Research

Researches

Activity Report

Annual Report 2007

Download the Annual Report 2007 Executive Summary Following the departure of Dr Ralf Altmeyer, who was Director between 2003-2006, the Board of Directors has appointed at the last meeting (Paris, September 2006) Dr Roberto Bruzzone and Prof Malik Peiris as Chief Executive Officer (CEO) and Scientific Director(SD), respectively. During the past year, the new directorate team has carried out a strategic review of the role of HKU-Pasteur Research Centre within Hong Kong University, within Hong Kong and the Asia Pacific Region. In research, we concluded that the HKU-PRC has a particular niche to fill in bringing together the cutting edge developments in the cell-biology of infections disease, which is the strength of Institut Pasteur, with the expertise in the clinical virology and immunology of infectious disease, which is the strength of HKU. Through this synergy, we aim to develop novel approaches to confront the challenges posed by viral infections in Hong Kong and the Asia-Pacific region in general by utilizing the RESPARI network of the Pasteur Institutes, as well as the regional networks established by the HKU team. We have maintained our research focus on respiratory viral infections, with special emphasis on influenza and SARS, and on the mosquito borne disease of dengue. With influenza and coronaviruses in particular, we have a local niche advantage of expertise and complementarities with ongoing projects at HKU. We have decided to focus on exploiting expertise in key research tools established over the recent past, including viral pseudoparticles, viral-like particles, fluorescent markers, siRNA screening and cell imaging to achieve our research goals at HKU-PRC. This research direction then naturally extends to training activities in virology, immunity and cell biology of infectious disease. To the highly successful virology training course that is already ongoing on an annual basis, we aim to add training courses in immunity and the cell biology of infection. We next aim at consolidating and expanding these achievements by combining strategic investments in infrastructure that will enable the long-term development of highly competitive projects. Research The research program functions as three complementary teams: viz. Virus-Host Interactions led by Dr Beatrice Nal-Rogier, Viral Infection & Immunity led by Dr Joanna Ho, and the Screening Platform led by Dr Jean-Michel Garcia. The Virus-Host Interactions team lead by Dr Beatrice Nal-Rogier has expanded its studies on the identification of novel cellular targets that interact with viral components, viz. interactomes. We have performed, in collaboration with the Viral Genomics and Vaccination Laboratory (Institut Pasteur-Paris) a Yeast-Two-Hybrid (Y2H) screening to analyze the interactomes of the envelope proteins of 5 human coronaviruses that are of low and high pathogenicity in humans. This work has led to the identification of new virus-host protein interactions paving the way to a comparative analysis of the differential interactomes that should provide new insights on the pathogenicity of these viruses. Using a similar strategy we have identified a specific interaction with a protein involved in the establishment of cellular tight junctions at the apical side of epithelial cells. These data are very exciting in view of recent findings that implicate cell polarity as a crucial factor during early and late stages of coronavirus infection. On the basis of these and other preliminary data one grant has been submitted at the last call for proposals from the Research Grant Council (RGC) and three more to the Research Fund for the Control of Infectious Diseases (RFCID). One declaration of invention has been filed with the Patent Office of Institut Pasteur. The Viral Infection & Immunity team led by Dr Joanna Ho has been recently funded by RFCID for a project entitled “Interaction of NK activatory receptors and hemagglutinin from avian flu – Potential implication of NKp44 in anti-flu therapy”. Work carried out this year has led to the completion of a manuscript that was published in the Journal of Virology (the top specialist journal in the field). The Viral Infection & Immunity group has been strengthened by the recruitment of 2 research assistants and one MPhil student. In addition, two PhD candidates are currently working as technicians pending the result of their application. A second RFCID-funded project addresses the role of antibody mediated enhancement (ADE) in the pathogenesis of SARS. In vitro studies have revealed that specific antibodies induced by either SARS-CoV infection (for example in convalescent sera from patients with SARS) or SARS vaccines (sera from animals immunized with putative SARS vaccines) can facilitate the entry of SARS-CoV to human B cell lines which are otherwise refractory to the virus (in the absence of such antibody) because these B cells lack the ACE2 receptor necessary for viral entry. Such enhancing antibodies may potentially lead to lymphopenia, which is a notable feature of SARS. This is also of major relevance as a possible adverse consequence of a potential SARS vaccine. ADE has been incriminated in immunopathology of the animal coronavirus disease feline infectious peritonitis where vaccination has led to enhanced disease and it is clearly important to investigate its role in SARS. We have compared humoral immune response elicited by different vaccine formulations and uncovered distinct patterns of antibody-mediated entry of SARS-CoV into hematopoietic cells despite similar abilities of the sera to neutralize receptor-mediated infection of ACE2-bearing cells. Interestingly, immunization of mice with whole inactivated SARS-CoV virion elicited neutralizing antibody response lacking ADE potency. One additional proposal to look into the cellular mechanisms of ADE has been prepared for the annual RFCID call. Continuing this line of investigation we are initiating studies on the role of ADE in facilitating viral entry of avian viruses in human FcR bearing cells. The