RESUMEN
We consolidate and present data for the sexual stages of five North American species of Orphella, fungal members of trichomycetes previously classified within Harpellales. Three species emendations accommodate the newly recognized characters, including not only the coiled zygospores and accompanying cells but also other morphological traits not provided in the original descriptions for O. avalonensis, O. haysii, and O. hiemalis. We describe three new species, Orphella cataloochensis from both the Smoky Mountains in USA and two provinces in Canada as well as O. pseudoavalonensis and O. pseudohiemalis, both from the Cascade Range, in Oregon, USA. Key morphological features for all known species are summarized and reviewed, with illustrations of some of the North American taxa to update and supplement the literature. The entire suite of morphological characters is discussed, with emphasis on species relationships and hypotheses on possible vicariant origins. We also present a molecular phylogeny based on nuc rDNA 18S and 28S, which supports Orphella as a lineage distinct from Harpellales, and we establish a new order, Orphellales, for it. With the combination of sexual features, now known for 12 of the 14 species of Orphella, and new molecular data, the group is now better characterized, facilitating and hopefully also promoting future studies toward a better understanding of their relationships, origins, and evolutionary history as stonefly gut-dwelling fungi.
Asunto(s)
Hongos/clasificación , Hongos/aislamiento & purificación , Filogenia , Canadá , Análisis por Conglomerados , ADN de Hongos/química , ADN de Hongos/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Hongos/citología , Hongos/genética , Tracto Gastrointestinal/microbiología , Microscopía , ARN Ribosómico 18S/genética , ARN Ribosómico 28S/genética , Análisis de Secuencia de ADN , Estados UnidosAsunto(s)
Tracto Gastrointestinal/inmunología , Helmintiasis/inmunología , Pulmón/inmunología , Moco/inmunología , Infecciones por Protozoos/inmunología , Sistema Urogenital/inmunología , Tracto Gastrointestinal/microbiología , Tracto Gastrointestinal/parasitología , Helmintiasis/parasitología , Humanos , Pulmón/microbiología , Pulmón/parasitología , Micosis/inmunología , Micosis/parasitología , Infecciones por Protozoos/parasitología , Sistema Urogenital/microbiología , Sistema Urogenital/parasitologíaRESUMEN
In this review, we examine the evidence that intestinal helminths can control harmful inflammatory responses and promote homeostasis by triggering systemic immune responses. Induction of separable components of immunity by helminths, which includes type 2 and immune regulatory responses, can both contribute toward the reduction in harmful type 1 immune responses that drive certain inflammatory diseases. Despite inducing type 2 responses, intestinal helminths may also downregulate harmful type 2 immune responses including allergic responses. We consider the possibility that intestinal helminth infection may indirectly affect inflammation by influencing the composition of the intestinal microbiome. Taken together, the studies reviewed herein suggest that intestinal helminth-induced responses have potent systemic effects on the immune system, raising the possibility that whole parasites or specific molecules produced by these metazoans may be an important resource for the development of future immunotherapies to control inflammatory diseases.
Asunto(s)
Helmintiasis/inmunología , Helmintiasis/parasitología , Interacciones Huésped-Parásitos/inmunología , Parasitosis Intestinales/inmunología , Parasitosis Intestinales/parasitología , Animales , Modelos Animales de Enfermedad , Helmintiasis/complicaciones , Helmintiasis/diagnóstico , Helmintiasis/metabolismo , Helmintiasis/microbiología , Helmintiasis/terapia , Humanos , Inflamación/inmunología , Inflamación/microbiología , Inflamación/parasitología , Inflamación/patología , Parasitosis Intestinales/complicaciones , Parasitosis Intestinales/diagnóstico , Parasitosis Intestinales/metabolismo , Parasitosis Intestinales/microbiología , Parasitosis Intestinales/terapia , Mucosa Intestinal/inmunología , Mucosa Intestinal/microbiología , Mucosa Intestinal/parasitología , Mucosa Intestinal/patología , Síndrome Metabólico/etiología , MicrobiotaRESUMEN
Helminth infection can prevent type 1 diabetes (T1D); however, the regulatory mechanisms inhibiting disease remain largely undefined. In these studies, nonobese diabetic (NOD) IL-4(-/-) mice were infected with the strictly enteric nematode parasite, Heligmosomoides polygyrus. Short-term infection, 5-7 weeks of age, inhibited T1D onset, as late as 40 weeks of age. CD4(+) T-cell STAT6 phosphorylation was inhibited, while suppressed signal transducer and activator of transcription 1 phosphorylation was sustained, as were increases in FOXP3(-), CD4(+) T-cell interleukin (IL)-10 production. Blockade of IL-10 signaling in NOD-IL-4(-/-), but not in NOD, mice during this short interval abrogated protective effects resulting in pancreatic ß-cell destruction and ultimately T1D. Transfer of CD4(+) T cells from H. polygyrus (Hp)-inoculated NOD IL-4(-/-) mice to NOD mice blocked the onset of T1D. These studies indicate that Hp infection induces non-T-regulatory cells to produce IL-10 independently of STAT6 signaling and that in this Th2-deficient environment IL-10 is essential for T1D inhibition.
