George Cross has been concerned with the study of pathogenic parasitic protozoa — especially their metabolic activities, genetic properties and membrane structure. He was the first to grow insect forms of African trypanosomes in a defined culture medium and this led to the discovery of the threonine pathway for the generation of acetate in trypanosomes. He subsequently established amino acid sequences for surface coat antigens from distinct variants of Trypanosoma brucei and characterised the gene sequences which control the synthesis of these variant antigens. This work revealed unique signal sequences at both ends of the polypeptide and novel glycosylation of C-terminal serine or aspartic acid residues of the antigens. Protective antigens from a murine malaria parasite have been identified and isolated and this work has advanced progress towards the production of a vaccine against blood-stage malaria.
Interest and expertise
Biochemistry and molecular cell biology
Leeuwenhoek Medal and Lecture
On 'The genetics and cell biology of antigenic variation in trypanosomes'.