HLA-B*57 and IFNL4-related polymorphisms are associated with protection against HIV-1 disease progression in controllers.

Background: HIV-1-controllers maintain HIV-1 viremia at low levels (normally <2000 HIV-RNA copies/mL) without antiretroviral treatment. However, some HIV-1-controllers have evidence of immunologic progression with marked CD4+T-cell decline. We investigated host genetic factors associated with protection against CD4+T-cell loss in HIV-1-controllers. Methods: We analysed the association of interferon lambda 4 (IFNL4)-related polymorphisms and HLA-B haplotypes within Long Term Non-Progressor HIV-1-controllers ((LTNP-C), defined by maintaining CD4+T-cells counts >500 cells/mm3 for more than 7 years after HIV-1 diagnosis) versus non-LTNP-C, who developed CD4+T-cells counts <500 cells/mm3 Both a Spanish study cohort (n=140) and an international validation cohort (n=914) were examined. Additionally, in a subgroup of individuals HIV-1-specific T-cell responses and soluble cytokines were analysed RESULTS: HLA-B*57 was independently associated with the LTNP-C phenotype (OR=3.056 (1.029-9.069) p=0.044 and OR=1.924 (1.252-2.957) p=0.003) while IFNL4 genotypes represented independent factors for becoming non-LTNP-C (TT/TT, ss469415590, OR=0.401 (0.171-0.942) p=0.036 or A/A, rs12980275, OR=0.637 (0.434-0.934) p=0.021) in the Spanish and validation cohort, respectively, after adjusting for sex, age at HIV-1 diagnosis, IFNL4-related polymorphisms and different HLA-B haplotypes. LTNP-C showed lower plasma IP-10 (p=0.019) and higher IFN-γ (p=0.02) levels than the HIV-1-controllers with diminished CD4+T-cell numbers. Moreover, LTNP-C exhibited higher quantities of IL2+CD57- and IFN-γ+CD57- HIV-1-specific CD8+T-cells (p=0.002 and 0.041, respectively) than non-LTNP-C. Conclusions: We have defined genetic markers able to segregate stable HIV-1-controllers from those who experience CD4+T-cell decline. These findings allow for identification of HIV-1-controllers at risk for immunologic progression, and provide avenues for personalized therapeutic interventions and precision medicine for optimizing clinical care of these individuals.

Validation and comparison of instruments to identify frail patientes in primary care settings: Study protocol.

BACKGROUND: In the last few years several indices and tools, aimed at identifying frail subjects in various care settings have been developed. However, to date none of them has been incorporated into usual practice in the primary care setting. The purposes of this study are: 1) to evaluate the predictive capacity of the Tilburg Frailty Indicator (TFI), the Gérontopôle Frailty Screening Tool (GFST) and the KoS model together with two biomarker levels (SOX2 and p16INK4a) for adverse events related to frailty; 2) to determine differences in the use of healthcare services according to frailty. METHODS/DESIGN: Prospective multicentre cohort study with a 2-year follow-up. The study will be performed in primary care centres of Gipuzkoa and Costa del Sol, both located in Spain. Autonomous, non-institutionalized individuals aged 70 and over that agree to participate in this study will constitute the study population. A total of 900 individuals will be randomly selected from the healthcare administrative data bases of the participating health services. Data will be collected at baseline and at 1 and 2 years. The main independent variables assessed at baseline will be TFI outcomes, GFST and the KoS model, together with the expression of SOX2 and p16INK4a levels. During follow-up, loss of autonomy, the occurrence of death and consumption of healthcare resources will be assessed. DISCUSSION: The main focus of this work is the identification and evaluation of several instruments constructed under different rationales to identify frail subjects in primary care settings. The resulting outcomes have potential for direct application to the primary care practice. Early identification of the onset of functional impairment of elderly is an essential, still unresolved aspect in the prevention of dependence in the scope of primary care.

