Role of Vicia villosa-adherent CD8+ T cells in the immune response to Epstein-Barr virus.
Epstein-Barr virus (EBV) is a lymphotropic human herpesvirus which is also a polyclonal B-cell activator. We show here that Vicia villosa-adherent CD8+ T (VV-T) cells, which have a contrasuppressive activity, play an important role in the B-cell response to EBV and that T-helper cells are not required for antibody production against EBV particles. We have examined this activity by measuring anti-EBV IgM antibody production by B cells in vitro in the presence and the absence of both T-helper and VV-T cells. The presence or absence of T-helper cells did not affect antibody production. Our results suggest that the antigen-presenting activity of VV-T cells was virus specific, while the contrasuppressive activity was not. Control experiments carried out in parallel using human cytomegalovirus (CMV) produced similar results also for CMV-specific IgM production. Taken together, our data lead us to hypothesize that VV-T cells might also play other roles in EBV infections: on the one hand, by presenting EBV to B cells, VV-T cells could contribute to the spread of viral infection of B lymphocytes, as the latter are the exclusive targets for EBV immortalization within the immune system; on the other hand, by inhibiting the effect of T-suppressor cells on T-helper cells, VV-T cells could indirectly help the latter maintain their lymphokine producing activity, especially interleukin-2 and interferon-gamma production, which in turn could directly or indirectly (i.e., by stimulating natural killer and T cells) contribute to control of the EBV infection.
Kundu
S K
SK
Department of Microbiology & Immunology, University of Montreal, Québec, Canada.
Menezes
J
J
D000914:Antibodies, Viral / Q000096:biosynthesis; D001402:B-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D003587:Cytomegalovirus / Q000276:immunology; D004854:Herpesvirus 4, Human / Q000276:immunology*; D006801:Humans; D007075:Immunoglobulin M / Q000096:biosynthesis; D037102:Lectins / Q000502:physiology*; D037121:Plant Lectins; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
D000914:Antibodies, Viral; D007075:Immunoglobulin M; D037102:Lectins; D037121:Plant Lectins; C042242:Vicia lectins