part as major histocompatibility complex (MHC) class II+ "interdigitating cells" in the thymus during thymocyte development. Thymic DC have been implicated in tolerance induction and also by some authors in inducing major histocompatibility complex restriction of thymocytes. Most of our knowledge about thymic DC was obtained using highly invasive and manipulatory experimental protocols such as thymus reaggregation cultures, suspension cultures, thymus grafting, and bone marrow reconstitution experiments. The DC used in those studies had to go through extensive isolation procedures or were cultured with recombinant growth factors. Since the functions of DC after these in vitro manipulations have been reported to be not identical to those of DC in vivo, we intended to establish a system that would allow us to investigate DC function avoiding artificial interferences due to handling. Here we present a transgenic mouse model in which we targeted gene expression specifically to DC. Using the CD 11c promoter we expressed MHC class II I-E molecules specifically on DC of all tissues, but not on other cell types. We report that I-E expression on thymic DC is sufficient to negatively select I-E reactive CD4+ T cells, and to a less complete extent, CD8+ T cells. In contrast, it only DC expressed I-E in a class II-deficient background, positive selection of CD4+ T cells could not be observed. Thus negative, but not positive, selection events can be induced by DC in vivo.
Assuntos
Células Dendríticas/fisiologia , Antígenos de Histocompatibilidade Classe II/genética , Linfócitos T/fisiologia , Animais , Antígenos CD11/genética , Clonagem Molecular , Antígenos de Histocompatibilidade Classe II/fisiologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Ratos , Timo/imunologiaRESUMO
A striking feature of the T cell receptor (TCR) beta chain structure is the large FG loop that protrudes freely into the solvent on the external face of the Cbeta domain. We have already shown that a transgene-encoded Vbeta8.2(+) TCR beta chain lacking the complete Cbeta FG loop supports normal development and function of conventional alpha/beta T cells. Thus, the FG loop is not absolutely necessary for TCR signaling. However, further analysis has revealed that a small population of alpha/beta T cells coexpressing NK1.1 are severely depleted in these transgenic mice. The few remaining NK1.1 T cells have a normal phenotype but express very low levels of TCR. We find that the TCR Vbeta8.2(+) chain lacking the Cbeta FG loop cannot pair efficiently with the invariant Valpha14-Jalpha281 TCR alpha chain commonly expressed by this T cell family. Consequently, fewer NK1.1 T cells develop in these mice. Our results suggest that expression of the Valpha14(+) TCR alpha chain is particularly sensitive to TCR-beta conformation. Development of NK1.1 T cells appears to need a TCR-beta conformation dependent on the presence of the Cbeta loop that is not necessarily required for assembly and function of TCRs on most alpha/beta T cells.
Assuntos
Células Matadoras Naturais/metabolismo , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Animais , Células Cultivadas , Citometria de Fluxo , Regulação da Expressão Gênica no Desenvolvimento/imunologia , Fígado/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos , Camundongos Knockout , Camundongos Transgênicos , Ligação Proteica , Conformação Proteica , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Transdução de Sinais/imunologiaRESUMO
The striking and unique structural feature of the T cell receptor (TCR) beta chain is the bulky solvent-exposed FG loop on the Cbeta domain, the size of almost half an immunoglobulin domain. The location and size of this loop suggested immediately that it could be a crucial structural link between the invariant CD3 subunits and antigen-recognizing alpha/beta chains during TCR signaling. However, functional analysis does not support the above notion, since transgene coding for TCR beta chain lacking the complete FG loop supports normal alpha/beta T cell development and function.
