The viral transcription group determines the HLA class I cellular immune response against human respiratory syncytial virus.

The cytotoxic T-lymphocyte-mediated killing of virus-infected cells requires previous recognition of short viral antigenic peptides bound to human leukocyte antigen class I molecules that are exposed on the surface of infected cells. The cytotoxic T-lymphocyte response is critical for the clearance of human respiratory syncytial virus infection. In this study, naturally processed viral human leukocyte antigen class I ligands were identified with mass spectrometry analysis of complex human leukocyte antigen-bound peptide pools isolated from large amounts of human respiratory syncytial virus-infected cells. Acute antiviral T-cell response characterization showed that viral transcription determines both the immunoprevalence and immunodominance of the human leukocyte antigen class I response to human respiratory syncytial virus. These findings have clear implications for antiviral vaccine design.

Uso de heparina sódica en técnicas continuas de depuración extrarrenal / Use of sodium heparine in Continuous Extrarenal Depuration Techniques

OBJETIVO: comprobar la relación que existe entre el uso o no de heparina sódica y la coagulación de los filtros en técnicas continuas de depuración extrarrenal (TCDE). MATERIAL Y MÉTODO: estudio descriptivo transversal realizado en una Unidad de Cuidados Intensivos (UCI) durante dos años. Se incluyeron a todos los pacientes que en dicho periodo fueron sometidos a TCDE. Se recogieron variables sociodemográficas, uso de heparina sódica, duración, motivos de retirada y coagulación del filtro. Se utilizó estadística descriptiva e inferencia estadística mediante la prueba T de Student y U de Mann-Whitney. RESULTADOS: se obtuvo una muestra de 50 pacientes y 162 filtros. En un 66% de los pacientes se utilizó heparina. La media de duración del filtro con heparina fue 27,1 horas frente a las 19 horas en los no se utilizó (p= 0,004). El principal motivo de retirada de los filtros fue la coagulación, tanto en los que se usó heparina (71%), como en los que no se usó (70%). CONCLUSIONES: la utilización de heparina sódica en TCDE aumenta la vida media del filtro. La coagulación del filtro es el motivo de retirada más habitual. El uso de heparina sódica conlleva un retraso en la coagulación del filtro

OBJECTIVE: to confirm the relationship existing between using or not using sodium heparine and filter clotting in Continuous Extrarenal Depuration Techniques (CEDTs). MATERIALS AND METHOD: a transversal descriptive study conducted in the Intensive Care Unit (ICU) during two years. All patients who underwent CEDT during that period were included in the study. Sociodemographic variables were collected, as well as the use of sodium heparine, duration, reasons for removal, and filter clotting. Descriptive statistics and statistical inference were used, through Student's t Test and Mann-Whitney U Test. RESULTS: a sample of 50 patients and 162 filters was obtained. Heparine was used in 66% of patients. The mean duration of the filter with heparine was 27.1 vs. 19 hours in those were it was not used (p= 0.004). The main reason for removing filters was clotting, both for those where heparine was used (71%), and for those where it was not used (70%). CONCLUSIONS: the use of sodium heparine in CEDT increases the mean life of the filter. Filter clotting is the most usual reason of removal. The use of sodium heparine entails a delay in filter clotting

Diversity of natural self-derived ligands presented by different HLA class I molecules in transporter antigen processing-deficient cells.

The transporter associated with antigen processing (TAP) translocates the cytosol-derived proteolytic peptides to the endoplasmic reticulum lumen where they complex with nascent human leukocyte antigen (HLA) class I molecules. Non-functional TAP complexes and viral or tumoral blocking of these transporters leads to reduced HLA class I surface expression and a drastic change in the available peptide repertoire. Using mass spectrometry to analyze complex human leukocyte antigen HLA-bound peptide pools isolated from large numbers of TAP-deficient cells, we identified 334 TAP-independent ligands naturally presented by four different HLA-A, -B, and -C class I molecules with very different TAP dependency from the same cell line. The repertoire of TAP-independent peptides examined favored increased peptide lengths and a lack of strict binding motifs for all four HLA class I molecules studied. The TAP-independent peptidome arose from 182 parental proteins, the majority of which yielded one HLA ligand. In contrast, TAP-independent antigen processing of very few cellular proteins generated multiple HLA ligands. Comparison between TAP-independent peptidome and proteome of several subcellular locations suggests that the secretory vesicle-like organelles could be a relevant source of parental proteins for TAP-independent HLA ligands. Finally, a predominant endoproteolytic peptidase specificity for Arg/Lys or Leu/Phe residues in the P(1) position of the scissile bond was found for the TAP-independent ligands. These data draw a new and intricate picture of TAP-independent pathways.