Conocimientos y actitudes de los mayores hacia el documento de voluntades anticipadas / Seniors’ knowledge of and attitudes to advance directive documents

Objetivos: El objetivo de este estudio es determinar los conocimientos y las actitudes que presentan las personas mayores hacia el documento de voluntades anticipadas.MétodosEstudio descriptivo transversal, realizado en atención primaria en las provincias de Albacete y Guadalajara (n = 464).ResultadosEl 86,2% (intervalo de confianza del 95% [IC95%]: 83,0-89,5) de los sujetos no conocía el documento y solo el 3,4% (IC95%: 1,7-5,3) lo había formalizado. El 76,7% (IC95%: 72,8-80,7) consideró que la existencia del documento es conveniente. Las variables asociadas mediante regresión logística con una mejor actitud hacia las voluntades anticipadas fueron el nivel de instrucción (odds ratio [OR] = 4,7; IC95%: 2,6-8,4) y haber vivido una experiencia en que el documento hubiese ayudado (OR = 1,9; IC95%: 1,1-3,4).ConclusionesLos mayores muestran una actitud positiva hacia las voluntades anticipadas, pero la proporción de personas que conocen el documento es baja (AU)

Objectives: The aim of this study was to determine seniors’ knowledge of and attitudes toward advancedirective documents.Methods: We carried out a cross-sectional descriptive study in a primary care setting in the provinces ofAlbacete and Guadalajara, Spain (n = 464).Results: A total of 86.2% (95% CI: 83.0-89.5) of the participants were unaware of advance directive documents and only 3.4% (95% CI: 1.7-5.3) had formalized one. These documents were positively viewedby 76.7% of the participants (95% CI: 72.8-80.7). The variables associated with positive attitudes towardadvance directives in logistic regression were educational level (OR = 4.7; 95% CI: 2.6-8.4) and experienceof a situation in which such a document would have helped (OR = 1.7; 95% CI: 1.1-3.4).Conclusions: Seniors had positive attitudes toward advance directives, but the proportion of personsaware of these documents was low (AU)

Hepatitis C virus replication in Caucasian HIV controllers.

Whether HIV controllers, patients who spontaneously control HIV viraemia, are able to control hepatitis C virus (HCV) infection, in terms of spontaneous clearance or lower HCV replication, is not well understood. To assess to what extent Caucasian HIV controllers are able to control HCV replication and potential associated factors, plasma HIV-1 and HCV RNA levels, anti-HCV antibodies, HCV genotype and human leucocyte antigens (HLA) typing were determined in samples from 75 HIV controllers (33 viraemic controllers, <1000 HIV-1 RNA copies/mL, and 42 elite controllers, <40 HIV-1 RNA copies/mL) and compared with 261 HIV-infected noncontrollers. We did not find differences in the HCV spontaneous clearance rates between groups. However, we interestingly found a lower HCV viral load in HIV controllers, alongside a different distribution of HCV genotypes in relation to the comparison group. In addition, HLA-B57 was associated with a lower HCV viral load in the control group and HIV controllers, and conversely, HLA-B35 with higher HCV viral load in HIV controllers. The subrepresentation of HCV genotype 1 and the overrepresentation of HLA-B57 only partly explained the lower HCV viral load found in HIV controllers. In fact, HIV controller status was independently associated with lower HCV viral load, together with HCV genotype non-1, the presence of HLA-B57 and absence of HLA-B35. Caucasian HIV controllers are able to better control HCV replication, in terms of lower HCV viral load levels. These findings support the idea that some common host mechanisms are involved in the defence against these two persistent infections.

Estudio del sueño en pacientes con infección por el virus de la inmunodeficiencia humana / Sleep study in HIV patients

No disponible

Síndrome de Kartagener e infertilidad / Kartagener´s syndrome e infertility

Las disquinesias ciliares primitivas son etiologías raras de esterilidad primaria en caso del hombre (prevalencia 1/ 6000 a 1/ 40000). El síndrome de Kartagener es una entidad particular entre esta disquinesias ciliares primitivas. Se transmite según un modo autosómico recesivo. Se distingue por la asociación de un situs inverso, poliposis naso-sinusal y de una dilatación de los bronquios. Esta inmovilidad ciliar esta en el origen de numerosas infecciones broncopulmonares, sinusales y en el hombre, de infertilidad. Describiendo la observación de una pareja en la cual el hombre es portador de este síndrome, son analizados los orígenes genéticos de esta disquinesia y discutidas las diferentes opiniones observadas en la literatura

Primary ciliary dyskinesia is a rare etiology of sterility in man (prevalence betwen 1/ 6000 and 1/ 40000). Kartagener’s syndrome is an autosomal recessive disorder, characterized by total or parcial dysfunction of the ciliary or flagellated cells. This syndrome associates situs inversus, sinusitis, bronchiectasis and occasionally sterility in males. We report a case of inmotile cilia syndrome with male infertility and compare the data with four other couples reported in the literature. The difficulty is to select and alive sperm cell for ICSI

Carcinoma tubárico primitivo y polimiositis / Primary primitive fallopian tube carcinoma and polymiositis

