The Suppressed Induction of Human Mature Cytotoxic T Lymphocytes Caused by Asbestos Is Not due to Interleukin-2 Insufficiency

• Published in: Journal of immunology research 2016-01, Vol.2016 (2016), p.1-10
• Main Authors: Otsuki, Takemi, Yoshitome, Kei, Lee, Suni, Matsuzaki, Hidenori, Nishimura, Yasumitsu, Kumagai-Takei, Naoko, Hayashi, Hiroaki
• Format: Article
• Language: English
• Subjects: Asbestos; Asbestos - adverse effects; Biomarkers; Carcinogens; CD8-Positive T-Lymphocytes - cytology; CD8-Positive T-Lymphocytes - immunology; CD8-Positive T-Lymphocytes - metabolism; Cell Differentiation - drug effects; Cell Differentiation - immunology; Cell division; Cytokines; Cytotoxicity; Cytotoxicity, Immunologic; Grants; Granzymes - metabolism; Humans; Hypersensitivity - immunology; Hypersensitivity - metabolism; Immunology; Immunosuppression; Interleukin-2 - metabolism; Interleukin-2 - pharmacology; Leukocytes, Mononuclear - immunology; Leukocytes, Mononuclear - metabolism; Lymphocyte Activation - drug effects; Lymphocyte Activation - immunology; Lymphocyte Culture Test, Mixed; Lymphocytes; Medical schools; Mesothelioma; Occupational health; Signal transduction; Studies; T-Lymphocytes, Cytotoxic - cytology; T-Lymphocytes, Cytotoxic - immunology; T-Lymphocytes, Cytotoxic - metabolism
• ISSN: 2314-8861; 2314-7156
• DOI: 10.1155/2016/7484872

We previously reported that exposure to chrysotile B (CB) asbestos suppressed the induction of mature cytotoxic T lymphocytes (CTLs) during mixed lymphocyte reaction assays (MLRs) with a decrease in the proliferation of immature CTLs. However, the mechanism responsible for the effect of asbestos fibers on the differentiation of CTLs remains unclear. Since interleukin-2 (IL-2) is a regulator of T lymphocyte proliferation, we examined the effect of IL-2 addition on suppressed CTL differentiation in CB-exposed cultures using flow cytometry (FCM). When IL-2 was added at 1 ng/mL on the second day of MLRs, the asbestos-caused decreases in the proliferation and percentages of CD25+ and CD45RO+ cells in CD8+ lymphocytes were not recovered by IL-2 addition, although the decrease in percentage of granzyme B+ cells was partially recovered. CD8+ lymphocytes from the IL-2-treated culture with asbestos showed the same degree of cytotoxicity as those in cultures without IL-2 or asbestos. These findings indicate that IL-2 insufficiency is not the main cause for the suppressed induction of CTLs by asbestos exposure, although they suggest a potential for the improvement of such suppressed CTL functions. Secretory factors other than IL-2 in addition to membrane-bound stimulatory molecules may play a role in asbestos-caused suppressed CTL differentiation.