Characterization of a 70-kDa, EBV gp350/220-binding protein on HSB-2 T cells

J Immunol. 1994 Nov 15;153(10):4418-26.


EBV binds and infects HSB-2 T cells via a receptor distinct from CD21. To further study this novel EBV receptor, we expressed the first 470 amino acids of the EBV-gp350/220 using the baculovirus expression system. The recombinant gp350/220(1-470) has a m.w. of 95 kDa, reacts with anti-gp350/220 Abs, and binds CD21 in ELISA. Radiolabeled gp350/220(1-470) binds both HSB-2 and Raji cells. The gp350/220(1-470) protein also inhibits EBV binding to both HSB-2 and Raji, detected by flow cytometry. Lysates of HSB-2 cells compete with CD21 for binding to gp350/220(1-470), suggesting that the two receptors bind related epitopes on the recombinant protein. Scatchard analysis reveals that gp350/220(1-470) binds to 34,000 high affinity sites/HSB-2 cell (Kd = 0.92 x 10(-8) M) compared with the 97,000 high affinity sites bound/Raji cell (Kd = 1.78 x 10(-8) M). Utilizing a gp350/220(1-470)-affinity matrix, we identify a 70-kDa (55-kDa nonreduced) protein on the surfaces of 125I-labeled HSB-2 cells. Binding of this protein to the matrix is inhibited by anti-gp350/220 Ab 72A1. In summary, we characterize a novel EBV-binding molecule on HSB-2 cells, compare its reactivity with gp350/220 to that of CD21, and provide evidence of a gp350/220-reactive, 70-kDa protein on the surfaces of HSB-2 cells. In view of previous evidence of HSB-2 infectivity by EBV, we propose that the 70 kDa protein represents the novel EBV receptor.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antigens, Viral / metabolism*
  • Base Sequence
  • Binding, Competitive
  • Callithrix
  • Cell Line
  • Herpesvirus 4, Human / metabolism*
  • Humans
  • Molecular Sequence Data
  • Molecular Weight
  • Receptors, Complement 3d / metabolism
  • Receptors, Virus / metabolism*
  • Recombinant Proteins / metabolism
  • T-Lymphocytes / metabolism*
  • Viral Matrix Proteins / metabolism*


  • Antigens, Viral
  • EBV-associated membrane antigen, Epstein-Barr virus
  • Receptors, Complement 3d
  • Receptors, Virus
  • Recombinant Proteins
  • Viral Matrix Proteins