title: Uptake of poly-dispersed single-walled carbon nanotubes and decline of functions in mouse NK cells undergoing activation.
abstract: The interaction of poly-dispersed acid-functionalized single-walled carbon nanotubes (AF-SWCNT) with NK cells undergoing activation was examined. Exposure to AF-SWCNT during NK activation in vitro by interleukin (IL)-2, and in vivo by Poly(I:C) significantly lowered cytotoxic activity generated against YAC-1 tumor cells. Recoveries of spleen NK1.1(+) cells as well as the activated subset of NK cells (NK1.1(+)CD69(+) cells) were significantly reduced by the AF-SWCNT exposure. The proportion of apoptotic NK cells (NK1.1(+) phosphatidylserine(+)) in the spleen cell preparations activated in vitro was also significantly elevated. Expression levels of CD107a [for assessing NK cell degranulation] as well as of FasL marker [mediating non-secretory pathway of NK cell killing] were significantly lower in cells exposed to AF-SWCNT during the activation phase. Intracellular levels of interferon (IFN)-γ and tumor necrosis factor (TNF)-α in the cells were also significantly reduced. Fluorescent AF-SWCNT (FAF-SWCNT) were internalized by the NK cells and uptake was significantly greater in activated cells. Confocal microscopy indicated the internalized FAF-SWCNT were localized to the cytoplasm of the NK cells. These results indicated that AF-SWCNT were internalized by NK cells and caused a general down-regulation of a variety of parameters associated with NK cell cytotoxicity and other cellular functions.
authors.affiliation: a School of Life Sciences , Jawaharlal Nehru University , New Delhi , India ;|b Faculty of Life Sciences and Biotechnology , South Asian University , New Delhi , India.
authors.forename: Anwar
authors.initials: A
authors.lastname: Alam
authors.affiliation: a School of Life Sciences , Jawaharlal Nehru University , New Delhi , India ;
authors.forename: Niti
authors.initials: N
authors.lastname: Puri
authors.affiliation: b Faculty of Life Sciences and Biotechnology , South Asian University , New Delhi , India.
authors.forename: Rajiv K
authors.initials: RK
authors.lastname: Saxena
mesh_terms: D000818:Animals; D017209:Apoptosis; D015550:Cell Degranulation; D045744:Cell Line, Tumor; D003593:Cytoplasm / Q000378:metabolism; D003602:Cytotoxicity, Immunologic; D015536:Down-Regulation; D007371:Interferon-gamma / Q000378:metabolism; D007376:Interleukin-2 / Q000378:metabolism; D007694:Killer Cells, Natural / Q000276:immunology*; D008213:Lymphocyte Activation; D008223:Lymphoma / Q000276:immunology*; D051379:Mice; D037742:Nanotubes, Carbon / Q000706:statistics & numerical data; D009374:Neoplasms, Experimental; D011070:Poly I-C / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D007376:Interleukin-2; D037742:Nanotubes, Carbon; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D011070:Poly I-C
keywords: AF-SWCNT; CD107; FasL; IL-2; NK cells; Poly(I:C); apoptosis; confocal microscopy; cytokines; cytotoxicity; degranulation; flow cytometry