Method for analysing immunodeficiency virus (HIV) phenotypic characteristics

Method for analysing a phenotypic characteristic of HIV viruses present in a biological specimen from a patient, said phenotypic characteristic resulting from one or more mutations of the viral genome liable to influence the viral infection, characterised in that it comprises:

• a) the extraction of the nucleic acids contained in said biological specimen,
• b) at least one PCR amplification of a segment of the nucleic acids from step (a), each with a pair of primers bordering a nucleic acid sequence of the viral genome liable to comprise at least one mutation,
• c) the preparation of a vector comprising the parts of an HIV virus genome required for viral replication except for the segment amplified in step (b) and, if applicable, except for the gene coding for envelope protein.
• d) the transfection of a first cell host with:
• the nucleic acids contained in step (b),
• the vector prepared in step (c),
• if applicable, a second vector comprising a gene coding for an envelope protein if the envelope gene is deleted from the vector prepared in step (c),
• to obtain a chimeric virus by homologous recombination,
• e) the culture of said first cell host under conditions enabling the production of viral particles during a single replication cycle,
• f) the infection by the viral particles obtained in step (e) of at least one second cell host liable to be infected by an HIV virus or an HIV pseudotype virus and comprising, if applicable, a marker gene that can only be activated following viral infection,
• g) the detection and/or quantification of the marker expressed in step (f) in order to detect at least one characteristic of the HIV viruses present in the biological specimen.