Edema agudo de pulmón secundario a síndrome de absorción intravascular durante histeroscopia: a propósito de un caso / Acute pulmonary edema secondary to intravascular absorption syndrome during hysteroscopy: A case report

La histeroscopia es un procedimiento endoscópico que estudia el interior de la cavidad uterina y del canal endocervical con objetivo diagnóstico-terapéutico. Para obtener una visualización óptima de las estructuras se utilizan diversos fluidos como el suero salino fisiológico. Una complicación poco frecuente es la sobredosificación de volumen, lo cual puede asociarse a un síndrome de absorción intravascular tras histeroscopia, normalmente tras procedimientos largos o disección de tejidos. Respecto de este síndrome, no se disponen datos de incidencia y prevalencia, existiendo pocos casos reportados en relación a solución salina fisiológica. Se presenta el caso de una paciente sometida a resección miomatosa, que, como consecuencia del síndrome de absorción vascular, dio lugar a edema agudo de pulmón que requirió ingreso en la Unidad de Cuidados Intensivos.(AU)

Hysteroscopy is an exploratory endoscopic technique that studies the interior of the uterine cavity and the endocervical canal. Various fluids, such as physiological saline, are used to optimise visualisation of the internal structures during this procedure. A rare complication of hysteroscopy is fluid overload, which can be associated with intravascular absorption syndrome, usually after lengthy procedures or tissue dissection. There are no data on the incidence and prevalence of this syndrome, and few cases involving physiological saline solution have been reported. We present a case of hysteroscopic myomectomy complicated by vascular absorption syndrome, which gave rise to acute pulmonary oedema that required admission to the intensive care unit.(AU)

Acute pulmonary oedema secondary to intravascular absorption syndrome during hysteroscopy: A case report.

Hysteroscopy is an exploratory endoscopic technique that studies the interior of the uterine cavity and the endocervical canal. Various fluids, such as physiological saline, are used to optimise visualisation of the internal structures during this procedure. A rare complication of hysteroscopy is fluid overload, which can be associated with intravascular absorption syndrome, usually after lengthy procedures or tissue dissection. There are no data on the incidence and prevalence of this syndrome, and few cases involving physiological saline solution have been reported. We present a case of hysteroscopic myomectomy complicated by vascular absorption syndrome, which gave rise to acute pulmonary oedema that required admission to the intensive care unit.

How to Create Trusted Tribological Characterization Data of Soft Polymers as Input for FEM Simulations?

Soft polymers such as the investigated polyurethane, characterized by low Young's moduli and prone to high shear deflection, are frequently applied in pneumatic cylinders. Their performance and lifetime without external lubrication are highly determined by the friction between seal and shaft and the wear rate. FEM simulation has established itself as a tool in seal design processes but requires input values for friction and wear depending on material, load, and velocity. This paper presents a tribological test configuration for long stroke, reciprocating movement, allowing the generation of data which meet the requirements of input parameters for FEM simulations without the geometrical influences of specific seal profiles. A numerical parameter study, performed with an FEM model, revealed the most eligible sample geometry as a flat, disc-shaped sample of the polymer glued on a stiff sample holder. At the same time, the study illustrates that the sensitivity of the contact pressure distribution to Poisson's ratio and CoF can be minimized by the developed and verified setup. It ensures robust, reliable, and repeatable experimental results with uniform contact pressures and constant contact areas to be used in databases and FEM simulations of seals, enabling upscaling from generically shaped samples to complex seal profiles.

Influence of suture size on the frictional performance of surgical suture evaluated by a penetration friction measurement approach.

The frictional performances of surgical sutures have been found to play a vital role in their functionality. The purpose of this paper is to understand the frictional performance of multifilament surgical sutures interacting with skin substitute, by means of a penetration friction apparatus (PFA). The influence of the size of the surgical suture was investigated. The relationship between the friction force and normal force was considered, in order to evaluate the friction performance of a surgical suture penetrating a skin substitute. The friction force was measured by PFA. The normal force applied to the surgical suture was estimated based on a Hertzian contact model, a finite element model (FEM), and a uniaxial deformation model (UDM). The results indicated that the penetration friction force increased as the size of the multifilament surgical suture increased. In addition, when the normal force was predicted by UDM, it was found that the ratio between the friction force and normal force decreased as the normal force increased. A comparison of the results suggested that the UDM was appropriate in predicting the frictional behavior of surgical suturing.

