| 1. |
|
|
| 2. |
- Chen, Q, et al.
(författare)
-
Identification of Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) as the rosetting ligand of the malaria parasite P. falciparum
- 1998
-
Ingår i: The Journal of experimental medicine. - : Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 187:1, s. 15-23
-
Tidskriftsartikel (refereegranskat)abstract
- Severe Plasmodium falciparum malaria is characterized by excessive sequestration of infected and uninfected erythrocytes in the microvasculature of the affected organ. Rosetting, the adhesion of P. falciparum–infected erythrocytes to uninfected erythrocytes is a virulent parasite phenotype associated with the occurrence of severe malaria. Here we report on the identification by single-cell reverse transcriptase PCR and cDNA cloning of the adhesive ligand P. falciparum erythrocyte membrane protein 1 (PfEMP1). Rosetting PfEMP1 contains clusters of glycosaminoglycan-binding motifs. A recombinant fusion protein (Duffy binding-like 1–glutathione S transferase; Duffy binding-like-1–GST) was found to adhere directly to normal erythrocytes, disrupt naturally formed rosettes, block rosette reformation, and bind to a heparin-Sepharose matrix. The adhesive interactions could be inhibited with heparan sulfate or enzymes that remove heparan sulfate from the cell surface whereas other enzymes or similar glycosaminoglycans of a like negative charge did not affect the binding. PfEMP1 is suggested to be the rosetting ligand and heparan sulfate, or a heparan sulfate–like molecule, the receptor both for PfEMP1 binding and naturally formed erythrocyte rosettes.
|
|
| 3. |
|
|
| 4. |
- Cruz, Silian, et al.
(författare)
-
Mouse monoclonal antibodies against outer membrane proteins of a vaccine strain of Neisseria meningitidis B : 4:P1.15
- 1998
-
Ingår i: Minerva Biotecnologica. - 1120-4826. ; 10:2, s. 65-70
-
Tidskriftsartikel (refereegranskat)abstract
- Background. Neisseria meningitidis (Nm) is a Gram negative diplococcus causing bacterial meningitis and fulminant septicemia. In order to allow efficient characterization of infecting strains, antibody reagents for use as analytical tools have proven to be invaluable tools. Similarly, antibodies against relevant bacterial antigens may guide in the selection of components to be included in developing vaccine strategies. Methods. We have thus developed mouse monoclonal antibodies specific for class 1, 3 and 5 antigens expressed by the B:4:P1.15 isolate CU385/83, also being used in a recently developed protective vaccine. In particular, two antibodies CB-Nm.1 and CB- Nm.2 recognize epitopes partly overlapping the subserotype (class 1 antigens) and serotype (class 3 antigen) specificities detected by the previously defined antibodies C6 and 15-1-P4 respectively, were evaluated. Results. As judged by strain recognition, the absolute requirement for binding differs between both the class 1-specific and class 3 specific antibodies suggesting the importance of using multiple antibodies when evaluating subserotype/serotype characteristics of clinical isolates of Nm by serological methods. Conclusion. Furthermore, the development of antibodies crossreactive with subserotype/serotype antigens may partly explain the ability of outer membrane protein vaccine to induce protective activity against strains considered as carrying different class 1 and 3 antigens as determined by available (sub)serotyping reagents.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
- Fernandez, V, et al.
(författare)
-
Small, clonally variant antigens expressed on the surface of the Plasmodium falciparum-infected erythrocyte are encoded by the rif gene family and are the target of human immune responses
- 1999
-
Ingår i: The Journal of experimental medicine. - : Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 190:10, s. 1393-1403
-
Tidskriftsartikel (refereegranskat)abstract
- Disease severity in Plasmodium falciparum infections is a direct consequence of the parasite's efficient evasion of the defense mechanisms of the human host. To date, one parasite-derived molecule, the antigenically variant adhesin P. falciparum erythrocyte membrane protein 1 (PfEMP1), is known to be transported to the infected erythrocyte (pRBC) surface, where it mediates binding to different host receptors. Here we report that multiple additional proteins are expressed by the parasite at the pRBC surface, including a large cluster of clonally variant antigens of 30–45 kD. We have found these antigens to be identical to the rifins, predicted polypeptides encoded by the rif multigene family. These parasite products, formerly called rosettins after their identification in rosetting parasites, are prominently expressed by fresh isolates of P. falciparum. Rifins are immunogenic in natural infections and strain-specifically recognized by human immune sera in immunoprecipitation of surface-labeled pRBC extracts. Furthermore, human immune sera agglutinate pRBCs digested with trypsin at conditions such that radioiodinated PfEMP1 polypeptides are not detected but rifins are detected, suggesting the presence of epitopes in rifins targeted by agglutinating antibodies. When analyzed by two-dimensional electrophoresis, the rifins resolved into several isoforms in the pI range of 5.5–6.5, indicating molecular microheterogeneity, an additional potential novel source of antigenic diversity in P. falciparum. Prominent polypeptides of 20, 22, 76–80, 140, and 170 kD were also detected on the surfaces of pRBCs bearing in vitro–propagated or field-isolated parasites. In this report, we describe the rifins, the second family of clonally variant antigens known to be displayed by P. falciparum on the surface of the infected erythrocyte.
|
|
| 9. |
|
|
| 10. |
|
|
