Blockade of the pathway including Programmed death-ligand 1 (PD-L1) and its receptor Programmed cell death protein 1 (PD-1) has produced clinical benefits in patients with a variety of cancers. Elevated levels of soluble PD-L1 (sPD-L1) have been associated with worse prognosis in renal cell carcinoma and multiple myeloma. However, the regulatory roles and function of sPD-L1 particularly in connection with immune checkpoint blockade treatment are not fully understood. We identified four splice variants of PD-L1 in melanoma cells, and all of them are secreted. Secretion of sPD-L1 resulted from alternate splicing activities, cytokine induction, cell stress, cell injury and cell death in melanoma cells. Pretreatment levels of sPD-L1 were elevated in stage IV melanoma patient sera compared to healthy donors. High pre-treatment levels of sPD-L1 were associated with increased likelihood of progressive disease in patients treated by CTLA-4 or PD-1 blockade. Although changes in circulating sPD-L1 early after treatment could not distinguish responders from those with progressive disease, after five months of treatment by CTLA-4 or PD-1 blockade patients who had increased circulating sPD-L1 had greater likelihood of developing a partial response. Induction of sPD-L1 was associated with increased circulating cytokines after CTLA-4 blockade but not following PD-1 blockade. Circulating sPD-L1 is a prognostic biomarker that may predict outcomes for subgroups of patients receiving checkpoint inhibitors.

Although great success has been obtained in the clinic, the current immune checkpoint inhibitors still face two challenging problems: low response rate and immune-related adverse effects (irAEs). Here we report the combination of immunogenic chemotherapy and locally expressed PD-L1 trap fusion protein for efficacious and safe cancer immunotherapy. We demonstrate that oxaliplatin (OxP) boosts anti-PD-L1 mAb therapy against murine colorectal cancer. By design of a PD-L1 trap and loading its coding plasmid DNA into a lipid-protamine-DNA nanoparticle, PD-L1 trap is produced transiently and locally in the tumor microenvironment, and synergizes with OxP for tumor inhibition. Significantly, unlike the combination of OxP and anti-PD-L1 mAb, the combination of OxP and PD-L1 trap does not induce obvious Th17 cells accumulation in the spleen, indicating better tolerance and lower tendency to irAEs. The reports here may highlight the potential of applying PD-L1 inhibitor, especially locally expressed PD-L1 trap, in cancer therapy following OxP-based chemotherapy.

We describe the saliva microbiome diversity in Batwa Pygmies, a former hunter-gatherer group from Uganda, using next-generation sequencing of partial 16S rRNA sequences. Microbial community diversity in the Batwa is significantly higher than in agricultural groups from Sierra Leone and the Democratic Republic of Congo. We found 40 microbial genera in the Batwa, which have previously not been described in the human oral cavity. The distinctive composition of the salvia microbiome of the Batwa may have been influenced by their recent different lifestyle and diet.

BackgroundThe advent of genomics-based technologies has revolutionized many fields of biological enquiry. However, chromosome walking or flanking sequence cloning is still a necessary and important procedure to determining gene structure. Such methods are used to identify T-DNA insertion sites and so are especially relevant for organisms where large T-DNA insertion libraries have been created, such as rice and Arabidopsis. The currently available methods for flanking sequence cloning, including the popular TAIL-PCR technique, are relatively laborious and slow.ResultsHere, we report a simple and effective fusion primer and nested integrated PCR method (FPNI-PCR) for the identification and cloning of unknown genomic regions flanked known sequences. In brief, a set of universal primers was designed that consisted of various 15-16 base arbitrary degenerate oligonucleotides. These arbitrary degenerate primers were fused to the 3' end of an adaptor oligonucleotide which provided a known sequence without degenerate nucleotides, thereby forming the fusion primers (FPs). These fusion primers are employed in the first step of an integrated nested PCR strategy which defines the overall FPNI-PCR protocol. In order to demonstrate the efficacy of this novel strategy, we have successfully used it to isolate multiple genomic sequences namely, 21 orthologs of genes in various species of Rosaceace, 4 MYB genes of Rosa rugosa, 3 promoters of transcription factors of Petunia hybrida, and 4 flanking sequences of T-DNA insertion sites in transgenic tobacco lines and 6 specific genes from sequenced genome of rice and Arabidopsis.ConclusionsThe successful amplification of target products through FPNI-PCR verified that this novel strategy is an effective, low cost and simple procedure. Furthermore, FPNI-PCR represents a more sensitive, rapid and accurate technique than the established TAIL-PCR and hiTAIL-PCR procedures.

