Genetically restricted and unrestricted antigen specific helper factors
Feldmann M., Fischer A., Zanders EJ., Beverley PCL.
Some human antigen specific helper factors (HF) derived from long term human T helper cell lines are genetically restricted in their action. Other human HF's, derived from 4-6 day cultures, are capable of activating mouse spleen cell cultures, and hence are not xenogeneically restricted. While it is possible that these results suggest a heterogeneity of HF, we have also found that some long term lines make both antigen specific HF and non specific factors. In this case the whole supernatant appears unrestricted but specific, suggesting a possible explanation for the variable degree of genetic restriction.