DIFFERENTIAL EXPRESSION OF FERRITIN HEAVY-CHAIN IN THP-1 CELLS INFECTED WITH MYCOBACTERIUM-BOVIS BCG

To identify the host genes induced or suppressed by infection of mycob acteria, the reverse transcriptase polymerase chain reaction (RT-PCR) and the differential display reverse transcriptase polymerase chain re action (DD RT-PCR) methods were used. In this study, cDNAs complement to mRNA extracted from human peripheral monocyte derived naive THP-1 c ells, THP-1 cells infected with live Mycobacterium bovis BCG, THP-1 ce lls treated with heat-killed BCG, and THP-1 cells incubated with IgG-c oated glass-beads were compared on the sequencing gel. One (TG2-1) of the clones selected by DD RT-PCR is 446 bp long and is identical to hu man ferritin heavy (H) chain gene. Northern blot analysis confirmed th at ferritin H chain gene has been markedly over-expressed in monocytic THP-1 cells incubated with live and dead M. bovis BCG. Differential d isplay techniques of host genes whose expression levels were varied by infection of mycobacteria could provide information about the respons e of macrophages to mycobacterial infection.