Assuntos
Receptores de Antígenos de Linfócitos T alfa-beta/genética , Linfócitos T/imunologia , Animais , Divisão Celular , Linhagem Celular , Citometria de Fluxo , Hibridomas , Imunoglobulina G/análise , Camundongos , Camundongos Endogâmicos , Camundongos Transgênicos , Mutagênese , Nitro-Hidroxi-Iodofenilacetato/imunologia , Ovalbumina/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/química , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Deleção de Sequência , TransfecçãoRESUMO
Hybridoma cell lines secreting antibodies specific to (3-nitro-4-hydroxyphenyl) acetyl (NP) were generated by fusion of NP-immunized SJL spleen cells with the SP2/0 cell line. One hybridoma (N-hybridoma) anti-NP antibody (mu, lambda2) was found to partially inhibit (35-40%) the binding of the predominant idiotype in primary C57BL/6 anti-NP antibodies (NPb). Iodinated hybridoma antibody could be completely bound with anti-idiotypic antiserum made against either specifically purified C57BL/6 anti-NP antibodies, SJL anti-NP antibodies, or N-hybridoma antibody. The idiotypic specificities defined with anti-idiotypic antiserum made against N-hybridoma antibody were termed NP-1 idiotype. Strain distribution and genetic mapping studies indicate that the gene(s) controlling the production of NP-1 idiotype is closely associated with Igh-1b and Igh-1e alleles and mapped within the same chromosomal segment that controls the synthesis of NPb idiotype. However, unlike NPb idiotype, the expression of NP-1 idiotype is not influenced by the gene(s) that control lambda1 chain synthesis. Thus, SJL mice that produce low or undetectable levels of NPb idiotype due to a defect in lambda1 chain production express high levels of NP-1 idiotype. Specifically purified C57BL/6 and SJL anti-NP antibodies fully express NP-1 idiotype, the level of which correlates with the level of lambda2 chain-bearing molecules. Nonetheless, further experiments indicate that lambda1-bearing anti-NP antibodies can express extremely weak NP-1 idiotypic cross-reactivity.
Assuntos
Idiótipos de Imunoglobulinas , Cadeias Leves de Imunoglobulina/biossíntese , Cadeias lambda de Imunoglobulina/biossíntese , Nitrofenóis/imunologia , Animais , Especificidade de Anticorpos , Sítios de Ligação de Anticorpos , Mapeamento Cromossômico , Reações Cruzadas , Cabras , Cobaias , Hibridomas/imunologia , Idiótipos de Imunoglobulinas/biossíntese , Camundongos , Camundongos Endogâmicos C57BL , Fenilacetatos , CoelhosRESUMO
We have established in culture 13 clones from the thymus of a 14-d B10.BR mouse embryo and characterized 8 of them. All eight FT clones have the TCR-gamma and -beta genes in germline configuration. They express mRNA for the gamma, but not for the beta nor the alpha genes. All eight FT clones are Thy-1+, Ly-1+, LFA-1+, Pgp-1+, H-2K+, and T3-. Three phenotypes could be distinguished on the basis of Lyt-2, L3T4, and IL-2-R expression: Lyt-2+, L3T4-, IL-2-R+ (I); Lyt-2+, L3T4-, IL-2-R- (II); and Lyt-2+, L3T4+, IL-2-R+ (III) cells. All eight clones grow in rIL-4 and six clones also proliferate in rIL-2. Antibodies specific for IL-2-R inhibit their response to rIL-2 but not to rIL-4. The eight FT clones synthesize mRNA for IL-4 after stimulation in vitro and none of them exhibit cytolytic activity or helper function for B lymphocytes. We conclude that the FT clones are at a very early stage of T cell development, that the expression of Lyt-2 and L3T4 surface molecules can precede that of the antigen receptor, and that the same fetal thymocyte can use both IL-4 and IL-2 as growth factor.
