Abstract
By using an ELISA, increased levels of the soluble form (sgp130) of gp130, the IL-6 signal transducer, were detected in the sera of various HTLV-1-associated conditions (HC, ATL, HAM) as compared to normal healthy individuals. Sgp130levels seemed to be correlated with disease severity. The 94KD of sgp130 was specifically precipitated in the sera of HTLV-1-infected patients as revealed by Western blot analysis. A reverse transcriptase (RT)-polymerase chain reaction (PCR) method was used to detect the message for transmembrane (TM) lacking gp130 in mRNA isolated from peripheral blood mononuclear cells (PBMCs) of patients infected with or without HTLV-1 and those of various hematopoietic cell lines. Two PCR products, 648 and 507bp were observed in the PBMCs from HTLV-1-infected patients. But the 507bp PCR product was not detected in the PBMCs from normal healthy individuals and HTLV-1-positive cell lines although the 648bp product was equally expressed. A nucleotide sequence analysis of the 507bp fragment showed deletion of the 141bp at the region spanning from nucleotide 1702 (G) to 1842 (T) of the 648bp product that matched completely with a conventional gp130 molecule. This deleted region was located upstream of the transmembrane (TM) domain, but not within the TM region itself. However, no frame shift was observed. These results indicate that the generation of sgp130 may not be due to an alternative splicing mechanism.