HKU-PRC screening platform team, led by Dr Jean-Michel Garcia, remains actively implicated in drug discovery projects but has more recently broadened its interests to sero-epidemiology studies for immuno-surveillance and diagnosis of highly pathogenic avian influenza infections. One important achievement has been the publication of a manuscript describing the validation of the H5 hemagglutinin pseudotyped lentiviral particles (H5pp) for sero-diagnostic and epidemiological studies. This line of investigation is being actively pursued with appropriate collaborations with industry as well as academic partners. The more detailed validation of this method is ongoing using clinical sera from patients with H5N1 disease in Vietnam (in collaboration with Dr Menno De Jong, Hospital for Tropical Diseases, Ho Chi Minh City) and we are also testing H5N1 sera of vaccinated subjects from clinical trials (in collaboration with the pharmaceutical organizations, Sanofi-Pasteur and Baxter). These companies have shown a keen interest in the potential use of our method as an additional serological technique to detect vaccine-induced immune responses, have taken out rights to license this method and are exploring this possibility using this platform on a fee-for service basis. We have been also been involved in the transfer of this technology to the Institut Pasteur-Cambodia and the Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam. We have continued in parallel our efforts in the drug discovery program and have successfully completed the first phase of the screening campaign for inhibitors of dengue replication, which has identified 20 hits. One declaration of invention is in preparation. An extension of the application of viral pseudotypes in serology has been to explore the possible role of lentiviral pseudotypes and virus like particles (VLPs) to investigate virus receptor interactions of influenza. We have used VLPs expressing the H5 virus haemagglutinin on the lentivirus backbone in experiments utilizing Saturation Transfer Difference Nuclear Magnetic Resonance (STD-NMR) in collaboration with Dr Mark von Itzstein at the Institute of Glycomics, Griffith University, Australia. A paper reporting the feasibility of this approach for investigating viral haemagglutinin-glycan interactions has recently been published in Angewandte Chemie, the highly prestigious chemistry journal. This technique now opens up the possibility of a systematic analysis of the viral haemagglutinin-glycan receptor interactions of the highly pathogenic H5N1 virus. It provides, on the one hand, a novel tool to re-assess the glycans that bind the avian H5-haemagglutinin and, on the other hand, an exploration of the impact of viral mutations on such binding. Three new grant proposals have been submitted: to the Pasteur network (ACIP), to the RFCID and to the Area of Excellence. Teaching The project to establish a Teaching & Training Center of Excellence in Biomedical Research has received a boost by the decision of the Li Ka Shing Faculty of Medicine to grant an interest-free loan to equip part of the 3rd floor of the Dexter HC Man Building where lab space for practical course has been planned. The annual Pasteur-Asia Virology Course has now been validated by HKU as part of its Research Postgraduate Curriculum. The 4th Pasteur Asia Virology course, on the theme “INFLUENZA AND OTHER EMERGING RESPIRATORY VIRAL INFECTIONS” was held in July 2007 was very successful. Twenty nine students from 8 countries were selected and scientists from all over the world (15 different countries) came to share their expertise. Two new courses, Immunology and Cell Biology are being planned as part of a gradual expansion of the teaching activity of the center. In addition, HKU-PRC is actively collaborating with HKU Faculty to help strengthening the imaging facility on the campus. A Cell Imaging workshop has been organized in February 2008 and two more international workshops have been planned in 2008 (applications submitted to the Croucher Foundation). HKU-PRC continues its efforts to promote scientific exchanges between Hong Kong and Institut Pasteur through the Pasteur-Croucher Exchange Program. Two students are now working on their PhD thesis in Paris and the 3rd seminar series, held in September 2007, attracted more quality candidates. Network projects HKU-PRC relies on a number of strategic collaborations and network projects. Dr Roberto Bruzzone has become the Scientific Coordinator of the RESPARI program that federates the 8 Institutes of the Pasteur-Asia network in a multi-center project that tackles several aspects of acute respiratory infections, through the implementation of clinical, epidemiological, fundamental and translational research projects. Prof Malik Peiris is the Coordinator of the 8-year research program “Control of Pandemic and Inter-pandemic Influenza” that has been awarded a HK$ 76 millions by the University Grants Committee in the fourth round of its Areas of Excellence (AoE) scheme. The HKU-PRC participated in this application and will contribute its expertise on the cell biology of viral infections in relation to pathogenesis, host response and innate-immunity. Financial situation The financial situation has been defined under the Consolidated Agreement stipulating that the Centre will receive intramural funding from HKU (HK$6.1 million per annum in cash plus in kind contributions) up to the end of the revised term (November 2011). Starting in 2005 more intramural funds have been made available from Institut Pasteur (€80K per annum in cash).The center still holds grants from the French Ministry of Health and the Li Ka Shing Foundation, and has successfully competed with projects submitted to Hong Kong funding agencies. However, the draw-down of the special RAP/PDF fund allocated to the center at its foundation may require re-adjusting the level of staff employed. In summary, the financial position of the Centre is considered as healthy with a total net asset of HK$5.73M and a balance of cash and cash equivalent of HK$7.38M stood at June 30, 2007.