Reduced Uterine Tissue Damage during Chlamydia muridarum Infection in TREM-1,3-Deficient Mice.

Genital infections with Chlamydia trachomatis can lead to uterine and oviduct tissue damage in the female reproductive tract. Neutrophils are strongly associated with tissue damage during chlamydial infection, while an adaptive CD4 T cell response is necessary to combat infection. Activation of triggering receptor expressed on myeloid cells-1 (TREM-1) on neutrophils has previously been shown to induce and/or enhance degranulation synergistically with Toll-like receptor (TLR) signaling. Additionally, TREM-1 can promote neutrophil transepithelial migration. In this study, we sought to determine the contribution of TREM-1,3 to immunopathology in the female mouse genital tract during Chlamydia muridarum infection. Relative to control mice, trem1,3-/- mice had no difference in chlamydial burden or duration of lower-genital-tract infection. We also observed a similar incidence of hydrosalpinx 45 days postinfection in trem1,3-/- compared to wild-type (WT) mice. However, compared to WT mice, trem1,3-/- mice developed significantly fewer hydrometra in uterine horns. Early in infection, trem1,3-/- mice displayed a notable decrease in the number of uterine glands containing polymorphonuclear cells and uterine horn lumens had fewer neutrophils, with increased granulocyte colony-stimulating factor (G-CSF). trem1,3-/- mice also had reduced erosion of the luminal epithelium. These data indicate that TREM-1,3 contributes to transepithelial neutrophil migration in the uterus and uterine glands, promoting the occurrence of hydrometra in infected mice.

The Prognostic Significance of Low-Frequency Somatic Mutations in Metastatic Cutaneous Melanoma.

Background: Little is known about the prognostic significance of somatically mutated genes in metastatic melanoma (MM). We have employed a combined clinical and bioinformatics approach on tumor samples from cutaneous melanoma (SKCM) as part of The Cancer Genome Atlas project (TCGA) to identify mutated genes with potential clinical relevance. Methods: After limiting our DNA sequencing analysis to MM samples (n = 356) and to the CANCER CENSUS gene list, we filtered out mutations with low functional significance (snpEFF). We performed Cox analysis on 53 genes that were mutated in ≥3% of samples, and had ≥50% difference in incidence of mutations in deceased subjects versus alive subjects. Results: Four genes were potentially prognostic [RAC1, FGFR1, CARD11, CIITA; false discovery rate (FDR) < 0.2]. We identified 18 additional genes (e.g., SPEN, PDGFRB, GNAS, MAP2K1, EGFR, TSC2) that were less likely to have prognostic value (FDR < 0.4). Most somatic mutations in these 22 genes were infrequent (< 10%), associated with high somatic mutation burden, and were evenly distributed across all exons, except for RAC1 and MAP2K1. Mutations in only 9 of these 22 genes were also identified by RNA sequencing in >75% of the samples that exhibited corresponding DNA mutations. The low frequency, UV signature type and RNA expression of the 22 genes in MM samples were confirmed in a separate multi-institution validation cohort (n = 413). An underpowered analysis within a subset of this validation cohort with available patient follow-up (n = 224) showed that somatic mutations in SPEN and RAC1 reached borderline prognostic significance [log-rank favorable (p = 0.09) and adverse (p = 0.07), respectively]. Somatic mutations in SPEN, and to a lesser extent RAC1, were not associated with definite gene copy number or RNA expression alterations. High (>2+) nuclear plus cytoplasmic expression intensity for SPEN was associated with longer melanoma-specific overall survival (OS) compared to lower (≤ 2+) nuclear intensity (p = 0.048). We conclude that expressed somatic mutations in infrequently mutated genes beyond the well-characterized ones (e.g., BRAF, RAS, CDKN2A, PTEN, TP53), such as RAC1 and SPEN, may have prognostic significance in MM.

Prophylactic efficacy of BeneFIX vs Alprolix in hemophilia B mice.

FIX binds tightly to collagen IV. Furthermore, a FIX mutant, FIXK5R, which binds better than wild-type FIX to collagen IV, provides better hemostasis than wild-type FIX, long after both are undetectable in the plasma. There is also credible evidence of extravascular FIX. Here, we use the saphenous vein bleeding model to compare the efficacy of recombinant FIXFc (Alprolix) and wild-type FIX (BeneFIX) in hemophilia B mice 7 days postinfusion. Although the terminal half-life of Alprolix is significantly longer than that of BeneFIX, at equal doses Alprolix is not better at controlling bleeding 7 days postinfusion, presumably because of the extravascular FIX. Both BeneFIX and Alprolix exhibit a linear response in clotting efficacy up to 150 IU/kg, where they appear to saturate an extravascular compartment, because there is no additional prophylactic benefit from higher doses. A robust pool of extravascular FIX is clearly observed surrounding blood vessels, localized to the same region as collagen IV, in 2 representative human tissues: liver and skeletal muscle. We see no increased risk for thrombosis at 250 IU/kg FIX at 6 hours postinfusion. In summary, 7 days postinfusion into hemophilia B mice, BeneFIX and Alprolix are hemostatically indistinguishable despite the latter's increased half-life. We predict that doses of FIX ∼3 times higher than the currently recommended 40 to 50 IU/kg will, because of FIX's large extravascular compartment, efficiently prolong prophylactic hemostasis without thrombotic risk.