MYCN repression of Lifeguard/FAIM2 enhances neuroblastoma aggressiveness.

Neuroblastoma (NBL) is the most common solid tumor in infants and accounts for 15% of all pediatric cancer deaths. Several risk factors predict NBL outcome: age at the time of diagnosis, stage, chromosome alterations and MYCN (V-Myc Avian Myelocytomatosis Viral Oncogene Neuroblastoma-Derived Homolog) amplification, which characterizes the subset of the most aggressive NBLs with an overall survival below 30%. MYCN-amplified tumors develop exceptional chemoresistance and metastatic capacity. These properties have been linked to defects in the apoptotic machinery, either by silencing components of the extrinsic apoptotic pathway (e.g. caspase-8) or by overexpression of antiapoptotic regulators (e.g. Bcl-2, Mcl-1 or FLIP). Very little is known on the implication of death receptors and their antagonists in NBL. In this work, the expression levels of several death receptor antagonists were analyzed in multiple human NBL data sets. We report that Lifeguard (LFG/FAIM2 (Fas apoptosis inhibitory molecule 2)/NMP35) is downregulated in the most aggressive and undifferentiated tumors. Intringuingly, although LFG has been initially characterized as an antiapoptotic protein, we have found a new association with NBL differentiation. Moreover, LFG repression resulted in reduced cell adhesion, increased sphere growth and enhanced migration, thus conferring a higher metastatic capacity to NBL cells. Furthermore, LFG expression was found to be directly repressed by MYCN at the transcriptional level. Our data, which support a new functional role for a hitherto undiscovered MYCN target, provide a new link between MYCN overexpression and increased NBL metastatic properties.

Visna/Maedi virus genetic characterization and serological diagnosis of infection in sheep from a neurological outbreak.

An extensive outbreak characterized by the appearance of neurological symptoms in small ruminant lentivirus (SRLV) infected sheep has been identified in Spain, but the genetic characteristics of the strain involved and differential diagnostic tools for this outbreak remain unexplored. In this work, 23 Visna-affected naturally infected animals from the outbreak, 11 arthritic animals (both groups presenting anti-Visna/Maedi virus serum antibodies), and 100 seronegative animals were used. Eight of the Visna-affected animals were further studied post-mortem by immunohistochemistry. All had lesions in spinal cord, being the most affected part of the central nervous system in six of them. A representative strain of the outbreak was isolated. Together with other proviral sequences from the outbreak the virus was assigned to genotype A2/A3. In vitro culture of the isolate revealed that viral production was slow/low in fibroblast-like cells but it was high in blood monocyte-derived macrophages. The long terminal repeat (LTR) of the viral genome of this isolate lacked an U3-duplication, but its promoter activity in fibroblast-like cells was normal compared to other strains. Thus, viral production could not be inferred from the LTR promoter activity in this isolate. Analysis of the viral immunodominant epitopes among SRLV sequences of the outbreak and other known sequences allowed the design of a synthetic SU peptide ELISA that detected the Visna affected animals, representing a tool of epidemiological interest to control viral spread of this highly pathogenic strain.

Impact of peritonitis on long-term survival of peritoneal dialysis patients.