Los autores aportan un caso de asociación de un carcinoma tubárico primitivo a una polimiositis. Se trata de una paciente de 53 años, que consultó por dolores pelvianos, metrorragias y leucorreas amarillentas, con una masa pelviana de difícil movilización y móvil a la exploración clínica, y una masa laterouterina derecha con hidrosálpinx en la ecografía pelviana. El diagnóstico definitivo lo aportó el examen ana tomoclínico de la pieza de anexectomía derecha. La histerectomía total sin conservación anexial no dejó residuo tumoral. La paciente perdió contacto con nosotros sin tratamiento complementario y reconsultó 3 años después por una impotencia funcional de los miembros superiores, seguida de los inferiores, mialgias, alteraciones de la deglución y aparición de una adenopatía supraclavicular izquierda. Los exámenes clínicos, paraclínicos y anatomopatológicos mostraron que se trataba de un adenocarcinoma tubárico derecho con recaída ganglionar pelviana y metastásica supraclavicular izquierda, con polimiositis paraneoplásica. La paciente se ha beneficiado de 6 sesiones de quimioterapia, después de radioterapia en el hueco subclavicular izquierdo, a la dosis de 45 Gy. La respuesta al tratamiento ha sido excelente, y la paciente está en remisión completa después de un margen de 50 meses tras el diagnóstico. La asociación de cáncer de la trompa con una polimiositis es excepcional, y es necesaria una terapia antineoplásica rápida para tratar el cáncer y la polimiositis paraneoplásica (AU)

We report a case of a primitive fallopian tube carcinoma associated with polymyositis. A 53­year-old woman consulted for pelvic pain, metrorrhagia, and leukorrhea. Physical examination revealed a renitent and mobile mass in the pelvis. Ultrasonography showed a right lateral uterine mass with hydrosalpinx. Pathological examination of the right annexectomy specimen provided the definitive diagnosis. No residual tumor was found at total hysterectomy with bilateral annexectomy. The patient was lost to follow-up for 3 years without complementary treatment and then consulted again for functional disability first of the upper limbs and subsequently of the lower limbs with myalgia, swallowing disorders and left supraclavicular node enlargement resulting from pelvic relapse of the right fallopian tube adenocarcinoma and left supraclavicular metastasis with paraneoplastic polymyositis. The patient was given 6 courses of chemotherapy with radiotherapy (45 Gy) centered on the left clavicular region. The patient showed excellent response to treatment, and remains in complete remission 50 months after diagnosis. The association of fallopian tube carcinoma with polymyositis is exceptional, requiring rapid treatment effective against the cancer and paraneoplastic polymyositis (AU)

Aproximación psicológica a la hiperemesis gravídica / The psychological approach in hyperemesis gravidarum

Los vómitos incoercibles gravídicos son un fenómeno que no atañe más que al 1-2% de las mujeres encintas, hospitalizadas en caso de conducta anoréxica que no cede. El tratamiento consiste en un aislamiento completo, rehidratación y medicación antiemética. La práctica del aislamiento, instituida más o menos hacia 1914, está en consonancia con la creencia según la cual estas mujeres eran simuladoras que esperaban el derecho a un aborto gracias a este síntoma. Al aislarlas de su entorno conyugal y familiar, los equipos médicos indagan sobre la revelación de su deseo abortivo. Trata este trabajo de evaluar la actualidad de este análisis. Dos entrevistas psicológicas semidirigidas, realizadas a 40 mujeres encintas hospitalizadas por vómitos incoercibles gravídicos en un servicio ginecoobstétrico de nivel 3 y tratadas según el protocolo establecido, entre los años 2001-2003. Entre las 40 pacientes, se han establecido 4 grupos. El primero (n = 10) estaba formado por pacientes consideradas con un conflicto consciente frente a la gestación sin, por otra parte, desear el aborto, conflicto que es resuelto con rapidez. El segundo (n = 14) estaba formado por pacientes con diversos antecedentes obstétricos, confrontándoles al vacío del niño perdido y a la dificultad de aceptar el niño que ellas mismas portan. El tercer grupo (n = 9) lo formaban pacientes que creían o temían vivir un drama obstétrico que su madre había vivido, episodio a menudo lejos de su consciente, que aflora en la entrevista. El cuarto grupo (n = 7) lo constituían pacientes para las que la unión temprana madre-niño de pecho fue de mala calidad, y caen en la misma repetición de las mismas actitudes fragilizadoras que su madre con respecto a su futuro hijo. Una sola interrupción voluntaria del embarazo fue realizada en una mujer de este grupo. El tratamiento con aislamiento se corresponde con la posibilidad de evitar una interrupción involuntaria del embarazo, entre otros aspectos, fuera de la presión familiar, y contribuye a la posibilidad de elaboración de maniobras ambivalentes fuertes, sin reclamar necesariamente la interrupción de la gestación. Se adjunta un anexo (anexo I) como modelo de cuestionario (AU)

