Novel antimalarial antibodies highlight the importance of the antibody Fc region in mediating protection.

Parasite drug resistance and difficulties in developing effective vaccines have precipitated the search for alternative therapies for malaria. The success of passive immunization suggests that immunoglobulin (Ig)-based therapies are effective. To further explore the mechanism(s) by which antibody mediates its protective effect, we generated human chimeric IgG1 and IgA1 and a single-chain diabody specific for the C-terminal 19-kDa region of Plasmodium yoelii merozoite surface protein 1 (MSP119), a major target of protective immune responses. These novel human reagents triggered in vitro phagocytosis of merozoites but, unlike their parental mouse IgG2b, failed to protect against parasite challenge in vivo. Therefore, the Fc region appears critical for mediating protection in vivo, at least for this MSP119 epitope. Such antibodies may serve as prototype therapeutic agents, and as useful tools in the development of in vitro neutralization assays with Plasmodium parasites.

[1]  I. McGregor,et al.  Gamma-Globulin and Acquired Immunity to Human Malaria , 1961, Nature.

[2]  Marjolein van Egmond,et al.  FcαRI-positive liver Kupffer cells: Reappraisal of the function of immunoglobulin A in immunity , 2000, Nature Medicine.

[3]  R. Johnson,et al.  Upregulation of Fas Ligand by Simian Immunodeficiency Virus—A nef-arious Mechanism of Immune Evasion? , 1997, The Journal of experimental medicine.

[4]  M. Glennie,et al.  Mechanisms of G-CSF- or GM-CSF-stimulated tumor cell killing by Fc receptor-directed bispecific antibodies. , 2001, Journal of immunological methods.

[5]  F. Lunel,et al.  Mechanisms underlying the monocyte-mediated antibody-dependent killing of Plasmodium falciparum asexual blood stages , 1995, The Journal of Experimental Medicine.

[6]  H. Wolf,et al.  Anti‐inflammatory properties of human serum IgA: induction of IL‐1 receptor antagonist and FcαR (CD89)‐mediated down‐regulation of tumour necrosis factor‐alpha (TNF‐α) and IL‐6 in human monocytes , 1996 .

[7]  M. Walport,et al.  Splenic Fc receptor function in host defense and anemia in acute Plasmodium falciparum malaria. , 1990, The Journal of infectious diseases.

[8]  Jaeger,et al.  Effects of cytokines, complement, and antibody on the neutrophil respiratory burst and phagocytic response to Plasmodium falciparum merozoites , 1992, Infection and immunity.

[9]  J. Woof,et al.  Fc receptors and immunity to parasites. , 2001, Trends in parasitology.

[10]  M. Hulett,et al.  Molecular basis of Fc receptor function. , 1994, Advances in immunology.

[11]  A. Ferrante,et al.  The role of complement, antibody, and tumor necrosis factor alpha in the killing of Plasmodium falciparum by the monocytic cell line THP-1 , 1997, Infection and immunity.

[12]  J. McCafferty,et al.  Antibody engineering: a practical approach , 1997 .

[13]  D. Kaslow,et al.  Pathways and strategies for developing a malaria blood-stage vaccine. , 1998, Annual review of immunology.

[14]  Tominari Kobayashi,et al.  T-cell activation and cytokine production via a bispecific single-chain antibody fragment targeted to blood-stage malaria parasites. , 2003, Blood.

[15]  J. Woof,et al.  Amino Acid Sequence Requirements in the Hinge of Human Immunoglobulin A1 (IgA1) for Cleavage by Streptococcal IgA1 Proteases , 2003, Infection and Immunity.

[16]  A. Cowman,et al.  Antibodies against Merozoite Surface Protein (Msp)-119 Are a Major Component of the Invasion-Inhibitory Response in Individuals Immune to Malaria , 2001, The Journal of experimental medicine.

[17]  Adrian Ozinsky,et al.  Phagocytosis of microbes: complexity in action. , 2002, Annual review of immunology.

[18]  J. Dunlop,et al.  Identification of Residues in the CH2/CH3 Domain Interface of IgA Essential for Interaction with the Human Fcα Receptor (FcαR) CD89* , 1999, The Journal of Biological Chemistry.

[19]  J. V. D. van de Winkel,et al.  Immunotherapeutic perspective for bispecific antibodies. , 2000, Immunology today.

[20]  A. Thomas,et al.  The Fab fragments of monoclonal IgG to a merozoite surface antigen inhibit Plasmodium knowlesi invasion of erythrocytes. , 1984, Molecular and biochemical parasitology.

[21]  E. Sanders,et al.  Central Role of Complement in Passive Protection by Human IgG1 and IgG2 Anti-pneumococcal Antibodies in Mice1 , 2003, The Journal of Immunology.

