Distinct and non-cross-reactive epitopes are recognized on B16 melanoma by LAK cells and anti-B16 monoclonal antibodies.

摘要: Two rat anti-B16 melanoma monoclonal antibodies (MoAb), designated IB16-6 and IB16-8, recognize an epitope expressed with high density on the surface of B16 parental cells B16-F1, F10, F10FLR, BL6 sublines. The purpose this study was to define by means cytolytic clonogenic assays whether these MoAbs reacted same or distinct determinants as those recognized targets lymphokine-activated killer (LAK) cells. Using 125I-labeled antibody Scatchard analysis, affinity constant (KA) determined range from 5.6 9.4 x 10(8) liter/M number receptor sites per cell 4.8 10(4) 2.5 10(5). effects MoAb LAK activity were either preincubating 51Cr-labeled target varying concentrations MoAb, followed assay, exposing unlabeled then carrying out a 10-day assay. Over wide concentrations, IB16-8 had minimal activity, even at up 1 mg there no changes in sensitivity colony-forming ability. Enzymatic treatment trypsin pronase completely removed but did not alter These observations indicate that recognition unit reactive determinant(s) is resistant proteolytic enzymes. molecular structure each remains be determined.