Abstract: Disclosed is a method for producing, in one step, “made to measure” double-stranded DNA vectors from molecular bricks including sequences of interest in the presence of a one and only type IIs restriction enzyme.

Abstract: The present invention relates to the field of preventive or therapeutic anti-tumoral vaccine. More specifically, the present invention relates to live animal tumour cells having a negative MHC-I phenotype, to methods for the production of such MHC-I negative cells, and to their therapeutic use as anti-tumoral agents, particularly via their capacity to activate natural killer (NK) cells. The invention further relates to methods for modulating the level of expression of MHC-I molecules on animal tumour cells, for example by use of specific culture conditions, and/or by use of exogenous agents which directly or indirectly affect levels of MHC-I expression. The invention also concerns activated NK cells and their therapeutic use as anti-tumoral agents.