A family of proteins structurally and functionally related to the E6-AP ubiquitin-protein ligase.

E6-AP is a 100-kDa cellular protein that interacts with the E6 protein of the cancer-associated human papillomavirus types 16 and 18. The E6/E6-AP complex binds to and targets the p53 tumor-suppressor protein for ubiquitin-mediated proteolysis. E6-AP is an E3 ubiquitin-protein ligase which accepts ubiquitin from an E2 ubiquitin-conjugating enzyme in the form of a thioester and then directly transfers the ubiquitin to targeted substrates. The amino acid sequence of E6-AP shows similarity to a number of protein sequences over an approximately 350-aa region corresponding to the carboxyl termini of both E6-AP and the E6-AP-related proteins. Of particular note is a conserved cysteine residue within the last 32-34 aa, which in E6-AP is likely to be the site of ubiquitin thioester formation. Two of the E6-AP-related proteins, a rat 100-kDa protein and a yeast 95-kDa protein (RSP5), both of previously unknown function, are shown here to form thioesters with ubiquitin. Mutation of the conserved cysteine residue of these proteins destroys their ability to accept ubiquitin. These data strongly suggest that the rat 100-kDa protein and RSP5, as well as the other E6-AP-related proteins, belong to a class of functionally related E3 ubiquitin-protein ligases, defined by a domain homologous to the E6-AP carboxyl terminus (hect domain).

Noticias sobre el virus del papiloma humano y su vacuna en la prensa valenciana (2006-2011)

La introducción de la vacuna contra el virus del papiloma humano (VPH) dirigida a mujeres adolescentes ha tenido en España un desarrollo no exento de cierta controversia. Asociada inicialmente al mensaje de «vacuna contra el cáncer de útero» que ofrecía una nueva posibilidad de lucha contra esa enfermedad, obtuvo una réplica que moderaba la euforia con un mensaje dirigido a probar evidencias. Mientras se administraba la segunda dosis de vacuna (febrero de 2009) ocurrió un suceso inesperado en Valencia relacionado con la aparición de acontecimientos adversos tras la administración de la vacuna en dos adolescentes, que tuvo un explosivo tratamiento mediático. Este estudio analiza el alcance y el contenido de las noticias aparecidas en dos periódicos regionales valencianos de gran tirada durante el sexenio 2006-2011 que mencionan al VPH, su vacuna y el cáncer de útero. Se discute la influencia que los mensajes emitidos hayan podido tener en la aceptabilidad de la vacuna.

Notificación de reacciones adversas a la vacuna frente al virus del papiloma humano en la Comunidad Valenciana (2007-2011)

Introducción: En 2009, 2 casos de convulsiones en adolescentes tras la administración de la vacuna tetravalente frente al virus del papiloma humano (VPH) generaron impacto mediático y afectaron negativamente la confianza del público en esta vacuna. Nuestros objetivos fueron describir las sospechas de reacciones adversas (SRA) notificadas al Centro Autonómico de Farmacovigilancia de la Comunidad Valenciana (CAFCV) tras la administración de la vacuna frente al VPH y comparar la tasa de notificación de síncope y convulsiones de esta vacuna con la de otras vacunas administradas en adolescentes. Material y métodos: Estudio descriptivo de las notificaciones de SRA relacionadas con esta vacuna recibidas por el CAFCV entre 2007 y 2011. Resultados: Las manifestaciones clínicas más comunicadas fueron mareos, cefalea y síncope. Las tasas de notificación de síncope o pérdida de conciencia y convulsiones con la vacuna frente al VPH fueron de 17 y 3,2 por 100.000 dosis administradas, respectivamente, y de 15 y 1,6 para síncope o pérdida de conciencia y convulsiones sincopales ocurridas el día de la vacunación. Las tasas de notificación de síncope o pérdida de conciencia y convulsiones fueron de 6,4 y 0,4 para otras vacunas. Conclusiones: Las tasas de notificación de síncope o pérdida de conciencia y convulsiones fueron mayores para la vacuna frente al VPH que para otras vacunas administradas en adolescentes; esto es consistente con la atención mediática originada por la vacuna y con hallazgos de estudios previos. No obstante, la información obtenida sobre las SRA a la vacuna sugiere un buen perfil de seguridad.

