[The release and absorption of small ribonucleoprotein complexes (alpha RNPs) in cultures of transformed rat fibroblasts and human epidermoid carcinoma]. / Eksport i pogloshchenie malykh ribonukleoproteinovykh kompleksov (al'fa RNP) v kul'turakh transformirovannykh krysinykh fibroblastov i épidermoidnoi kartsinomy cheloveka.

The release of alpha RNPs and their absorbtion by the cells from culture medium were studied. The rat fibroblasts of parental serum-dependent cell line LRec-1, and of selected serum-free cell line LRec-1sf rapidly released and absorbed alpha RNPs. In the latter case, both auto- and heterologous alpha RNPs were seen to penetrate, whereas only autologous alpha RNPs entered LRec-1 cells. Besides, the ability to rapid export and absorbtion of autocrine alpha RNPs was demonstrated for human epidermoid carcinoma cell line A431. Both LRec-1 and LRec-1sf cells expressed mRNAs with homology to ID-like nucleotide sequences, the level of mRNA expression decreasing markedly when serum-dependent LRec-1 cells were grown in serum-free medium.

[The immunomodulating and immunoprotective activity of small ribonucleoprotein complexes (alpha RNPs) from the LRec-1sf cell line]. / Immunomoduliruiushchaia i immunoprotektivnaia aktivnost' malykh ribonukleoproteinovykh kompleksov (al'fa RNP) iz kletok linii LRec-1sf.

Effect of nuclear and released into culture medium alpha RNPs (N- and R-alpha-RNPs, resp.) produced by transformed rat embryo fibroblasts of serum-free cell line LRec-1sf on the nonsensibilized mouse splenocyte cytotoxicity (NK-mediated cell lysis) was studied. A preliminary treatment with N-alpha-RNPs resulted in decreasing K562 cell sensitivity to splenocyte cytotoxicity, whereas pretreatment of the splenocytes themselves exerted no cytotoxic effect. The target cell preincubation with R-alpha-RNPs had no influence on K562 cell resistance to NK cell cytotoxicity. The identical splenocyte preincubation was without action on their cytotoxic effect to LRec-1sf cells, however, resulted in an increase of the K562 cell lysis. The addition of R-alpha-RNPs into splenocyte/target cell mixtures had no influence on NK-mediated lysis, when K562 cells were used as a target cell line, but suppressed the NK-mediated lysis of LRec-1sf cells. The results of the present experiments suggest that alpha RNPs produced by LRec-1sf cell line exhibit the capacity for modulating both mouse NK cytotoxicity, and the transformed cell sensitivity to NK-mediated lysis.