Assuntos
Antígenos de Superfície/genética , Receptores de Antígenos de Linfócitos T/genética , Linfócitos T/imunologia , Animais , Antígenos Ly/genética , Divisão Celular , Células Cultivadas , Células Clonais , Embrião de Mamíferos , Interleucina-2/genética , Interleucina-2/farmacologia , Interleucina-4 , Interleucinas/genética , Interleucinas/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Camundongos Endogâmicos DBA , Hibridização de Ácido Nucleico , Fenótipo , RNA Mensageiro/genética , Linfócitos T/metabolismo , Acetato de Tetradecanoilforbol/farmacologiaRESUMO
Antibodies to hapten 2-phenyloxazolone (phOx) of all BALB/c and DBA/2 mice have the same idiotype and the same major (public) isoelectric focusing pattern whose main spectrotype is called Ox-1. Neither of these characteristics could be readily demonstrated in anti-phOx antibodies of C57BL, C3H or LP mice; these antibodies were heterogeneous, and lacked public spectrotypes. Also, a fine specificty difference could be demonstrated between anti-phOx antibodies of BALB/c and C5MBL mice; the latter have a higher relative affinity than the former for a structural analogue of phOx (2-o-iodophenyloxazolone). The three BALB/c characteristics were inherited in congenic and recombinant inbred strains as an allotype-linked block, defining a new VH marker, VHphOx. Murine anti-phOx antibodies were found to exhibit three types of conservatism: (a) Every individual mouse of strains BALB/c, DBA/2 or BAB-14 had an almost indistinguishable IEF pattern. (b) These patterns (and the cross-reactive idiotype) remained virtually unchanged during an immunization course of 70 days. (c) An identical idiotype (and in some cases IEF pattern) was present in mouse strains of five different allogroups.
Assuntos
Especificidade de Anticorpos , Idiótipos de Imunoglobulinas/genética , Camundongos Endogâmicos/imunologia , Oxazóis/imunologia , Oxazolona/imunologia , Animais , Feminino , Haptenos , Alótipos de Imunoglobulina/genética , Memória Imunológica , Focalização Isoelétrica , Camundongos , Camundongos Endogâmicos/genética , Oxazolona/análogos & derivados , Especificidade da Espécie , Relação Estrutura-AtividadeRESUMO
We describe mice that express a transgenic T cell receptor alpha/beta (TCR-alpha/beta) specific for peptide 111-119 from influenza hemagglutinin presented by I-Ed class II major histocompatibility complex (MHC) molecules. The transgenic TCR is expressed on CD4+8- as well as CD4-8+ mature T cells even in mice that are deficient in rearrangement or do not express endogenous TCR-alpha genes. The CD4-8+ T cells require I-Ed class II MHC molecules for positive selection and can be activated to proliferate and to kill by I-Ed molecules presenting the relevant peptide. Full maturation of these cells, however, also requires the presence of class I MHC molecules. The results are compatible with the notion that T cell maturation requires multiple receptor-ligand interactions and establish an exception to the rule that class II-restricted TCRs are exclusively expressed by mature CD4+8- cells.
Assuntos
Antígenos CD8/análise , Proteínas de Ligação a DNA , Antígenos de Histocompatibilidade Classe II/fisiologia , Receptores de Antígenos de Linfócitos T alfa-beta/fisiologia , Subpopulações de Linfócitos T/imunologia , Timo/imunologia , Animais , Antígenos CD4/análise , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas/análise , Receptores de Antígenos de Linfócitos T alfa-beta/genéticaRESUMO
The continuous proliferating bone marrow clones C4-77, C4-86, and C4-95 express low levels of Thy-1 and Ly-1 surface antigens, but no detectable surface antigens normally present on thymocytes, peripheral mature T lymphocytes, cells of the B lymphocyte or myeloid lineages. They contain the T cell antigen receptor genes alpha, beta, and the T cell-specific gene gamma in the germline configuration, and they express functional receptors for IL-3 and nonfunctional receptors for IL-2. The C4 clones are able to home and undergo differentiation in the thymus of sublethally irradiated mice and give rise in vivo to phenotypically and functionally mature peripheral T lymphocytes displaying several antigen specificities. In vitro 5-Azacytidine induces the C4 clones to express Lyt-2 and L3T4 T cell differentiation antigens, and renders them amenable to be switched from IL-3 to IL-2 dependence. However, the C4 clones seem incapable of giving rise to B lymphocytes either in vivo or in vitro. They self-renew in vitro in the presence of IL-3 every 12-14 h. We conclude that the C4 clones represent cells at the earliest stage of T cell development, i.e., Pro-T lymphocytes.
