Therapeutic KRAS inhibition drives effective interferon-mediated antitumor immunity in immunogenic lung cancers.

Recently developed KRAS inhibitory drugs are beneficial to lung cancer patients harboring KRAS mutations, but drug resistance frequently develops. Because of the immunosuppressive nature of the signaling network controlled by oncogenic KRAS, these drugs can indirectly affect antitumor immunity, providing a rationale for their combination with immune checkpoint blockade. In this study, we have characterized how KRAS inhibition reverses immunosuppression driven by oncogenic KRAS in a number of preclinical lung cancer models with varying levels of immunogenicity.

Effect of Relative Humidity on Transfer of Aerosol-Deposited Artificial and Human Saliva from Surfaces to Artificial Finger-Pads.

Surface to hand transfer of viruses represents a potential mechanism for human exposure. An experimental process for evaluating the touch transfer of aerosol-deposited material is described based on controlling surface, tribological, and soft matter components of the transfer process. A range of high-touch surfaces were evaluated.

Adenosine 2A receptor and TIM3 suppress cytolytic killing of tumor cells via cytoskeletal polarization.

Tumors generate an immune-suppressive environment that prevents effective killing of tumor cells by CD8 cytotoxic T cells (CTL). It remains largely unclear upon which cell type and at which stage of the anti-tumor response mediators of suppression act. We have combined an in vivo tumor model with a matching in vitro reconstruction of the tumor microenvironment based on tumor spheroids to identify suppressors of anti-tumor immunity that directly act on interaction between CTL and tumor cells and to determine mechanisms of action.

PD-1 suppresses the maintenance of cell couples between cytotoxic T cells and target tumor cells within the tumor.

The killing of tumor cells by CD8 T cells is suppressed by the tumor microenvironment, and increased expression of inhibitory receptors, including programmed cell death protein-1 (PD-1), is associated with tumor-mediated suppression of T cells. To find cellular defects triggered by tumor exposure and associated PD-1 signaling, we established an ex vivo imaging approach to investigate the response of antigen-specific, activated effector CD8 tumor-infiltrating lymphocytes (TILs) after interaction with target tumor cells. Although TIL-tumor cell couples readily formed, couple stability deteriorated within minutes.

Systems Imaging of the Immune Synapse.

Three-dimensional live cell imaging of the interaction of T cells with antigen-presenting cells (APCs) visualizes the subcellular distributions of signaling intermediates during T cell activation at thousands of resolved positions within a cell. These information-rich maps of local protein concentrations are a valuable resource in understanding T cell signaling. Here, we describe a protocol for the efficient acquisition of such imaging data and their computational processing to create four-dimensional maps of local concentrations.

PKCθ links proximal T cell and Notch signaling through localized regulation of the actin cytoskeleton.

Notch is a critical regulator of T cell differentiation and is activated through proteolytic cleavage in response to ligand engagement. Using murine myelin-reactive CD4 T cells, we demonstrate that proximal T cell signaling modulates Notch activation by a spatiotemporally constrained mechanism. The protein kinase PKCθ is a critical mediator of signaling by the T cell antigen receptor and the principal costimulatory receptor CD28.

Computational spatiotemporal analysis identifies WAVE2 and cofilin as joint regulators of costimulation-mediated T cell actin dynamics.

Fluorescence microscopy is one of the most important tools in cell biology research because it provides spatial and temporal information to investigate regulatory systems inside cells. This technique can generate data in the form of signal intensities at thousands of positions resolved inside individual live cells. However, given extensive cell-to-cell variation, these data cannot be readily assembled into three- or four-dimensional maps of protein concentration that can be compared across different cells and conditions.

Gene expression profile and functionality of ESC-derived Lin-ckit+Sca-1+ cells are distinct from Lin-ckit+Sca-1+ cells isolated from fetal liver or bone marrow.

In vitro bioreactor-based cultures are being extensively investigated for large-scale production of differentiated cells from embryonic stem cells (ESCs). However, it is unclear whether in vitro ESC-derived progenitors have similar gene expression profiles and functionalities as their in vivo counterparts. This is crucial in establishing the validity of ESC-derived cells as replacements for adult-isolated cells for clinical therapies.

Universal post-arrival screening for child refugees in Australia: isn't it time?

It is known that the refugee population in Australia is at risk of tuberculosis (TB) and children with TB infection can develop active disease with devastating consequence. Currently, in New South Wales (NSW) and possibly other Australian States and Territories, there are different and complex health-screening pathways for newly arrived refugees. This is compounded by various factors, such as social and language difficulties for refugees to access healthcare and limited pre-embarkation screening.

Evidence from the structure and function of cytochromes c(2) that nonsulfur purple bacterial photosynthesis followed the evolution of oxygen respiration.

Cytochromes c(2) are the nearest bacterial homologs of mitochondrial cytochrome c. The sequences of the known cytochromes c(2) can be placed in two subfamilies based upon insertions and deletions, one subfamily is most like mitochondrial cytochrome c (the small C2s, without significant insertions and deletions), and the other, designated large C2, shares 3- and 8-residue insertions as well as a single-residue deletion. C2s generally function between cytochrome bc(1) and cytochrome oxidase in respiration (ca 80 examples known to date) and between cytochrome bc(1) and the reaction center in nonsulfur purple bacterial photosynthesis (ca 21 examples).

An alternative to the accepted phylogeny of purple bacteria based on 16S rRNA: analyses of the amino acid sequences of cytochromes C2 and C556 from Rhodobacter (Rhodovulum) sulfidophilus.