Hyperemesis gravidarum is a phenomenon that only affects 1 or 2% of pregnant women, who require hospitalization if their anorexic behaviour does not cease. Treatment consists of isolation, anti-vomiting drugs, and rehydration therapy. The practice of isolation was instituted in approximately 1914, and was based on the belief that they were pretending to have this symptom in order to be given an abortion. By isolating them from their husband and family, the medical staff hoped that this desire would be revealed. We have tried to evaluate the reality of this analysis. Two psychological interviews were carried out using a questionnaire on 40 pregnant women at the time of their admission for hyperemesis gravidarum in a level 3 Gynaecology/Obstetric unit from 2001-2003. All received the treatment described. Four groups were established amongst the 40 patients. The first group (n=10) were patients with a conscious conflict about their pregnancy, who did not want an abortion, this conflict was resolved rapidly. The second group (n=14): were patients with diverse obstetric antecedents, confronting the previous loss of a child and the difficulty of accepting the child that they were now carrying. The third group (n=9) were women who were afraid of a dramatic obstetric event, which the mother had experienced. Although they were not conscious of it, it surfaced during interview. The fourth group (n=7): patients whose own early mother-child relationship was poor feared that they would have the same attitude towards their babies. In this group, only one termination of pregnancy was carried out. Isolation treatment may help in avoiding an involuntary termination of pregnancy, away from family pressure. It may possibly contribute to the elaboration of strongly ambivalent manoeuvres without termination of pregnancy being sought (AU)

Enfermedades mitocondriales y gestación / Mitochondrial disease and pregnancy

Los autores aportan la observación de una gestación en una primípara afectada de citopatía mitocondrial, descubierta 3 años antes, ante la aparición progresiva de nefropatía tubulointersticial, debilidad muscular, neuropatía óptica bilateral y leucoencefalopatía detectada por resonancia magnética nuclear. Se estableció el diagnóstico por una biopsia muscular y por un estudio enzimático por espectrofotometría, que mostró un déficit combinado de los complejos I, II, III y IV de la cadena respiratoria mitocondrial. La búsqueda de la mutación genética fue negativa. La gestación se complicó por una preeclampsia severa, una diabetes gestacional que necesitó insulinoterapia y una insuficiencia renal grave, por lo que se impuso una extracción prematura por cesárea en la semana 30 de amenorrea. La evolución inmediata del recién nacido, de sexo femenino, con peso de 1.070 g, no planteó ningún problema especial. A la edad de 2 años, no presenta ningún signo de afección mitocondrial. Por el contrario, la evolución materna fue mala, con crisis convulsivas e insuficiencia renal terminal, actualmente en tratamiento con diálisis con la perspectiva de un próximo trasplante renal (AU)

We report the case of a primigravid woman with a mitochondrial disorder affecting the energy-generating pathway of oxidative phosphorylation discovered 3 years after the appearance of progressive proximal tubular renal insufficiency, muscular weakness, bilateral optical neuropathy and diffuse leucoencephalopathy detected on magnetic resonance imaging of the brain. Her diagnosis was made on the basis of abnormal mitochondria on a muscle biopsy and of spectophotometric deficiencies of the complexes I, II, III and IV of the respiratory chain. The search for specific genetic mutation was negative. Her pregnancy was complicated by severe preeclampsia, gestational diabetes requiring insulin, and severe renal failure, necessitating premature delivery by cesarean section at 30 weeks gestation. The evolution of the 1070g female neonate was uneventful, and at two years of age she shows no signs of mitochondrial disease. However, the mother’s postpartum was complicated by seizures and terminal renal failure, for which she is currently having dialysis whilst waiting for a renal transplant in the near future (AU)

[Identification of the allergenic taxa of pollen in patients with pollinosis to determine the risk season]. / Identificación de los taxones de pólenes alergénicos en pacientes polínicos para conocer la temporada de riesgo.