Asunto(s)
Diabetes Mellitus Tipo 1/inmunología , Diabetes Mellitus Tipo 1/prevención & control , Interleucina-10/inmunología , Intestinos/parasitología , Nematospiroides dubius/inmunología , Infecciones por Strongylida/inmunología , Células Th2/inmunología , Animales , Autoantígenos/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Citocinas/genética , Citocinas/inmunología , Femenino , Regulación de la Expresión Génica , Células Secretoras de Insulina/patología , Interferón gamma/inmunología , Interferón gamma/metabolismo , Interleucina-10/metabolismo , Interleucina-4/deficiencia , Islotes Pancreáticos/inmunología , Tejido Linfoide/inmunología , Tejido Linfoide/metabolismo , Ratones , Ratones Endogámicos NOD , Ratones Noqueados , Fenotipo , Fosforilación , Receptores de Interleucina-10/antagonistas & inhibidores , Factor de Transcripción STAT1/metabolismo , Factor de Transcripción STAT6/metabolismo , Transducción de Señal , Células TH1/inmunología , Células TH1/metabolismo , Células Th2/metabolismoRESUMEN
The development of T helper 1 (Th1) versus Th2 cells is a major branch point in the immune response. It is an important determinant of whether the response to an infectious pathogen will lead to protection of the host or dissemination of the disease. Recent studies have suggested that this process is governed by distinct sets of signals provided by dendritic cells upon interactions with specific infectious agents. A model is proposed that links together the pathogen, the innate response and Th-cell polarization.
Asunto(s)
Enfermedades Transmisibles/inmunología , Células TH1/inmunología , Células Th2/inmunología , Animales , Quimiocinas/metabolismo , Citocinas/metabolismo , Células Dendríticas/inmunología , Humanos , Modelos Biológicos , Transducción de Señal , Factores de Transcripción/metabolismoRESUMEN
Studies have indicated that purified soluble polysaccharide antigens can elicit T cell-independent Ig responses in vivo, although these responses can be modulated by T cells in a noncognate manner. Relatively little is known, however, concerning the parameters that regulate polysaccharide-specific, as well as protein-specific, Ig isotype responses to an intact extracellular bacterium. Using the murine in vivo humoral response to intact Streptococcus pneumoniae as a model it can be shown that CD4+ T-cell receptor alphabeta+ T cells deliver help for both polysaccharide- and protein-specific Ig responses. However, these responses differ fundamentally in their mechanism of action.
Asunto(s)
Formación de Anticuerpos , Infecciones Neumocócicas/inmunología , Streptococcus pneumoniae/inmunología , Subgrupos de Linfocitos T/inmunología , Animales , Linfocitos T CD4-Positivos/inmunología , Células Dendríticas/inmunología , Células Dendríticas/microbiología , Isotipos de Inmunoglobulinas/inmunología , Modelos Inmunológicos , Receptores de Antígenos de Linfocitos T alfa-beta/inmunologíaRESUMEN
Neural-network classifiers were used to detect immunological differences in groups of chronic fatigue syndrome (CFS) patients that heretofore had not shown significant differences from controls. In the past linear methods were unable to detect differences between CFS groups and non-CFS control groups in the nonveteran population. An examination of the cluster structure for 29 immunological factors revealed a complex, nonlinear decision surface. Multilayer neural networks showed an over 16% improvement in an n-fold resampling generalization test on unseen data. A sensitivity analysis of the network found differences between groups that are consistent with the hypothesis that CFS symptoms are a consequence of immune system dysregulation. Corresponding decreases in the CD19(+) B-cell compartment and the CD34(+) hematopoietic progenitor subpopulation were also detected by the neural network, consistent with the T-cell expansion. Of significant interest was the fact that, of all the cytokines evaluated, the only one to be in the final model was interleukin-4 (IL-4). Seeing an increase in IL-4 suggests a shift to a type 2 cytokine pattern. Such a shift has been hypothesized, but until now convincing evidence to support that hypothesis has been lacking.