Natural HLA-B*2705 protein ligands with glutamine as anchor motif: implications for HLA-B27 association with spondyloarthropathy.

The presentation of short viral peptide antigens by human leukocyte antigen (HLA) class I molecules on cell surfaces is a key step in the activation of cytotoxic T lymphocytes, which mediate the killing of pathogen-infected cells or initiate autoimmune tissue damage. HLA-B27 is a well known class I molecule that is used to study both facets of the cellular immune response. Using mass spectrometry analysis of complex HLA-bound peptide pools isolated from large amounts of HLA-B*2705(+) cells, we identified 200 naturally processed HLA-B*2705 ligands. Our analyses revealed that a change in the position (P) 2 anchor motif was detected in the 3% of HLA-B*2705 ligands identified. B*2705 class I molecules were able to bind these six GlnP2 peptides, which showed significant homology to pathogenic bacterial sequences, with a broad range of affinities. One of these ligands was able to bind with distinct conformations to HLA-B27 subtypes differentially associated with ankylosing spondylitis. These conformational differences could be sufficient to initiate autoimmune damage in patients with ankylosing spondylitis-associated subtypes. Therefore, these kinds of peptides (short, with GlnP2, and similar low affinity to all HLA-B27 subtypes tested but with unlike conformations in differentially ankylosing spondylitis-associated subtypes) must not be excluded from future researches involving potential arthritogenic peptides.

A viral, transporter associated with antigen processing (TAP)-independent, high affinity ligand with alternative interactions endogenously presented by the nonclassical human leukocyte antigen E class I molecule.

The transporter associated with antigen processing (TAP) enables the flow of viral peptides generated in the cytosol by the proteasome and other proteases to the endoplasmic reticulum, where they complex with nascent human leukocyte antigen (HLA) class I. Later, these peptide-HLA class I complexes can be recognized by CD8(+) lymphocytes. Cancerous cells and infected cells in which TAP is blocked, as well as individuals with unusable TAP complexes, are able to present peptides on HLA class I by generating them through TAP-independent processing pathways. Here, we identify a physiologically processed HLA-E ligand derived from the D8L protein in TAP-deficient vaccinia virus-infected cells. This natural high affinity HLA-E class I ligand uses alternative interactions to the anchor motifs previously described to be presented on nonclassical HLA class I molecules. This octameric peptide was also presented on HLA-Cw1 with similar binding affinity on both classical and nonclassical class I molecules. In addition, this viral peptide inhibits HLA-E-mediated cytolysis by natural killer cells. Comparison between the amino acid sequences of the presenting HLA-E and HLA-Cw1 alleles revealed a shared structural motif in both HLA class molecules, which could be related to their observed similar cross-reactivity affinities. This motif consists of several residues located on the floor of the peptide-binding site. These data expand the role of HLA-E as an antigen-presenting molecule.

Multiple viral ligands naturally presented by different class I molecules in transporter antigen processing-deficient vaccinia virus-infected cells.

The transporter associated with antigen processing (TAP) delivers the viral proteolytic products generated by the proteasome in the cytosol to the endoplasmic reticulum lumen that are subsequently recognized by cytotoxic T lymphocytes (CTLs). However, several viral epitopes have been identified in TAP-deficient models. Using mass spectrometry to analyze complex human leukocyte antigen (HLA)-bound peptide pools isolated from large numbers of TAP-deficient vaccinia virus-infected cells, we identified 11 ligands naturally presented by four different HLA-A, HLA-B, and HLA-C class I molecules. Two of these ligands were presented by two different HLA class I alleles, and, as a result, 13 different HLA-peptide complexes were formed simultaneously in the same vaccinia virus-infected cells. In addition to the high-affinity ligands, one low-affinity peptide restricted by each of the HLA-A, HLA-B, and HLA-C class I molecules was identified. Both high- and low-affinity ligands generated long-term memory CTL responses to vaccinia virus in an HLA-A2-transgenic mouse model. The processing and presentation of two vaccinia virus-encoded HLA-A2-restricted antigens took place via proteasomal and nonproteasomal pathways, which were blocked in infected cells with chemical inhibitors specific for different subsets of metalloproteinases. These data have implications for the study of the effectiveness of early empirical vaccination with cowpox virus against smallpox disease.

