Abstract: A TH1 specific CD4 T cell line, inducing an efficient CD8 response against an infection caused by an infectious agent, is obtained by removing from a donor a biological sample containing T cells; isolating the CD4+ T cells from said sample; simultaneously providing dendritic cells isolated from the same sample or another sample derived from the same donor, subjecting the previously isolated CD4+ T cells to in vitro immunisation with a peptide of a protein of the infectious agent exhibiting at least a T epitope, in the presence of the previously obtained dendritic cells; performing at least a restimulation, in the same conditions as for immunization, optionally substituting the dendritic cells with B cells from the same donor.