The life cycle of the malaria parasite is very complex and provides a number of potential targets for vaccination. In this thesis, data on two plasmodial asexual blood stage antigens (RAP-2 and Pf332) are presented. A partial aim of the work presented herein was to investigate the mechanisms responsible for the destruction of erythroid cells in anaemia, and more specifically to define the role of the rhoptry associated protein (RAP)-2 and other members of the RAP complex, RAP-1 and -3 in processes resulting in anaemia. Antibodies to the RAP complex were shown to have the potential to mediate the destruction of RAP-2-tagged erythroid cells by phagocytosis or by complement activation and lysis. In addition, antibodies to RAP-1 and RAP-2 could induce the apoptotic death of RAP-2- tagged erythroblasts. The frequency and functionality of naturally occurring RAP-2 antibodies in the sera of anaemic and non-anaemic Cameroonian children were also investigated. All sera tested contained RAP-2-reactive antibodies by both immunofluorescence and flow cytometry. The anaemic group of children had higher levels of IgG than the non-anaemic ones, while the levels of IgM were similar. With respect to IgG subclasses, higher levels of IgG3 were seen in the non-anaemic individuals as compared to anaemic subjects. The non-anaemic individuals recognised a greater proportion of RAP-2-tagged RBCs and activated complement to a greater extent than the anaemic ones. Earlier studies observed that humans continuously exposed to malaria, recognised Pf332 extensively. Further studies revealed that Pf332 antibodies were able to inhibit parasite growth and cytoadherence in vitro. Making use of Pf332-C231, a sub-fragment of Pf332, we studied the effects/mode of action of C231-specific antibodies on P. falciparum parasite growth and development in vitro. The antibodies appeared to act mainly on late stage parasites by two main mechanisms: 1) through the induction of abnormal/pyknotic parasites, and, 2) RBC lysis (disintegration of RBCs), thus limiting parasite growth and development. The antibody isotype in this context was IgG. Following the removal of immune pressure, parasites resumed growth, albeit at a much slower rate. The results suggest that during natural infections, antibodies to C231 could play a role in parasite control. In summary, these data suggest that antibodies to both antigens could be instrumental in immune responses leading to disease control, but could also mediate pathology. / At the time of the doctoral defense, the following publication was unpublished and had a status as follows: Paper 3: Manuscript.

Bibliography: leaves 197-274. / 274, [146] leaves, [9] leaves of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Aims to characterize the cell-mediated immune response to Salmonella infection in mice, by comparing the antigen presenting cell activity of peritoneal cells (PCs) obtained from infected mice with that of PCs from normal mice and analysing the T cell subsets induced by primary and secondary Salmonella infections. / Thesis (Ph.D.)--University of Adelaide, Dept. of Microbiology and Immunology, 1993?

Diss. (sammanfattning) Stockholm : Univ., 2005. / Härtill 4 uppsatser.

Diss. (sammanfattning) Umeå : Umeå universitet, 2006. / Härtill 4 uppsatser.

Thesis (M.P.H.M.)--Mahidol University, 1999.

Thesis (M.A.)--Humboldt State University, 2008. / Includes bibliographical references (leaves 98-104). Also available via Humboldt Digital Scholar.

Thesis (Ph.D.)--University of California, San Francisco, 2004. / Bibliography: leaves 85-92. Also available online.

Thesis--Catholic University of America. / Includes bibliographical references (p. 21-23).

Thesis (M.S.)--University of Wisconsin--Madison, 1947. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 44-48).

Thesis (M. Phil.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves 102-113).