Conocimientos sobre resucitación cardiopulmonar del profesional enfermero en unidades sin monitorización de pacientes / Knowledge of cardiopulmonary resuscitation by the nursing professional in patient monitoring units

Objetivos: determinar el grado de conocimiento sobre resucitación cardiopulmonar(RCP) en los profesionales enfermeros de unidades sin monitorización de pacientes del Hospital General de Ciudad Real, así como la relación entre el grado de conocimiento y la edad y el tiempo de experiencia profesional.Material y métodos: estudio descriptivo transversal realizado en unidades médicas y quirúrgicas en el Hospital General de Ciudad Real sobre una población de 94 enfermeras. Se utilizó un cuestionario de elaboración propia que recorría las recomendaciones internacionales sobre RCP y que podía oscilar entre 0 y 10 (máximo nivel de conocimientos). Se calcularon índices de estadística descriptiva e inferencia estadística (test de X2) para contrastar la hipótesis de asociación entre edad y tiempo de experiencia profesional con el nivel de conocimientos. Resultados: se obtuvo una tasa de respuesta del 85,1%. Un 85% eran mujeres.La media de respuestas correctas fue de 3,4. No se encontraron diferencias significativas en cuanto a conocimiento entre los distintos servicios estudiados (p = 0,79), ni con la edad (p = 0,32), ni con el tiempo de experiencia profesional (p = 0,32).Conclusiones: los profesionales enfermeros no conocen adecuadamente las últimas recomendaciones sobre RCP, que tienen su origen en el informe del Consejo Europeo de Resucitación del año 2005. Los centros sanitarios han de proporcionar una atención eficaz a las víctimas de las paradas cardiacas, asegurando que sus plantillas reciben entrenamiento regular y actualizado, mediante la implantación de programas de RCP hospitalarios orientado a conseguir una aplicación correcta de las recomendaciones internacionales en esta materia (AU)

Objectives: to determine the degree of knowledge on cardiopulmonary resuscitation of nursing professionals in patient monitoring units at the Ciudad Real General Hospital, as well as the relationship between the degree of knowledge and the age and time of professional experience. Material and methods: cross-sectional descriptive study carried out inmedical and surgical units at the Ciudad Real General Hospital on a population comprised of 94 nurses. A self-elaborated questionnaire was used containing the international recommendations on CPR and which varied inscore between 0 and 10 (maximum level of knowledge). Descriptive statistics indexes and statistical inference were calculated a (test de X2) to compare the association hypothesis between age and time of professional experience and the level of knowledge.Results: a response rate of 85,1% was obtained. 85% were women. The mean for correct answers was 3,4. No significant differences were found with regard to knowledge among the different hospital department studied(p = 0,79), neither regarding age (p = 0,32), or the time of professional experience (p = 0,32).Conclusions: nursing professionals do not have a sufficient knowledge ofthe latest CPR recommendations derived from the 2005 European Resuscitation Council. Health centres should provide more effective medical care to of cardiac arrest victims by ensuring that their staff received regular and up-to-date training via the implantation of hospital CPR programmes aimedat achieving the correct administration of the international recommendations on the subject (AU)

Unusual viral ligand with alternative interactions is presented by HLA-Cw4 in human respiratory syncytial virus-infected cells.