Características de los vídeos en español publicados en Youtube sobre la vacuna contra el virus del papiloma humano

Fundamentos: Internet constituye un recurso de búsqueda de información relacionada con la salud. El objetivo de este trabajo fue conocer las características de los vídeos en idioma español de YouTube relacionados con la vacuna contra el virus del papiloma humano (VPH). Métodos: Se realizó un estudio observacional a partir de una búsqueda en YouTube el 26 de julio de 2013, con las palabras claves: “vacuna virus papiloma humano”, “vacuna VPH”, “vacuna Gardasil”, “vacuna Cervarix”. Se establecieron categorías por tipo, fuente de publicación y predisposición favorable o no hacia la vacuna. Se registró el número de visitas, tiempo de duración de los videos y origen de los 20 vídeos más visitados. Resultados. Se encontraron 1.080 videos registrados, 170 fueron seleccionados y clasificados como: noticias locales (n=39; 37 favorables, 2 desfavorables; 2:06:29; 42972 visitas), noticias nacionales (n=32; 30/2; 1:49:27; 50138 visitas), creados por subscritores de YouTube (n=21; 13/8; 2:50:35; 144655 visitas), entrevistas (n=21; 20/1; 1:44:39; 10991 visitas), anuncios (n=21; 19/2; 0:27:05; 28435 visitas), conferencias (n=17; 15/2; 3:25:39; 27206 visitas), documentales (n=16; 12/4; 2:11:31; 30629 visitas), y noticias internacionales (n=3; 3/0; 0:11:33; 1667 visitas). De los 20 videos más reproducidos predominan los favorables a la vacunación (n=12; 0:43:43; 161.789 visitas) frente a los desfavorables (n=8; 2:44:14; 86.583 visitas). Conclusiones. Predominan los videos que tiene una opinión favorable hacia la vacuna contra el VPH, aunque los videos de contenido negativo son los más extensos y reproducidos.

Host-dependent Anopheles flavirostris larval distribution reinforces the risk of malaria near water

Malaria control strategies are more likely to be successful if groups at high risk can be accurately predicted. Given that mosquitoes have an obligate aquatic phase we were interested in determining how vector larval abundance relates to the spatial distribution of human malaria infection. We examined the relationship between malaria parasite prevalence and distance from vector larval habitat, and vector larval abundance and distance from human habitation, in separate studies in rural, low-endemic areas of the Philippines. Parasite prevalence among symptomatic patients was significantly higher among those living in proximity ( less than or equal to 50 m) to potential larval habitats of the major vector, Anopheles flavirostris (adjusted odds ratio [AOR] 2.64, P = 0.02 and AOR 3.43, P = 0.04). A larval survey of A. flavirostris revealed a higher density of early and late instars near human habitation (adjusted P < 0.05). The results suggest that larvae are associated with human habitation, thereby reinforcing malaria risk in people living close to larval habitats. This has implications for understanding the interaction between vectors, hosts, and parasites, and the potential for success of localized malaria control measures.

Impaired Antigen Presentation and Effectiveness of Combined Active/Passive Immunotherapy for Epithelial Tumors