Asunto(s)
Síndrome de Fatiga Crónica/inmunología , Linfocitos B/inmunología , Humanos , Redes Neurales de la Computación , Factores de Riesgo , Linfocitos T/inmunologíaRESUMEN
The requirements for B7 costimulation during an in vivo humoral response to an intact extracellular bacteria have not been reported. In this study we immunized mice with Streptococcus pneumoniae (R36A) to determine the B7 requirements for induction of Ig, specific for two determinants on R36A, the phosphorylcholine (PC) determinant of C-polysaccharide and pneumococcal surface protein A (PspA). We show that the primary anti-PspA response, the development of PspA-specific memory, and the induction of the secondary anti-PspA response in primed mice were completely dependent upon B7 costimulation. Of note, costimulation was required only briefly after the secondary immunization compared with after the primary immunization for optimal induction of Ig. Blockade of B7 costimulation at the time of secondary immunization also completely abrogated the established state of memory, but did not induce tolerance. In contrast to the anti-PspA response, the primary anti-PC response involved only a very short period of B7 costimulation. Whereas B7-2 alone was required for induction of the primary anti-PspA and anti-PC responses, a redundant role for B7-1 and B7-2 was noted for the PspA-specific secondary response. CTLA4Ig blocked both the anti-PC and anti-PspA responses equally well over a wide range of bacterial doses. These studies demonstrate a critical, but variable, role for B7-dependent costimulation during an Ig response to an extracellular bacteria.
Asunto(s)
Antígenos CD/fisiología , Antígeno B7-1/fisiología , Inmunización Secundaria , Inmunoconjugados , Isotipos de Inmunoglobulinas/biosíntesis , Glicoproteínas de Membrana/fisiología , Polisacáridos Bacterianos/inmunología , Streptococcus pneumoniae/inmunología , Abatacept , Animales , Anticuerpos Bloqueadores/administración & dosificación , Anticuerpos Monoclonales/administración & dosificación , Antígenos CD/inmunología , Antígenos CD/metabolismo , Antígenos de Diferenciación/administración & dosificación , Antígeno B7-1/inmunología , Antígeno B7-1/metabolismo , Antígeno B7-2 , Proteínas Bacterianas/inmunología , Antígenos CD28/genética , Antígenos CD28/fisiología , Antígeno CTLA-4 , Relación Dosis-Respuesta Inmunológica , Epítopos/inmunología , Fragmentos Fc de Inmunoglobulinas/administración & dosificación , Inmunoglobulina G/biosíntesis , Isotipos de Inmunoglobulinas/sangre , Memoria Inmunológica , Inmunosupresores/administración & dosificación , Inyecciones Intraperitoneales , Cinética , Ligandos , Glicoproteínas de Membrana/antagonistas & inhibidores , Glicoproteínas de Membrana/inmunología , Glicoproteínas de Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fosforilcolina/inmunología , Polisacáridos Bacterianos/administración & dosificación , Proteínas Recombinantes de Fusión/administración & dosificación , Proteínas Recombinantes de Fusión/inmunologíaRESUMEN
Injection of mice with a foreign anti-IgD Ab stimulates B and T cell activation that results in large cytokine and Ab responses. Because most anti-IgD-activated B cells die before they can be stimulated by activated T cells, and because IL-4 prolongs the survival of B cells cultured with anti-Ig, we hypothesized that treatment with IL-4 at the time of anti-IgD Ab injection would decrease B cell death and enhance anti-IgD-induced Ab responses. Instead, IL-4 treatment before or along with anti-IgD Ab suppressed IgE and IgG1 responses, whereas IL-4 injected after anti-IgD enhanced IgE responses. The suppressive effect of early IL-4 treatment on the Ab response to anti-IgD was associated with a rapid, short-lived increase in IFN-gamma gene expression but decreased CD4+ T cell activation and decreased or delayed T cell production of other cytokines. We examined the possibilities that IL-4 stimulation of IFN-gamma production, suppression of IL-1 or IL-2 production, or induction of TNF-alpha or Fas-mediated apoptosis could account for IL-4's suppressive effect. The suppressive effect of IL-4 was not reversed by IL-1, IL-2, or anti-TNF-alpha or anti-IFN-gamma mAb treatment, or mimicked by treatment with anti-IL-2Ralpha (CD25) and anti-IL-2Rbeta (CD122) mAbs. Early IL-4 treatment failed to inhibit anti-IgD-induced Ab production in Fas-defective lpr mice; however, the poor responsiveness of lpr mice to anti-IgD made this result difficult to interpret. These observations indicate that exposure to IL-4, while T cells are first being activated by Ag presentation, can inhibit T cells activation or promote deletion of responding CD4+ T cells.