Assuntos
Células da Medula Óssea , Células-Tronco Hematopoéticas/citologia , Linfócitos T/citologia , Animais , Antígenos de Superfície/análise , Diferenciação Celular , Divisão Celular , Células Clonais/citologia , DNA Recombinante , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Camundongos Endogâmicos DBA , Camundongos Mutantes , Fenótipo , Receptores de Antígenos de Linfócitos T/genética , Linfócitos T/imunologiaRESUMO
The three-dimensional structure of an unglycosylated T cell antigen receptor (TCR) beta chain has recently been determined to 1.7 A resolution. To investigate whether this soluble beta chain (murine V beta 8.2J beta 2.1C beta 1) retains superantigen (SAG)-binding activity, we measured its affinity for various bacterial SAGs in the absence of MHC class II molecules. Dissociation constants (KDs) were determined using two independent techniques: surface plasmon resonance detection and sedimentation equilibrium. Specific binding was demonstrated to staphylococcal enterotoxins (SEs) B, C1, C2, and C3 and to streptococcal pyrogenic exotoxin A (SPEA), consistent with the known proliferative effects of these SAGs on T cells expressing V beta 8.2. In contrast, SEA, which does not stimulate V beta 8.2-bearing cells, does not bind the recombinant beta chain. Binding of the beta chain to SAGs was characterized by extremely fast dissociation rates (> 0.1 s-1), similar to those reported for certain leukocyte adhesion molecules. Whereas the beta chain bound SEC1, 2, and 3 with KDs of 0.9-2.5 microM, the corresponding value for SEB was approximately 140 microM. The much weaker binding to SEB than to SEC1, 2, or 3 was surprising, especially since SEB was found to actually be 3- to 10-fold more effective, on a molar basis, than the other toxins in stimulating the parental T cell hybridoma. We interpret these results in terms of the ability of SEC to activate T cells independently of MHC, in contrast to SEB. We have also measured SE binding to the glycosylated form of the beta chain and found that carbohydrate apparently does not contribute to recognition, even though the N-linked glycosylation sites at V beta 8.2 residues Asn24 and Asn74 are at or near the putative SAG-binding site. This result, along with the structural basis for the V beta specificity of SEs, are discussed in relation to the crystal structure of the unglycosylated beta chain.
Assuntos
Enterotoxinas/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Superantígenos/metabolismo , Enterotoxinas/metabolismo , Glicosilação , Humanos , Cinética , Ativação Linfocitária , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Proteínas Recombinantes , Solubilidade , Staphylococcus aureus/imunologia , Relação Estrutura-Atividade , UltracentrifugaçãoRESUMO
The three-dimensional structure of the complex between a T cell receptor (TCR) beta chain (mouse Vbeta8.2Jbeta2.1Cbeta1) and the superantigen (SAG) staphylococcal enterotoxin C3 (SEC3) has been recently determined to 3.5 resolution. To evaluate the actual contribution of individual SAG residues to stabilizing the beta-SEC3 complex, as well as to investigate the relationship between the affinity of SAGs for TCR and MHC and their ability to activate T cells, we measured the binding of a set of SEC3 and staphylococcal enterotoxin B (SEB) mutants to soluble recombinant TCR beta chain and to the human MHC class II molecule HLA-DR1. Affinities were determined by sedimentation equilibrium and/or surface plasmon detection, while mitogenic potency was assessed using T cells from rearrangement-deficient TCR transgenic mice. We show that there is a clear and simple relationship between the affinity of SAGs for the TCR and their biological activity: the tighter the binding of a particular mutant of SEC3 or SEB to the TCR beta chain, the greater its ability to stimulate T cells. We also find that there is an interplay between TCR-SAG and SAG-MHC interactions in determining mitogenic potency, such that a small increase in the affinity of a SAG for MHC can overcome a large decrease in the SAG's affinity for the TCR. Finally, we observe that those SEC3 residues that make the greatest energetic contribution to stabilizing the beta-SEC3 complex ("hot spot" residues) are strictly conserved among enterotoxins reactive with mouse Vbeta8.2, thereby providing a basis for understanding why SAGs having other residues at these positions show different Vbeta-binding specificities.