Background: Although immunization with tumor antigens can eliminate many transplantable tumors in animal models, immune effector mechanisms associated with successful immunotherapy of epithelial cancers remain undefined. Methods: Skin from transgenic mice expressing the cervical cancer-associated tumor antigen human papillornavirus type 16 (HPV16) E6 or E7 proteins from a keratin 14 promoter was grafted onto syngeneic, non-transgenic mice. Skin graft rejection was measured after active immunization with HPV16 E7 and adoptive transfer of antigen-specific T cells. Cytokine secretion of lymphocytes from mice receiving skin grafts and immunotherapy was detected by enzyme-linked immunosorbent assay, and HPV16 E7-specific memory CD8(+) T cells were detected by flow cytometry and ELISPOT. Results: Skin grafts containing HPV16 E6- or E7-expressing keratinocytes were not rejected spontaneously or following immunization with E7 protein and adjuvant. Adoptive transfer of E7-specific T-cell receptor transgenic CD8(+) T cells combined with immunization resulted in induction of antigen-specific interferon gamma-secreting CD8(+) T cells and rejection of HPV16 E7-expressing grafts. Specific memory CD8(+) T cells were generated by immunotherapy. However, a further HPV16 E7 graft was rejected from animals with memory T cells only after a second E7 immunization. Conclusions: Antigen-specific CD8(+) T cells can destroy epithelium expressing HPV16 E7 tumor antigen, but presentation of E7 antigen from skin is insufficient to reactivate memory CD8(+) T cells induced by immunotherapy. Thus, effective cancer immunotherapy in humans may need to invoke sufficient effector as well as memory T cells.

Functional memory CD8+ T cells can be generated in vivo without evident T help

Synthetic cytotoxic T cell (CTL) epitope peptides provide an effective and safe means of vaccination against cancers and viruses, as these peptides can induce specific CD8+ effector T cells in vivo. However, the effector CD8+ T cells induced by the minimal CTL epitope peptides do not last past about 3 weeks after the induction and no functional memory CD8+ T cells are generated. It is held that simultaneous induction of CD4+ T cells by incorporating peptides containing T-helper epitopes in the vaccine at the time of primary vaccination are necessary for the induction of long-lived functional memory CD8+ T cells. We now report that, surprisingly, incorporation of medium length (>20 AA) peptides devoid of detectable T-helper epitopes in a minimal CTL epitope-based vaccine can also induce long-lasting! functional rumour antigen specific memory CD8+ T cells that are capable of promoting protection against tumour challenge. This observation may have implications for the formulation of therapeutic anti-cancer and anti-virus peptide vaccines where a strong induction of CD4 T help would be undesirable. (C) 2004 Elsevier Ltd. All rights reserved.

ISCOMATRIX (TM) adjuvant: An adjuvant suitable for use in anticancer vaccines

Human Papillomavirus type 16 (HPV16) E6 and E7 oncoproteins are associated with cervical cancer development and progression and can therefore be used as target antigens for cancer immunotherapy. In this study we evaluated the immunogenicity in mice, of different vaccine formulations using recombinant HPV16 derived E6E7 or E7GST fusion proteins. When co-administered with ISCOMATRIX(TM) adjuvant, these E6E7 proteins consistently induced E7 specific CTL, in vivo tumor protection, antibody and DTH responses. ISCOMATRIX(TM) adjuvant has been developed for use in the formulation of novel human vaccines and has been evaluated for safety and toxicity in human trials. A formulation containing aluminum hydroxide (Al(OH)(3)) gave a lesser degree of E7 specific antibody, and no local E7 specific CTL response but similar DTH and tumor protection. These findings demonstrate the potential of ISCOMATRIX(TM) adjuvant to stimulate both cellular and humoral immune responses to endogenously processed target antigens, and hence is the preferred adjuvant when CTL responses are desirable. (C) 2004 Elsevier Ltd. All rights reserved.