Asunto(s)
Inmunoglobulina E/biosíntesis , Inmunoglobulina G/biosíntesis , Inmunosupresores , Interleucina-4/fisiología , Activación de Linfocitos/inmunología , Linfocitos T/inmunología , Animales , Anticuerpos Monoclonales/administración & dosificación , Femenino , Cabras , Inmunoglobulina D/administración & dosificación , Inmunoglobulina E/sangre , Inmunoglobulina G/sangre , Inmunosupresores/administración & dosificación , Inyecciones Intravenosas , Interferón gamma/inmunología , Interleucina-1/antagonistas & inhibidores , Interleucina-1/biosíntesis , Interleucina-2/antagonistas & inhibidores , Interleucina-2/biosíntesis , Interleucina-4/administración & dosificación , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos MRL lpr , Receptores de Interleucina-2/antagonistas & inhibidores , Factor de Necrosis Tumoral alfa/fisiologíaRESUMEN
B7 costimulation is a required component of many type 2 immune responses, including allergy and protective immunity to many nematode parasites. This response includes elevations in Th2 cytokines and associated effector functions including elevations in serum IgG1 and IgE and parasite expulsion. In studies of mice infected with Trichuris muris, blocking B7 ligand interactions inhibited protective immunity, suppressed IL-4 production, and enhanced IFN-gamma production, but unexpectedly did not inhibit production of the Th2 cytokine, IL-13. Blocking both IFN-gamma and B7 restored protective immunity, which was IL-13 dependent, but did not restore IL-4 or associated IgE responses. Although IL-13 was required for worm expulsion in mice in which both IFN-gamma and B7 were blocked, IL-4 could mediate expulsion in the absence of both IL-13 and IFN-gamma. These studies demonstrate that 1) B7 costimulation is required to induce IL-4, but not IL-13 responses; 2) IL-13 is elevated in association with the IFN-gamma response that occurs following inhibition of B7 interactions, but can only mediate IL-4-independent protection when IFN-gamma is also inhibited; and 3) increased IL-13 production, in the absence of increased IL-4 production, is not associated with an IgE response, even in the absence of IFN-gamma.
Asunto(s)
Antígeno B7-1/fisiología , Inmunoconjugados , Interferón gamma/fisiología , Interleucina-13/fisiología , Tricuriasis/inmunología , Trichuris/inmunología , Abatacept , Animales , Antígenos CD , Antígenos de Diferenciación/administración & dosificación , Antígeno B7-1/metabolismo , Antígeno CTLA-4 , Citocinas/antagonistas & inhibidores , Citocinas/biosíntesis , Citocinas/uso terapéutico , Femenino , Inmunosupresores/administración & dosificación , Inyecciones Intravenosas , Interferón gamma/antagonistas & inhibidores , Interferón gamma/biosíntesis , Interferón gamma/genética , Interleucina-13/biosíntesis , Interleucina-4/deficiencia , Interleucina-4/genética , Mucosa Intestinal/inmunología , Mucosa Intestinal/metabolismo , Mucosa Intestinal/parasitología , Ligandos , Ratones , Ratones Endogámicos AKR , Ratones Endogámicos BALB C , Ratones Noqueados , Células Th2/inmunología , Células Th2/metabolismo , Tricuriasis/parasitología , Trichuris/crecimiento & desarrolloRESUMEN
Multiple pathways may be involved in the development of interleukin 4 (IL-4) producing T helper (Th) cells and the associated type 2 immune response. Increasing evidence suggests that the strength of signals delivered to the T cell may favor the development of the type 2 response. In contrast, antigen-presenting cell- (APC) derived stimuli produced following pattern recognition receptor binding during the innate response promotes the development of interferon-gamma (IFN-gamma) producing cells and the associated type 1 immune response. In many cases, the balance between increased signaling strength and the innate response may determine whether the type 2 response develops. T cell receptor (TCR), CD4, and costimulatory molecule interactions may all contribute to signal strength, but the type 2 immune response may be particularly dependent on the availability of coreceptor and costimulatory molecule interactions. B7 ligand interactions are required for the development of the type 2 immune response and interaction of CD28 with either B7-1 or B7-2 can provide sufficient signals for its initiation. In B7-2-deficient mice, the initial type 2 immune response is intact, but the response is not sustained, suggesting that B7-2 is important at later stages of the type 2 immune response. The roles of CD28 and CTLA-4 during the type 2 response remain unclear. The type 2 response to infectious pathogens is pronounced in CD28-/- mice, suggesting that other costimulatory molecule interactions can substitute for CD28 for the development of IL-4 producing T cells and the associated type 2 immune response.
