Development of novel treatments for hepatitis C

Microanatomy of the liver immune system

The critical metabolic functions of the liver often eclipse any perception of its role as an immune organ. However, the liver as a mediator of systemic and local innate immunity and an important site of immune regulation is now an accepted concept. Complex repertoires of lymphoid and non-lymphoid cells are key to hepatic defense and immunoregulation. Hepatic cells of myeloid lineage include Kupffer cells and dendritic cells. Intrahepatic lymphocytes are distinct both in phenotype and function from their counterparts in any other organ and include both conventional (CD4+ and CD8+ alphabeta T cell receptor (TCR)+ T cells, B cells, natural killer (NK) cells) and nonconventional lymphoid cells (natural killer T (NKT) cells, gamma delta TCR+ T cells, CD4- CD8- T cells). Many hepatic T cells express the TCR at an intermediate level and the great majority of them either coexpress NK cell markers (NKT cells) or they are apoptosing peripheral T cells. The percentage of activated (CD69+) and memory (CD45RB low+) lymphocytes is much higher while naive (CD62L high) and resting T cells as well as B lymphocytes are underrepresented in the liver. The discovery of major populations of lymphoid cells in the liver that differ phenotypically, functionally and even perhaps developmentally from populations in other regions has been key to the evolving perception of the liver as a regulatory lymphoid organ. This chapter will focus on these populations and how they contribute to immune surveillance against malignant, infectious and autoimmune disease of the liver.

Discovery of a novel HCV helicase inhibitor by a de novo drug design approach

Herein we report a successful application of a computer-aided design approach to identify a novel HCV helicase inhibitor. A de novo drug design methodology was used to generate an initial set of structures that could potentially bind to a putative binding site. Further structure refinement was carried out through docking a series of focused virtual libraries. The most promising compound was synthesised and it exhibited a submicromolar inhibition of the HCV helicase.