Centre for Virus Research

Lab head: Professor Anthony Cunningham
Location: The Westmead Institute for Medical Research, Westmead Hospital

An Australian centre for HIV and Hepatitis Vilrology research, Westmead Millennium Institute, and one of the premier HIV reasearch laboratories in Australia.

The Role of Interferon Regulatory Factors in HIV Induction of Interferon in Macrophages

Primary supervisor: Anthony Cunningham

Research Background

The main target cell for HIV is the CD4 T-lymphocyte in which HIV explosively replicates resulting in rapid cell death. However HIV is also able to replicate in other cells of the immune system. In macrophages a non-cytopathic infection occurs and these cells remain long lived. Macrophages therefore serve as a viral reservoir and act to constantly reseed the immune system of infected individuals with fresh virus. When cells come into contact with a foreign antigen they secrete antiviral molecules called interferons (IFN) which help to protect them and bystander cells from viral infection by inducing the expression of hundreds of IFN stimulated genes (ISG). We have recently shown that HIV is able to directly induce a small subset of these ISGs in macrophages while at the same time blocking interferon induction. The IFN regulatory factor (IRF) family are known to play key roles in modulating both IFN induction and the expression of ISGs.


Research Aim

To establish the role of specific IRFs in HIV induction of ISGs in macrophages.


Research Plan

We have recently shown that following HIV infection of macrophages and dendritic cells a small subset of ISGs is up-regulated. Among this subset are many members of the interferon regulatory family; namely IRF1,2,4,7 and 8. We have preliminary data which demonstrates that HIV induced IRF1 is required for efficient virus replication and in macrophages also for ISG induction. In this project we will examine the roles of HIV induced IRFs on interferon and ISG induction.

Firstly we will determine whether the proteins encoded by these genes are also up-regulated. We will then express a variety of IRFs in 293T cells to examine the independent gene profiles that these transcription factors are able to trigger. We will also over express these proteins in macrophages and determine the effects on HIV replication. Finally key IRFs will be silenced in macrophages and the HIV infectivity levels determined alongside the ability to induce interferon.

This project will provide a comprehensive education in production of macrophages from human blood; HIV infectivity assays, quantitative PCR and microarrays (QPCR) for determining changes in gene expression levels; silencing RNA technology; western blot and flow cytometry to determine protein expression levels.

Discipline: Infectious diseases and Immunology
Co-supervisors: NAJLA NASR, Andrew Harman
Keywords: Macrophages, Cell & Molecular Biology, HIV/AIDS