Asunto(s)
Antígeno B7-1/metabolismo , Antígenos CD28/metabolismo , Inmunoconjugados , Interleucina-4/biosíntesis , Células Th2/inmunología , Abatacept , Animales , Antígenos CD , Antígenos de Diferenciación/metabolismo , Antígeno B7-1/genética , Antígenos CD28/genética , Antígeno CTLA-4 , Ratones , Ratones Mutantes , Transducción de Señal , Infecciones por Strongylida/inmunologíaRESUMEN
In vivo Ig responses to soluble, haptenated polysaccharide (PS) Ags are T cell independent and do not require CD40 ligand (CD40L). However, little is known regarding the regulation of in vivo PS-specific Ig responses to intact bacteria. We immunized mice with a nonencapsulated, type 2 Streptococcus pneumoniae (R36A) and compared the parameters that regulated in vivo Ig isotype responses to the bacterial cell wall C-PS determinant, phosphorylcholine (PC), relative to Ig responses to the cell wall protein, pneumococcal surface protein A. Consistent with previous reports using soluble PS and protein Ags, the anti-PC and anti-pneumococcal surface protein A responses differed in that the anti-PC response was induced more rapidly, had a distinctive Ig isotype profile, and failed to demonstrate boosting upon secondary challenge with R36A. However, in contrast to previous studies, the IgG anti-PC response was TCR-alphabeta+ T cell dependent, required CD40L, and was blocked by administration of CTLA4 Ig. The nature of the T cell help for the anti-PC response had distinct features in that it was only partially blocked by CTLA4 Ig and was dependent upon both CD4+ and CD8+ T cells. Surprisingly, whereas the IgM anti-PC response was largely T cell independent, a strong requirement for CD40L was still observed, suggesting the possibility of an in vivo T cell-independent source for CD40L-dependent help. These data suggest that the regulatory parameters that govern in vivo Ig responses to purified, soluble PS Ags may not adequately account for PS-specific Ig responses to intact bacteria.
Asunto(s)
Antígeno B7-1/fisiología , Antígenos CD40/fisiología , Inmunoglobulina G/biosíntesis , Isotipos de Inmunoglobulinas/biosíntesis , Glicoproteínas de Membrana/fisiología , Polisacáridos Bacterianos/administración & dosificación , Streptococcus pneumoniae/inmunología , Subgrupos de Linfocitos T/inmunología , Animales , Proteínas Bacterianas/administración & dosificación , Proteínas Bacterianas/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Antígenos CD40/genética , Ligando de CD40 , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Inmunización Secundaria , Inmunoglobulina M/biosíntesis , Inyecciones Intraperitoneales , Ligandos , Glicoproteínas de Membrana/deficiencia , Glicoproteínas de Membrana/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fosforilcolina/administración & dosificación , Fosforilcolina/inmunología , Polisacáridos Bacterianos/inmunología , Receptores de Antígenos de Linfocitos T alfa-beta/deficiencia , Receptores de Antígenos de Linfocitos T alfa-beta/genética , Receptores de Antígenos de Linfocitos T alfa-beta/inmunología , Receptores de Antígenos de Linfocitos T gamma-delta/deficiencia , Receptores de Antígenos de Linfocitos T gamma-delta/genética , Receptores de Antígenos de Linfocitos T gamma-delta/inmunología , Subgrupos de Linfocitos T/metabolismo , Subgrupos de Linfocitos T/microbiología , Factores de TiempoRESUMEN
BACKGROUND: Some research immunologists have suggested that major depression amd chronic fatigue syndrome (CFS) are characterized by immune activation. To test this hypothesis, we compared immunological function in patients with major depression and in patients with CFS who developed major depression after the onset of CFS to that of sedentary healthy controls. METHODS: Subjects completed the Centers for Epidemiological Study-Depression (CES-D) questionnaire and allowed venisection. We performed flow cytometric analysis on 13 groups of white blood cells and used a reverse transcriptase PCR method to assay m-RNA of eight cytokines. RESULTS: CES-D scores were high in both patient groups and did not differ significantly. We found no evidence for immune activation in either patient group. Instead the data suggested immunological downregulation in depression. LIMITATIONS: Not all the subjects in the two patient groups were off antidepressants. CONCLUSIONS: The data indicate that immune activation is not necessary in depression--either alone or with CFS.
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Antígenos CD/inmunología , Citocinas/inmunología , Trastorno Depresivo Mayor/inmunología , Síndrome de Fatiga Crónica/inmunología , Miembro 7 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/inmunología , Adulto , Trastorno Depresivo Mayor/complicaciones , Trastorno Depresivo Mayor/psicología , Síndrome de Fatiga Crónica/complicaciones , Síndrome de Fatiga Crónica/psicología , Femenino , Humanos , Masculino , Encuestas y CuestionariosRESUMEN
This study was conducted to evaluate the immunological response to an exhaustive treadmill exercise test in 20 female chronic fatigue syndrome patients compared to 14 matched sedentary controls. Venipuncture was performed at baseline and 4 min, 1 hr, and 24 hr postexercise. White blood cells were labeled for monoclonal antibody combinations and were quantified by FACsan. Cytokines were assayed utilizing quantitative RT/PCR. No group difference was seen in VO2peak (28.6 +/- 1.6 vs 30.9 +/- 1.2 ml.kg-1.min-1; P > 0.05). However, 24 hr after exercise the patients' fatigue levels were significantly increased (P < 0.05). The counts of WBC, CD3+ CD8+ cells, CD3+ CD4+ cells, T cells, B cells, natural killer cells, and IFN-gamma changed across time (P's < 0.01). No group differences were seen for any of the immune variables at baseline or after exercise (P's > 0.05). The immune response of chronic fatigue syndrome patients to exhaustive exercise is not significantly different from that of healthy nonphysically active controls.
