High levels of ecto-5′-nucleotidase (CD73) have been implicated in immune suppression and tumor progression, and have also been observed in cancer patients who progress on anti–PD-1 immunotherapy. Although regulatory T cells can express CD73 and inhibit T cell responses via the production of adenosine, less is known about CD73 expression in other immune cell populations. We found that tumor-infiltrating NK cells upregulate CD73 expression and the frequency of these CD73-positive NK cells correlated with larger tumor size in breast cancer patients. In addition, the expression of multiple alternative immune checkpoint receptors including LAG-3, VISTA, PD-1, and PD-L1 was significantly higher in CD73-positive NK cells than in CD73-negative NK cells. Mechanistically, NK cells transport CD73 in intracellular vesicles to the cell surface and the extracellular space via actin polymerization–dependent exocytosis upon engagement of 4-1BBL on tumor cells. These CD73-positive NK cells undergo transcriptional reprogramming and upregulate IL-10 production via STAT3 transcriptional activity, suppressing CD4-positive T cell proliferation and IFN-γ production. Taken together, our results support the notion that tumors can hijack NK cells as a means to escape immunity and that CD73 expression defines an inducible population of NK cells with immunoregulatory properties within the tumor microenvironment.

Marine sponges are vital components of benthic and coral reef ecosystems, providing shelter and nutrition for many organisms. In addition, sponges act as an essential carbon and nutrient link between the pelagic and benthic environment by filtering large quantities of seawater. Many sponge species harbor a diverse microbial community (including Archaea, Bacteria and Eukaryotes), which can constitute up to 50% of the sponge biomass. Sponges of the genus Cinachyrella are common in Caribbean and Floridian reefs and their archaeal and bacterial microbiomes were explored here using 16S rDNA tag pyrosequencing. Cinachyrella specimens and seawater samples were collected from the same South Florida reef at two different times of year. In total, 639 OTUs (12 archaeal and 627 bacterial) belonging to 2 archaeal and 21 bacterial phyla were detected in the sponges. Based on their microbiomes, the six sponge samples formed two distinct groups, namely sponge group 1 (SG1) with low diversity (Shannon-Weiner index: 3.73 ± 0.22) and SG2 with higher diversity (Shannon-Weiner index: 5.95 ± 0.25). Hosts’ 28S rDNA sequences further confirmed that the sponge specimens were composed of two taxa closely related to Cinachyrella kuekenthalli. Both sponge groups were dominated by Proteobacteria, but Alphaproteobacteria were significantly more abundant in SG1. SG2 harbored many bacterial phyla (>1% of sequences) present in low abundance or below detection limits (<0.07%) in SG1 including: Acidobacteria, Chloroflexi, Gemmatimonadetes, Nitrospirae, PAUC34f, Poribacteria and Verrucomicrobia. Furthermore, SG1 and SG2 only had 95 OTUs in common, representing 30.5% and 22.4% of SG1 and SG2’s total OTUs, respectively. These results suggest that the sponge host may exert a pivotal influence on the nature and structure of the microbial community and may only be marginally affected by external environment parameters.

Lyme disease is caused by infection with the bacterium Borrelia burgdorferi (Bb), which is transmitted to humans by deer ticks. The infection manifests usually as a rash and minor systemic symptoms; however, the bacteria can spread to other tissues, causing joint pain, carditis, and neurological symptoms. Lyme neuroborreliosis presents itself in several ways, such as Bell’s palsy, meningitis, and encephalitis. The molecular basis for neuroborreliosis is poorly understood. Analysis of the changes in the expression levels of messenger RNAs and non-coding RNAs, including microRNAs, following Bb infection could therefore provide vital information on the pathogenesis and clinical symptoms of neuroborreliosis. To this end, we used cultured primary human astrocytes, key responders to CNS infection and important components of the blood-brain barrier, as a model system to study RNA and microRNA changes in the CNS caused by Bb. Using whole transcriptome RNA-seq, we found significant changes in 38 microRNAs and 275 mRNAs at 24 and 48 hours following Bb infection. Several of the RNA changes affect pathways involved in immune response, development, chromatin assembly (including histones) and cell adhesion. Further, several of the microRNA predicted target mRNAs were also differentially regulated. Overall, our results indicate that exposure to Bb causes significant changes to the transcriptome and microRNA profile of astrocytes, which has implications in the pathogenesis, and hence potential treatment strategies to combat this disease.

Of the around 7,000 known rare diseases worldwide, disease-modifying treatments are available for fewer than 5%, leaving millions of individuals without specialized therapeutic strategies. In recent years, antisense oligonucleotides (ASOs) have shown promise as individualized genetic interventions for rare genetic diseases. However, there is currently no consensus on which disease-causing DNA variants are suitable candidates for this type of genetic therapy. The Patient Identification Working Group of the N=1 Collaborative (N1C), alongside an international group of volunteer assessors, has developed and piloted consensus guidelines for assessing the eligibility of pathogenic variants towards ASO treatments. We herein present the N1C VARIANT ( V ariant A ssessments towa r ds El i gibility for An tisense Oligonucleotide T reatment) guidelines, including the guiding scientific principles and our approach to consensus building. Pathogenic, disease-causing variants can be assessed for the three currently best-established ASO treatment approaches: splice correction, exon skipping, and downregulation of RNA transcripts. A genetic variant is classified as either “eligible”, “likely eligible”, “unlikely eligible”, or “not eligible” in relation to the different approaches, or “unable to assess”. We also review key considerations for assessment for upregulation of transcripts from the wildtype allele, an emerging ASO therapeutic strategy. We provide additional tools and training material to enable clinicians and researchers to use these guidelines for their eligibility assessments. With this initial edition of our N1C VARIANT guidelines, we provide the rare genetic disease community with guidance on how to identify suitable candidates for variant-specific ASO-based therapies and the possibility of integrating such assessments into routine clinical practice.

DNA methylation is an essential epigenetic modification that plays a crucial role in regulating gene expression and maintaining genomic stability. With the advancement in sequencing technology, methylation studies have provided valuable insights into the diagnosis of rare diseases through the various identification of episignatures, epivariation, epioutliers, and allele-specific methylation. However, current methylation studies are not without limitations. This mini-review explores the current understanding of DNA methylation in rare diseases, highlighting the key mechanisms and diagnostic potential, and emphasizing the need for advanced methodologies and integrative approaches to enhance the understanding of disease progression and design more personable treatment for patients, given the nature of rare diseases.