The IC50 of anti-Pfs25 antibody in membrane-feeding assay varies among species

• Published in: Vaccine 2010-06, Vol.28 (27), p.4423-4429
• Main Authors: Cheru, Lediya, Wu, Yimin, Diouf, Ababacar, Moretz, Samuel E, Muratova, Olga V, Song, Guanhong, Fay, Michael P, Miller, Louis H, Long, Carole A, Miura, Kazutoyo
• Format: Article
• Language: English
• Subjects: Allergy and Immunology; Applied microbiology; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Immunization; Life cycle. Host-agent relationship. Pathogenesis; Malaria; Microbiology; Mosquitoes; Oocysts; Parasites; Protozoa; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies (general aspects)
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2010.04.036

Abstract Plasmodium falciparum surface protein 25 (Pfs25) is a candidate for transmission-blocking vaccines (TBVs). Anti-Pfs25 antibodies block the development of oocysts in membrane-feeding assays and we have shown the activity correlates with antibody titer. In this study, we purified Pfs25-specific IgGs to convert antibody titer to μg/mL and determined the amount of antibody required to inhibit 50% of oocyst development (IC50 ). The IC50 were, 15.9, 4.2, 41.2, and 85.6 μg/mL for mouse, rabbit, monkey and human, respectively, and the differences among species were significant. Anti-Pfs25 sera from rabbit, monkey and human showed different patterns of competition against 6 mouse monoclonal antibodies, and the avidity of antibodies among four species were also different. These data suggests that information obtained from animal studies which assess efficacy of TBV candidates may be difficult to translate to human immunization.