Blood, Vol. 94 No. 1 (July 1), 1999:
pp. 326-332
Inhibitory Activity of Human Lactoferrin and Its Peptide on Chondroitin
Sulfate A-, CD36-, and Thrombospondin-Mediated Cytoadherence of
Plasmodium falciparum-Infected Erythrocytes
Shigetoshi Eda,
Keiko Eda,
Jacques G. Prudhomme, and
Irwin W. Sherman
From Department of Biology, University of California, Riverside, CA.
Lactoferrin (LF), a human serum protein, strongly inhibited the
adherence of Plasmodium falciparum-infected erythrocytes (PE) to immobilized chondroitin sulfate A (CSA)-conjugated albumin at a
concentration of 100 µg/mL and blocked the PE binding to CD36-expressing Chinese hamster ovary (CHO) cells, as
well as immobilized CD36 at concentrations of 5 µg/mL and 100 µg/mL, respectively. Biotinylated LF bound to CD36 in a saturable
manner, and such binding was inhibited by unlabeled LF and the
anti-CD36 monoclonal antibody, 8A6, suggesting specificity of binding.
Additionally, LF inhibited PE binding to immobilized thrombospondin
(TSP) at a concentration of 100 µg/mL, and specific binding of LF to
TSP was confirmed using biotinylated LF. LF inhibited PE binding to C32
amelanotic melanoma cells in a dose-dependent manner. A peptide of LF,
Arg-Asn-Met Arg-Lys-Val Arg-Gly-Pro-Pro-Val-Ser-Cys (amino acid
residues 25-37 of LF), which has been suggested to contribute to LF
binding to various materials, including CSA, inhibited PE binding to
immobilized CSA-conjugated albumin, immobilized CD36, CD36-expressing
CHO cells, immobilized TSP, and C32 amelanotic melanoma cells, as well
as LF itself. These results suggest that LF peptide may provide the
basis for developing agents that are able to inhibit CSA-, CD36-, and
TSP-mediated cytoadherence of PE.
