Cytomegalovirus-infected adherent cells interact synergistically and antagonistically with Staphylococcus aureus protein A in vitro.
Cytomegalovirus (CMV) has been shown to exert suppressive effects on the immune response but also to have mitogenic properties. A bacterial product, protein A from Staphylococcus aureus (SpA) was chosen to study possible interactions in vitro between bacterial products and adherent cells incubated with infectious CMV and ultraviolet light (UV)-inactivated CMV. Small amounts of infectious CMV potentiated SpA-induced DNA synthesis and Ig secretion measured by induction of plaque-forming cells (PFC). The reason for this may be that CMV in small amounts may act in synergism with the non-specific mitogen SpA. UV-inactivated CMV did not influence these responses except for a markedly enhanced PFC induction with SpA in lymphocytes from seronegative individuals. This remarkable synergism with SpA was also seen in enriched B cells. No synergism was seen in lymphocytes from seropositive donors. Large amounts of infectious CMV markedly reduced SpA-induced immune responses. Preliminary data suggest that the immunosuppressive effects are mediated by an interleukin 1 inhibitory factor. CMV was not shown to be a polyclonal B-cell activator but may, possibly in small amounts, act as such together with bacterial products, which would explain certain autoimmune phenomena. To conclude, CMV could in interaction with a bacterial product generate both synergistic and suppressive effects on immune response.
Paulin
T
T
Department of Clinical Immunology, Karolinska Institute, Huddinge Hospital, Stockholm, Sweden.
Ringdén
O
O
Wahren
R
R
D001402:B-Lymphocytes / Q000378:metabolism; D002448:Cell Adhesion; D002472:Cell Transformation, Viral; D003587:Cytomegalovirus / Q000187:drug effects / Q000502:physiology*; D004279:DNA, Viral / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D006462:Hemolytic Plaque Technique; D006801:Humans; D007136:Immunoglobulins / Q000096:biosynthesis; D013205:Staphylococcal Protein A / Q000037:antagonists & inhibitors*; D013601:T-Lymphocytes / Q000378:metabolism
D004279:DNA, Viral; D007136:Immunoglobulins; D013205:Staphylococcal Protein A