title: Differential roles of T-cell subsets in regulation of ultraviolet radiation induced cutaneous photocarcinogenesis.
abstract: Ultraviolet (UV) radiation, in particular the midwavelength range (UVB; 290-320 nm), is one of the most significant risk factors for the development of nonmelanoma skin cancer. UVB radiation-induced immunosuppression, which occurs in both humans and laboratory animals, contributes to their pathogenesis. However, there are conflicting reports on the relative role of CD4(+) and CD8(+) T cells in UVB induced skin cancer. The purpose of this study was to delineate the contribution of these two cell subpopulations to UVB induced immunosuppression and tumor development using C3H/HeN (WT), CD4 knockout (CD4(-/-) ) and CD8 knockout (CD8(-/-) ) mice. We observed that UVB induced skin carcinogenesis was retarded in terms of number of tumors per group, tumor volume and percentage of mice with tumors, in mice deficient in CD4(+) T cells compared with wild-type mice, whereas significantly greater (P < 0.05) numbers of tumors occurred in CD8(-/-) mice. These results indicate that, CD4(+) T cells promote tumor development while CD8(+) T cells have the opposite effect. Further, we found that CD4(+) T cells from tumor-bearing mice produced interleukin (IL)-4, IL-10, and IL-17 whereas CD8(+) T cells produced interferon-γ. Manipulation of T-cell subpopulations that are induced by UVB radiation could be a means of preventing skin cancers caused by this agent.
authors.affiliation: Department of Dermatology and Skin Diseases Research Center, University of Alabama, Birmingham, AL, USA.
authors.forename: Tahseen H
authors.initials: TH
authors.lastname: Nasti
authors.forename: Omer
authors.initials: O
authors.lastname: Iqbal
authors.forename: Iman A
authors.initials: IA
authors.lastname: Tamimi
authors.forename: James T
authors.initials: JT
authors.lastname: Geise
authors.forename: Santosh K
authors.initials: SK
authors.lastname: Katiyar
authors.forename: Nabiha
authors.initials: N
authors.lastname: Yusuf
mesh_terms: D000818:Animals; D005260:Female; D051379:Mice; D012878:Skin Neoplasms / Q000139:chemically induced* / Q000503:physiopathology; D016176:T-Lymphocyte Subsets / Q000378:metabolism* / Q000528:radiation effects*; D014466:Ultraviolet Rays / Q000009:adverse effects*