HUMAN PATHOGENIC MYCOPLASMA SPECIES INDUCED CYTOKINE GENE-EXPRESSION IN EPSTEIN-BARR-VIRUS (EBV)-POSITIVE LYMPHOBLASTOID CELL-LINES

We addressed the question whether the in vitro interaction of two Epst ein-Barr virus (EBV)-genome-positive B cell lines (EB-3 and HilB-gamma ) with either Mycoplasma pneumoniae or M. hominis, with the 'AIDS-rela ted' mycoplasma species (M. fermentans, M. fermentans subsp. incognitu s, M. penetrans, M. genitalium) or with mycoplasma species known to be mere commensals of the respiratory tract (M. orale and M. salivarium) would result in expression of mRNAs for IL-2, IL-2R, IL-4 and IL-6 as determined by reverse transcriptase (RT)-PCR after 4 and 24 h of cocu ltivation. The pattern of cytokine gene expression observed depended o n (i) the origin of the transformed cell line, (ii) the pathogenicity of the Mycoplasma species, and (iii) the length of cocultivation. The EBV-immortalized lymphoblastoid cell line HilB-gamma showed mRNA expre ssion for IL-2, IL-2-receptor, IL-4 and IL-6 peaking 24 h after stimul ation with M. pneumoniae and all AIDS-related mycoplasma species teste d. The Burkitt lymphoma cell line EB-3 showed a distinct and isolated strong II-2/IL-2 R-mRNA expression within 4h after contact with the pa thogenic and all of the AIDS related mycoplasma species. In neither EB V-containing cell line cytokine was gene expression detectable after s timulation with the commensal mycoplasma species, M. orale and M. sali varium, indicating species differences in the ability of mycoplasmas t o interact with and stimulate B-cell lines. Our data suggest that some mycoplasma species may act as immunomodulatory cofactors by eliciting inappropriate cytokine gene expression in B cells latently infected w ith EBV. Therefore this cultivation model may prove useful in evaluati ng the pathogenetic potential of novel isolated mycoplasma species. (C ) 1998 Academic Press Limited.