Geoffrey W. Hoffmann
Encyclopedia
Geoffrey W. Hoffmann, is an Australian
-Canadian
theoretical biologist
. Hoffmann was a faculty member in the Department of Physics at the University of British Columbia
and is currently chairman and chief scientist at Network Immunology Inc. in Vancouver, Canada. He is best known for symmetric immune network theory
.
then obtained a PhD (Dr. rer. nat., Technische Universität Braunschweig
) as a student of Manfred Eigen
for research done at the Max Planck Institute for Biophysical Chemistry
in Göttingen.
His initial work in theoretical biology addressed Leslie Orgel
's paradox in origin of life theories. Hoffmann showed that an early sloppy translation machinery can be stable against the error catastrophe envisaged by Orgel and provided analyses of the expected occurrence of required catalytic activities and exclusion of disruptive catalytic activities. These calculations support the view that the origin of replication and metabolism together is plausible.
, where Niels Jerne had proposed that the immune system is a network, consisting of antibodies and lymphocytes that recognize not only things that are foreign to the body, but also each other. Immune network theory
became, and remains, Hoffmann's primary research focus. He developed the symmetrical immune network theory based on Jerne’s hypothesis. This theory involves symmetrical stimulatory, inhibitory and killing interactions, and is a framework for understanding, using a small number of postulates, a number of immunological phenomena that are not readily explained otherwise.
pathogenesis, Hoffmann and his lab at the University of British Columbia contributed basic research relevant to the search for an HIV vaccine. Achievements included the co-discovery of "second symmetry", a co-study on antibodies made in a normal immune response that bind both to foreign invaders and to antibodies with the same specificity, and the discovery, with others, that mice immunized with foreign lymphocytes make anti HIV antibodies.
The analogy resulted in the discovery of a neural network in which neurons exhibit hysteresis and thus can learn without synaptic modification. He also discovered, with Davenport, a way to add hidden neurons to Hopfield neural networks
and thus extend their associative memory capacity.
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
-Canadian
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
theoretical biologist
Mathematical and theoretical biology
Mathematical and theoretical biology is an interdisciplinary scientific research field with a range of applications in biology, medicine and biotechnology...
. Hoffmann was a faculty member in the Department of Physics at the University of British Columbia
University of British Columbia
The University of British Columbia is a public research university. UBC’s two main campuses are situated in Vancouver and in Kelowna in the Okanagan Valley...
and is currently chairman and chief scientist at Network Immunology Inc. in Vancouver, Canada. He is best known for symmetric immune network theory
Immune network theory
The immune network theory is a theory of how the adaptive immune system works, that has been developed since 1974 mainly by Niels Jerne and Geoffrey W. Hoffmann. The theory states that the immune system is an interacting network of lymphocytes and molecules that have variable regions...
.
Education and early research
Hoffmann studied physics at the University of MelbourneUniversity of Melbourne
The University of Melbourne is a public university located in Melbourne, Victoria. Founded in 1853, it is the second oldest university in Australia and the oldest in Victoria...
then obtained a PhD (Dr. rer. nat., Technische Universität Braunschweig
Technische Universität Braunschweig
The TU Braunschweig is the oldest University of Technology in Germany. It was founded in 1745 as Collegium Carolinum and is a member of TU9, an incorporated society of the most renowned and largest German Institutes of Technology. Today it has about 13,000 students, making it the third largest...
) as a student of Manfred Eigen
Manfred Eigen
Manfred Eigen is a German biophysical chemist who won the 1967 Nobel Prize in Chemistry for work on measuring fast chemical reactions.-Career:...
for research done at the Max Planck Institute for Biophysical Chemistry
Max Planck Institute for Biophysical Chemistry
The Max Planck Institute for Biophysical Chemistry in Göttingen is a research institute of the Max Planck Society. Currently, 812 people work at the Institute, 353 of them are scientists....
in Göttingen.
His initial work in theoretical biology addressed Leslie Orgel
Leslie Orgel
Leslie Eleazer Orgel FRS was a British chemist.Born in London, England, Orgel received his B.A. in chemistry with first class honours from Oxford University in 1949...
's paradox in origin of life theories. Hoffmann showed that an early sloppy translation machinery can be stable against the error catastrophe envisaged by Orgel and provided analyses of the expected occurrence of required catalytic activities and exclusion of disruptive catalytic activities. These calculations support the view that the origin of replication and metabolism together is plausible.
Immune network theory
Hoffmann subsequently joined the Basel Institute for ImmunologyBasel Institute for Immunology
The Basel Institute for Immunology was founded in 1969 as a basic research institute in immunology located at 487 Grenzacherstrasse, Basel, Switzerland on the Rhine River down the street from the main Hoffmann-La Roche campus near the Swiss-German border. The institute opened its doors in 1971...
, where Niels Jerne had proposed that the immune system is a network, consisting of antibodies and lymphocytes that recognize not only things that are foreign to the body, but also each other. Immune network theory
Immune network theory
The immune network theory is a theory of how the adaptive immune system works, that has been developed since 1974 mainly by Niels Jerne and Geoffrey W. Hoffmann. The theory states that the immune system is an interacting network of lymphocytes and molecules that have variable regions...
became, and remains, Hoffmann's primary research focus. He developed the symmetrical immune network theory based on Jerne’s hypothesis. This theory involves symmetrical stimulatory, inhibitory and killing interactions, and is a framework for understanding, using a small number of postulates, a number of immunological phenomena that are not readily explained otherwise.
Application to HIV pathogenesis
Because symmetrical immune network theory offers a novel model of HIVHIV
Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
pathogenesis, Hoffmann and his lab at the University of British Columbia contributed basic research relevant to the search for an HIV vaccine. Achievements included the co-discovery of "second symmetry", a co-study on antibodies made in a normal immune response that bind both to foreign invaders and to antibodies with the same specificity, and the discovery, with others, that mice immunized with foreign lymphocytes make anti HIV antibodies.
Neural networks
Hoffmann noted many similarities between the immune system and the brain, including that:- both systems have memory and are able to respond appropriately to a wide range of stimuli
- both networks consist of comparable numbers of cells, and
- both systems have a profound sense of self.
The analogy resulted in the discovery of a neural network in which neurons exhibit hysteresis and thus can learn without synaptic modification. He also discovered, with Davenport, a way to add hidden neurons to Hopfield neural networks
Hopfield net
A Hopfield network is a form of recurrent artificial neural network invented by John Hopfield. Hopfield nets serve as content-addressable memory systems with binary threshold units. They are guaranteed to converge to a local minimum, but convergence to one of the stored patterns is not guaranteed...
and thus extend their associative memory capacity.
Network theory of war
Hoffmann proposed that wars are enabled by selective processes that influence how individuals advance within societies. He argues that such processes occur in all societies, democratic or not, and can be counteracted by increased contact between individual citizens across national or cultural divides.Further reading
- Immune Network Theory, by Geoffrey W. Hoffmann, 2008; www.physics.ubc.ca/~hoffmann/ni.html.