The retinoblastoma tumor suppressor protein (pRB) and related p107 and p130 "pocket proteins" function together with the E2F transcription factors to repress gene expression during the cell cycle and development. Recent biochemical studies have identified the multisubunit DREAM pocket protein complexes in Drosophila melanogaster and Caenorhabditis elegans in regulating developmental gene repression. Although a conserved DREAM complex has also been identified in mammalian cells, its physiological function in vivo has not been determined. Here we addressed this question by targeting Lin9, a conserved core subunit of DREAM. We found that LIN9 is essential for early embryonic development and for viability of adult mice. Loss of Lin9 abolishes proliferation and leads to multiple defects in mitosis and cytokinesis because of its requirement for the expression of a large set of mitotic genes, such as Plk1, Aurora A, and Kif20a. While Lin9 heterozygous mice are healthy and normal, they are more susceptible to lung tumorigenesis induced by oncogenic c-Raf than wild-type mice. Together these experiments provide the first direct genetic evidence for the role of LIN9 in development and mitotic gene regulation and they suggest that it may function as a haploinsufficient tumor suppressor.The retinoblastoma tumor suppressor protein (pRB) and related p107 and p130 "pocket proteins" function together with the E2F transcription factors to regulate gene expression during the cell cycle (7). The identification of evolutionary conserved pocket protein/E2F complexes in Drosophila melanogaster has provided new insights into E2F-mediated gene regulation (21,24). These multisubunit complexes, alternatively called dREAM or Myb-MuvB (MMB), consist of at least eight subunits, including the repressor dE2F2 and one of the two retinoblastoma-related proteins, RBF1 or RBF2. In addition, the complex also contains Drosophila dMYB and three Myb-interacting proteins. RNA interference (RNAi)-mediated depletion of several subunits of the complex demonstrated a role in stable repression of developmental genes, although more recent genome-wide studies have found that dREAM/ MMB also functions in activation of genes involved in G 2 and mitosis (2,13,21,24).Remarkably, all subunits of dREAM/MMB, except for dMYB, are related to the Caenorhabditis elegans synMuv class B genes that antagonize RAS-induced vulva differentiation (3,9). Indeed, several synMuv proteins form a multisubunit complex that is highly related to dREAM/MMB (14). Therefore, in analogy to dREAM/MMB, it has been suggested that DRM mainly functions in gene repression during development (14).We and others recently identified a complex in human cells that is closely related to dREAM and DRM (20,25,31,40). The human complex, alternatively called LINC or human DREAM, consists of a five-protein core module that binds in quiescent cells to the repressors p130 and E2F4. In S phase this binding is lost and B-MYB associates with the complex. The high degree of conservation of the DREAM-like complex...

Abstract Background Mold-active primary antifungal prophylaxis (PAP) is routinely recommended in neutropenic patients with newly diagnosed acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome (MDS) undergoing remission-induction chemotherapy (RIC). Isavuconazole (ISAV) is an extended spectrum mold-active triazole and has superior tolerability and fewer significant drug–drug interactions compared with other triazoles. Methods In our investigator-initiated, phase 2 trial, treatment-naive adult patients with AML or MDS starting RIC received ISAV per the dosing recommendations in the US label until neutrophil recovery (absolute neutrophil count [ANC] ≥ 0.5 × 109/L) and attainment of complete remission, occurrence of invasive fungal infection (IFI), or for a maximum of 12 weeks. The primary endpoint was the incidence of proven/probable IFI during ISAV PAP and up to 30 days after the last dose. Results Sixty-five of 75 enrolled patients received ISAV PAP (median age, 67 years, median ANC at enrollment, 0.72 × 109/L). Thirty-two patients (49%) received oral targeted leukemia treatments (venetoclax, FTL3 inhibitors). Including the 30-day follow-up period, probable/proven and possible IFIs were encountered in 4 (6%) and 8 patients (12%), respectively. ISAV trough serum concentrations were consistently > 1 µg/mL, showed low intraindividual variation, and were not significantly influenced by chemotherapy regimen. Tolerability of ISAV was excellent, with only 3 cases (5%) of mild to moderate elevations of liver function tests and no QTc prolongations. Conclusions ISAV is a safe and effective alternative for PAP in patients with newly diagnosed AML/MDS undergoing RIC in the era of recently approved or emerging small-molecule antileukemia therapies. Clinical Trials Registration NCT03019939.

