Related Experiment Videos
Down regulation of Qa gene expression on drug-modified tumor cells
E Leroy1, D Lattuada, C Casnici
1Department of Pharmacology, School of Medicine, University of Milan, Italy.
Background:
Mouse leukemia, L1210, strongly enhances its immunogenicity following in vivo treatment with 5-(3-3'-dimethyl-1-triazeno) imidazole-4-carboxamide (DTIC). Previous experiments have shown that transformed cells elicit a cell-mediated response accountable for rejection and resistance to a subsequent injection of parental tumor into a syngeneic host. L1210 expresses classical H-2 class I molecules, and since it has been shown that DTIC treatment does not modify the expression of these molecules, this is a suitable model to study nonclassical class I antigens, such as Qa2 glycoproteins, and their potential role in tumorigenicity.
Methods:
Cloned cells from L1210 were treated with DTIC and then H-2D, and Qa antigen expression was studied on four clones, before and after xenogenization with DTIC.
Results And Conclusions:
a strong decrease of Qa2 molecule expression was demonstrated by radioimmunoassay and immunofluorescent staining and was confirmed by FACS and 2D-gel analysis. The presence or the absence of Qa antigens on tumor cells could thus be involved in tolerance or rejection of tumor cells in syngeneic animals.
Insights
Treatment with 5-(3-3'-dimethyl-1-triazeno) imidazole-4-carboxamide (DTIC) decreases Qa2 molecule expression on L1210 mouse leukemia cells. This finding suggests Qa antigens may influence tumor cell tolerance or rejection in syngeneic hosts.
Area of Science:
- Immunology
- Oncology
- Molecular Biology
Background:
- Mouse leukemia L1210 enhances immunogenicity after in vivo 5-(3-3 -dimethyl-1-triazeno) imidazole-4-carboxamide (DTIC) treatment.
- Transformed cells can elicit a cell-mediated response leading to rejection and resistance against subsequent tumor cell injection.
- L1210 cells express H-2 class I molecules, and DTIC treatment does not alter their expression, making it a suitable model for studying nonclassical class I antigens like Qa2 glycoproteins.
Purpose of the Study:
- To investigate the role of nonclassical class I antigens, specifically Qa2 glycoproteins, in tumorigenicity.
- To determine the effect of DTIC treatment on Qa antigen expression in L1210 leukemia cells.
Main Methods:
- Cloned L1210 cells were treated with DTIC.
- Expression of H-2D and Qa antigens was analyzed on four clones before and after xenogenization with DTIC.
- Techniques included radioimmunoassay, immunofluorescent staining, FACS, and 2D-gel electrophoresis.
Main Results:
- A significant decrease in Qa2 molecule expression was observed after DTIC treatment.
- This reduction was confirmed by multiple analytical methods including FACS and 2D-gel analysis.
Conclusions:
- DTIC treatment leads to a substantial decrease in Qa2 molecule expression on L1210 cells.
- The presence or absence of Qa antigens on tumor cells may play a role in the development of tolerance or rejection in syngeneic animals.