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Citocinas/sangre , Síndrome de Fatiga Crónica/inmunología , Recuento de Leucocitos , Subgrupos Linfocitarios/inmunología , Esfuerzo Físico , Adulto , Citocinas/genética , Prueba de Esfuerzo/métodos , Femenino , Citometría de Flujo , Humanos , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
T cells require CD28/CTLA-4 costimulatory molecule interactions in addition to Ag-specific signals through the TCR for in vivo effector Th cell function. Some studies have suggested that the ligands for these costimulatory molecules may differentially influence effector T cell function with B7-2 favoring a type 2 response and B7-1 favoring a type 1 response, while other studies have suggested that these molecules may be redundant. The recent development of B7-2-deficient mice permits the direct analysis of the requirement of B7-2 during a type 2 immune response to an infectious pathogen. We have examined, in B7-2-deficient mice, effector Th cell function and the associated type 2 immune response following infection with Heligmosomoides polygyrus, a natural murine parasitic nematode. Elevations in cytokine gene expression and protein secretion were pronounced and comparable in inoculated B7-2-/- and B7-2+/+ mice at day 8 after H. polygyrus inoculation. However, by day 14 after infection, increases in T cell cytokine expression were markedly inhibited in H. polygyrus-inoculated B7-2-/- mice. Furthermore, elevations in serum IgE and germinal center formation were inhibited at later stages of the immune response, while elevations in serum IgG1 persisted. These findings suggest that certain T-dependent components vary in their B7-2-dependency during the type 2 immune response. They further demonstrate that B7-2 interactions are not necessary for the initiation of the type 2 immune response, but are instead required for its progression after the development of effector T cells.
Asunto(s)
Antígenos CD/fisiología , Citocinas/biosíntesis , Sistema Digestivo/parasitología , Glicoproteínas de Membrana/fisiología , Nematospiroides dubius/inmunología , Células Th2/inmunología , Animales , Antígenos CD/genética , Antígeno B7-2 , Sistema Digestivo/inmunología , Fertilidad/inmunología , Centro Germinal/inmunología , Centro Germinal/metabolismo , Centro Germinal/parasitología , Glicoproteínas de Membrana/genética , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Nematospiroides dubius/crecimiento & desarrollo , Infecciones por Strongylida/inmunología , Infecciones por Strongylida/parasitología , Células Th2/metabolismoRESUMEN
OBJECTIVE: To define the phenotype of cells in the perivascular and vascular infiltrates of Palmerston North (PN) mice and the cytokines that those cells produce. METHODS: Immunohistologic analysis, flow cytometric analysis, and reverse transcriptase-polymerase chain reaction (RT-PCR) studies were performed on tissues and cells from female PN mice and age-matched and sex-matched DBA/2 mice. RESULTS: With aging, PN mice developed a female-predominant, lupus-like disease, with a severe systemic mononuclear cell perivasculitis and vasculitis. The perivasculitis involved arteries and veins in kidney, liver, brain, and lung; the vasculitis predominantly involved veins and venules. The perivascular and vascular infiltrates in female PN mice were composed mainly of an unusual cell type that expressed phenotypic markers characteristic of both T cells (Thy1+, CD3+, CD4+, T cell receptor + [TCR+]) and B cells (B220+). In addition, the infiltrates contained a smaller number of conventional CD4+,B220- T cells and macrophages. Very few CD8+ T cells or surface Ig+ B cells were seen. Unlike the Thy1+,B220+ T cells present in MRL/lpr mice, most of which were CD4-,CD8- and TCRalpha/beta+, the majority of the Thy1+,B220+ T cells in the perivascular/vascular infiltrates of PN mice were CD4+ and expressed either TCRalpha/beta or TCRgamma/delta. By immunohistologic staining, the cells in the perivascular and vascular infiltrates in the kidneys of older PN mice were shown to produce interleukin-4 (IL-4), IL-6, and IL-10, but not IL-2, interferon-gamma, transforming growth factor beta, tumor necrosis factor alpha, or IL-1beta. By RT-PCR, the kidneys of older PN mice were found to express high levels of IL-4, IL-6, and IL-10 messenger RNA. CONCLUSION: The vascular and perivascular infiltrates in PN mice are composed predominantly of an unusual subpopulation of T cells that are Thy1+,B220+,CD4+,CD8-, express either TCRalpha/beta or TCRgamma/delta, and produce mainly type 2 cytokines. The exact role of these cells in the immunopathogenesis of lupus-like disease in PN mice remains to be elucidated.
