[Influence of dioxide titanium nanoparticles on immune system indicators in rats]

We investigated the possible influence of titanium dioxide TiO2 nanoparticles (NPs) (rutile form) on immunological parameters in rats. The experiment was carried out on 40 male Wistar rats, separated on 4 groups. Rats of 1 and 2 groups received intragastrically deionized water, 3 and 4 groups - aqueous dispersion of NPs in dose of 100 mg/kg body weight every day. Rats of 2 and 4 groups were immunized intraperitoneally with 100 mkg egg ovalbumin (OVA) on the 1st, 3rd and 5th days of the experiment. On day 21 was administered an additional 10 mkg OVA. In this study were assessed the concentration of specific IgG antibodies (humoral immune response), levels of IL-6, IL-10 and TNF-alpha, expression of lymphocyte antigens CD45RA, CD3, CD4, CD8, CD161alpha, phagocytic activity of neutrophils, lymphocyte apoptosis, hematology characteristics of blood. The studies showed that intra-gastric administration of rats with NPs in rutile form generates significant increase of humoral immune response against food antigen (p<0,05 according to the Student t-test). In the analysis of leukogram it was found a significant decrease of immature cells in immunized animals when exposed to NPs. Administration of NPs resulted in a significant decrease of the relative numbers of B-lymphocytes in immunized animals, and generated a significant increase in the phagocytic activity of peripheral blood neutrophils. Stimulation index of phagocytosis significantly increased at reception of NP by non-sensitized animals. Effects of NP rutile on levels of cytokine production (IL- 6, IL-10, TNF-alpha), on hematological characteristics of blood were insignificant both in intact and immunized animals. Thus, it is shown the intragastric administration of NP rutile has some influence on the specific and nonspecific unit of immune system in immunized and intact rats.