Analysis of differentially regulated mRNAs in peripheral blood monocytes of berylliosis patients after in vitro stimulation.

In berylliosis and other granulomatous diseases the macrophage is regarded as effector cell in granuloma formation. However, little is known about granuloma-associated regulation of genes in these cells. Differential display reverse transcription polymerase chain reaction (DDRT-PCR) is an attractive method for detection of differentially expressed genes. Since DDRT-PCR requires a comparably low quantity of RNA, its application to rare and limited amounts of clinical samples is convenient. In the present study we applied DDRT-PCR in a multiple and complex comparison of expressed sequence tags induced in response to various granuloma-associated and control stimuli. Since we are interested in granuloma-restricted changes, we tested peripheral blood monocytes from berylliosis patients by DDRT-PCR stimulated with up to nine different stimuli, including BeSO4, the causal agent of berylliosis. Comparison of a total of 1663 sequence tags in four berylliosis patients revealed a mean of 32.5-37.4% differentially regulated sequence tags in peripheral blood monocytes of berylliosis patients, caused by stimuli including beryllium or Mycobacterium tuberculosis and control stimuli such as Latex or Zymosan. In 7.7-28.0% of the analyzed sequence tags we detected a differential regulation restricted to the presence of granuloma-associated stimuli BeSO4, HgS, LiCO3, NiSO4, lipopolysaccharide, and/or heat killed M. tuberculosis; 1.4-12.3% were induced by more than one granuloma-associated stimulus. Alterations associated with BeSO4 and one of the named stimuli were detected in 1.4-4.5%. An exclusive association with BeSO4 was found in 2.6-5.7% of the analyzed sequence tags.