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gp140, the C3d receptor of human B lymphocytes, is also the Epstein-Barr virus receptor
Abstract:
The relationship between gp140, the membrane C3d receptor (CR2) of human B lymphocytes, and the Epstein-Barr virus receptor (EBVR) was analyzed by using the polyclonal anti-gp140, previously prepared by immunizing rabbits with highly purified gp140 (isolated by some of us) from CR2/EBVR-positive Raji cells. Polyclonal anti-gp72, a C3-binding membrane component, not related to the EBVR but also expressed on the Raji cell surface, was used as a control. Binding of rabbit IgG and EBV on cells was assessed by using immunofluorescence techniques with analysis by flow cytofluorometry. A semiquantitative bioassay was also used to measure the EBV binding. Polyclonal monospecific anti-gp140 IgG inhibits directly the binding of EBV to Raji cells at the same concentration that inhibits the binding of EC3d on cells, whereas a 35 times higher concentration of anti-gp72 IgG or preimmune serum IgG does not. Anti-gp140 IgG treatment also inhibits the induction of EBV-determined nuclear antigen in normal tonsil B lymphocytes or in EBV-negative Ramos cells, whereas high concentrations of anti-gp72 IgG or preimmune serum IgG have no effect. These data strongly suggest that gp140, the CR2 of human B lymphocytes, is also the EBVR.
Insights
The study identifies gp140, the C3d receptor (CR2) on human B lymphocytes, as the Epstein-Barr virus receptor (EBVR). This finding reveals gp140
Area of Science:
- Immunology
- Virology
- Cell Biology
Background:
- The Epstein-Barr virus (EBV) receptor (EBVR) on human B lymphocytes is crucial for viral entry.
- gp140 is a known membrane protein on B lymphocytes, identified as the C3d receptor (CR2).
- The precise identity of EBVR has been a subject of investigation.
Purpose of the Study:
- To investigate the relationship between gp140 (CR2) and the Epstein-Barr virus receptor (EBVR).
- To determine if gp140 functions as the EBV receptor on human B lymphocytes.
Main Methods:
- Utilized polyclonal anti-gp140 IgG and anti-gp72 IgG antibodies.
- Assessed binding of EBV and C3d to Raji cells using immunofluorescence and flow cytofluorometry.
- Measured EBV binding via a semiquantitative bioassay.
- Evaluated the inhibition of EBV-determined nuclear antigen induction in lymphocytes.
Main Results:
- Polyclonal anti-gp140 IgG directly inhibited both EBV and C3d binding to Raji cells at equivalent concentrations.
- Anti-gp72 IgG and preimmune serum IgG did not inhibit EBV binding, even at 35 times higher concentrations.
- Anti-gp140 IgG treatment inhibited EBV-induced nuclear antigen formation in lymphocytes, while anti-gp72 IgG did not.
Conclusions:
- gp140, the C3d receptor (CR2) of human B lymphocytes, is also the Epstein-Barr virus receptor (EBVR).
- These findings establish a direct role for gp140 in EBV binding and subsequent cellular events.