HLA genotyping, non classical HLA-I-G solubile molecules and cytokine production in 28 established human tumour cell lines. Considerations for in vitro biological investigations and human anti-tumour vaccine therapy.

Aim. Human tumour cell lines play an important ròle in basic and applied research. Recently, several celI banks have been created providing mutated phenotypes for the investigation of the biological and genetic bases of disease and for evaluating a potential use in cancer vaccine therapy. In fact celIlines produce factors that could interfere with biological functions so we decided to investigate some of them because they are taken into consideration as candidates for human anticancer vaccination procedures, Our attention was directed to the in vitro studies of cell-mediated mechanisms against tumour-associated antigens (TAA). Materials and methods. We characterized 28 ATee tumour celI lines originated from different organs for the HLA-A,B and DR phenotypes and we investigated the expression of HLA -class I products at the cell membrane. Furthermore, we tested the celliines for their capacity to modulate soluble classical HLA-class I and non-classical HLA-G1IHLA-G5 antigens, recently claimed to be tolerogenie molecuIes, and for the spontaneous production of cytokines. Resulis. The results identified specific HLA genotypes, with a significant increase in single allele detection at the HLA-A,B and DR loci when compared to healthy subjects. Cytofluorimetric analysis detected HLA class I expression at the celi membrane level in alI the celliines investigated. ELISA investigation displayed a polymorphism in the production of soluble classical HLA-class I antigens (17/28), and furthermore a percentage of these celi lines (8/17) showed a contemporary modulation of soluble non-classical HLA-G molecules. Conclusions. These data suggest the modulation of tolerogenic molecules in a large percentage or the investigated celllines. In addition, a spontaneous cytokine production able to interfere with the inflammation response was ohserved. These observations advocate for a careful analysis and characterization of celllines candidates for in vitro or in vivo studies.