title: ZnO nanoparticles induced adjuvant effect via toll-like receptors and Src signaling in Balb/c mice.
abstract: Our previous studies indicated that zinc oxide nanoparticles (ZnO NPs) have adjuvant properties to a known allergen ovalbumin (OVA) in Balb/c mice. Therefore, in this study, we focused on the mechanisms involved in adjuvant responses induced by ZnO NPs. The eosinophil counts in the Peyers' patches of intestine and ICAM-1, Cox2 protein expressions were enhanced in the ZnO NPs/OVA group. Following screening of toll-like receptors (TLRs), TLR 2, 4 and 6 were found to be increased. Accordingly, we found that downstream proteins of TLRs such as myeloid differentiation primary response protein-88 (MyD88), IL-1 receptor associated kinase 1 (IRAK 1), and TNFR-associated factor 6 (TRAF 6) were also found to be enhanced in the ZnO NPs/OVA-induced group. These inflammatory responses underlined the critical roles of TLRs in the inflammatory response. ZnO NPs increased the mRNA levels of inflammatory cytokine IL-1β and protein expression of several mediators, including Cox2, PGE2, MMP-9 and finally caspase 1 in macrophages. Another pathway for adjuvant effect is Src which was found to be significantly affected by the activation of p-Lyn, p-Syk, IP3, p-PLC-γ and cAMP. Ca(2+) influx was significantly increased as well in the ZnO NPs/OVA group. These findings demonstrated the differential role of TLRs in regulation of the ZnO NPs-induced adjuvant responses causing the inflammation. We therefore, conclude that ZnO NPs have significant adjuvant effect via following Src kinase and TLRs signaling that ascribed to inflammatory responses due to recruitment and activation of adhesion molecules and inflammatory cells. The adjuvant property of ZnO NPs may help in planning strategies for its therapeutic use.
authors.affiliation: Food, Drug and Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), M.G. Marg, Post Box No. 80, Lucknow 226001, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi, India.
authors.forename: Ruchi
authors.initials: R
authors.lastname: Roy
authors.affiliation: Food, Drug and Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), M.G. Marg, Post Box No. 80, Lucknow 226001, India.
authors.forename: Dinesh
authors.initials: D
authors.lastname: Kumar
authors.affiliation: Food, Drug and Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), M.G. Marg, Post Box No. 80, Lucknow 226001, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi, India.
authors.forename: Akanksha
authors.initials: A
authors.lastname: Sharma
authors.affiliation: Food, Drug and Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), M.G. Marg, Post Box No. 80, Lucknow 226001, India.
authors.forename: Parul
authors.initials: P
authors.lastname: Gupta
authors.affiliation: Central Pathology Laboratory, Gheru Campus, CSIR-Indian Institute of Toxicology Research, Lucknow 226001, India.
authors.forename: Bhushan P
authors.initials: BP
authors.lastname: Chaudhari
authors.affiliation: Food, Drug and Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), M.G. Marg, Post Box No. 80, Lucknow 226001, India.
authors.forename: Anurag
authors.initials: A
authors.lastname: Tripathi
authors.affiliation: Food, Drug and Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), M.G. Marg, Post Box No. 80, Lucknow 226001, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi, India.
authors.forename: Mukul
authors.initials: M
authors.lastname: Das
authors.affiliation: Food, Drug and Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), M.G. Marg, Post Box No. 80, Lucknow 226001, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi, India. Electronic address: pddwivedi@yahoo.com.
authors.forename: Premendra D
authors.initials: PD
authors.lastname: Dwivedi
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D020170:Caspase 1 / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000378:metabolism; D005260:Female; D007249:Inflammation / Q000276:immunology; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D053592:Interleukin-1 Receptor-Associated Kinases / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000187:drug effects; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D053594:Myeloid Differentiation Factor 88 / Q000378:metabolism; D053758:Nanoparticles / Q000737:chemistry*; D010047:Ovalbumin / Q000276:immunology; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D048029:TNF Receptor-Associated Factor 6 / Q000378:metabolism; D051195:Toll-Like Receptor 2 / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000378:metabolism; D051216:Toll-Like Receptor 6 / Q000378:metabolism; D051193:Toll-Like Receptors / Q000378:metabolism*; D015034:Zinc Oxide / Q000737:chemistry / Q000494:pharmacology*; D019061:src-Family Kinases / Q000378:metabolism*
chemical_list: D000276:Adjuvants, Immunologic; C090509:Icam1 protein, mouse; D053583:Interleukin-1beta; C507780:Myd88 protein, mouse; D053594:Myeloid Differentiation Factor 88; D012333:RNA, Messenger; D048029:TNF Receptor-Associated Factor 6; C493486:Tlr2 protein, mouse; C493487:Tlr4 protein, mouse; C495369:Tlr6 protein, mouse; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051216:Toll-Like Receptor 6; D051193:Toll-Like Receptors; D018799:Intercellular Adhesion Molecule-1; D010047:Ovalbumin; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2; C060902:lyn protein-tyrosine kinase; D019061:src-Family Kinases; D053592:Interleukin-1 Receptor-Associated Kinases; C507769:Irak1 protein, mouse; D020170:Caspase 1; D015034:Zinc Oxide
keywords: Adjuvant; Src signaling; Toll-like receptors; Zinc oxide nanoparticles