ANALISIS SEKUEN GEN laten membrane protein 2A (1m 2A) Epstein-Barr Virus BAGIAN EPITOP Cytotoxic T Lymphocyte (CTL) PADA KARS1NOMA NASOFARING (ANALYSIS OF A GENE SEQUENCE OF latent membrane protein

ABSTRACT Epstein-Barr Virus (EBV) is one of the etiological agents for Nasopharyngeal Carcinoma (NPC). The incidence rate of NPC at Sardjito Hospital Yogyakarta seems to increase yearly. EBV effects B lymphocyte leading to lymphoblastoid Cell Line (LCL) in vitro, and it express several antigensone of them is known as a Latent Membrane Protein 2A (LMP 2A). LMP 2A is potential target of CTL that controls immune response in NPC. CTL plays an important role in selluier immune reponse by recognizing an epitope-HLA class I complex expressed on target cell surface. Evade immune response by the virus causes persistent infection to the host. This evade immune response is due to alteration of amino acid sequence at certain epitope recognized by CTL. Previous data on HLA typing of both NPC patients and healthy controls showed a possession of HLA-A2, HLA-A11 and HLA-A24. The study was aimed at investigating the LMP 2A gene of EBV at CTL epitope that restricted HLA-A24 (TYGPVFMCL epitope) of NPC. Step of studies were preparing LCL, isolation -of DNA, LMP 2A gene amplification related to HLA-A24- restricted CTL epitope followed by sequencing prosedure. 1. Fakultas Kedokteran Universitas Airlangga Surabaya. 2. Fakultas Kedokteran Universitas Gadjah Mada Yogyakarta. Five samples showed nucleotide changes of LMP 2A gene at CTL epitopes compared to Prototype (B 95.8). Four sample showed nucleotide change, namely G to C encoding amino acid cystein to serine at 8 position of TYGPVFMCL epitope. One of 5 EBV isolates showed nucleotide change from A to G, T to C, and TC to CG encoding amino acid methionin to valin, cystein to serine and leusin to prolin at 7,8,9 position of TYGPVFMCL epitope, respectively. Keyworlds: Nasopharyngeal Carcinoma,Epstein-Barr Virus,Imp 2A, CTL epitope