Chronic inflammatory diseases of the lung are leading causes of morbidity and mortality worldwide. Many of these disorders can be attributed to abnormal immune responses to environmental stimuli and infections. As such, understanding the innate host defense pathways and their regulatory systems will be critical to developing new approaches to treatment. In this regard, there is increasing interest in the role of microRNAs (miRNAs) in the regulation of pulmonary innate host defense responses and the inflammatory sequelae in respiratory disease. In this review, we discuss recent findings that indicate an important role for miRNAs in the regulation in mouse models of various respiratory diseases and in host defense against bacterial and viral infection. We also discuss the potential utility and limitations of targeting these molecules as anti-inflammatory strategies and also as a means to improve pathogen clearance from the lung.

Micro RNAs (miRNAs) are a class of small regulatory RNAs, which posttranscriptionally repress protein production of the targeted messenger RNAs (mRNAs). Accumulating evidence has suggested lineage-specific miRNAs have contributed to lineage-specific characteristics. However, the birth and death of these miRNAs, particularly in primates, largely remain unexplored. We herein characterized the evolutionary history of a newly discovered miRNA cluster on primate X-chromosome, spanning a approximately 33-kb region in human Xq27.3. The cluster consists of six distinct miRNAs, four of which are compactly organized in a 3-kb region belonging to a phylogenetic group distinct from the other two miRNAs. By comparing the genomic structure of this cluster in human with four other primates (chimpanzee, orangutan, rhesus macaque, and marmoset), we identified several previously uncovered miRNAs in these primates that share orthology with the human miRNAs. We found the entire miRNA cluster was well conserved among primate species but unidentifiable in other mammalian species (including mouse, rat, cat, dog, horse, cow, opossum, and platypus), suggesting that the formation of this cluster was after the primate-rodent split but before the emergence of New-World Monkey (represented by marmoset). Our analysis further revealed complex evolutionary dynamics on this locus, characterized by extensive duplication events. Phylogenetic analysis revealed birth and death of the miRNAs within this region, accompanied by rapid evolution, which highlighted their functional importance. These miRNAs are primarily expressed in primate epididymis, part of the male reproductive system. Our analysis showed that their predicted target mRNAs are significantly enriched for several functional classes relevant to epididymal physiology, such as morphogenesis of epithelium and tube development. Furthermore, several genes controlling sperm maturation and male fertility are confidently predicted to be their targets. Collectively, we argue these miRNAs might play an important role in epididymal morphogenesis and sperm maturation and in establishing primate-specific epididymal characteristics.

To identify synergistic combinations of different food additives, the antimicrobial effects of thymol and carvacrol against Salmonella Typhimurium were assessed alone and in combination with various other preservatives including EDTA, acetic acid, lactic acid, and citric acid. Overall, growth of Salmonella Typhimurium was significantly inhibited in Mueller-Hinton broth containing thymol, carvacrol, EDTA, acetic acid, lactic acid, or citric acid at concentrations of 400 mg/liter, 400 microl/liter, 300 mg/liter, 0.2% (vol/vol), 0.2% (vol/vol), and 0.2% (wt/vol), respectively. The combination of different antimicrobials such as thymol or carvacrol with EDTA, thymol or carvacrol with acetic acid, and thymol or carvacrol with citric acid all resulted in significantly reduced populations of Salmonella Typhimurium. In samples treated with combinations, these antimicrobials had synergistic effects compared with samples treated with thymol, carvacrol, EDTA, acetic acid, or citric acid alone. However, the combined use of lactic acid with thymol or carvacrol did not produce a synergistic effect against Salmonella Typhimurium. Thus, some chelators or organic acids can be used as food preservatives in combination with thymol and carvacrol to reduce the concentrations needed to produce an adequate antimicrobial effect.

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