Abstract
Dialyzable leukocyte extracts (DLE) have been shown to contain Transfer Factor (TF), which is able to transfer DTH (delayed-type hypersensitivity) activity from a positive donor to a negative recipient with antigen specificity. DLE have been used for the treatment of patients with various types of immunodeficiencies. Many reports on DLE have dealt with not only transfer activity but also other biological activities, and therapeutic effectiveness of DLE is regarded as the integration of those activities.
DLE are produced from human leukocyte lysate and in some cases the lysate is treated with DNase. Japanese Red Cross Blood Center has been supplying RCTF-1 as DLE which has been produced from DNase treated lysate. It had been reported that DLE from DNase treated Iysate (DNase (+) • DLE) and from DNase non-treated lysate (DNase (-) •DLE) both have the same ability of DTH transfer. In many foreign countries DNase(-) •DLE have been adopted for clinical use. Therefor, we studied the effects of DNase (-) and DNase (-) •DLE for human leukocyte blastformation and IgG production in vitro.
DNase (+) •DLE decreased PHA stimulated lymphocyte blastformation and IgG production, but DNase(-) •DLE did not. These inhibitory activities were resistant to promase treatment, and partially purified fraction of DEAE-Sephacel chromatography showed similar UV (ultraviolet) adsorpted patterns to nucleotide's. On the other hand, DNase (-) •DLE did not show a similar UV spectram pattern. Accordingly, it is possible that these inhibitors were unspecified oligonucleotides, appearing from the step of DNase treatment of lysate.
Improvement by DLE therapy has been reported for a variety of diseases, regardless of whether DNase (+) •DLE or DNase (-) •DLE were used. They are almost similar in clinical effectiveness. Thus, the inhibitory activities of DNase (+) •DLE in vitro, shown in this report, may be irrelevant to the activity in vivo. So, it seems to be better to use DNase (-) •DLE for studying DLE function in vitro.
