Frequent expression of the Epstein-Barr virus (EBV)-induced gene, EBI3, an IL-12 p40-related cytokine, in Hodgkin and Reed-Sternberg cells

Epstein-Barr virus (EBV)-associated Hodgkin lymphoma (HL) and nasopharyngeal carcinoma (NPC) usually occur in patients without clinically manifest deficiencies in anti-viral immunity. In spite of expressing viral proteins, both tumours are apparently able to escape EBV-specific immunity in vivo. EB13 is an EBV-induced cytokine homologous to the interleukin (IL)-12 p40 subunit and can heterodimerize with IL-12 p35. It has been suggested that EB13 may function to antagonize IL-12 and to inhibit the development of a Th1 immune response. EB13 expression has been studied in tumour entities frequently associated with EBV infection to examine if EB13 might contribute to local modulation of the immune response. It is shown that EB13 is strongly expressed in Hodgkin and Reed-Sternberg cells in 32 of 33 HL cases, independently of the EBV status of the tumour cells. Furthermore, EB13 expression was detected in the epithelial tumour cells of six of 40 NPC biopsies but not in Burkitt lymphomas. The results suggest that EB13 may be an additional component of the repertoire employed by Hodgkin and Reed-Sternberg cells to inhibit an effective anti-tumour or anti-viral immune response. Copyright (C) 2002 John Wiley Sons, Ltd.