Abstract: The invention concerns an isolated animal cell comprising at least a transgene including at least a nucleotide sequence coding for at least a human polypeptide involved in the recognition and/or antigenic activation by T cells. The invention is characterised in that said cell, or a progeny of said cell, expresses at least all or part of the or said human polypeptide(s), and the homologous endogenous animal gene coding for an animal polypeptide homologous with said human peptide is invalid. The invention also concerns the corresponding transgenic animal. The cell and the transgenic animal of the invention can be used in a method for screening compounds which modulate an immune response in humans. The invention further concerns the use of the inventive cell as cell rendered autologous or tolerated by the immune system.

Abstract: The invention concerns an isolated animal cell comprising at least a transgene including at least a nucleotide sequence coding for at least a human polypeptide involved in the recognition and/or antigenic activation by T cells. The invention is characterised in that said cell, or a progeny of said cell, expresses at least all or part of the or said human polypeptide(s), and the homologous endogenous animal gene coding for an animal polypeptide homologous with said human peptide is invalid. The invention also concerns the corresponding transgenic animal. The cell and the transgenic animal of the invention can be used in a method for screening compounds which modulate an immune response in humans. The invention further concerns the use of the inventive cell as cell rendered autologous or tolerated by the immune system.

Abstract: The invention relates to a transgenic non-human animal cell characterized in that it expresses at least one nucleotide sequence coding for at least one of the chains of human receptors of the fragment Fc of IgE immunoglobulins (Fc&egr;R)) and a nucleotide sequence coding fo a human origin, characterized in that the murine gene coding for the chain Fc&egr;)R) of the human receptor is inactive. The invention also relates to a corresponding transgenic animal and a method for understanding physiopathological elements involved in immediate hypersensitivity and/or inflammatory mechanisms. The invention further relates to a method for screening active compounds on interactions between human IgE's and the receptors thereof.

Abstract: The invention relates to a transgenic non-human animal cell expressing at least one transgene coding for at least one reporter protein, characterized in that the expression of said reporter protein is correlated to the expression of at least one protein which is naturally produced by said cell and which is specific for a type of polarization of the immune response and/or an effector function of the immune response. The invention also relates to a corresponding transgenic animal. According to the invention, the cell and the transgenic animal can be used in a method for characterizing the type of immune response, i.e. Th1 and Th2, caused by an immunogene, a pathogen or chemical agent.

Abstract: The invention concerns any lipopeptide characterized in that it comprises: a peptide part comprising the peptide sequence consisting of about 30 to about 50 of the last contiguous amino acids of the interferon-&ggr; (IFN-&ggr;) C-terminal end of mammals, whereof, if required, the last 3 to 20 amino acids have been suppressed; and one or several lipophilic parts comprising C4-C20 chain of carbon atoms, saturated or unsaturated, linear or branched, or a steroid group. The invention also concerns any lipopeptide such as defined above containing one or several CD8, and/or CD4, and/or B epitopes. The invention further concerns medicines or vaccines containing any polypeptide such as defined above.