Analysis of HLA-G gene expression in B-lymphocytes from chronic lymphocytic leukemia patients.

BACKGROUND The human leukocyte antigen G (HLA-G) molecule exhibits limited tissue distribution, low polymorphism and alternative splicings that generate seven HLA-G isoforms. HLA-G exerts multiple immunoregulatory functions. Recent studies indicate an ectopic up-regulation in tumor cells that may favor their escape from anti-tumor immune responses. This study it is an effort to clarify the presence of HLA-G in B-cell chronic lymphocytic leukemia (B-CLL) patients. METHODS HLA-G mRNA expression was studied in a pilot study in circulating B-CLL and also healthy controls by reverse transcription (RT)-PCR using a set of pan-HLA-G primers. RESULTS RT-PCR was performed on B-cells from 74 B-CLL patients and 12 healthy controls. The data showed HLA-G gene expression in 20% of the B-CLL patients. No expression of HLA-G could be detected in the healthy control group. CONCLUSION These data suggest that HLA-G is expressed at the gene level in B cells from B-CLL patients but not in B cells from healthy controls. Further study is required to clarify the role of HLA-G as a regulatory factor that could affect immune response in B-CLL patients.