Differential display analysis of mRNA from human tonsil B lymphocytes and isolation of new EST from activated B lymphocytes

Objective To clone the novel B lymphocyte activation gene. Methods The differential display RT PCR (DDRT PCR) technique was applied to compare mRNA from human tonsil resting and activated B lymphocytes. The differential display cDNA fragments were recovered, reamplified and cloned into pGEM T vectors, then Northern blots were carried out to analyse those fragments. The positive cDNA fragments were sequenced. Results Sixty two differential display cDNA fragments were obtained. Twenty of the 62 cDNA fragments which were mainly or uniquely expressed on activated B lymphocytes were cloned into pGEM T vectors, among which 6 clones were confirmed expressible on activated B cells by Northern blot analysis and named EST XB11, XD11, YA1, ZD11, ZD12 and ZE1 respectively. The sequence analysis had been finished. Four clones (XB11, YA1, ZD11 and ZD12) had high homology with recorded genes and one (XD11) was novel by a computer search against GenBank, EMBL and DDBJ DNA databases. The clone (ZE1) had 95% homology with human T cell secreted chemokine I 309, but they had different transcript. Conclusions Two cDNA fragments (XD11, ZE1) are supposed to be potentially representive of novel B cell activation genes and this research lays a foundation for cloning novel B cell activation genes.