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Lupus Eritematoso Sistémico/genética , Lupus Eritematoso Sistémico/inmunología , Vasculitis/genética , Vasculitis/inmunología , Animales , Linfocitos B/inmunología , Modelos Animales de Enfermedad , Femenino , Expresión Génica/inmunología , Interferón gamma/genética , Interleucina-1/genética , Interleucina-10/genética , Interleucina-2/genética , Interleucina-4/genética , Interleucina-6/genética , Ratones , Ratones Endogámicos DBA , Ratones Endogámicos MRL lpr , Ratones Endogámicos NZB , Ratones Endogámicos , Fenotipo , ARN Mensajero/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Linfocitos T/inmunología , Factor de Crecimiento Transformador beta/genéticaRESUMEN
We have conducted a double-blind study to assess the possible involvement of the human herpesviruses (HHVs) HHV6, HHV7, Epstein-Barr virus (EBV), and cytomegalovirus in chronic fatigue syndrome (CFS) patients compared to age-, race-, and gender-matched controls. The CFS patient population was composed of rigorously screened civilian and Persian Gulf War veterans meeting the Centers for Disease Control and Prevention's CFS case definition criteria. Healthy control civilian and veteran populations had no evidence of CFS or any other exclusionary medical or psychiatric condition. Patient peripheral blood mononuclear cells were analyzed by PCR for the presence of these HHVs. Using two-tailed Fisher's exact test analyses, we were unable to ascertain any statistically significant differences between the CFS patient and control populations in terms of the detection of one or more of these viruses. This observation was upheld when the CFS populations were further stratified with regard to the presence or absence of major axis I psychopathology and patient self-reported gradual versus acute onset of disease. In tandem, we performed serological analyses of serum anti-EBV and anti-HHV6 antibody titers and found no significant differences between the CFS and control patients.
Asunto(s)
Síndrome de Fatiga Crónica/virología , Infecciones por Herpesviridae/diagnóstico , Herpesviridae/aislamiento & purificación , Síndrome del Golfo Pérsico/virología , Adulto , Anticuerpos Antivirales/sangre , Citomegalovirus/genética , Citomegalovirus/inmunología , Citomegalovirus/aislamiento & purificación , Cartilla de ADN , ADN Viral/análisis , Método Doble Ciego , Antígenos Nucleares del Virus de Epstein-Barr/análisis , Antígenos Nucleares del Virus de Epstein-Barr/inmunología , Síndrome de Fatiga Crónica/inmunología , Femenino , Genes Inmediatos-Precoces/inmunología , Herpesviridae/genética , Herpesviridae/inmunología , Infecciones por Herpesviridae/inmunología , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/inmunología , Herpesvirus Humano 4/aislamiento & purificación , Herpesvirus Humano 6/genética , Herpesvirus Humano 6/inmunología , Herpesvirus Humano 6/aislamiento & purificación , Herpesvirus Humano 7/genética , Herpesvirus Humano 7/inmunología , Herpesvirus Humano 7/aislamiento & purificación , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/virología , Masculino , Persona de Mediana Edad , Síndrome del Golfo Pérsico/inmunología , Pruebas Serológicas , Proteínas de la Matriz Viral/análisis , Proteínas de la Matriz Viral/inmunologíaRESUMEN
The purpose of this study was to evaluate immune function through the assessment of lymphocyte subpopulations (total T cells, major histocompatibility complex [MHC] I- and II-restricted T cells, B cells, NK cells, MHC II-restricted T-cell-derived naive and memory cells, and several MHC I-restricted T-cell activation markers) and the measurement of cytokine gene expression (interleukin 2 [IL-2], IL-4, IL-6, IL-10, IL-12, gamma interferon [IFN-gamma], and tumor necrosis factor alpha [TNF-alpha]) from peripheral blood lymphocytes. Subjects included two groups of patients meeting published case definitions for chronic fatigue syndrome (CFS)-a group of veterans who developed their illness following their return home from participating in the Gulf War and a group of nonveterans who developed the illness sporadically. Case control comparison groups were comprised of healthy Gulf War veterans and nonveterans, respectively. We found no significant difference for any of the immune variables in the nonveteran population. In contrast, veterans with CFS had significantly more total T cells and MHC II+ T cells and a significantly higher percentage of these lymphocyte subpopulations, as well as a significantly lower percentage of NK cells, than the respective controls. In addition, veterans with CFS had significantly higher levels of IL-2, IL-10, IFN-gamma, and TNF-alpha than the controls. These data do not support the hypothesis of immune dysfunction in the genesis of CFS for sporadic cases of CFS but do suggest that service in the Persian Gulf is associated with an altered immune status in veterans who returned with severe fatiguing illness.
