A Tale of Two Clusters: An Analysis of Gas-phase Metallicity and Nebular Gas Conditions in Proto-cluster Galaxies at z ∼ 2

The ZFIRE survey has spectroscopically confirmed two proto-clusters using the MOSFIRE instrument on Keck I: One at z = 2.095 in COSMOS and another at z = 1.62 in UKIRT Infrared Deep Sky Survey (UDS). Here, we use an updated ZFIRE data set to derive the properties of ionized gas regions of proto-cluster galaxies by extracting fluxes from emission lines Hβ 4861 Å, [O iii] 5007 Å, Hα 6563 Å, [N ii] 6585 Å, and [S ii] 6716,6731 Å. We measure gas-phase metallicity of members in both proto-clusters using two indicators, including a strong-line indicator relatively independent of the ionization parameter and electron density. Proto-cluster and field galaxies in both UDS and COSMOS lie on the same Mass-Metallicity Relation with both metallicity indicators. We compare our results to recent IllustrisTNG results, which report no significant gas-phase metallicity offset between proto-cluster and field galaxies until z = 1.5. This is in agreement with our observed metallicities, where no offset is measured between proto-cluster and field populations. We measure tentative evidence from stacked spectra that indicate UDS high-mass proto-cluster and field galaxies have differing [O iii]/Hβ ratios; however, these results are dependent on the sample size of the high-mass stacks

Functional characterization of human natural killer cells responding to Mycobacterium bovis bacille Calmette-Guérin

The kinetics of activation and induction of several effector functions of human natural killer (NK) cells in response to Mycobacterium bovis bacille Calmette-Guérin (BCG) were investigated. Owing to the central role of monocytes/macrophages (MM) in the initiation and maintenance of the immune response to pathogens, two different experimental culture conditions were analysed. In the first, monocyte-depleted nylon wool non-adherent (NW) cells from healthy donors were stimulated with autologous MM preinfected with BCG (intracellular BCG). In the second, the NW cells were directly incubated with BCG, which was therefore extracellular. In the presence of MM, CD4(+) T lymphocytes were the cell subset mainly expressing the activation marker, CD25, and proliferating with a peak after 7 days of culture. In contrast, in response to extracellular BCG, the peak of the proliferative response was observed after 6 days of stimulation, and CD56(+) CD3(−) cells (NK cells) were the cell subset preferentially involved. Such proliferation of NK cells did not require a prior sensitization to mycobacterial antigens, and appeared to be dependent upon contact between cell populations and bacteria. Following stimulation with extracellular BCG, the majority of interferon-γ (IFN-γ)-producing cells were NK cells, with a peak IFN-γ production at 24–30 hr. Interleukin (IL)-2 and IL-4 were not detectable in NK cells or in CD3(+) T lymphocytes at any time tested. IL-12 was not detectable in the culture supernatant of NW cells stimulated with extracellular BCG. Compared to the non-stimulated NW cells, the NW cells incubated for 16–20 hr with BCG induced the highest levels of expression of apoptotic/death marker on the NK-sensitive K562 cell line. BCG also induced expression of the activation marker, CD25, and proliferation, IFN-γ production and cytotoxic activity, on negatively selected CD56(+) CD3(−) cells. Altogether, the results of this study demonstrate that extracellular mycobacteria activate several NK-cell functions and suggest a possible alternative mechanism of NK-cell activation as the first line of defence against mycobacterial infections

The E3 ligase Cbl-b and TAM receptors regulate cancer metastasis via natural killer cells

