CD40 Ligation Downregulates EBNA-2 and LMP-1 Expression in EBV-transformed Lymphoblastoid Cell Lines

Int J Cancer. 2002 Jun 10;99(5):705-12. doi: 10.1002/ijc.10417.

Abstract

Epstein-Barr virus (EBV) drives the proliferation of human B cells in vitro and during primary infection in vivo. The transformed immunoblasts express nuclear proteins EBNA1-6, transcribed from the Cp/Wp promoter, and the membrane proteins LMP-1, -2A and -2B (lymphoblastoid type of latency). EBV persists through life in resting memory B cells with a restricted type of latency in the absence of the Cp/Wp promoter activity. Since CD40 crosslinking can reportedly inhibit the growth of EBV-transformed lymphoblastoid cell lines (LCLs), we have examined the effect of CD40 ligation on the expression of EBNAs and LMP-1 and on Cp EBV promoter activity together with several phenotypic markers. CD40 crosslinking led to a partial downregulation of EBNA-2, EBNA3-6 and LMP-1 in LCLs, paralleled by downregulation of Cp promoter activity. It also induced upregulation of the germinal center marker CD77 on the LCL cells. Our findings suggest that the encounter of proliferating EBV-transformed immunoblasts with CD40L, as would occur when normal B cells generate memory cells in germinal centers, may switch the viral transcription program from the full lymphoblastoid to a more restricted latency program in a proportion of cells. This would permit virus persistence in the B-cell memory compartment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Antigens, CD / analysis
  • B-Lymphocytes / immunology
  • B-Lymphocytes / metabolism*
  • B-Lymphocytes / virology*
  • Blotting, Western
  • CD40 Antigens / metabolism*
  • CD40 Ligand / metabolism
  • CD40 Ligand / pharmacology
  • Carrier Proteins / genetics*
  • Cell Division / drug effects
  • Cell Line
  • Cell Transformation, Viral
  • Cytoskeletal Proteins
  • Epstein-Barr Virus Nuclear Antigens / genetics*
  • Flow Cytometry
  • Fluorescent Antibody Technique
  • Gene Expression Regulation / drug effects
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • LIM Domain Proteins
  • RNA, Messenger / analysis
  • Reverse Transcriptase Polymerase Chain Reaction
  • Viral Proteins

Substances

  • Adaptor Proteins, Signal Transducing
  • Antigens, CD
  • CD40 Antigens
  • Carrier Proteins
  • Cytoskeletal Proteins
  • EBNA-2 protein, Human herpesvirus 4
  • Epstein-Barr Virus Nuclear Antigens
  • Intracellular Signaling Peptides and Proteins
  • LIM Domain Proteins
  • PDLIM7 protein, human
  • RNA, Messenger
  • Viral Proteins
  • CD40 Ligand