Piloting international production of rapid relative effectiveness assessments of pharmaceuticals.

BACKGROUND: This article describes the lessons learned from an international pilot assessment using the first version of the HTA Core Model® and Guidelines for rapid Relative Effectiveness Assessment (REA) of pharmaceuticals based on input from three different perspectives: the assessors, the users (health technology assessment organisations) and the marketing authorisation holder. METHODS: A pilot assessment was performed of pazopanib for the treatment of advanced or metastatic renal cell carcinoma for which 54 individuals from 22 EUnetHTA member organisations from 16 European countries gave their contribution. The work was divided in eight domain teams. Subsequently, results of these domain teams were synthesised in one pilot report. Feedback on the outcomes of the pilot was gathered throughout the project and through structured surveys. RESULTS: The first version of the assessment was produced in six months and consisted of 55 question and answer pairs, 8 domain reports and a synthesis section that combined the results from the different domains. The organisation of the pilot required intense coordination. Main points of criticism on the assessment were the lengthiness of the document and overlap of information throughout the assessment. CONCLUSIONS: A reduction in the number of authoring organisations and individuals participating is necessary to avoid information overlap and increase efficiency in undertaking the assessment. Involving several organisations (e.g. five) in an in-depth review could still ensure the benefit of broad participation from various countries. The focus of a rapid REA should be on the first four domains of the Model.

Up-regulation of host cell genes during interferon-gamma-induced persistent Chlamydia pneumoniae infection in HL cells.

As a step toward understanding the role played by host gene expression in the development and pathogenesis of persistent Chlamydia pneumoniae infection, modulation of the host-cell transcriptional response during interferon (IFN)- gamma -induced persistent C. pneumoniae infection of HL cells was examined by a cDNA array and then selectively by a real-time quantitative reverse transcription-polymerase chain reaction. We identified 9 host cell genes whose transcription was consistently altered during IFN- gamma -induced persistent C. pneumoniae infection. The strongest up-regulation of persistent infection, compared with controls (active infection and IFN- gamma ) was identified for insulin-like growth factor-binding protein 6, IFN-stimulated protein 15 kDa, cyclin D1, and interleukin-7 receptor genes. These results suggest that, during persistent infection, C. pneumoniae reprograms the host transcriptional machinery that regulates a variety of cellular processes, including adhesion, regulation of the cell cycle, growth, and inflammatory response, all of which might play important roles in the pathogenesis of persistent C. pneumoniae infection.

Production of Chlamydia pneumoniae proteins in Bacillus subtilis and their use in characterizing immune responses in the experimental infection model.

Due to intracellular growth requirements, large-scale cultures of chlamydiae and purification of its proteins are difficult and laborious. To overcome these problems we produced chlamydial proteins in a heterologous host, Bacillus subtilis, a gram-positive nonpathogenic bacterium. The genes of Chlamydia pneumoniae major outer membrane protein (MOMP), the cysteine-rich outer membrane protein (Omp2), and the heat shock protein (Hsp60) were amplified by PCR, and the PCR products were cloned into expression vectors containing a promoter, a ribosome binding site, and a truncated signal sequence of the alpha-amylase gene from Bacillus amyloliquefaciens. C. pneumoniae genes were readily expressed in B. subtilis under the control of the alpha-amylase promoter. The recombinant proteins MOMP and Hsp60 were purified from the bacterial lysate with the aid of the carboxy-terminal histidine hexamer tag by affinity chromatography. The Omp2 was separated as an insoluble fraction after 8 M urea treatment. The purified proteins were successfully used as immunogens and as antigens in serological assays and in a lymphoproliferation test. The Omp2 and Hsp60 antigens were readily recognized by the antibodies appearing after pulmonary infection following intranasal inoculation of C. pneumoniae in mice. Also, splenocytes collected from mice immunized with MOMP or Hsp60 proteins proliferated in response to in vitro stimulation with the corresponding proteins.

Enhanced T-cell immunogenicity of plasmid DNA vaccines boosted by recombinant modified vaccinia virus Ankara in humans.

In animals, effective immune responses against malignancies and against several infectious pathogens, including malaria, are mediated by T cells. Here we show that a heterologous prime-boost vaccination regime of DNA either intramuscularly or epidermally, followed by intradermal recombinant modified vaccinia virus Ankara (MVA), induces high frequencies of interferon (IFN)-gamma-secreting, antigen-specific T-cell responses in humans to a pre-erythrocytic malaria antigen, thrombospondin-related adhesion protein (TRAP). These responses are five- to tenfold higher than the T-cell responses induced by the DNA vaccine or recombinant MVA vaccine alone, and produce partial protection manifest as delayed parasitemia after sporozoite challenge with a different strain of Plasmodium falciparum. Such heterologous prime-boost immunization approaches may provide a basis for preventative and therapeutic vaccination in humans.