Restoration of delayed hypersensitivity to sheep erythrocytes by thymosin treatment of T-cell-depleted mice.
Calf thymosin was injected subcutaneously in daily doses of 0.1 to 3 mg for 12 to 15 days into adult thymectomized, irradiated, bone marrow-reconstituted (THXB) mice. Thymosin partially restored the ability of the T-cell-depleted host to develop delayed-type hypersensitivity to sheep erythrocytes. The degree of restoration varied from 50 to 75% of control values. Thymosin treatment of normal mice potentiated the footpad responsiveness to sheep erythrocytes by as much as 50% over that of untreated controls. The optimum dosage of thymosin seemed to be in the 200- to 500-mug range, and multiple injections were essential for a significant response. Tweleve daily injections of 100 to 500 mug of thymosin restored T-cell reactivity to the THXB mouse, but the responsiveness decayed relatively rapidly once the treatment was stopped. The restoration of immune responsiveness to sheep erythrocytes in T-cell-depleted mice provides a convenient means of demonstrating activity in thymosin preparations in vivo.
D000818:Animals; D004912:Erythrocytes / Q000276:immunology*; D005528:Foot / Q000276:immunology; D006614:Hindlimb / Q000276:immunology; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D011828:Radiation Chimera; D012756:Sheep; D013601:T-Lymphocytes / Q000276:immunology*; D013934:Thymectomy; D013947:Thymosin / Q000494:pharmacology*; D013949:Thymus Extracts / Q000494:pharmacology*; D013997:Time Factors
D013949:Thymus Extracts; D013947:Thymosin