Polyacrylamide gel disc electrophoresis was employed to analyze changes in serum proteins from normal and tumor-bearing hamsters. A hamster-derived A. melanoma No. 3 was implanted in groups of hamsters and the sera analyzed prior to and after metastatic development. Significant changes were observed in several globulin regions with the most dramatic changes occurring in the Α-globulin region.
Human peripheral lymphocytes were stimulated to incorporate tritiated thymidine when cultured with anti-δ. The stimulation of lymphocytes by anti-δ inversely correlates to PHA-induced lymphocyte transformation. In addition, lymphocytes from individuals with low serum IgD levels exhibited a significant response to anti-δ, whereas, those with normal or slightly elevated levels of serum IgD showed minimal stimulation. This study is the first to provide evidence that cell surface IgD may regulate metabolic functions of lymphocytes and is consistent with the idea that IgD is a ‘triggering’ receptor.
Human transfer factor (TF) was fractionated by exclusion chromatography and the fractions were tested for biologic activity in vivo and in vitro. Specific TF activity in vivo was found to reside in the major UV-absorbing peak (Fraction III). Fraction III eluted at 2.7 × V0 and transferred tuberculin, candida, or KLH-reactivity to previously negative recipients. Fraction III from nonreactive donors was ineffective.
When the fractions were tested in vitro, we found that both the mitogenic activity of whole TF and the suppressive activity to mitogen activation when present in TF was found in Fraction I. Fraction III contained components responsible for augmentation of PHA and PWM responses. In addition, Fraction III contained the component responsible for antigen-dependent augmentation of lymphocyte transformation. Fraction IV was suppressive to antigen-induced lymphocyte transformation. These data suggest that TF preparations contain components which can affect immune reactions in both specific and nonspecific ways.
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