Dr Alexander McLellan was recently successful in obtaining Marsden funding for a study on newly identified nano-particles termed exosomes. Exosomes are sub-cellular particles released from a variety of cells.
In a recent ground breaking discovery, his group showed that exosomes contained antibodies, an important component of the body's immune system. These newly identified structures were only released from B cells, a type of white blood cell, following the receipt of a precise set of signals from another cell type.
The work is based at Otago and has now attracted collaborations with researchers in North America, Australia and Germany.
Dr McLellan's group will now investigate whether human B cells recycle antibody in lipid particles as a way to enhance the immune response.
"We already know that these lipid-bound forms of antibody play a role in recycling antibodies. The new project will determine if these structures play a role in amplifying the immune response," he said.
"This is in contrast to the well studied role of the highly soluble form of antibody which functions exclusively to destroy pathogens."
Previous work in his laboratory had determined that B cells pull in tiny pieces of pathogens bound to the surface of B cells by antibody.
Instead of destroying the pathogen fragments by a process of "digestion", Dr McLellan's group was surprised to find that the B cells ‘recycle' the pathogen fragments and release these into the extracellular space, still bound to antibody.
The recycled pathogen fragments may trigger other white blood cells involved in the immune response.
"The Marsden funding for future work in this area has added to the thrill of the original findings and I am very happy that we will be able to continue to contribute to this field of immunology," he said.
Dr McLellan is a senior lecturer in the Dept. of Microbiology and Immunology and leads a research group studying the interaction of pathogens and cancer with the body's immune system.
He has an active research record authored over 35 peer-reviewed papers in high-impact journals and contributed to several book chapters.
Dr McLellan gained a PhD from the University of Otago and his doctoral work contributed to the publication of nine papers, five of these as first author.
In 1998, Dr McLellan took up a Postdoctoral Fellowship in the Department of Dermatology at the Germany's University of Würzburg. This link with European counterparts has been maintained through ongoing collaborations with researchers in Switzerland, Austria and Germany.
Since his return to Otago, he has built working collaborations with several local groups and is director of the Otago Flow Cytometry Facility.
His recent paper in the highly-ranked Journal of Immunology defines new mechanisms for immune cell communication and activation during the immune response.
He is active in several other areas of immunology and is currently working on the role of a white blood cell, termed a ‘natural Killer cell', in immunity to cancers, a non-invasive test for renal transplant rejection as well as studying responses to a tuberculosis vaccine.
Dr McLellan is a mentor for undergraduate and postgraduate students and enjoys teaching at all levels, including contributions to courses in Continuing Education, University of the Third Age, Health Sciences First Year and Pharmacy.