345 research outputs found

    Spitzer Mid-to-Far-Infrared Flux Densities of Distant Galaxies

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    We study the infrared (IR) properties of high-redshift galaxies using deep Spitzer 24, 70, and 160 micron data. Our primary interest is to improve the constraints on the total IR luminosities, L(IR), of these galaxies. We combine the Spitzer data in the southern Extended Chandra Deep Field with a K-band-selected galaxy sample and photometric redshifts from the Multiwavelength Survey by Yale-Chile. We used a stacking analysis to measure the average 70 and 160 micron flux densities of 1.5 < z < 2.5 galaxies as a function of 24 micron flux density, X-ray activity, and rest-frame near-IR color. Galaxies with 1.5 < z < 2.5 and S(24)=53-250 micro-Jy have L(IR) derived from their average 24-160 micron flux densities within factors of 2-3 of those derived from the 24 micron flux densities only. However, L(IR) derived from the average 24-160 micron flux densities for galaxies with S(24) > 250 micro-Jy and 1.5 < z < 2.5 are lower than those derived using only the 24 micron flux density by factors of 2-10. Galaxies with S(24) > 250 micro-Jy have S(70)/S(24) flux ratios comparable to sources with X-ray detections or red rest-frame IR colors, suggesting that warm dust possibly heated by AGN may contribute to the high 24 micron emission. Based on the average 24-160 micron flux densities, nearly all 24 micron-selected galaxies at 1.5 < z < 2.5 have L(IR) < 6 x 10^12 solar luminosities, which if attributed to star formation corresponds to < 1000 solar masses per year. This suggests that high redshift galaxies may have similar star formation efficiencies and feedback processes as local analogs. Objects with L(IR) > 6 x 10^12 solar luminosities are quite rare, with a surface density ~ 30 +/- 10 per sq. deg, corresponding to ~ 2 +/- 1 x 10^-6 Mpc^-3 over 1.5 < z < 2.5.Comment: Accepted for Publication in ApJ. AASTeX format. 34 pages, 12 figures. Updated references and other small textual revision

    BCG hydrogel promotes CTSS-mediated antigen processing and presentation, thereby suppressing metastasis and prolonging survival in melanoma.

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    BACKGROUND The use of intralesional Mycobacterium bovis BCG (intralesional live BCG) for the treatment of metastatic melanoma resulted in regression of directly injected, and occasionally of distal lesions. However, intralesional-BCG is less effective in patients with visceral metastases and did not significantly improve overall survival. METHODS We generated a novel BCG lysate and developed it into a thermosensitive PLGA-PEG-PLGA hydrogel (BCG hydrogel), which was injected adjacent to the tumor to assess its antitumor effect in syngeneic tumor models (B16F10, MC38). The effect of BCG hydrogel treatment on contralateral tumors, lung metastases, and survival was assessed to evaluate systemic long-term efficacy. Gene expression profiles of tumor-infiltrating immune cells and of tumor-draining lymph nodes from BCG hydrogel-treated mice were analyzed by single-cell RNA sequencing (scRNA-seq) and CD8+ T cell receptor (TCR) repertoire diversity was assessed by TCR-sequencing. To confirm the mechanistic findings, RNA-seq data of biopsies obtained from in-transit cutaneous metastases of patients with melanoma who had received intralesional-BCG therapy were analyzed. RESULTS Here, we show that BCG lysate exhibits enhanced antitumor efficacy compared to live mycobacteria and promotes a proinflammatory tumor microenvironment and M1 macrophage (MΦ) polarization in vivo. The underlying mechanisms of BCG lysate-mediated tumor immunity are dependent on MΦ and dendritic cells (DCs). BCG hydrogel treatment induced systemic immunity in melanoma-bearing mice with suppression of lung metastases and improved survival. Furthermore, BCG hydrogel promoted cathepsin S (CTSS) activity in MΦ and DCs, resulting in enhanced antigen processing and presentation of tumor-associated antigens. Finally, BCG hydrogel treatment was associated with increased frequencies of melanoma-reactive CD8+ T cells. In human patients with melanoma, intralesional-BCG treatment was associated with enhanced M1 MΦ, mature DC, antigen processing and presentation, as well as with increased CTSS expression which positively correlated with patient survival. CONCLUSIONS These findings provide mechanistic insights as well as rationale for the clinical translation of BCG hydrogel as cancer immunotherapy to overcome the current limitations of immunotherapies for the treatment of patients with melanoma

    Characterization of the microbiome of nipple aspirate fluid of breast cancer survivors.

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    The microbiome impacts human health and disease. Until recently, human breast tissue and milk were presumed to be sterile. Here, we investigated the presence of microbes in the nipple aspirate fluid (NAF) and their potential association with breast cancer. We compared the NAF microbiome between women with a history of breast cancer (BC) and healthy control women (HC) using 16S rRNA gene amplicon sequencing. The NAF microbiome from BC and HC showed significant differences in community composition. Two Operational Taxonomic Units (OTUs) showed differences in relative abundances between NAF collected from BC and HC. In NAF collected from BC, there was relatively higher incidence of the genus Alistipes. By contrast, an unclassified genus from the Sphingomonadaceae family was relatively more abundant in NAF from HC. These findings reflect the ductal source DNA since there were no differences between areolar skin samples collected from BC and HC. Furthermore, the microbes associated with BC share an enzymatic activity, Beta-Glucuronidase, which may promote breast cancer. This is the first report of bacterial DNA in human breast ductal fluid and the differences between NAF from HC and BC. Further investigation of the ductal microbiome and its potential role in breast cancer are warranted
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