Positive selection of activated T cells of the T8 (CD8) sub‐type by immunomagnetic separation

By conjugating a monoclonal IgM antibody of CD8-specificity to magnetite-containing polymer particles, we have developed a rapid and simple one-step procedure for positive selection of T8 cells. The method ensured good yield and viability of pure T8 cells. The positively selected T8-fraction from MLC activated T cells retained their cytolytic capacity and gave a moderate proliferative response. Most of the proliferative response occurred in the negatively selected T4 population which showed only a marginal cytotoxic activity against PHA blasts as target cells. Transferrin receptor expression, as measured in a direct radiobinding assay, could also be demonstrated both among pure T4 and T8 cells upon MLC-activation.