Mucormycoses are life-threatening infections in immunocompromised patients. This study characterizes the response of human mononuclear cells to different Mucorales and Ascomycota. PBMC, monocytes, and monocyte derived dendritic cells (moDCs) from healthy donors were stimulated with resting and germinated stages of Mucorales and Ascomycota. Cytokine response and expression of activation markers were studied. Both inactivated germ tubes and resting spores of Rhizopus arrhizus and other human pathogenic Mucorales species significantly stimulated mRNA synthesis and secretion of proinflammatory cytokines. Moreover, R. arrhizus spores induced the upregulation of co-stimulatory molecules on moDCs and a specific T-helper cell response. Removal of rodlet hydrophobins by hydrofluoric acid treatment of A. fumigatus conidia resulted in enhanced immunogenicity, whereas the cytokine response of PBMCs to dormant R. arrhizus spores was not influenced by hydrofluoric acid. Scanning electron micrographs of Mucorales spores did not exhibit any morphological correlates of rodlet hydrophobins. Taken together, this study revealed striking differences in the response of human mononuclear cells to resting stages of Ascomycota and Mucorales, which may be explained by absence of an immunoprotective hydrophobin layer in Mucorales spores.

Pharmacological immune checkpoint blockade has revolutionized oncological therapies, and its remarkable success has sparked interest in expanding checkpoint inhibitor therapy in infectious diseases. Herein, we evaluated the efficacy of programmed cell death protein 1 (PD-1) blockade in a murine invasive pulmonary aspergillosis model. We found that, compared with isotype-treated infected control mice, anti–PD-1–treated mice had improved survival, reduced fungal burden, increased lung concentrations of proinflammatory cytokines and neutrophil-attracting chemokines, and enhanced pulmonary leukocyte accumulation. Furthermore, combined treatment with anti–PD-1 and caspofungin resulted in a significant survival benefit compared with caspofungin or anti–PD-1 therapy alone, indicating a synergistic effect between PD-1 inhibitors and immunomodulatory antifungal agents.

Objectives Candida auris is an emerging, often MDR, yeast pathogen. Efficient animal models are needed to study its pathogenicity and treatment. Therefore, we developed a C. auris fruit fly infection model. Methods TollI-RXA/Tollr632 female flies were infected with 10 different C. auris strains from the CDC Antimicrobial Resistance bank panel. We used three clinical Candida albicans strains as controls. For drug protection assays, fly survival was assessed along with measurement of fungal burden (cfu/g tissue) and histopathology in C. auris-infected flies fed with fluconazole- or posaconazole-containing food. Results Despite slower in vitro growth, all 10 C. auris isolates caused significantly greater mortality than C. albicans in infected flies, with >80% of C. auris-infected flies dying by day 7 post-infection (versus 67% with C. albicans, P < 0.001–0.005). Comparison of C. auris isolates from different geographical clades revealed more rapid in vitro growth of South American isolates and greater virulence in infected flies, whereas the aggregative capacity of C. auris strains had minimal impact on their growth and pathogenicity. Survival protection and decreased fungal burden of fluconazole- or posaconazole-fed flies infected with two C. auris strains were in line with the isolates’ disparate in vitro azole susceptibility. High reproducibility of survival curves for both non-treated and antifungal-treated infected flies was seen, with coefficients of variation of 0.00–0.31 for 7 day mortality. Conclusions Toll-deficient flies could provide a fast, reliable and inexpensive model to study pathogenesis and drug activity in C. auris candidiasis.