c.mackay@garvan.org.au

Arthritis and Inflammation program
Garvan Institute of Medical Research
384 Victoria st. Darlinghurst NSW 2010 Australia
Ph ++61-2-92958405
Mobile 0413443728 (int. ++61-413443728)
Fax ++61-2-92958404

Characterization of the Therapeutic Potential of Anti-GM-CSF Antibodies.
(In Collaboration with Ian Sutton)

Granulocyte Macrophage-Colony Stimulating Factor (GM-CSF) is a haemopoietic regulator and key proinflammatory cytokine. Observations from a number of animal models of autoimmune diseases indicate that GM-CSF has pro-inflammatory activities which contribute to the development of disability. Studies investigating the role of GM-CSF in the pathogenesis of collagen-induced arthritis (CIA) and experimental allergic encephalitis (EAE) indicate that antibodies which neutralize GM-CSF activity could be a useful therapeutic in the treatment of human autoimmune diseases such as Rheumatoid Arthritis and Multiple Sclerosis.

Project 1: Characterization of the Therapeutic Potential of Anti-GM-CSF Antibodies

We have developed a number of antibodies that react with GM-CSF and this project is structured so that these antibodies will be further characterized in order to determine which antibodies have therapeutic potential. Initially, antibodies will be tested for their ability to inhibit GM-CSF activity in a functional assay, affinity of binding to GM-CSF and cross reactivity between murine and human GM-CSF. Antibodies with functional inhibitory effects will be tested for potential therapeutic efficacy in the animal disease models EAE and CIA. 

Selected References (Available on request)

• Hamilton JA. GM-CSF in inflammation and autoimmunity. Trends Immunol. 2002 Aug;23(8):403-8.

• McQualter JL et al., Granulocyte macrophage colony-stimulating factor: a new putative therapeutic target in multiple sclerosis. J Exp Med. 2001 Oct 1;194(7):873-82

Autoimmunity Program
(In collaboration with Dr Frederic Sierro)
Our laboratory is interested in the cellular and molecular mechanisms implicated in the onset and/or the maintenance of autoimmune diseases like rheumatoid arthritis, lupus or Sjögren syndrome.

Project 2: Identification of cellular and molecular factors responsible for autoimmunity

We identified in mouse models and in some human patients, marginal zone B cells (MZB) as the cell population that is expanded during the course of some of these inflammatory diseases. A number of these cells are relocating to affected organs. Therefore this cell population is considered as one of the main suspects.

We have characterized the transcript profile of these cells using microarray technology and have identified potential target genes. To investigate the role of a several of these genes, we are currently generating knockout mice and monoclonal antibodies. The aim of this project will be to validate the differential expression of these genes and to gain insights into their function and their role in the immune response. The project will involve a variety of techniques including cell culture, transfection, real-time PCR and immunohistochemistry as well as ELISA and mouse models of inflammatory disease (eg arthritis).

Selected References (Available on request)

• Batten, M., J. Groom, et al. (2000). "BAFF mediates survival of peripheral immature B lymphocytes." J Exp Med 192(10): 1453-66.

• Groom, J., S. L. Kalled, et al(2002). "Association of BAFF/BLyS overexpression and altered B cell differentiation with Sjogren's syndrome." J Clin Invest 109(1): 59-68.

In mice transgenic (tg) for the soluble factor, BAFF (B cell activation factor), the immune system fails to prevent the emergence of autoreactive lymphocytes, resulting in the development of a disease comparable to SLE (systemic lupus erythematosus), RA (rheumatoid arthritis) and Sjögren's syndrome. Many clues on when and where (which immune cells are implicated) BAFF is affecting the immune system have been gained over the last years. But the mechanism of how BAFF is acting in the cell still has to be largely deciphered.

Collaborators generated an inducible KO mouse for a specific TNF-R associated factor (TRAF): TRAF2. Interestingly the B cell phenotype of this mouse was really similar to the one of the BAFF tg mice. Receptors of BAFF are members of the TNF-R family and some were proposed to interact with TRAF2. We hypothesize that TRAF2 is a key signal transducer of BAFF signaling.

The aim of this project will be to test this hypothesis by crossing and phenotyping TRAF2 KO and BAFF KO mice. The project will involve a variety of techniques including cell culture, PCR and immunohistochemistry as well as ELISA, FACS and mouse models of inflammatory disease (eg  arthritis).

Selected References (Available on request)

• Batten, M., J. Groom, et al. (2000). "BAFF mediates survival of peripheral immature B lymphocytes." J Exp Med 192(10): 1453-66.

• Mak, T. W. and W. C. Yeh (2002). "Signaling for survival and apoptosis in the immune system." Arthritis Res 4 Suppl 3: S243-52