The Central Role of Leukotriene B4 in Epstein Barr Virus Activated Innate Immunity In Vitro

Leukotriene B4 (LTB4) is a potent fast acting lipid mediator produced mainly by activated granulocytes and monocytes. Epstein Barr Virus (EBV) is ubiquitous in humans. Primary infection is usually asymptomatic in young children, but in adolescents, who are most often the subjects of the infection, it is followed often by the characteristic syndrome of infectious mononucleosis (IM). We have assessed the contribution of LTB4 to the primary response in EBV infected cord blood leukocyte cultures and found that addition of LTB4 led to inhibition of the EBV induced B lymphocyte proliferation. Some of the symptoms of IM can be regarded as a consequence of the activation of the innate immunity system. Our results indicate that LTB4 may play a pathophysiological role in this process. The overall effect of LTB4 in mononucleosis is hard to predict. The endogenous production of LTB4 in affected IM tissue might be of importance for the host defence but at the same time strengthen the symptoms. Therefore further studies are warranted to elucidate whether LTB4 is involved in the symptomatology of mononucleosis. If so, administration of pharmacological inhibitors of the synthesis or the action of leukotrienes may be beneficial in severe cases.