Asunto(s)
Síndrome de Fatiga Crónica/inmunología , Síndrome del Golfo Pérsico/inmunología , Adulto , Antígenos CD/sangre , Estudios de Casos y Controles , Citocinas/genética , Síndrome de Fatiga Crónica/genética , Femenino , Expresión Génica , Humanos , Células Asesinas Naturales/inmunología , Subgrupos Linfocitarios/inmunología , Masculino , Persona de Mediana Edad , Modelos Biológicos , Síndrome del Golfo Pérsico/genética , ARN Mensajero/sangre , ARN Mensajero/genética , Subgrupos de Linfocitos T/inmunologíaRESUMEN
A competitive PCR assay (cPCR) was used to quantify swine cytokine responses to parasite infection. Internal standards (deleted cDNA competitor molecules [DcDNA mimics]) were produced and tested for swine interleukin-12 (IL-12), interleukin-10 (IL-10) and hypoxanthine phosphoribosyltransferase (HPRT) from PCR generated cDNA cloned in plasmid vectors. Deletion clones for the cDNA competitor molecules (DcDNA mimics) were generated for IL-10, IL-12 and HPRT by PCR in a single step and verified by (1) amplification of the expected smaller PCR product with the original primers, (2) appropriate fragment size released by restriction digestion of the deleted clone, and (3) correct sequence of the new DcDNA insert. DcDNA mimics were used to quantitate cytokine gene mRNA production during experimental and natural infections of swine with the gastrointestinal nematode parasite Trichuris suis. Mesenteric lymph node cells were collected from control and infected pigs at the time of maximal pathogenicity (35 days after infection) and snap frozen. After RNA extraction, samples were reverse transcribed (RT) to cDNA. cPCR was performed using the housekeeping gene HPRT DcDNA mimic and HPRT specific primers to insure RNA integrity and concentration. Cytokine cDNA content in these samples was then quantitated using cytokine mimics and gene specific primers. IL-10 gene expression in MLN draining the colon of pigs experimentally infected with T. suis increased 10-20 fold at day 35 compared to control pigs. IL-12 gene expression was not detectable in MLN of these pigs, but was detectable in MLN of pigs exposed naturally to T. suis on a contaminated dirt lot that also exhibited signs of secondary bacterial invasion. Swine IL-10 and IL-12 gene expression can be quantitated in local mesenteric tissues. This cPCR assay will enable scientists to quantitate cytokine gene expression in swine and determine the nature of immune responses to important infectious diseases.
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ADN Complementario/química , Interleucina-10/genética , Interleucina-12/genética , Porcinos/inmunología , Animales , Clonación Molecular , Colon/inmunología , Colon/parasitología , Cartilla de ADN/química , ADN Complementario/genética , Electroforesis en Gel de Agar/veterinaria , Regulación de la Expresión Génica , Hipoxantina Fosforribosiltransferasa/química , Hipoxantina Fosforribosiltransferasa/genética , Interleucina-10/análisis , Interleucina-10/biosíntesis , Interleucina-12/análisis , Interleucina-12/biosíntesis , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/parasitología , ARN Mensajero/química , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Porcinos/genética , Porcinos/parasitología , Enfermedades de los Porcinos/inmunología , Tricuriasis/inmunología , Tricuriasis/veterinaria , Trichuris/inmunologíaRESUMEN
Chronic fatigue syndrome, which can occur after acute infection and last for years, is characterized by severe and persistent fatigue. Others have reported decreases in mouse running activity following infection and have suggested this may provide an animal model for studying chronic fatigue. Voluntary running is a highly motivated activity in mice, which will often run 5-7 mi/day in our laboratory. Following 2 weeks of acclimation to running wheels with food and water available ad lib, female BALB/c mice received 0.2-mL tail vein injections of killed Brucella abortus (BA) or saline vehicle. Subsequently the effects on voluntary running and grooming behavior were determined. Injection of BA caused an immediate large decrease in running and a lack of grooming. Vehicle injections produced no changes in behavior. After the first several days of reduced running behavior, levels of running and grooming slowly returned back to normal over the next 2-4 weeks, with substantial individual differences in the rate of recovery. The pattern of running during recovery was intriguing in that BA mice first ran at normal levels just after the lights went out, but they stopped after only 1-2 h. As recovery proceeded, they gradually increased the duration of the running bout during the night. Because this model uses voluntary exertion and the ability to run for longer periods of time characterizes recovery, the model may be a good one for studying the biologic underpinnings of chronic fatigue.