Selective interferon-induced enhancement of tumor-associated antigens on a spectrum of freshly isolated human adenocarcinoma cells

Freshly isolated cells from patients with pleural or peri-toneal effusions cytologically diagnosed as adenocarcinoma(n = 43), malignant nonepithelial neoplasms (n = 10), and benign (n = 8) were analyzed for expression of constitutive levels of the tumor antigens TAG-72 [recognized by mono-clonal antibody (MAb) B72.3] and carcinoembryonic anti-gen (CEA) (recognized by MAb COL-4) as well as the classI and class II major histocompatibility (MHC) antigens, and the ability of human interferons (Hu-IFNs) to enhance cellsurface expression of those antigens as measured by MAb binding. Both type I and type II IFNs enhanced the expres-sion of TAG-72 and CEA and altered the level of expressionof the MHC antigens. Comparative studies of three differ-ent Hu-IFNs (IFN-αA, IFN.-β_ser, and IFN-λ) revealed that IFN-λ was the most potent in augmenting either B72.3 or COL-4 binding. Unlike the IFN-λ -mediated induction of the class II human leukocyte antigens, the change in tu-mor antigen expression consisted of enhanced constitutiveantigen expression; de novo induction of either TAG-72 orCEA could not be achieved by either type I or type IIIFN. Of 43 effusions isolated from different adenocarcinoma pa-tients, 42 (97.7%) expressed either CEA or TAG-72, and treatment with Hu-IFN increased the level of expression of either antigen in 36 of 42 samples (85.7%). These studies demonstrate the augmentation of tumor-associated antigenson human carcinoma cells isolated from serous effusions by Hu-IFNs which may be used to enhance the targeting of con-jugated MAbs to human carcinoma lesions. [J Natl CancerInst 81:502-512, 1989]