Synthesis and immunological effect of thymic humoral factor-gamma-2 analogues.

Nine analogues of thymic humoral factor (THF)-gamma-2 were prepared by the solid-phase method, and their in vitro restoring effect on the impaired blastogenic response of phytohemagglutinin(PHA)-stimulated T-lymphocytes of uremic patients with infectious diseases were examined. The results were as follows: [Arg6]-THF-gamma-2 exhibited higher restoring activity than that of our synthetic THF-gamma-2. [Sar4]-, [Val1]-, [Arg3]-, [Gly5]-, and [Asn3]-THF-gamma-2 were also active but less potent than that of our synthetic THF-gamma-2. Three other peptides, [beta-Ala4]-, [Arg2]-, and [Gln2]-THF-gamma-2, did not show any restoring activity on the impaired blastogenic response of uremic patients with infectious disease.