Oral presentation | Open | Published:
Anti-tumor antibody profile analysis to harness the potentials of B cells in melanomas and the natural humoral immune response
Journal for ImmunoTherapy of Cancervolume 1, Article number: O4 (2013)
Natural humoral immune response and autoimmune mechanisms have great importance in keeping the balance of tumorimmunity, although it has not yet been fully understood. We aimed to reveal potential anti-tumor immune response by immunoglobulin (Ig) profile analysis of patients with metastatic melanomas.
A complex panel assay has been performed at expressed DNA and protein levels on antibodies originating from patients' peripheral blood (n = 92) or cancerous tissue biopsies (n= 87) (ETT TUKEB 16462- 02/2010). Heavy and light chain immunoglobulin variable gene regions were sequenced and analysed with Vector NTI Advance 11, Bioedit 7.0, ClustalX2.0.11, TreeView 1.6.6 programs using available databases (IMGT, Blast). Patients' sera, purified human Ig preparations and antibody fragments from tumor infiltrating B cells were tested by ELISA, immunofluorescence FACS and confocal laser microscopy.
Cluster analysis revealed specific antibody variable region gene subgroups in the VH3 family, amongst which there are the ones with cancer associated antigen binding capacity. The purified immunoglobulin's strong SK-Mel28 melanoma binding potential paralleled with the clinical outcome. Some selected expressed antibody fragments showed tumor associated antigen labelling on melanoma tissues (Fig. 1). A competitive cell membrane ELISA has been standardized for measuring patients' sera in terms of various cancer associated antigen binding capacity. Data are under evaluation concerning their value to predict anti cancer humoral immune response.
We could prove the extensive presence of highly tumor associated unique GD3 sialilated glycosphingolipid specific antibody variable regions in patients with melanoma. Our novel panel assay confirmed the potentials of antibody profile analysis in characterizing anti tumor humoral immune response and its worth for diagnostics.
The Harrry J. Lloyd Charitable Trust Melanoma Research Foundation Award and previous Fulbright No1206103 and OTKA T048933 Grants are acknowledged.