Assuntos
Enterotoxinas/metabolismo , Antígeno HLA-DR1/metabolismo , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Superantígenos/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Ativação Linfocitária , Camundongos , Camundongos Transgênicos , Dados de Sequência Molecular , Mutação , Linfócitos T/imunologiaRESUMO
BACKGROUND AND AIMS: minilaparotomy (MC) and laparoscopic cholecystectomy (LC) are commonly applied surgical techniques in the management of symptomatic gallstone disease. Both techniques are used in day surgery patients, but to our knowledge MC and LC have not been compared in randomised trials as day surgery procedures. MATERIAL AND METHODS: in this randomised parallel group clinical trial we compared the suc-cess rate of day surgery of MC with that of LC in 60 consecutive patients with non-complicated symptomatic gallstones presented for elective surgery at the Kuusankoski District Hospital (n = 38) and the Kuopio University Hospital (n = 22). Twenty nine patients underwent MC and 31 LC. The patients' outcome was recorded up to four weeks after the operation. RESULTS: the success rate as a day surgery for MC was 66% (19/29) and that for LC 55% (17/31) with no difference between the two groups. Chronic cholecystitis, postoperative nausea and vomiting were significant variables associated with failure in day surgery. There was no difference between the two groups in operation time, perioperative bleeding, conversion to conventional open cholecystectomy (one with MC and three with LC), length of hospital stay or sick leave. Three patients developed superficial infection (two with MC and one with LC). One patient with conversion in the LC-group developed a common bile duct stricture and was readmitted at the 10th postoperative day. DISCUSSION: both MC and LC are feasible surgical techniques for day surgery. However, appropriate prevention and prompt management of established postoperative nausea and vomit-ing and careful patient selection are important aspects for success of short-stay approach. If there is a sign of chronic cholecystitis preoperatively, it might be considered as a contraindication for day surgery.
Assuntos
Colecistectomia Laparoscópica , Colecistectomia/métodos , Colelitíase/cirurgia , Procedimentos Cirúrgicos Ambulatórios/métodos , Colecistite/etiologia , Colecistite/cirurgia , Colelitíase/complicações , Contraindicações , Humanos , Laparotomia/métodos , Tempo de Internação , Estudos ProspectivosRESUMO
The crystal structure of the extracellular portion of the beta chain of a murine T cell antigen receptor (TCR), determined at a resolution of 1.7 angstroms, shows structural homology to immunoglobulins. The structure of the first and second hypervariable loops suggested that, in general, they adopt more restricted sets of conformations in TCR beta chains than those found in immunoglobulins; the third hypervariable loop had certain structural characteristics in common with those of immunoglobulin heavy chain variable domains. The variable and constant domains were in close contact, presumably restricting the flexibility of the beta chain. This may facilitate signal transduction from the TCR to the associated CD3 molecules in the TCR-CD3 complex.
Assuntos
Receptores de Antígenos de Linfócitos T alfa-beta/química , Sequência de Aminoácidos , Animais , Gráficos por Computador , Cristalografia por Raios X , Região Variável de Imunoglobulina/química , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , Conformação Proteica , Dobramento de Proteína , Estrutura Secundária de Proteína , Complexo Receptor-CD3 de Antígeno de Linfócitos T/química , Alinhamento de Sequência , Transdução de SinaisRESUMO
The recent findings demonstrating the unexpected low affinity of a T-cell receptor towards its ligand have created a puzzle, as the high sensitivity and exquisite specificity of T cells and the low affinity of T-cell receptors are, at first glance, not compatible features. However, the close scrutiny of the parameters of T-cell antigen recognition in the actual space where ligation events occur has revealed that the low affinity of the T-cell receptor is perfectly compatible with T-cell function.
