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Localization of Knops system antigens in the long homologous repeats of complement receptor 1
Author(s) -
Tamasauskas Daniel,
Powell Vivien,
Schawalder Alissa,
Yazdanbakhsh Karina
Publication year - 2001
Publication title -
transfusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.045
H-Index - 132
eISSN - 1537-2995
pISSN - 0041-1132
DOI - 10.1046/j.1537-2995.2001.41111397.x
Subject(s) - allotype , antigen , antibody , biology , receptor , microbiology and biotechnology , complement system , homologous chromosome , complement receptor 1 , immunology , virology , genetics , gene
BACKGROUND: The Sl a (Knops system) located on complement receptor 1 (CR1) has been associated with malarial rosetting, a process associated with severe malarial infections. Moreover, the long homologous repeats (LHRs) B and C of CR1 were implicated in rosette formation. As a step toward mapping the location of Knops system antigens, truncated CR1 proteins have been expressed and their ability to inhibit antibodies to the high‐incidence Knops system antigens was assessed. STUDY DESIGN AND METHODS: Individual LHRs (A, B, C, and D) of CR1 of the common CR1*1 (F) allotype were expressed as secreted forms in 293T cells. Their abilities to specifically neutralize Knops system antibodies were tested by both hemagglutination and flow cytometry. RESULTS: Three examples of anti‐Kn a (n = 6) were almost completely inhibited by LHR‐C and three by LHR‐D. Two examples of anti‐McC a (n = 2) and seven examples of anti‐Sl a (n = 8) were inhibited by LHR‐D. Both examples of anti‐Yk a (n = 2) were partially inhibited by LHR‐D. CONCLUSION: The high‐incidence Knops system antigens reside within LHR‐D and to a lesser extent within LHR‐C. Because of the role of Sl a antigen in malaria rosetting, these results indicate that LHR‐D may represent an additional malaria interaction region in CR1.