The effects of interleukin-13 (IL-13) and interleukin-4 (IL-4) on cellular functions were shown to be quite similar. We provide evidence that in monocytes as well as in T lymnhocytes both IL-4 and IL-13 activate the same recentlv identified transcrintion factor NF-IL4 which binds to the specific responsive element IG4RE. In addition, we show that a nuclear factor activated by interferon-y also interacts with the IL-4RE. It differs from NkIL4 in the electrophoretic mobility of the complex with DNA, in its DNA-binding speciticity and in the proteins interacting with the DNA sequence. Sensitivity against various enzyme inhibitors suggests that components of the signal transduction pathway are shared by all three cytokines.

No abstract

Specific expression of the Epstein-Barr virus (EBV) immediate-early and early gene products Zta, Rta, I'ta, and MSta by a recombinant vaccinia virus system allowed us to analyze the first steps in the induction of the lytic cycle in EBV-infected Burkitt lymphoma (BL) cells and lymphoblastoid cell lines (LCLs). Significant differences in the induction of early genes were found between these cell types: whereas in BL cells the trans activator Zta was found to induce key steps of the early lytic cycle, only minor activities of Zta were noted in LCLs. Contrary to Zta, the trans activator Rta was found to be highly effective in LCLs. These observations suggest that Rta may play an important role in the activation of the early lytic cycle in LCLs, although it cannot be activated by Zta. The latter may be a reason for the lower tendency of LCLs to switch into the lytic cycle compared with BL cells or differentiated epithelial cells.

SummaryA method is described for the identification of type A and type B isolates of Epstein-Barr virus (EBV) by means of the polymerase chain reaction. The use of three pairs of primers specific for genomic sequences coding for the two forms of EBV nuclear antigen (EBNA), 2A and 2B, and for a DNA sequence from the BamZ/BamR region allows the reliable and rapid detection of type A and B viruses in as little as 1000 EBV positive cells.Epstein-Barr virus (EBV), type A and B; Epstein-Barr virus nuclear antigen (EBNA) 2A and 2B; Polymerase chain reaction Two types, A and B, of Epstein-Barr virus (EBV) have been identified which show DNA sequence divergence within the BamHI WYH region of the genome. This region encodes for the Epstein-Barr nuclear antigen 2 (EBNA 2) which accordingly exists as two antigenically different alleles, EBNA 2A and EBNA 2B. Recently, Rowe et al. (1989) showed that the distinction between the two types extends beyond the EBNA 2 gene to the EBNA 3 family of proteins. Whereas type B virus was previously found mainly in equatorial Africa (Zimber et al., 1986) recent findings indicate that this type is also widespread in other

No abstract