BACKGROUND: Determining the risk season for the presence of pollen in the atmosphere aids primary care physicians in the diagnosis and treatment of allergic diseases. Our objective was to identify the taxa of pollen that cause allergic rhinoconjunctivitis in a sample of patients from a health center who presented seasonal symptoms. METHODS: We designed an observational, cross-sectional, non-randomized study to be carried out in the Cazoña Health Center in Santander, Spain. We selected 30 volunteers of both sexes, aged between 13 and 69 year old, who suffered seasonal rhinoconjunctivitis symptoms and who had always lived in Santander. Patients underwent skin-prick tests with the 25 pollen extracts routinely used in Spain, house dust mite (HDM), cat dander and Alternaria extracts by means of the Prick-Film system. The test result was expressed as the percentage of the papule area caused by histamine. Measurement was performed by scanning the copied papule area with the Prick-Scan program for PC. RESULTS: All patients were positive to grass pollen, 26 % were sensitized to grass pollen only and 23 % were also sensitized to other non-pollen allergens. Twenty-seven percent tested positive to Plantago, 20 % to Quercus and 13 % to Morus; the remaining pollen extracts were positive in less than 10 %. Fifty-six percent of the patients were positive to HDM and 6 % to cat dander. CONCLUSIONS: A warning period for pollinosis patients in the city of Santander can be defined. In our case, the important period is the grass pollen season, since the remaining pollen taxa sensitized few patients. Most of our patients were also sensitized to HDM.

HIV envelope protein inhibits MHC class I presentation of a cytomegalovirus protective epitope.

CTL recognize peptides that derive from viral protein Ags by proteolytic processing and are presented by MHC class I molecules. In this study we tested whether coexpression of viral Ags in the same cell leads to competition between them. To this end, two L(d)-restricted epitopes derived from HIV-1 envelope gp160 (ENV) and from CMV pp89 phosphoprotein were coexpressed. HIV ENV strain IIIB, but not MN variant, impaired recognition by specific CTL of CMV pp89 epitope 9pp89. Susceptibility to inhibition after ENV coexpression was inversely related to the amount of antigenic 9pp89 peptide processed from different antigenic constructs. In line with it, competition decreased the yield of naturally processed antigenic 9pp89 peptide bound to MHC class I molecules in coinfected cells. Also, point mutants of the presenting MHC class I molecule differed in their competition pattern. Collectively, the data imply that competition operates at the step of MHC-peptide complex assembly or stabilization. We conclude that, although not the rule, in certain combinations there is interference between different Ags expressed in the same cell and presented by the same MHC class I allele. These studies have implications for vaccine development and for understanding immunodominance.

Sequential cleavage by metallopeptidases and proteasomes is involved in processing HIV-1 ENV epitope for endogenous MHC class I antigen presentation.

Antigenic peptides derived from viral proteins by multiple proteolytic cleavages are bound by MHC class I molecules and recognized by CTL. Processing predominantly takes place in the cytosol of infected cells by the action of proteasomes. To identify other proteases involved in the endogenous generation of viral epitopes, specifically those derived from proteins routed to the secretory pathway, we investigated presentation of the HIV-1 ENV 10-mer epitope 318RGPGRAFVTI327 (p18) to specific CTL in the presence of diverse protease inhibitors. Both metalloproteinase and proteasome inhibitors decreased CTL recognition of the p18 epitope expressed from either native gp160 or from a chimera based on the hepatitis B virus secretory core protein as carrier protein. Processing of this epitope from both native ENV and the hepatitis B virus secretory core chimeric protein appeared to proceed by a TAP-dependent pathway that involved sequential cleavage by proteasomes and metallo-endopeptidases; however, other protease activities could replace the function of the lactacystin-sensitive proteasomes. By contrast, in a second TAP-independent pathway we detected no contribution of metallopeptidases for processing the ENV epitope from the chimeric protein. These results show that, in the classical TAP-dependent MHC class I pathway, endogenous Ag processing of viral proteins to yield the p18 10-mer epitope requires metallo-endopeptidases in addition to proteasomes.

Generation of MHC class I peptide antigens by protein processing in the secretory route by furin.

Cytosolic degradation of endogenously synthesized proteins by the proteasome and translocation of processed peptides to the endoplasmic reticulum by the transporters associated with antigen presentation constitutes the classical route for antigen presentation by MHC class I proteins. We have previously defined an alternative pathway in the secretory route involving proteolytic maturation of precursor proproteins for chimeric hepatitis B virus secretory core protein HBe containing a class I epitope at its carboxy-terminus. We extend those results by demonstrating that intracellular delivery of the trans-Golgi network protease furin increases both proteolytic maturation and antigen presentation of the chimeric HBe proteins. An additional class I epitope from the HIV envelope gp160 protein was inserted into this COOH-terminal region of two different chimeric HBe proteins. This epitope was also presented to CTL in a transporter-independent manner involving furin, and protein maturation and antigen presentation were also enhanced by furin over-expression. Presentation of this second epitope was restricted by a different class I allele, thus suggesting that antigen presentation by this new pathway may apply to any antigenic epitope and class I molecule. These results define the furin proteolytic maturation pathway of HBe in the secretory route as a general antigen processing route for MHC class I presentation.