[22]  K. J. Dorrington,et al.  Fcγ Receptor of the Murine Macrophage-Like Cell Line P388D1 I. The Binding of Homologous and Heterologous Immunoglobulin G , 1979 .

[23]  R. Owens,et al.  Purification and characterization of chimeric human IgA1 and IgA2 expressed in COS and Chinese hamster ovary cells. , 1993, Journal of immunology.

[24]  A. Cattaneo,et al.  An integrated vector system for the eukaryotic expression of antibodies or their fragments after selection from phage display libraries. , 1997, Gene.

[25]  A. Holder,et al.  Passive Immunization with Antibodies against Three Distinct Epitopes on Plasmodium yoelii Merozoite Surface Protein 1 Suppresses Parasitemia , 1998, Infection and Immunity.

[26]  A. Holder,et al.  Antibodies that Inhibit Malaria Merozoite Surface Protein–1 Processing and Erythrocyte Invasion Are Blocked by Naturally Acquired Human Antibodies , 1997, The Journal of experimental medicine.

[27]  A. Holder,et al.  A malaria merozoite surface protein (MSP1)-structure, processing and function. , 1992, Memorias do Instituto Oswaldo Cruz.

[28]  R. Kontermann,et al.  Optimized linker sequences for the expression of monomeric and dimeric bispecific single-chain diabodies. , 2001, Protein engineering.

[29]  F. Geissmann,et al.  A Subset of Human Dendritic Cells Expresses IgA Fc Receptor (CD89), Which Mediates Internalization and Activation Upon Cross-Linking by IgA Complexes , 2001, The Journal of Immunology.

[30]  Jonathan E. Allen,et al.  Genome sequence and comparative analysis of the model rodent malaria parasite Plasmodium yoelii yoelii , 2002, Nature.

[31]  D. Salmon,et al.  Role of immune serum and complement in stimulation of the metabolic burst of human neutrophils by Plasmodium falciparum , 1986, Infection and immunity.

[32]  David L. Tabb,et al.  A proteomic view of the Plasmodium falciparum life cycle , 2002, Nature.

[33]  Andrew Boyd,et al.  Single-chain antibodies produced by phage display against the C-terminal 19 kDa region of merozoite surface protein-1 of Plasmodium yoelii reduce parasite growth following challenge. , 2002, Vaccine.

[34]  A. Verhoeven,et al.  Heterotypic FcγR Clusters Evoke a Synergistic Ca2+ Response in Human Neutrophils (*) , 1995, The Journal of Biological Chemistry.

[35]  R. Williams,et al.  Crystal structure of a diabody, a bivalent antibody fragment. , 1994, Structure.

[36]  D. Ratner,et al.  Universal PCR amplification of mouse immunoglobulin gene variable regions: the design of degenerate primers and an assessment of the effect of DNA polymerase 3' to 5' exonuclease activity. , 2000, Journal of immunological methods.

[37]  D. Taylor,et al.  Identification of Anti‐Plasmodium falciparum Antibodies in Human Breast Milk , 1992, Scandinavian journal of immunology. Supplement.

[38]  R. Pauwels,et al.  Specific Migratory Dendritic Cells Rapidly Transport Antigen from the Airways to the Thoracic Lymph Nodes , 2001, The Journal of experimental medicine.

[39]  A. Sabchareon,et al.  Antibodies that protect humans against Plasmodium falciparum blood stages do not on their own inhibit parasite growth and invasion in vitro, but act in cooperation with monocytes , 1990, The Journal of experimental medicine.

[40]  T. Daly,et al.  Fc receptors are not required for antibody-mediated protection against lethal malaria challenge in a mouse model. , 1998, Journal of immunology.

[41]  L. Presta,et al.  Inhibitory Fc receptors modulate in vivo cytoxicity against tumor targets , 2000, Nature Medicine.

[42]  M. Klein,et al.  Studies on the Fc gamma receptor of the murine macrophage-like cell line P388D1. II. Binding of human IgG subclass proteins and their proteolytic fragments. , 1979, Journal of immunology.

[43]  J. Breman,et al.  The ears of the hippopotamus: manifestations, determinants, and estimates of the malaria burden. , 2001, The American journal of tropical medicine and hygiene.

[44]  K. J. Dorrington,et al.  Studies on the Fc gamma receptor of the murine macrophage-like cell line P388D1. I. The binding of homologous and heterologous immunoglobulin G1. , 1979, Journal of immunology.

[45]  A. Saul,et al.  A Robust Neutralization Test for Plasmodium falciparum Malaria , 2001, The Journal of experimental medicine.