Fiona J. McCallum

Learn More
Substantial evidence indicates that antibodies to Plasmodium falciparum merozoite antigens play a role in protection from malaria, although the precise targets and mechanisms mediating immunity remain unclear. Different malaria antigens induce distinct immunoglobulin G (IgG) subclass responses, but the importance of different responses in protective(More)
Twenty-six female brown marsupial mice in a laboratory colony were mated at intervals ranging from 1 to 20 days between coitus and ovulation. The numbers of corpora lutea and normal embryos were counted. A multiple regression model examined the parabolic relationship between the proportion of normal embryos and the time from coitus to ovulation. The(More)
The frequency of HLA-B8 was significantly increased in pancreatic islet cell antibody (P.I.C.A)-positive patients (61%) compared with P.I.C.A.-negative patients (35%) and a control population (28%). This increased frequency of HLA-B8 was even more striking in diabetics in whom P.I.C.A. persisted for more than 5 years (71%). Thus the association of HLA-B8(More)
Antibodies that inhibit Plasmodium falciparum invasion of erythrocytes are believed to be an important component of immunity against malaria. During blood-stage infection, P. falciparum can use different pathways for erythrocyte invasion by varying the expression and/or utilization of members of 2 invasion ligand families: the erythrocyte-binding antigens(More)
BACKGROUND Antibodies to P. falciparum apical membrane protein 1 (AMA1) may contribute to protective immunity against clinical malaria by inhibiting blood stage growth of P. falciparum, and AMA1 is a leading malaria vaccine candidate. Currently, there is limited knowledge of the acquisition of strain-specific and cross-reactive antibodies to AMA1 in humans,(More)
BACKGROUND An understanding of the mechanisms mediating protective immunity against malaria in humans is currently lacking, but critically important to advance the development of highly efficacious vaccines. Antibodies play a key role in acquired immunity, but the functional basis for their protective effect remains unclear. Furthermore, there is a strong(More)
BACKGROUND Antibodies that inhibit the growth of blood-stage Plasmodium falciparum may play an important role in acquired and vaccine-induced immunity in humans. However, the acquisition and activity of these antibodies is not well understood. METHODS We tested dialysed serum and purified immunoglobulins from Kenyan children and adults for inhibition of(More)
Abs that inhibit Plasmodium falciparum invasion of erythrocytes form an important component of human immunity against malaria, but key target Ags are largely unknown. Phenotypic variation by P. falciparum mediates the evasion of inhibitory Abs, contributing to the capacity of P. falciparum to cause repeat and chronic infections. However, Ags involved in(More)
Antibodies play a key role in acquired human immunity to Plasmodium falciparum (Pf) malaria and target merozoites to reduce or prevent blood-stage replication and the development of disease. Merozoites present a complex array of antigens to the immune system, and currently, there is only a partial understanding of the targets of protective antibodies and(More)
Malaria is a disease caused by a protozoan of the Plasmodium genus and results in 0.5-0.7million deaths per year. Increasing drug resistance of the parasite and insecticide resistance of mosquitoes necessitate alternative control measures. Numerous vaccine candidates have been identified but none have been able to induce robust, long-lived protection when(More)