Effects of Anti-Retroviral Drugs to Expression of Cell Surface Adhesion Molecules and Hypermutation of Immunoglobulin Heavy Chain Variable Gene of HIV-Related Lymphoma

Abstract

It has been known that non-Hodgkin's lymphomas (NHL) are a major complication in human immunodeficiency virus (HIV) infection, and a major cause of death in HIV infected patients. Recently, it has been reported that highly active anti-retroviral therapy (HAART) declines the incidence of HIV-related lymphoma. In this study, we tried to make in vitro model of HIV-related lymphoma by Epstein-Barr virus transformation, and to examine the cellular and molecular characteristics of the HIV-related lymphoma cells derived from patients with HIV infection. PBMCs from 10 patients HIV infection and 10 HIV-negative normal individuals were obtained by Ficoll-Paque (Amersham Biosciences Corp. NJ) density gradient centrifugation. Lymphoblastoid cell lines (LCL) were obtained from each patient through transformation with Epstein-Barr virus (B95-8). Cells were cultured with RPMI 1640 medium (GIBCO, Grand Island, NY) supplemented with 10% fetal calf serum (FCS) (JRH Bioscences, Inc. Lenexa, Kansas), antibiotics, and L-glutamine and maintained at 37°C in an atmosphere containing 5% CO2. FACS analysis revealed the cells to be CD3−, CD4−, CD8−, CD5−, CD19+, CD20+, HLA-class I+, -class II+. After the establishment of LCLs, to obtain a highly purified population, CD19+LCLs were sorted on a FACS Vantage SE (Becton Dickinson, San Jose, CA). The purity of each CD19+LCLs population evaluated by FACS analysis was always higher than 98%. After growth advantage of LCLs, growth ability of the LCLs from HIV patients was examined by MTT assay. In results, there is no significant difference of growth ability between LCLs derived from HIV patients and those derived from normal individuals. Furthermore, the expression of cell adhesion molecules (CD11a, CD11b, CD18, CD50, and CD54) of LCLs was observed by FACS. The results showed that the expression of CD18 on LCLs derived from HIV patients was enhanced significantly in compared to those of normal LCLs. This phenomenon seems to be consistent with development of primary central nervous system (CNS) lymphoma. Furthermore, effects of anti-retroviral drugs to the expression of the adhesion molecules are examined. Somatic hypermutation of immunoglobulin heavy chain variable gene (IGHV) has been detected over 90% of HIV-related lymphoma. The effects of HAART to hypermuation of IGHV of LCL derived from HIV patients will be addressed.