Autocrine growth of human B lymphocytes: maintained response to autostimulatory factors is the special feature of immortalization by Epstein-Barr virus--a hypothesis

Use of allele-specific FAIRE to determine functional regulatory polymorphism using large-scale genotyping arrays

Following the widespread use of genome-wide association studies (GWAS), focus is turning towards identification of causal variants rather than simply genetic markers of diseases and traits. As a step towards a high-throughput method to identify genome-wide, non-coding, functional regulatory variants, we describe the technique of allele-specific FAIRE, utilising large-scale genotyping technology (FAIRE-gen) to determine allelic effects on chromatin accessibility and regulatory potential. FAIRE-gen was explored using lymphoblastoid cells and the 50,000 SNP Illumina CVD BeadChip. The technique identified an allele-specific regulatory polymorphism within NR1H3 (coding for LXR-α), rs7120118, coinciding with a previously GWAS-identified SNP for HDL-C levels. This finding was confirmed using FAIRE-gen with the 200,000 SNP Illumina Metabochip and verified with the established method of TaqMan allelic discrimination. Examination of this SNP in two prospective Caucasian cohorts comprising 15,000 individuals confirmed the association with HDL-C levels (combined beta = 0.016; p = 0.0006), and analysis of gene expression identified an allelic association with LXR-α expression in heart tissue. Using increasingly comprehensive genotyping chips and distinct tissues for examination, FAIRE-gen has the potential to aid the identification of many causal SNPs associated with disease from GWAS.

Increased spontaneous secretion of IL-6 from B cells of patients with B chronic lymphatic leukaemia (B-CLL) and autoimmunity

We studied B cells from 18 patients with B-CLL, six of them with autoimmune haemolytic anaemia, for spontaneous secretion of IL-6. Our aim was to determine whether the increased incidence of autoimmune disease found in B-CLL patients is associated with enhanced spontaneous IL-6 secretion. IL-6 was measured by the effect of B cell supernatants on the proliferation of an IL-6 dependent plasmacytoma cell line T1165. The highest IL-6 values (7.4 +/- 1.8 U/ml) were measured in supernatants derived on day 3 of culture from lymphocytes of the six patients with B-CLL and concomitant autoimmune disease. The maximal IL-6 values for 10 patients with B-CLL only were 2.8 +/- 0.3 U/ml and for 10 age-matched controls, 0.8 +/- 0.3 U/ml (P less than 0.01, each group compared with the other). We conclude that there is an association between B-CLL, autoimmune disease and the spontaneous in vitro secretion of IL-6. Further studies are needed to determine whether the IL-6 secretion plays a role in the pathogenesis of autoimmune disease in patients with B-CLL.