Systemic immune effects of titanium dioxide nanoparticles after repeated intratracheal instillation in rat.
The potential immune effects of titanium dioxide nanoparticles (nano-TiO₂) are raising concern. Our previous study verified that nano-TiO₂ induce local immune response in lung tissue followed by intratracheal instillation administration. In this study, we aim to evaluate the systemic immune effects of nano-TiO₂. Sprague Dawley rats were treated by intratracheal instillation with nano-TiO₂ at doses of 0.5, 4, and 32 mg/kg body weight, micro-TiO₂ with 32 mg/kg body weight and 0.9% NaCl, respectively. The exposure was conducted twice a week, for four consecutive weeks. Histopathological immune organs from exposed animals showed slight congestion in spleen, generally brown particulate deposition in cervical and axillary lymph node. Furthermore, immune function response was characterized by increased proliferation of T cells and B cells following mitogen stimulation and enhanced natural killer (NK) cell killing activity in spleen, accompanying by increased number of B cells in blood. No significant changes of Th1-type cytokines (IL-2 and INF-γ) and Th2-type cytokines (TNF-α and IL-6) were observed. Intratracheal exposure to nano-TiO₂ may be one of triggers to be responsible for the systemic immune response. Further study is needed to confirm long-lasting lymphocyte responses and the potential mechanisms.
Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, Jiangsu, China. fckxxz@gmail.com.
Yanyun
Y
Fu
Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, Jiangsu, China. zhangyingjian321@gmail.com.
Yanqiu
Y
Zhang
Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing 210009, Jiangsu, China. cxhpublic@gmail.com.
Xuhong
X
Chang
Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, Jiangsu, China. zhangyingjian321@gmail.com.
Yingjian
Y
Zhang
Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, Jiangsu, China. m837862513@gmail.com.
Shumei
S
Ma
Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, Jiangsu, China. sj331622547@gmail.com.
Jing
J
Sui
Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, Jiangsu, China. lhyin@seu.edu.cn.
Lihong
L
Yin
Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, Jiangsu, China. yppu@seu.edu.cn.
Yuepu
Y
Pu
Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, Jiangsu, China. gyliang@seu.edu.cn.
Geyu
G
Liang
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D007322:Instillation, Drug; D015850:Interleukin-6 / Q000097:blood; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology; D008168:Lung / Q000187:drug effects / Q000378:metabolism; D008198:Lymph Nodes / Q000473:pathology; D008297:Male; D053758:Nanoparticles / Q000737:chemistry* / Q000633:toxicity; D051381:Rats; D017207:Rats, Sprague-Dawley; D013154:Spleen / Q000166:cytology / Q000473:pathology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D014025:Titanium / Q000737:chemistry*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; C009495:titanium dioxide; D014025:Titanium