Microbicides 2004 Microbicides 200428-31 March 2004, Hilton London MetropoleThe conference42 million men, women and children worldwide were living with HIV by the end of December 2002 (source: UNAIDS), including five million newly-infected during that year alone. Another 45 million people will become infected between 2002 and 2010, unless the current transmission rates can be vastly reduced. Of the 42 million, 29.4 million live in sub-Saharan Africa and 58% of them are women. Not only are women more susceptible to HIV infection, many are powerless to insist on the use of condoms or other methods of protecting themselves. In this context, and with the knowledge that an effective HIV vaccine is unlikely to be available for several years, the need for an effective topical microbicide grows ever more urgent. 2004 should prove to be a landmark year in the field of microbicide development as the first Phase III trials of novel products are due to start – the next step along the road to making a microbicide available to the millions worldwide in desperate need of protection.The aims of the Microbicides 2004 conference are to:Report novel or innovative work in the microbicides fieldProvide updates on recent microbicides research, divided into three tracks: basic science, clinical science, and behavioural science (including public health and the microbicide marketplace)Provide a forum for the discussion of new developments in microbicide research including ethical, clinical, behavioural and methodological issuesPresent opportunities for knowledge-sharing between microbicide researchers, public-health workers and advocacy organisations.There will be an opening ceremony on the evening of Sunday 28 March at which politicians, policy makers and the international media are expected. The conference will run for a full three days, each of which will contain:Scientific overviews and presentations with plenary sessions, invited lecturers and presentations of original researchWorkshops to review issues unique to microbicides such as trial design and outcome measures, and ethical issues in the clinical trials of microbicidesPoster sessions. Focus on LondonFollowing the successful Microbicides conferences in Washington in 2000 and Antwerp in 2002, March 2004 sees the focus move to London.The venue is the Hilton Metropole Hotel, two minutes by taxi from Paddington station and the Heathrow Express, with a journey time from the airport of 15 minutes. The hotel is in walking distance of Hyde Park and London’s main shopping streets, and close to Imperial College. Accommodation will be available at the venue and other hotels in the vicinity.London in March offers a variety of diversions for out-of-conference relaxation, including sight-seeing and shopping; the arts and the theatre; and pubs, clubs and restaurants to suit every taste. Conference staff will be on hand to help delegates plan their spare time.To book your place or find out more information, e-mail info@microbicides2004.org.uk or telephone the Event Office on +44 (0) 20 7720 4411
Oral: invited speaker Oral: Track A Oral: Track B Oral: Track C Poster: Track A Poster: Track B Poster: Track C Abstract only Authors

02444 MANNOSE-SPECIFIC PLANT LECTINS AS POTENTIAL HIV MICROBICIDES

Balzarini, Jan*
Hatse, S.* , Vermeire, K.*, Princen, K.,* Van Laethem, K.*, De Clercq, E.*, Vandamme, A.-M.*, Egberink, H.**; Peumans, W.***, Van Damme, E.****& Schols, D.*
*Rega Institute For Medical Research, K.U.Leuven, B-3000 Leuven, Belgium; **Institute of Virology, Vetenary Faculty, 3584 Cl Utrecht, The Netherlands; ***Department of Fytopathology, K.U.Leuven, B-3000 Leuven, Belgium; ****Department of Molecular Biotechnology, Ghent University, B-9000 Gent, Belgium

A variety of mannose-specific plant lectins selectively inhibit in cell culture the replication of HIV-1 and HIV-2 strains, including virus strains that show resistance to other classes of anti-HIV drugs (EC50: 0.1-1.0 µg/ml). They also prevent syncytium formation between persistently-infected HUT-78/HIV and CEM/HIV cells and uninfected T-lymphocyte cells. Preexposure of the lectins to HIV-1 particles or persistently HIV-infected cells markedly increased the antiviral efficacy of the plant lectins. They interrupt the virus entry process by interfering with the virus envelope glycoprotein gp120. When exposed to escalating plant lectin concentrations, HIV-1 strains with decreased drug sensitivity could be isolated. A variety of amino acid changes were observed at the N-glycosylation sites and/or the serine or threonine residues that are part of the N-glycosylation motif in gp120. The degree of virus-drug resistance correlated with an increasing number of mutated glycosylation sites in gp120. These virus strains kept full sensitivity to other entry inhibitors such as dextran sulphate, bicyclam AMD3100, chicoric acid and enfuvirtide. The plant lectins under investigation were found to be not mitogenic, colorless and stable at lower pH and higher temperature (50°C). In conclusion, the plant lectins represent a well-defined class of anti-HIV drugs with a microbicidal potential and with a novel drug resistance profile different from that of other existing anti-HIV drugs.

Jan Balzarini
Rega Institute for Medical Research, Minderbroedersstraat 10, B-3000 Leuven, Belguim
(Telephone) 32-16-337341 (Fax) 32-16-337340 (E-mail) jan.balzarini@rega.kuleuven.ac.be