Assuntos
Receptores de Antígenos de Linfócitos T/imunologia , Animais , Células Apresentadoras de Antígenos/imunologia , Humanos , Ligantes , Conformação Proteica , Receptores de Antígenos de Linfócitos T/química , Linfócitos T/imunologiaRESUMO
BACKGROUND: Chronic low back pain is, in many countries, the main cause of long term disability in middle age. Patients with chronic low back pain are often referred for multidisciplinary treatment. Previous published systematic reviews on this topic included no randomised controlled trials and pooled together controlled and non-controlled studies. OBJECTIVES: To assess the effect of multidisciplinary bio-psycho-social rehabilitation on pain, function, employment, quality of life and global assessment outcomes in subjects with chronic disabling low back pain. SEARCH STRATEGY: We searched MEDLINE, EMBASE, PsychLIT, CINAHL, Health STAR, and The Cochrane Library from the beginning of the database to June 1998 using the comprehensive search strategy recommended by the Back Review Group of the Cochrane Collaboration. INTERVENTION specific key words for this review were: patient care team, patient care management, multidisciplinary, interdisciplinary, multiprofessional, multimodal, pain clinic and functional restoration. We also reviewed reference lists and consulted the editors of the Back Review Group of the Cochrane Collaboration. DESIGN: randomised controlled trials comparing multidisciplinary bio-psycho-social rehabilitation with a non-multidisciplinary control intervention. POPULATION: Adults with disabling low back pain of more than three months in duration. INTERVENTION: Patients had to be assessed and treated by qualified professionals according to a plan that addresses physical and at least one of psychological, or social/occupational dimensions. OUTCOMES: Only trials which reported treatment effect in at least one of pain, function, employment status, quality of life or global improvement.Exclusion: Pure educational interventions (back schools) and pure physical interventions were excluded. DATA COLLECTION AND ANALYSIS: Selection, data extraction and quality grading of studies was done by two independent authors using pre-tested data forms. Study quality was assessed according to the scheme recommended by the Back Review Group of the Cochrane Collaboration. Trials with internal validity scores of five or more in a ten point scale were considered high quality. Discrepancies between authors were resolved by consensus or by a third author. Given the marked heterogeneity in study settings, interventions and control groups we decided not to pool trial results in a meta-analysis. Instead, we summarized findings by strength of evidence and nature of intervention and control treatments. The evidence was judged to be strong when multiple high quality trials produced generally consistent findings. It was judged to be moderate when multiple low quality or one high quality and one or more low quality trials produced generally consistent findings. Evidence was considered to be limited when only one randomised trial existed or if findings of existing trials were inconsistent. MAIN RESULTS: Ten trials (12 randomised comparisons) were included. They randomised a total of 1964 patients with chronic low back pain. There was strong evidence that intensive multidisciplinary bio-psycho-social rehabilitation with a functional restoration approach improved function when compared with inpatient or outpatient non-multidisciplinary treatments. There was moderate evidence that intensive multidisciplinary bio-psycho-social rehabilitation with a functional restoration approach improved pain when compared with outpatient non-multidisciplinary rehabilitation or usual care. There was contradictory evidence regarding vocational outcomes of intensive multidisciplinary bio-psycho-social intervention. Some trials reported improvements in work readiness, but others showed no significant reduction in sickness leaves. Less intensive outpatient psycho-physical treatments did not improve pain, function or vocational outcomes when compared with non-multidisciplinary outpatient therapy or usual care. Few trials reported effects on quality of life or global assessments. AUTHORS' CONCLUSIONS: The reviewed trials provide evidence that intensive multidisciplinary bio-psycho-social rehabilitation with a functional restoration approach improves pain and function. Less intensive interventions did not show improvements in clinically relevant outcomes.