UNLABELLED: The impact of each episode of peritonitis on long-term survival of peritoneal dialysis (PD) patients has yet to be defined. OBJECTIVES: To determine the risk that each episode of peritonitis poses for patient survival and for the PD technique. PATIENTS: 1515 patients included in the Levante registry from 1 January 1993 to 31 December 2005. METHODS: Retrospective analysis of a multicentre registry using Cox regression for time-dependent variables. RESULTS: We analysed 1609 episodes of peritonitis in 716 patients (47.2%). In the univariate analysis, each case of peritonitis treated in the outpatient unit was associated with an increase in mortality (hazard ratio [HR] 1.99, P<.001), which was greater for episodes that required hospitalisation (HR 3.62, P<.001). Mortality increased with each successive episode in the same patient. Multivariate analysis confirmed the association of each case of peritonitis with lower long-term survival (HR 2.01, P<.001), with a different risk for episodes due to gram-positive and gram-negative bacteria and fungi (HR 1.73, 2.43 and 5.71, respectively; P<.001). Other variables associated with mortality were age, low residual renal function, absence of vascular access and comorbidity. Peritonitis was the only independent variable associated with technique failure (HR 1.29, P<.001), with a different risk for episodes due to gram-positive and gram-negative bacteria and fungi (HR 1.73, 2.43 and 5.71, respectively; P<.001). CONCLUSIONS: Episodes of peritonitis negatively influence long-term survival of patients on PD.

Specific T-cell proliferation to myelin peptides in relapsing-remitting multiple sclerosis.

BACKGROUND: The identification of major immunogenic peptides in multiple sclerosis (MS) is of great importance for the development of antigen-specific therapies. Cellular reactivity against a selected mix of seven myelin peptides was evaluated in vitro. The evolution of this reactivity over time and its correlation with clinical variables was also analysed. MATERIAL AND METHODS: Forty-two patients with MS, 15 with other demyelinating diseases and 40 healthy donors (HD) were studied. Cell proliferation was measured by 3[H] thymidine incorporation into samples obtained at 0, 3, 6 and 12months of MS patient follow-up. RESULTS: A positive reaction to the peptide mix was detected in 31 of the 42 patients (74%), 12 of the 40 HD (30%) and 6 of the 15 (40%) patients with other demyelinating diseases. Patients with positive proliferation had greater disability (EDSS score, 3 [1-5.5] vs. 1.0[1-2], P=0.021), higher number of relapses (7±4.1 vs. 3±1.2, P<0.001) and shorter time since the last relapse (9±7.5 vs. 32±12.3months, P=0.036). After 12months of follow-up, cell reactivity was maintained in 33 patients (78%). CONCLUSION: A high percentage of patients exhibit a significant and maintained reactivity to myelin peptides over time. Therefore, this mix may be useful as a source of antigen in the development of protocols aimed at inducing specific tolerance in MS.

Dendritic cells pulsed with antigen-specific apoptotic bodies prevent experimental type 1 diabetes.

Dendritic cells (DCs) are powerful antigen-presenting cells capable of maintaining peripheral tolerance. The possibility to generate tolerogenic DCs opens new therapeutic approaches in the prevention or remission of autoimmunity. There is currently no treatment inducing long-term tolerance and remission in type 1 diabetes (T1D), a disease caused by autoimmunity towards beta cells. An ideal immunotherapy should inhibit the autoimmune attack, avoid systemic side effects and allow islet regeneration. Apoptotic cells--a source of autoantigens--are cleared rapidly by macrophages and DCs through an immunologically silent process that contributes to maintaining tolerance. Our aims were to prevent T1D and to evaluate the re-establishment of peripheral tolerance using autologous DCs pulsed in vitro with apoptotic bodies from beta cells. Immature DCs derived from bone marrow of non-obese diabetic (NOD) mice were obtained and pulsed with antigen-specific apoptotic bodies from the beta cell line NIT-1. Those DCs that phagocytosed apoptotic cells diminished the expression of co-stimulatory molecules CD40 and CD86 and reduced secretion of proinflammatory cytokines. Moreover, these cells were resistant to increase the expression of co-stimulatory molecules after lipopolysaccharide activation. The administration of these cells to NOD transgenic mice expressing interferon-beta in their insulin-producing cells, a model of accelerated autoimmune diabetes, decreased diabetes incidence significantly and correlated positively with insulitis reduction. DCs pulsed with apoptotic cells that express disease-associated antigens constitutes a promising strategy to prevent T1D.

[Fluorescein angiography with Retcam in incontinentia pigmenti: a case report]. / Angiografía fluoresceínica con Retcam en incontinencia pigmenti: comunicación de un caso.

