ANTITUMOR IMMUNITY INDUCED BY HYBRID TUMOR-CELLS - COMPARISON BETWEEN HYBRIDS AND THE PARENTAL TUMOR

  • 1 January 1984
    • journal article
    • research article
    • Vol. 44  (2) , 487-492
Abstract
The ability of hybrid tumor cells to induce antitumor immunity was evaluated in the line 1 alveolar cell carcinoma (L1) model of BALB/c mice. Hybrid tumor cells were produced by fusing freshly dissociated L1 cells isolated from in vivo tumors with the hypoxanthine:aminopterin:thymidine-sensitive cell line, GM 347, derived from C3H mice. Each hybrid was characterized by DNA content and expression of H-2 antigens using a fluorescence-activated cell sorter. Irradiated L1 cells in the presence or absence of Corynebacterium parvum [Propionibacterium acnes] were capable of immunizing BALB/c mice against a challenge of live L1 cells, provided the challenge dose was small (50% LD50 was between 6 .times. 104 and 1.2 .times. 105 L1 cells). Testing of 5 hybrid clones and 1 uncloned hybrid line for their immunizing ability demonstrated a range in immunizing ability with none showing a statistically significant improvement in survival when compared to untreated controls. A tumor (labeled L1/A) which grew in 1 mouse immuized with clone MoHb-L1-C2 cells was removed and hybridized with GM 347 to yield a 2nd set of hybrids. Both this variant of L1 cells and a hybrid clone made from it (MoHb-L1A-C18) were capable of immunizing mice against a challenge of live L1/A. However, L1 cells were not able to immunize effectively against L1/A, and MoHb-L1A-C18 did not immunize against L1. This suggests that L1/A is a subpopulation of L1 cells with a different antigenic composition. The limited success of MoHb-L1A-C18 against L1/A, is thought to be due to the narrower range of antigenic specificities in L1/A and the ability of MoHb-L1A-C18 to represent an important antigenic subpopulation of L1/A.