Assuntos
Dor nas Costas/reabilitação , Dor nas Costas/psicologia , Doença Crônica , Humanos , Terapia Ocupacional/métodos , Psicoterapia , Ensaios Clínicos Controlados Aleatórios como Assunto , Apoio SocialRESUMO
A crosstalk between commensals, gut immune cells, and colonic epithelia is required for a proper function of intestinal mucosal barrier. Here we investigated the importance of two distinct intestinal dendritic cell (DC) subsets in controlling intestinal inflammation. We show that Clec9A-diphtheria toxin receptor (DTR) mice after depletion of CD103(+)CD11b(-) DCs developed severe, low-dose dextran sodium sulfate (DSS)-induced colitis, whereas the lack of CD103(+)CD11b(+) DCs in Clec4a4-DTR mice did not exacerbate intestinal inflammation. The CD103(+)CD11b(-) DC subset has gained a functional specialization that able them to repress inflammation via several epithelial interferon-γ (IFN-γ)-induced proteins. Among others, we identified that epithelial IDO1 and interleukin-18-binding protein (IL-18bp) were strongly modulated by CD103(+)CD11b(-) DCs. Through its preferential property to express IL-12 and IL-15, this particular DC subset can induce lymphocytes in colonic lamina propria and in epithelia to secrete IFN-γ that then can trigger a reversible early anti-inflammatory response in intestinal epithelial cells.
Assuntos
Antígenos CD/imunologia , Antígeno CD11b/imunologia , Colite/imunologia , Células Dendríticas/imunologia , Resistência à Doença/imunologia , Cadeias alfa de Integrinas/imunologia , Interferon gama/imunologia , Animais , Antígenos CD/genética , Antígeno CD11b/genética , Colite/induzido quimicamente , Colite/genética , Colite/patologia , Colo/imunologia , Colo/patologia , Células Dendríticas/patologia , Sulfato de Dextrana , Células Epiteliais/imunologia , Células Epiteliais/patologia , Feminino , Regulação da Expressão Gênica , Fator de Crescimento Semelhante a EGF de Ligação à Heparina/genética , Fator de Crescimento Semelhante a EGF de Ligação à Heparina/imunologia , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Indolamina-Pirrol 2,3,-Dioxigenase/imunologia , Cadeias alfa de Integrinas/genética , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/imunologia , Interferon gama/genética , Interleucina-12/genética , Interleucina-12/imunologia , Interleucina-15/genética , Interleucina-15/imunologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Lectinas Tipo C/genética , Lectinas Tipo C/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Receptores Imunológicos/genética , Receptores Imunológicos/imunologia , Transdução de SinaisRESUMO
A secreted form of the beta-chain of a T-cell receptor specific for a hemagglutinin peptide of influenza virus in the context of the major histocompatibility complex class II I-Ed molecule has been crystallized in a form suitable for X-ray diffraction analysis. The crystals are tetragonal, space group P4(1)2(1)2 (or P4(3)2(1)2), with cell dimensions a = b = 71.4 A, c = 312.9 A, and diffract to beyond 3.5 A resolution. The beta-chain appears to behave as a stable homodimer in solution.
Assuntos
Receptores de Antígenos de Linfócitos T/química , Sequência de Aminoácidos , Cristalização , Cristalografia por Raios X , Dados de Sequência MolecularRESUMO
Five lectins were used as fluorescence microscopic markers for sugar residues in skeletal muscle. Biopsy specimens were taken from patients with X-linked muscular dystrophy (Duchenne's and Becker's), patients with other neuromuscular diseases, and normal controls. In both the controls and the pathologic samples, concanavalin A gave a bright fluorescence of the myofiber surface, whereas soybean agglutinin and Dolichos biflorus agglutinin fluorescence was negative. Peanut agglutinin and wheat germ agglutinin were more avidly bound to the sarcolemma and/or endomysial connective tissue in the patients with X-linked muscular dystrophy than in the controls or the patients with other conditions. The altered saccharide pattern may reflect either a myofiber membrane change or a specific mesenchymal reaction in the dystrophic muscle.