CASE REPORT: The ophthalmic examination and results of fluorescein angiography using Retcam II are described in a patient with Incontinentia Pigmenti (IP). DISCUSSION: Angiography fluorescein is extremely valuable in detecting vascular lesions that were invisible with ordinary ophthalmoscopy. Retcam II allows documentation of these lesions which is very useful for diagnosis, treatment and follow-up of this disease (Arch Soc Esp Oftalmol 2009; 84: 529-532).

Angiografía fluoresceínica con Retcam en incontinencia pigmenti: comunicación de un caso / Fluorescein angiography with Retcam in incontinentia pigmenti: a case report

Caso Clínico: El examen oftalmológico y los resultadosde la angiografía fluoresceinica empleando laRetcam II, son descritos en una paciente con IncontinenciaPigmenti (IP).Discusión: La angiografía fluoresceinica es muyvaliosa detectando lesiones vasculares que eraninvisibles con oftalmoscopia normal. La Retcam IIpermite la documentación de dichas lesiones lo cuales muy útil para el diagnóstico, tratamiento y seguimientode esta enfermedad(AU)

Case report: The ophthalmic examination andresults of fluorescein angiography using Retcam IIare described in a patient with Incontinentia Pigmenti(IP).Discussion: Angiography fluorescein is extremelyvaluable in detecting vascular lesions that were invisiblewith ordinary ophthalmoscopy. Retcam IIallows documentation of these lesions which is veryuseful for diagnosis, treatment and follow-up of thisdisease(AU)

Myelin peptides in multiple sclerosis.

The development of specific therapies for organ-specific autoimmune diseases requires the identification of relevant immunogenic epitopes, recognized by both pathogenic T cells and autoantibodies. Here, we review the most relevant studies focused in the identification of peptides in multiple sclerosis (MS) and the distinct T cell reactivity induced in patients compared to controls. Only a few studies reported significant differences in terms of T cell reactivity to them. The current knowledge on this issue, and the diagnostic and therapeutic possibilities opened by the identification of pathogenic MS epitopes are discussed in this paper.

Treatment of monocytes with interleukin (IL)-12 plus IL-18 stimulates survival, differentiation and the production of CXC chemokine ligands (CXCL)8, CXCL9 and CXCL10.

During inflammation, interleukin (IL)-12 and IL-18 are produced by macrophages and other cell types such as neutrophils (IL-12), keratinocytes and damaged endothelial cells (IL-18). To explore the role of IL-12 and IL-18 in inflammatory innate immune responses we investigated their impact on human peripheral blood monocytes and mature bronchoalveolar lavage (BAL) macrophages. IL-12 and IL-18 together, but not alone, prevented spontaneous apoptosis of cultured monocytes, promoted monocyte clustering and subsequent differentiation into macrophages. These morphological changes were accompanied by increased secretion of CXC chemokine ligands (CXCL)9, CXCL10 (up to 100-fold, P < 0.001) and CXCL8 (up to 10-fold, P < 0.001) but not CCL3, CCL4 or CCL5. Mature macrophages (from BALs) expressed high basal levels of CXCL8, that were no modified upon stimulation with IL-12 and IL-18. In contrast, the basal production of CXCL9 and CXCL10 by BALs was increased by 10-fold (P < 0.001) in the presence of either IL-12 or IL-18 alone and by 50-fold in the presence of both cytokines. In conclusion, our results indicate a relevant role for IL-12 and IL-18 in the activation and resolution of inflammatory immune responses, by increasing the survival of monocytes and by inducing the production of chemokines. In particular, those that may regulate angiogenesis and promote the recruitment of monocytes, activated T cells (CXCL9 and CXCL10) and granulocytes (CXCL8).