Tumour metastasis is the primary cause of mortality in cancer patients and remains the key challenge for cancer therapy. New therapeutic approaches to block inhibitory pathways of the immune system have renewed hopes for the utility of such therapies2. Here we show that genetic deletion of the E3 ubiquitin ligase Cbl-b (casitas B-lineage lymphoma-b) or targeted inactivation of its E3 ligase activity licenses natural killer (NK) cells to spontaneously reject metastatic tumours. The TAM tyrosine kinase receptors Tyro3, Axl and Mer (also known as Mertk) were identified as ubiquitylation substrates for Cbl-b. Treatment of wild-type NK cells with a newly developed small molecule TAM kinase inhibitor conferred therapeutic potential, efficiently enhancing anti-metastatic NK cell activity in vivo. Oral or intraperitoneal administration using this TAM inhibitor markedly reduced murine mammary cancer and melanoma metastases dependent on NK cells. We further report that the anticoagulant warfarin exerts anti-metastatic activity in mice via Cbl-b/TAM receptors in NK cells, providing a molecular explanation for a 50-year-old puzzle in cancer biology3. This novel TAM/Cbl-b inhibitory pathway shows that it might be possible to develop a a 'pill' that awakens the innate immune system to kill cancer metastases. © 2014 Macmillan Publishers Limited.Fil: Paolino, Magdalena. Institute Of Molecular Biotechnology, Vienna; AustriaFil: Choidas, Axel. Lead Discovery Center GmbH; AlemaniaFil: Wallner, Stephanie. Medizinische Universitat Innsbruck; AustriaFil: Pranjic, Blanka. Institute Of Molecular Biotechnology, Vienna; AustriaFil: Uribesalgo, Iris. Institute Of Molecular Biotechnology, Vienna; AustriaFil: Loeser, Stefanie. Institute Of Molecular Biotechnology, Vienna; AustriaFil: Jamieson, Amanda M.. University Brown; Estados UnidosFil: Langdon, Wallace Y.. University of Western Australia; AustraliaFil: Ikeda, Fumiyo. Institute Of Molecular Biotechnology, Vienna; AustriaFil: Fededa, Juan Pablo. Institute Of Molecular Biotechnology, Vienna; Austria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Cronin, Shane J.. Institute Of Molecular Biotechnology, Vienna; AustriaFil: Nitsch, Roberto. Institute Of Molecular Biotechnology, Vienna; AustriaFil: Schultz-Fademrecht, Carsten. Lead Discovery Center GmbH; AlemaniaFil: Eickhoff, Jan. Lead Discovery Center GmbH; AlemaniaFil: Menninger, Sascha. Lead Discovery Center GmbH; AlemaniaFil: Unger, Anke. Lead Discovery Center GmbH; AlemaniaFil: Torka, Robert. Institute for Biochemistry Max-Planck; AlemaniaFil: Gruber, Thomas. Medizinische Universitat Innsbruck; AustriaFil: Hinterleitner, Reinhard. Medizinische Universitat Innsbruck; AustriaFil: Baier, Gottfried. Medizinische Universitat Innsbruck; AustriaFil: Wolf, Dominik. University Hospital Bonn; Alemania. Medical University Innsbruck; AustriaFil: Ullrich, Axel. Institute for Biochemistry Max-Planck; AlemaniaFil: Klebl, Bert M.. Lead Discovery Center GmbH; AlemaniaFil: Penninger, Josef M.. Institute Of Molecular Biotechnology, Vienna; Austri

Natural Killer (NK) Cells in Antibacterial Innate Immunity: Angels or Devils?

Natural killer (NK) cells were first described as immune leukocytes that could kill tumor cells and soon after were reported to kill virus-infected cells. In the mid-1980s, 10 years after their discovery, NK cells were also demonstrated to contribute to the fight against bacterial infection, particularly because of crosstalk with other leukocytes. A wide variety of immune cells are now recognized to interact with NK cells through the production of cytokines such as interleukin (IL)-2, IL-12, IL-15 and IL-18, which boost NK cell activities. The recent demonstration that NK cells express pattern recognition receptors, namely Toll-like and nucleotide oligomerization domain (NOD)-like receptors, led to the understanding that these cells are not only under the control of accessory cells, but can be directly involved in the antibacterial response thanks to their capacity to recognize pathogen-associated molecular patterns. Interferon (IFN)-γ is the predominant cytokine produced by activated NK cells. IFN-γ is a key contributor to antibacterial immune defense. However, in synergy with other inflammatory cytokines, IFN-γ can also lead to deleterious effects similar to those observed during sepsis. Accordingly, as the main source of IFN-γ in the early phase of infection, NK cells display both beneficial and deleterious effects, depending on the circumstances