Short viral antigens bound to human major histocompatibility complex (HLA) class I molecules are presented on infected cells. Vaccine development frequently relies on synthetic peptides to identify optimal HLA class I ligands. However, when natural peptides are analyzed, more complex mixtures are found. By immunoproteomics analysis, we identify in this study a physiologically processed HLA ligand derived from the human respiratory syncytial virus matrix protein that is very different from what was expected from studies with synthetic peptides. This natural HLA-Cw4 class I ligand uses alternative interactions to the anchor motifs previously described for its presenting HLA-Cw4 class I molecule. Finally, this octameric peptide shares its C-terminal core with the H-2D(b) nonamer ligand previously identified in the mouse model. These data have implications for the identification of antiviral cytotoxic T lymphocyte responses and for vaccine development.

TAP-independent human histocompatibility complex-Cw1 antigen processing of an HIV envelope protein conserved peptide.

Individuals with nonfunctional transporters associated with antigen processing (TAP) complexes are not particularly susceptible to viral infections or neoplasms. Therefore, their immune system must be reasonably efficient, and the present, though reduced, cytolytic CD8 αß T subpopulation specific for TAP-independent antigens may be sufficient to establish an immune defense protecting against viral infections in these individuals. The objective of the present study was to identify TAP-independent ligands from HIV gp160 protein. An analysis and comparison of complex human histocompatibility complex (HLA)-bound peptide pools isolated from large quantities of healthy or HIV gp160-expressing human cells was performed using mass spectrometry and bioinformatics tools. A conserved TAP-independent HLA peptide ligand endogenously processed and presented in infected human cells was identified. This ligand originates from the envelope protein bound to the HLA-Cw1 class I molecule with high affinity. It was concluded that HLA class I peptides derived from a large fraction of the N-terminal HIV envelope protein could be presented even in the absence of the TAP complex.

TLR4-independent upregulation of activation markers in mouse B lymphocytes infected by HRSV.

Human respiratory syncytial virus (HRSV) is the most common cause of severe respiratory infections in infants and young children, often leading to hospitalization. In addition, HRSV poses a serious health risk in immunocompromised individuals and the elderly. It has been reported that this virus can infect mouse antigen-presenting cells, including B lymphocytes. In these B cells, HRSV infection upregulates the expression of activation markers, including MHC class II and CD86, but not MHC class I molecules. Here, we report that HRSV infection of spleen B lymphocytes downregulated TLR4. Either blocking with anti-TLR4 antibody or genetic deletion, but not functional deficiency of TLR4, moderately reduced the infectivity of HRSV in B lymphocytes. HRSV-infected B lymphocytes with deleted TLR4 upregulated MHC class II and CD86 molecules to the same levels as TLR4(+) wild type B cells. Since the activation of monocytes and macrophages by HRSV was previously reported to depend on TLR4, the current study indicates that these cells and B lymphocytes respond to HRSV infection with different activation pathways.

H-2Ld class I molecule protects an HIV N-extended epitope from in vitro trimming by endoplasmic reticulum aminopeptidase associated with antigen processing.

In the classical MHC class I Ag presentation pathway, antigenic peptides derived from viral proteins by multiple proteolytic cleavages are transported to the endoplasmic reticulum lumen and are then exposed to ami-nopeptidase activity. In the current study, a long MHC class I natural ligand recognized by cytotoxic T lymphocytes was used to study the kinetics of degradation by aminopeptidase. The in vitro data indicate that this N-extended peptide is efficiently trimmed to a 9-mer, unless its binding to the MHC molecules protects the full-length peptide.

Multiple, non-conserved, internal viral ligands naturally presented by HLA-B27 in human respiratory syncytial virus-infected cells.

Cytotoxic T lymphocyte (CTL)-mediated death of virus-infected cells requires prior recognition of short viral peptide antigens that are presented by human leukocyte antigen (HLA) class I molecules on the surface of infected cells. The CTL response is critical for the clearance of human respiratory syncytial virus (HRSV) infection. Using mass spectrometry analysis of complex HLA-bound peptide pools isolated from large amounts of HRSV-infected cells, we identified nine naturally processed HLA-B27 ligands. The isolated peptides are derived from six internal, not envelope, proteins of the infective virus. The sequences of most of these ligands are not conserved between different HRSV strains, suggesting a mechanism to explain recurrent infection with virus of different HRSV antigenic subgroups. In addition, these nine ligands represent a significant fraction of the proteome of this virus, which is monitored by the same HLA class I allele. These data have implications for vaccine development as well as for analysis of the CTL response.