Efecto de la dureza del endospermo del maíz sobre las propiedades de hidratación y cocción / Influence of maize kernel hardness on flour hydration and cooking properties

El conocimiento acerca de la asociación entre las propiedades de cocción y la dureza del endospermo del maíz puede ayudar tanto a los nutricionistas como a los procesadores a seleccionar las materias primas para elaborar productos a base de maíz, particularmente aquellos que se consumen en forma de dispersiones cocidas. Se seleccionaron siete cultivares de maíz con distinta dureza, la que fue evaluada utilizando diferentes métodos. Los granos fueron descascarados, desgerminados y reducidos a harinas para determinar la composición, el poder de hinchamiento (PH), la solubilidad y la respuesta amilográfica. Los resultados mostraron que las diferencias en dureza de endospermo (directamente relacionada con el contenido de proteína de la harina), puede explicar las diferencias observadas tanto en el poder de hinchamiento como en los valores de consistencia amilográfica. Los cultivares de endospermo más duro muestran los menores valores de PH a alta temperatura y también los menores valores de consistencia amilográfica (viscosidad). Por el contrario los endospermos más blandos presentan los mayores valores de PH y de consistencia amilográfica. Estas diferencias son atribuidas a la restricción al hinchamiento de los gránulos del almidón que provoca la estructura de la matriz proteica. Las medida de dureza del endospermo y las de PH a 95 C pueden ser muy útiles para seleccionar cultivares que serán utilizados para lograr alimentos tales como atoles, polenta, etc.

Primary alloproliferative TH1 response induced by immature plasmacytoid dendritic cells in collaboration with myeloid DCs.

The role played by dendritic cell (DC) subsets in the immune response to alloantigens is not well defined. In vitro experiments have extensively shown that freshly isolated myeloid (M)DCs induce a strong T lymphocyte proliferation whereas plasmacytoid (P)DCs do not, unless activated by CD40 ligation. The aim of these studies was to explore whether the interplay among PDCs, MDCs and T cells modulates alloresponse. Freshly isolated MDCs and PDCs were merged in different proportions and used as antigen presenting cells (APCs) in mixed lymphocyte cultures (MLC). As described, isolated PDCs only induced a mild alloresponse, while MDCs were potent inducers of alloproliferation. Unexpectedly, when PDCs were merged with even low numbers of MDCs (down to 100 cells) and used as APCs, a potent Th1 cell proliferation was detected. Survival and maturation of PDCs was increased in these MLC conditions, which could partially explain the magnitude of the T-cell response. Interestingly, the proportion of IFNgamma-producing cells generated in such cultures was higher compared to MDC-stimulated cultures. These data suggest that the interaction between both DC subsets is determinant to generate a potent Th1 response, at least in an allogeneic situation, and may be relevant to the outcome of allogeneic stem cell transplantation.

Prevalencia y factores de riesgo asociados a la infección en el postoperatorio inmediato del trasplante hepático / Prevalence and risk factors for early postoperative infection after liver transplantation

OBJETIVO: Analizar los factores relacionados con la aparición de la infección en el postoperatorio precoz del trasplante hepático. PACIENTES Y MÉTODO: Estudio retrospectivo sobre 1000 trasplantes hepáticos en pacientes adultos, entre 1991- 2004. Se analizaron las variables pre, intra y postoperatorias de los receptores formando dos grupos al tomar como criterio la presencia o ausencia de infección. RESULTADOS: En 151 pacientes se produjo algún episodio infeccioso. Las infecciones bacterianas fueron las más frecuentes. Los factores que muestran significación estadística en el análisis multivariante son sexo (OR=0,54 [IC95%:0,33-0,90]), estadio de Child- Pugh (OR= 1,89 [IC95%:1,29-2,77]), cirrosis por virus C (OR=0,58 [IC95%:0,34-0,99]), síndrome postreperfusión (SPR) (OR= 1,82 [IC95%:1,03-3,21]), técnica de preservación de cava (OR= 0,43 [IC95%:0,22-0,84]), diabetes mellitus previa (OR= 2,38 [IC95%:1,34-4,22]), síndrome de distrés respiratorio (OR= 6,60 [IC95%:1,16-37,45]), edema pulmonar (OR= 2,36 [IC95%:1,44-3,86]), disfunción renal (OR= 3,25 [IC95%:1,89-5,60]) e insuficiencia renal aguda (OR= 20,24 [IC95%:9,88-41,46]), alteraciones neurológicas (OR= 3,36 [IC95%:1,94-5,82]), hemorragia postoperatoria (OR= 2,80 [IC95%:1,32-5,97]), disfunción del injerto (OR= 2,07 [IC95%:1,21-3,53]) y fallo primario (OR= 0,07 [IC95%:0,01-0,33]). CONCLUSIÓN: La infección es una complicación importante y su control continúa siendo difícil. Hay algunos factores que pueden ser mejorables con un manejo cuidadoso (fallo renal, edema pulmonar) o con una adecuada selección donante-receptor (disfunción inicial), otros en cambio son inherentes al procedimiento (SPR, sexo del paciente) y además se añade la inmunosupresión que actúa como auténtico modulador de la infección tanto en su aparición como en su propia expresividad clínica