Gene codon composition determines differentiation-dependent expression of a viral capsid gene in keratinocytes in vitro and in vivo

By establishing mouse primary keratinocytes (KCs) in culture, we were able, for the first time, to express papillomavirus major capsid (L1) proteins by transient transfection of authentic or codon-modified L1 gene expression plasmids. We demonstrate in vitro and in vivo that gene codon composition is in part responsible for differentiation-dependent expression of L1 protein in KCs. L1 mRNA was present in similar amounts in differentiated and undifferentiated KCs transfected with authentic or codon-modified L1 genes and had a similar half-life, demonstrating that L1 protein production is posttranscriptionally regulated. We demonstrate further that KCs substantially change their tRNA profiles upon differentiation. Aminoacyl-tRNAs from differentiated KCs but not undifferentiated KCs enhanced the translation of authentic L1 mRNA, suggesting that differentiation-associated change to tRNA profiles enhances L1 expression in differentiated KCs. Thus, our data reveal a novel mechanism for regulation of gene expression utilized by a virus to direct viral capsid protein expression to the site of virion assembly in mature KCs. Analysis of two structural proteins of KCs, involucrin and keratin 14, suggests that translation of their mRNAs is also regulated, in association with KC differentiation in vitro, by a similar mechanism

RNA interference for the treatment of cancer

RNA interference (RNAi) is the latest new technology in the field of genetic medicine in which specific genes can be turned off, or silenced, so as to affect a therapeutic outcome. It can be highly specific, works in the nanomolar range and is far more effective than the antisense approaches popular 10-15 years ago. Here we review the field and explore the potential role of RNAi in cancer therapy, highlighting recent progress and examining the hurdles that must be overcome before this promising technology is ready for clinical use. (C) 2006 Prous Science. All rights reserved.

Recombinant protein subunit vaccine synthesis in microbes:a role for yeast?

Objectives Recombinant protein subunit vaccines are formulated using protein antigens that have been synthesized in heterologous host cells. Several host cells are available for this purpose, ranging from Escherichia coli to mammalian cell lines. This article highlights the benefits of using yeast as the recombinant host. Key findings The yeast species, Saccharomyces cerevisiae and Pichia pastoris, have been used to optimize the functional yields of potential antigens for the development of subunit vaccines against a wide range of diseases caused by bacteria and viruses. Saccharomyces cerevisiae has also been used in the manufacture of 11 approved vaccines against hepatitis B virus and one against human papillomavirus; in both cases, the recombinant protein forms highly immunogenic virus-like particles. Summary Advances in our understanding of how a yeast cell responds to the metabolic load of producing recombinant proteins will allow us to identify host strains that have improved yield properties and enable the synthesis of more challenging antigens that cannot be produced in other systems. Yeasts therefore have the potential to become important host organisms for the production of recombinant antigens that can be used in the manufacture of subunit vaccines or in new vaccine development.

EULAR Recommendations for Women's Health and the Management of Family Planning, Assisted Reproduction, Pregnancy and Menopause in Patients with Systemic Lupus Erythematosus and/or Antiphospholipid Syndrome

OBJECTIVES: Develop recommendations for women's health issues and family planning in systemic lupus erythematosus (SLE) and/or antiphospholipid syndrome (APS). METHODS: Systematic review of evidence followed by modified Delphi method to compile questions, elicit expert opinions and reach consensus. RESULTS: Family planning should be discussed as early as possible after diagnosis. Most women can have successful pregnancies and measures can be taken to reduce the risks of adverse maternal or fetal outcomes. Risk stratification includes disease activity, autoantibody profile, previous vascular and pregnancy morbidity, hypertension and the use of drugs (emphasis on benefits from hydroxychloroquine and antiplatelets/anticoagulants). Hormonal contraception and menopause replacement therapy can be used in patients with stable/inactive disease and low risk of thrombosis. Fertility preservation with gonadotropin-releasing hormone analogues should be considered prior to the use of alkylating agents. Assisted reproduction techniques can be safely used in patients with stable/inactive disease; patients with positive antiphospholipid antibodies/APS should receive anticoagulation and/or low-dose aspirin. Assessment of disease activity, renal function and serological markers is important for diagnosing disease flares and monitoring for obstetrical adverse outcomes. Fetal monitoring includes Doppler ultrasonography and fetal biometry, particularly in the third trimester, to screen for placental insufficiency and small for gestational age fetuses. Screening for gynaecological malignancies is similar to the general population, with increased vigilance for cervical premalignant lesions if exposed to immunosuppressive drugs. Human papillomavirus immunisation can be used in women with stable/inactive disease. CONCLUSIONS: Recommendations for women's health issues in SLE and/or APS were developed using an evidence-based approach followed by expert consensus.

