More than 90 percent of all adults are carriers of the oncogenic Epstein-Barr Virus (EBV). Primary infection with this herpes virus as a young child is generally not linked to any symptoms, and usually offers life-long protection from its cancer-causing effect. However, for people who do not become infected with the virus until adolescence, the infection often leads to infectious mononucleosis (commonly known as glandular fever). Our immune systems can generally fend off this disease after a period of between one and several months. However, there is an increased risk of developing Hodgkin lymphoma at a later stage, a cancerous tumor of the lymphatic system. Immunologists from the University of Zurich have now discovered a risk factor that is in part responsible for the outbreak of infectious mononucleosis in young people.
Young natural killer cells combat primary infection
The researchers used an animal model to show that the loss of innate immune control by young natural killer cells can lead to infectious mononucleosis. "Young natural killer cells, which small children in particular have in abundance, seem to be especially suited to killing off the cells that multiply EBV", according to Christian M-nz, Professor of Experimental Immunology at the University of Zurich. "This weakens the primary infection and infectious mononucleosis does not break out".