In vivo imaging of α₁-antitrypsin polymers

Z α 1-antitrypsin deficiency results in the accumulation of polymers of mutant α 1-antitrypsin within hepatocytes. The resulting plasma deficiency of α 1-antitrypsin results in uncontrolled proteolysis and hence emphysema.  This is exacerbated by extracellular polymers formation within the lung that are pro-inflammatory.

We have developed the 2C1 monoclonal antibody that detects the pathological polymers of α 1-antitrypsin that form in vivo.  This antibody works in a wide range of imaging techniques and can distinguish between polymers formed under a range of different conditions (Ekeowa et al, PNAS, 2010). The aim is to use this antibody to image polymers of antitrypsin within the liver and the lungs in vivo.  This will quantify the burden of polymerised protein within these organs to allow: (i) a correlation between protein load, liver disease and emphysema, (ii) an imaging platform to assess efficacy of anti-polymer therapeutic strategies in vivo.

To develop this technology, a number of steps are required: (a) development of a suitable imaging agent, (b) production of a recombinant humanised antibody, (c) testing in animal models of disease and (d) patient trials. 

Aim of this project

• Expression and purification of the 2C1 monoclonal antibody.
• Conjugation of the 2C1 monoclonal antibody with cell penetrant peptides and fluorophores. 
• Determination of optimal conjugation conditions of peptides and fluorophores to the antibody by means of mass spectroscopy (MALDI TOF + LC MS)
• Confirmation that the final conjugate retains its affinity for polymers in ELISA assays.
• Finally, the cell penetration of the conjugate will be assessed in our COS-7 model of Z α1-antitrypsin deficiency and in our iPSC derived hepatocytes from an individual with Z α1-antitrypsin deficiency (Yusa et al, Nature, 2011).

Curriculum Vitae Dr. Imran Haq:

Dr. Haq has nine years of experience in the field of respiratory biology.  During his PhD, he studied the role of MMP-12 as a disease locus in Chronic Obstructive Pulmonary Disease in Prof. Noor Kalshekers' group.

Following this, he moved to the University of Cambridge, and later to the University College London (UCL), to undertake postdoctoral research with Prof. David Lomas.  Involving initially the elucidation of the early stages of polymer formation in α1-antitrypsin deficiency before working on therapeutic and diagnostic strategies.

The sum of this research has led to his participation as co-author in 18 publications. 

Dr. Haq will use the ALTA award to develop a diagnostic tool which will deliver In vivo imaging of α1-antitrypsin polymers, based on the novel 2C1 polymer specific monoclonal antibody.

Contact:

Wolfson Institute for Biomedical Research
University College London
London, UK.