OBJECTIVES: To analyze factors related to the development of infection soon after a liver transplant. PATIENTS AND METHOD: Retrospective study of 1000 liver transplants in adults between 1991 and 2004. Pre-, intra- and postoperative variables of recipients were analyzed in 2 groups according to whether infection did or did not develop. RESULTS: Infection developed in 151 patients. Bacterial infections were the most common type. Significant risk factors for infection in the multivariate analysis were sex (odds ratio [OR], 0.54; 95% confidence interval [CI], 0.33-0.90); Child-Pugh stage (OR, 1.89; 95% CI, 1.29-2,77); hepatitis C virus cirrhosis (OR, 0.58; 95% CI, 0.34-0.99); post-reperfusion syndrome (OR, 1.82; 95% CI, 1.03-3.21); vena cava preservation technique (OR, 0.43; 95% CI, 0.22-0.84); history of diabetes mellitus (OR, 2.38; 95% CI, 1.34-4.22); respiratory distress syndrome (OR, 6.60; 95% CI, 1.16-37.45); pulmonary edema (OR, 2.36; 95% CI, 1.44-3.86); renal dysfunction (OR, 3.25; 95% CI, 1.89-5.60); acute renal insufficiency (OR, 20.24; 95%CI, 9.88-41.46); neurological alterations (OR, 3.36; 95% CI, 1.94-5.82]); postoperative bleeding (OR, 2.80; 95% CI, 1.32-5.97); graft dysfunction (OR, 2.07; 95% CI, 1.21-3.53); primary graft failure (OR, 0.07; 95% CI, 0.01-0.33). CONCLUSION: Infection is a serious complication that continues to be difficult to control. Certain risk factors can be improved with careful management (kidney failure, pulmonary edema) or appropriate donor-recipient matching (initial dysfunction). Others, however, are inherent to the procedure (post-reperfusion syndrome, sex) or to immunosuppression, which acts as a true mediator of infection with regard to both its appearance and its clinical manifestation

[Influence of maize kernel hardness on flour hydration and cooking properties]. / Efecto de la dureza del endospermo del maíz sobre las propiedades de hidratación y cocción.

Knowledge of the association between cooking properties and endosperm hardness may help nutritionist and processors to select raw materials for preparing maize based food products, particularly those eaten as cooked dispersions. Seven commercial maize cultivars differing in hardness were selected to evaluate endosperm hardness on the kernels and some characteristics such as composition and hydration and cooking properties on the grits obtained from those maizes. Results show that the differences in endosperm hardness (directly related to grits protein content) can explain the differences in swelling and amylographic consistencies values. Cultivars with the hardest endosperm show the lowest values at high temperature. They also show the lowest amylographic consistencies. On the other hand softer endosperms present the highest swelling power and the highest amylographic consistencies. These differences are attributed to the restriction for starch swelling caused by the protein matrix. Endosperm hardness measurements and swelling power at 95 degrees C, can be useful to select cultivars that are going to be used to prepare maize based foods like atoles, polenta, etc.

Differential expression of the cytokine receptors for human interleukin (IL)-12 and IL-18 on lymphocytes of both CD45RA and CD45RO phenotype from tonsils, cord and adult peripheral blood.