[Fibronectin as a diagnostic marker in several determined neurological diseases]. / Fibronectina como marcador diagnóstico de determinadas enfermedades neurológicas.

OBJECTIVE: To determinate if fibronectin in CSF can be a useful parameter in the diagnosis of some neurologic illnesses. MATERIAL AND METHODS: We have studied 30 patients, subdivided in four groups, depending on the type of neurologic illness. We have chosen as control a 10-patient group, which came to the Emergency Service and were diagnosed as a suspicious of neurologic illness, but after this it was discarded. In the whole group we practiced a lumbar puncture, with cytology, systematic, biochemistry, cultures, immunoglobulins determination and fibronectin quantification by ELISA. RESULTS: We want to emphasize the increase in fibronectin levels in CSF in both the patients with bacterial meningitis and the multiple sclerosis groups, when it's compared with the control group. CONCLUSION: For this, the determination of fibronectin levels in CSF might be a useful parameter in the diagnosis of some neurologic illnesses.

Intracellular rate-limiting steps in MHC class I antigen processing.

Quantitative aspects of the endogenous pathway of Ag processing and presentation by MHC class I molecules to CD8+ CTL were analyzed over a wide range of Ag expression in recombinant vaccinia virus-infected cells expressing beta-galactosidase as model Ag. Only the amount of starting Ag was varied, leaving other factors unaltered. Below a certain level of Ag synthesis, increasing protein amounts led to a sharp rise in recognition by CTL. Higher levels of Ag expression led to a saturation point, which intracellularly limited the number of naturally processed peptides bound to MHC and thereby also CTL recognition. The rate-limiting step was located at the binding of the antigenic peptide to MHC inside the vaccinia virus-infected cell or before this event.

Major histocompatibility complex class I viral antigen processing in the secretory pathway defined by the trans-Golgi network protease furin.

Classical antigen presentation by major histocompatibility complex class I molecules involves cytosolic processing of endogenously synthesized antigens by proteasomes and translocation of processed peptides into the endoplasmic reticulum (ER) by transporters associated with antigen presentation (TAP). Alternative pathways for processing of endogenous antigens, generally involving the ER, have been suggested but not fully proved. We analyzed the potential for class I presentation of proteolytic maturation of secretory antigens in the exocytic pathway. We found that hepatitis B (HB) virus secretory core protein HBe can efficiently deliver COOH-terminally located antigenic peptides for endogenous class I loading in the absence of TAP. Antigen presentation to specific cytotoxic T lymphocytes correlates with protein maturation at the COOH terminus, since modification of maturation and transport of HBe through the secretory pathway alters antigen presentation. Both maturation and a necessary processing step occur in the Golgi or post-Golgi compartment. Antigen presentation is independent of proteasome activity, but inhibitors of the trans-Golgi network resident protease furin inhibit both HBe maturation and antigen presentation. These results define a new antigen processing pathway located in the secretory route, with a central role for proteolytic maturation mediated by the subtilisin protease family member furin as an efficient source for antigen presentation.

Selective involvement of proteasomes and cysteine proteases in MHC class I antigen presentation.

CTL recognize peptides derived from protein Ags bound to MHC-class I molecules. Proteasomes probably participate in the generation of these peptide epitopes. We investigated the role of proteasomes in the presentation of endogenously synthesized short viral proteins. To this end, we employed proteasome and cysteine protease inhibitors and two closely related recombinant vaccinia viruses that code for 17- and 19-amino acid-long products encompassing murine CMV 9pp89 epitope. Presentation of both minigene products required processing to shorter peptides and was independent of ubiquitination. Proteasomes were necessary for processing the 17-mer product, and cysteine proteases were not required. In contrast, the 19-mer product could be processed in parallel either by proteasomes or by cysteine proteases independently. These results highlight the diversity of alternative processing pathways even for short peptidic Ags, provide evidence for the involvement of cysteine proteases in MHC class I presentation, and show that cleavage by cysteine proteases is governed by sequences flanking the epitope.