Neonatal invariant Va24+ NKT lymphocytes are activated memory cells.

NKT cells are a small subset of T lymphocytes which express an invariant V(alpha24JalphaQ TCR and recognize glycolipids presented by CD1d. In adults, NKT cells have a memory phenotype, frequently associated with oligoclonal expansion, express NK cell markers, and produce TO cytokines upon primary stimulation. Because of these features, NKT cells are regarded as lymphocytes of innate immunity. We investigated NKT cells from cord blood to see how these cells appear in the absence of exogenous stimuli. We found that NKT cells are present at comparable frequencies in cord blood and adult peripheral blood mononuclear cells and in both cases display a memory (CD45RO+CD62L-) phenotype. However, neonatal NKT cells differ from their adult counterparts by the following characteristics: (1) they express markers of activation, such as CD25; (2) they are polyclonal; (3) they do not produce cytokines in response to primary stimulation. Together, our data show that human NKT cells arise in the newborn with an activated memory phenotype, probably due to recognition of an endogenous ligand(s). The absence of oligoclonal expansion and primary effector functions also suggest that neonatal NKT cells, despite their activated memory phenotype, require a further priming/differentiation event to behave as fully functional cells of innate immunity

Terahertz analysis of an East Asian historical mural painting

Terahertz (THz) spectroscopy and THz and imaging techniques are expected to have great potential for the non-invasive analysis of artworks. We have applied THz imaging to analyse the historic mural painting of a Lamaism temple by using a transportable time-domain THz imaging system; such an attempt is the first in the world. The reflection image revealed that there are two orange colours in the painting, although they appear the same to the naked eye. THz imaging can also estimate the depth of cracks. The colours were examined by X-ray fluorescence and Raman spectroscopy, and the results were found to be in good agreement. This work proved that THz imaging can contribute to the non-invasive analysis of cultural heritage

In vitro anti-tumour activity of α-galactosylceramide-stimulated human invariant Vα24+NKT cells against melanoma

α-galactosylceramide (KRN 7000, α-GalCer) has shown potent in vivo anti-tumour activity in mice, including against melanoma and the highly specific effect of inducing proliferation and activation of human Vα24+NKT-cells. We hypothesized that human Vα24+NKT-cells activated by α-GalCer might exhibit anti-tumour activity against human melanoma. To investigate this, Vα24+NKT-cells were generated from the peripheral blood of patients with melanoma after stimulation with α-GalCer pulsed monocyte-derived dendritic cells (Mo-DCs). Vα24+NKT-cells did not exhibit cytolytic activity against the primary autologous or allogeneic melanoma cell lines tested. However, proliferation of the melanoma cell lines was markedly suppressed by co-culture with activated Vα24+NKT-cells (mean ± SD inhibition of proliferation 63.9 ± 1.3%). Culture supernatants of activated Vα24+NKT-cell cultures stimulated with α-GalCer pulsed Mo-DCs exhibited similar antiproliferative activities against melanoma cells, indicating that the majority of the inhibitory effects were due to soluble mediators rather than direct cell-to-cell interactions. This effect was predominantly due to release of IFN-γ, and to a lesser extent IL-12. Other cytokines, including IL-4 and IL-10, were released but these cytokines had less antiproliferative effects. These in vitro results show that Vα24+NKT-cells stimulated by α-GalCer-pulsed Mo-DCs have anti-tumour activities against human melanoma through antiproliferative effects exerted by soluble mediators rather than cytolytic effects as observed against some other tumours. Induction of local cytokine release by activated Vα24+NKT-cells may contribute to clinical anti-tumour effects of α-GalCer. © 2001 Cancer Research Campaign http://www.bjcancer.co

Solution-processed semiconductors for next-generation photodetectors

Efficient light detection is central to modern science and technology.Current photodetectors mainly use photodiodes based on crystalline inorganic elementalsemiconductors, such as silicon, or compounds such as III–V semiconductors. Photodetectorsmade of solution-processed semiconductors — which include organic materials, metal-halideperovskites and quantum dots — have recently emerged as candidates for next-generation lightsensing. They combine ease of processing, tailorable optoelectronic properties, facile integrationwith complementary metal–oxide–semiconductors, compatibility with flexible substrates andgood performance. Here, we review the recent advances and the open challenges in the field ofsolution-processed photodetectors, examining the topic from both the materials and the deviceperspective and highlighting the potential of the synergistic combination of materials and deviceengineering. We explore hybrid phototransistorsand their potential to overcome trade-offsin noise, gain and speed, as well as the rapid advances in metal-halide perovskite photodiodesand their recent application in narrowband filterless photodetection

MHC-II-independent CD4+ T cells induce colitis in immunodeficient RAG-/- hosts.

CD4(+) alpha beta T cells from either normal C57BL/6 (B6) or MHC-II-deficient (A alpha(-/-) or A beta(-/-)) B6 donor mice engrafted into congenic immunodeficient RAG1(-/-) B6 hosts induced an aggressive inflammatory bowel disease (IBD). Furthermore, CD4(+) T cells from CD1d(-/-) knockout (KO) B6 donor mice but not those from MHC-I(-/-) (homozygous transgenic mice deficient for beta(2)-microglobulin) KO B6 mice induced a colitis in RAG(-/-) hosts. Abundant numbers of in vivo activated (CD69(high)CD44(high)CD28(high)) NK1(+) and NK1(-) CD4(+) T cells were isolated from the inflamed colonic lamina propria (cLP) of transplanted mice with IBD that produced large amounts of TNF-alpha and IFN-gamma but low amounts of IL-4 and IL-10. IBD-associated cLP Th1 CD4(+) T cell populations were polyclonal and MHC-II-restricted when derived from normal B6 donor mice, but oligoclonal and apparently MHC-I-restricted when derived from MHC-II-deficient (A alpha(-/-) or A beta(-/-)) B6 donor mice. cLP CD4(+) T cell populations from homozygous transgenic mice deficient for beta(2)-microglobulin KO B6 donor mice engrafted into RAG(-/-) hosts were Th2 and MHC-II restricted. These data indicate that MHC-II-dependent as well as MHC-II-independent CD4(+) T cells can induce a severe and lethal IBD in congenic, immunodeficient hosts, but that the former need the latter to express its IBD-inducing potential