Journal of Medical Virology 84:632–642 (2012) Carboxy-Terminal Sequence Variation of LMP1 Gene in Epstein–Barr-Virus-Associated Mononucleosis and Tumors From Serbian Patients Ana Banko, 1 * Ivana Lazarevic, 1 Maja Cupic, 1 Goran Stevanovic, 2 Ivan Boricic, 3 and Tanja Jovanovic 1 1 Institute of Microbiology and Immunology, Faculty of Medicine, University of Belgrade, Serbia 2 Clinic of Infectious and Tropical Diseases, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Serbia 3 Institute of Pathology, Faculty of Medicine, University of Belgrade, Serbia Seven strains of Epstein–Barr virus (EBV) are defined based on C-terminal sequence varia- tions of the latent membrane protein 1 (LMP1). Some strains, especially those with a 30-bp de- letion, are thought to be related to tumorigenic activity and geographical localization. The aims of the study were to determine the prevalence of different LMP1 strains and to investigate se- quence variation in the C-terminal region of LMP1 in Serbian isolates. This study included 53 EBV-DNA-positive plasma and tissue block samples from patients with mononucleosis syndrome, renal transplantation, and tumors, mostly nasopharyngeal carcinoma. The se- quence of the 506-bp fragment of LMP1 C terminus was used for phylogenetic analyses and identification of LMP1 strains, deletions, and mutations. The majority of isolates were non-deleted (66%), and the rest had 30-bp, rare 69-bp, or yet unknown 27-bp deletions, which were not related to malignant or non-malignant isolate origin. However, the majority of 69-bp deletion isolates were derived from patients with nasopharyngeal carcinoma. Less than five 33-bp repeats were found in the majority of non-deleted isolates (68.6%), whereas most 69-bp deletion isolates (75%) had five or six repeats. Serbian isolates were assigned to four LMP1 strains: B95-8 (32.1%), China 1 (24.5%), North Carolina (NC; 18.9%), and Mediterranean (Med; 24.5%). In NC isolates, three new muta- tions unique for this strain were identified. EBV EBNA2 genotypes 1 and 2 were both found, with dominance of genotype 1 (90.7%). This study demonstrated noticeable geographical- associated characteristics in the LMP1 C terminus of investigated isolates. J. Med. Virol. 84:632–642, 2012. ß 2012 Wiley Periodicals, Inc. KEY WORDS: Epstein–Barr virus (EBV); latent membrane protein 1 (LMP1); LMP1 strain; EBV genotype INTRODUCTION Epstein–Barr virus (EBV) is a highly prevalent hu- man gammaherpesvirus that persistently infects more than 90% of the adult population worldwide. EBV primary infection is usually asymptomatic, although at times it results in the benign lymphoproliferative disease, infectious mononucleosis, especially in later childhood or young adulthood in developing countries [Rickinson and Kieff, 2007]. As a result of its oncogen- ic potential, EBV has been etiologically associated with several human malignancies such as Burkitt’s lymphoma [Anwar et al., 1995], nasopharyngeal carci- noma [Chen et al., 1993], lymphoproliferative disor- ders such as post-transplantation lymphoproliferative disease [Gratama et al., 1991], Hodgkin’s lymphoma [Weiss et al., 1989], nasal NK/T cell lymphoma [Hara- buchi et al., 1990], and gastric adenocarcinoma [Imai et al., 1994]. However, the prevalence of EBV- Grant sponsor: Ministry of Science and Technological Devel- opment, Republic of Serbia; Grant number: 175073. Conflicts of interest: None. The work was performed at Institute of Microbiology and Immunology, Faculty of Medicine, University of Belgrade (Dr Subotica 1, 11000 Belgrade, Serbia) *Correspondence to: Dr. Ana Banko, MD, Institute of Microbiology and Immunology, Faculty of Medicine, University of Belgrade, Dr Subotica 1, 11000 Belgrade, Serbia. E-mail: anadjukic@med.bg.ac.rs Accepted 13 December 2011 DOI 10.1002/jmv.23217 Published online in Wiley Online Library (wileyonlinelibrary.com). ß 2012 WILEY PERIODICALS, INC.