Ultraviolet radiation induces differential calcium signals in human peripheral blood lymphocyte subsets.
Ultraviolet (UV) irradiation is known to suppress normal lymphocyte function, which allows UV phototherapy for a variety of applications. Although UV radiation is well known to cause DNA damage, recent findings indicate that UV irradiation can activate cellular signal-transduction processes. We have previously found that UV induces tyrosine phosphorylation in lymphocytes in a dose- and wavelength-dependent manner and also induces Ca2+ signals in Jurkat T cells via tyrosine phosphorylation of PLC gamma 1 and associated proteins. In this study, normal human lymphocyte subsets were examined for UV-induced Ca2+ responses. CD4+ and CD8+ T cells gave strong responses, whereas other cells did not. Although B cells did not have substantial Ca2+ signals, the pattern of UV-induced tyrosine phosphorylation was very similar to that observed after surface immunoglobulin cross-linking. We propose that the inhibitory effect of UV on lymphocyte function may be due in part to an active induction of tyrosine phosphorylation and Ca2+ signals by a process that bypasses normal receptor control.
Schieven
G L
GL
Bristol-Myers Squibb Pharmaceutical Research Institute, Seattle, Washington 98121.
Ledbetter
J A
JA
D015496:CD4-Positive T-Lymphocytes / Q000528:radiation effects; D002118:Calcium / Q000502:physiology*; D006801:Humans; D008213:Lymphocyte Activation; D016131:Lymphocyte Subsets / Q000528:radiation effects*; D010766:Phosphorylation; D015398:Signal Transduction / Q000528:radiation effects*; D050378:T-Lymphocytes, Regulatory / Q000528:radiation effects; D014443:Tyrosine / Q000097:blood / Q000528:radiation effects*; D014466:Ultraviolet Rays
D014443:Tyrosine; D002118:Calcium