VHH (i.e. recombinant derivative of peculiar heavy chain only antibodies present in camelids) directed against Duffy antigen receptor for chemokines (DARC). DARC which carries antigens defining the Duffy blood group system, is a human atypical chemokine receptor, the major receptor for Plasmodium vivax merozoite on erythrocytes, a protein implicated in cancer, inflammation, possibly HIV infection and AIDS progression.
VHH was obtained afer screening of a library prepared from a dromedary immunized against first extracellular domain of DARC. VHH does recognize DARC on cells and interacts with the Fy6 epitope. It does inhibit P. vivax invasion and chemokine binding (IL8). Its affinity to DARC is in the subnanomolar range. Expression plasmid (6 His) codes for a hemagglutinin tagged VHH.