The objective of this study was to demonstrate the variable expression of cytokine receptors on naive versus memory human CD4+ T cell subpopulations in tonsillar tissue, cord blood and adult blood. We prove that the receptors for both interleukin (IL)-12 and IL-18 are expressed exclusively on memory T cells. This observation was seen not only on the CD45RO+ memory T cells but also on a significant percentage of the CD45RA+, CD62L-, CD27- and CCR7- populations. Furthermore, CD45RA+ CD62L+, CD27+ or CCR7+ CD4+ T cells that expressed IL-12Rbeta1 and IL-18Ralpha did not express CD31, a marker for recent thymic emigrants. We reveal that cord blood lymphocytes do not express IL-12Rbeta1 whereas IL-18Ralpha expression was detected at low levels. Importantly, the IL-12Rbeta2 signalling chain, which is absent in all resting T cells, was up-regulated in both CD45RA+ and CD45RO+ T cells as a result of stimulation with anti-CD3 and anti-CD28 in vitro. This observed up-regulation was, however, restricted to 80% of the total CD4+ population. Finally, a very small proportion of the CD4+ CD45RO+ tonsillar T cells expressed the IL-12 and IL-18 receptors, thereby establishing the differential expression of these receptors between peripheral and tonsillar memory T cell subpopulations.

Differential up-regulation of HLA-DM, invariant chain, and CD83 on myeloid and plasmacytoid dendritic cells from peripheral blood.

Two main dendritic cell (DC) subsets have been described in peripheral blood, the myeloid subset or DC1 that is characterized by the presence of CD11c and the plasmacytoid subset or DC2 negative for this marker. The two subsets may perform different functions and have been defined as immunogenic (the myeloid subset) or tolerogenic (the plasmacytoid subset). The expression of human leukocyte antigen (HLA)-DM molecules, which act as peptide editors in the antigen presentation process, was studied in freshly isolated plasmacytoid and myeloid DCs from peripheral blood. The expression of the invariant chain (Ii), the major histocompatibility complex class II (MHC-II) : class II-associated Ii peptide (CLIP) complex, and CD83 was also investigated. The results showed that intracellular expression of HLA-DM and the Ii was significantly higher in the plasmacytoid than in the myeloid DC subset. In contrast, a higher fraction of cell expressing MHC-II : CLIP complex was found in the myeloid than in the plasmacytoid DC subpopulation. CD83 was not detected in any of these two subsets. Following culture of these cells with interleukin-3 (IL-3), tumor necrosis factor-alpha (TNFalpha) and/or heat shock protein-70 (HSP-70), the expression of intracellular HLA-DM was up-regulated in the myeloid DCs to levels similar to those found in the plasmacytoid DCs, whilst the Ii was down-regulated in the plasmacytoid subset to similar levels to those expressed in the myeloid DCs. In addition, CD83 was up-regulated in the myeloid (CD11c+) but not in the plasmacytoid (CD11c-) DCs. The expression pattern of these antigen-processing molecules could be related to the immaturity and function attributed to these DC subsets.

Protection against woodchuck hepatitis virus (WHV) infection by gene gun coimmunization with WHV core and interleukin-12.

Woodchuck hepatitis virus (WHV) and hepatitis B virus (HBV) are closely similar with respect to genomic organization, host antiviral responses, and pathobiology of the infection. T-cell immunity against viral nucleocapsid (HBcAg or WHcAg) has been shown to play a critical role in viral clearance and protection against infection. Here we show that vaccination of healthy woodchucks by gene gun bombardment with a plasmid coding for WHcAg (pCw) stimulates proliferation of WHcAg-specific T cells but that these cells do not produce significant levels of gamma interferon (IFN-gamma) upon antigen stimulation. In addition, animals vaccinated with pCw alone were not protected against WHV inoculation. In order to induce a Th1 cytokine response, another group of woodchucks was immunized with pCw together with another plasmid coding for woodchuck interleukin-12 (IL-12). These animals exhibited WHcAg-specific T-cell proliferation with high IFN-gamma production and were protected against challenge with WHV, showing no viremia or low-level transient viremia after WHV inoculation. In conclusion, gene gun immunization with WHV core generates a non-Th1 type of response which does not protect against experimental infection. However, steering the immune response to a Th1 cytokine profile by IL-12 coadministration achieves protective immunity. These data demonstrate a crucial role of Th1 responses in the control of hepadnavirus replication and suggest new approaches to inducing protection against HBV infection.