Effects of selected growth factors on lymphocyte stimulation in vitro

The immunological properties of selected growth factors (GF) [insulin-like GF (IGF-I), nerve GF (NGF), epidermal GF (EGF) multiplication stimulating a ctivity (MSA) and pooled human serum] were studied To determine the surface marker of early activation (CD69) of peripheral lymphocytes three-color fl ow cytometry was used after 4-h stimulation by mitogens (phytohemagglutinin , concanavalin A) or monoclonal antibodies (anti-CD3, anti-CD2/CD2R). The h ighest expression of the early activation marker CD69 was recorded after in cubation with MSA (200 ng/ml) and IGF-I (20 ng/ml) (p < 0.01). IGF-I at a c oncentration of I ng/ml had a significant stimulatory effect on the activat ion of CD4+ lymphocytes induced by anti-CD2/CD2R. GFs had no effect on phyt ohemagglutinin, concanavalin A or anti-CD3-induced lymphocyte stimulation a t any of the concentrations tested.