Regulators of cellular senescence and tumorigenesis

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Review: Head and neck squamous cell carcinoma in sub-Saharan Africa

Aim Review the literature from 1990 to 2013 to determine known anatomic sites, risk factors, treatments, and outcomes of head and neck squamous cell carcinoma (HNSCC) in sub-Saharan Africa. Methods Using a systematic search strategy, literature pertaining to HNSCC in sub-Saharan Africa was reviewed and patient demographics, anatomic sites, histology, stage, treatment, and outcomes were abstracted. The contributions of human immunodeficiency virus (HIV), human papillomavirus (HPV) and behavioural risk factors to HNSCC in the region were assessed. Results Of the 342 papers identified, 46 were utilized for review, including 8611 patients. In sub-Saharan Africa, the oropharyngeal/oral cavity was found to be the most common site, with 7750 cases (90% of all cases). Few papers distinguished oropharyngeal from oral cavity, making identification of possible HPV-associated oropharyngeal squamous cell carcinoma (SCC) difficult. SCC of the nasopharynx, nasal cavity, or paranasal sinuses was identified in 410 patients (4.8% of all cases). Laryngeal SCC was found in 385 patients (4.5% of all cases), and only 66 patients (0.8% of all cases) with hypopharyngeal SCC were identified. In 862 patients with data available, 43% used tobacco and 42% used alcohol, and reported use varied widely and was more common in laryngeal SCC than that of the oropharyngeal/oral cavity. Toombak and kola nut use was reported to be higher in patients with HNSCC. Several papers reported HIV-positive patients with HNSCC, but it was not possible to determine HNSCC prevalence in HIV-positive compared to negative patients. Reports of treatment and outcomes were rare. Conclusions The oropharyngeal/oral cavity was by far the most commonly reported site of HNSCC reported in sub-Saharan Africa. The roles of risk factors in HNSCC incidence in sub-Saharan Africa were difficult to delineate from the available studies, but a majority of patients did not use tobacco and alcohol.

Sobre-expresión de la proteína p 16 en biopsias con diagnóstico de NIC I, positivas para Genoma de Papiloma Virus Humano. Instituto del Cáncer. SOLCA Cuenca-Ecuador. 2009-2010.

Numerosos estudios mencionan que la sobreexpresión de la proteína p16, un marcador biológico que permite identificar lesiones preneoplásicas del epitelio exocervical, tendría una alta asociación con el Papiloma Virus Humano (HPV) de alto riesgo oncogénico. Es un estudio descriptivo correlacional cuyo objetivo fue establecer asociación de las Neoplasias Intraepiteliales Cervicales grado I (NIC I), HPV positivos, con la expresión del p16. Materiales, métodos y resultados: Es un estudio correlacional que se realizó en el período de noviembre de 2009 a noviembre de 2010; se presentaron 256 casos de NIC I de los cuales, 72 fueron HPV positivos; se practicó técnica de p16. La edad promedio de las mujeres fue de 41 años. Se encontró positividad para el p16 en 40 casos (55.6%) y fueron negativos 32 (44.4%). De los casos positivos para p16, los tipos virales más frecuentes fueron los de alto riesgo: 33 (82.5%). El p16 fue valorado en cuantía, distribución e intensidad, estableciéndose relación entre la intensidad del p16 con los virus de alto riesgo (p=0.038). Cuando se analizó la edad y el tipo viral, pacientes entre 20 y 40 años (36 casos, 90%) presentaron genoma de HPV de alto riesgo. Conclusiones: Existió correlación entre la intensidad del p16 con la presencia de HPV de alto riesgo, ayudando a seleccionar grupos con tendencia a la progresión de la enfermedad.