It is becoming increasingly apparent from complete genome sequences that 16S rRNA data, as currently interpreted, does not provide an unambiguous picture of bacterial phylogeny. In contrast, we have found that analysis of insertions and deletions in the amino acid sequences of cytochrome c2 has some advantages in establishing relationships and that this approach may have broad utility in acquiring a better understanding of bacterial relationships. The amino acid sequences of cytochromes c2 and c556 have been determined in whole or in part from four strains of Rhodobacter sulfidophilus.

Amino acid sequences of two high-potential iron-sulfur proteins (HiPIPs) from the moderately halophilic purple phototrophic bacterium, Rhodospirillum salinarum.

The amino acid sequences of two very different high-potential iron-sulfur protein (HiPIP) isozymes have been determined from the moderately halophilic purple phototrophic bacterium, Rhodospirillum salinarum. Iso-1 HiPIP, which is monomeric and contains 57 amino acid residues, is most similar to the Thiobacillus ferrooxidans iron-oxidizing enzyme (45% identity and a 6-residue deletion). On the other hand, iso-2 HiPIP, which is isolated as an oligomer, contains a peptide chain with 54 amino acid residues.

The distance between bacterial species in sequence space.

Despite the revolution caused by information from macromolecular sequences, the basis of bacterial classification remains the genus and the species. How do these terms relate to the variety of bacteria that exist on earth? In this paper, the inter- and intraspecies differences in amino acid sequence of several bacterial electron transport proteins, cytochromes c, and blue copper proteins are compared. For the soil and water organisms studied, bacterial species can be classed as "tight" when there is little intraspecies variation, or "loose" when this variation is large.

Evidence for two distinct azurins in Alcaligenes xylosoxidans (NCIMB 11015): potential electron donors to nitrite reductase.

We have isolated two type 1 copper-containing proteins (M(r) approximately 13K) from Alcaligenes xylosoxidans (NCIMB 11015) grown under denitrifying conditions. Amino acid sequence analysis of these two proteins shows one to be the previously identified azurin (Ambler, 1971), which we shall call azurin I, and the other to be a related, but previously undescribed, blue copper protein which we show to also be an azurin and propose to call azurin II. Thus, NCIMB 11015 becomes the second system where two distinct azurins are found, the other being Methylomonas J (Ambler & Tobari, 1989).

Amino acid sequences of two high-potential iron sulfur proteins (HiPIPs) from the moderately halophilic purple phototrophic bacterium Ectothiorhodospira vacuolata.

There are two equally abundant high-potential iron sulfur protein (HiPIP) isozymes present in the purple sulfur bacterium Ectothiorhodospira vacuolata. We have determined the amino acid sequences, which contain 71 and 72 residues. The two HiPIPs can be aligned without any internal insertions or deletions and are 65% identical to one another.

Amino acid sequences of cytochromes c2 and c' from the moderately halophilic purple phototrophic bacterium Rhodospirillum salexigens.

Rhodospirillum salexigens is a moderately halophilic purple phototrophic bacterium which grows optimally in 8% NaCl. The amino acid sequences of the two principal soluble cytochromes c have been determined. One of these is a cytochrome c2, similar in size to mitochondrial cytochrome c.

Amino acid sequences of cytochromes c-551 from the halophilic purple phototrophic bacteria, Ectothiorhodospira halophila and E. halochloris.

The cytochromes c-551 from Ectothiorhodospira halophila and E. halochloris contain 78 and 79 residues, respectively. The sequences can be aligned without the need to postulate any internal deletions or insertions to give 63% identity.

Amino acid sequence of a high redox potential ferredoxin (HiPIP) from the purple phototrophic bacterium Rhodopila globiformis, which has the highest known redox potential of its class.

Rhodopila globiformis HiPIP has a redox potential (ca. 450 mV) that is 100 mV higher than any other known iron-sulfur protein. The amino acid sequence contains 57 residues and can be aligned with that of Thiobacillus ferrooxidans without any insertions or deletions and is 51% identical.

Nucleotide sequence of the heme subunit of flavocytochrome c from the purple phototrophic bacterium, Chromatium vinosum. A 2.6-kilobase pair DNA fragment contains two multiheme cytochromes, a flavoprotein, and a homolog of human ankyrin.

The gene for the cytochrome subunit of Chromatium vinosum flavocytochrome c (sulfide dehydrogenase) was cloned from an EcoRI digest of chromosomal DNA. The mature cytochrome subunit contains 175 amino acid residues and two heme binding sites in agreement with the previously reported amino acid sequence. There is also a signal peptide of 25 residues, which apparently directs the protein to the periplasmic space.

Proteins and molecular palaeontology.

Protein taxonomy has existed as a concept at least since 1958, but despite the efforts of the past 30 years, comparative studies of protein sequence, structure and distribution have not revolutionized any areas of systematics. The most interesting results of single gene phylogenies have been the anomalies, such as insulin in hystricomorphs or cytochrome c in the rattlesnake. It is likely that protein sequence information can be obtained in sufficient quality and quantity from ancient material as to change this finding? The paper will assess possibilities and the likely limitations of chemical studies of ancient protein material.

Sequence variability in bacterial cytochromes c.

Cytochromes c are proteins that can be defined both phenotypically and by their possession of a characteristic sequence motif. Many sequences from bacterial sources are known, and new ones are being reported every year. An analysis can be made as to what fraction of new sequences are members of already known classes or subclasses, and how many map into previously uninhabited regions of sequence space.