Syntheses and immunological effects of thymic humoral factor-gamma 2 and its Phe7-substituted analogues

Thymic humoral factor-gamma 2 and five analogues modified at position 7 with various phenylalanine derivatives were synthesized by a solid-phase method. The synthetic peptides were tested for their effects on the impaired blastogenic response of phytohaemagglutin-stimulated T-lymphocytes of uraemic patients with infectious diseases. The synthetic thymic humoral factor-gamma 2 enhanced the blastogenic response of T-lymphocytes in the blood of the two patients tested. Of the synthetic peptides, [4-fluoro-Phe7]thymic humoral factor-gamma 2 exhibited the most potent effect.