BackgroundProphylactic and therapeutic vaccines often depend upon a strong activation of the innate immune system to drive a potent adaptive immune response, often mediated by a strong adjuvant. For a number of adjuvants immunological readouts may not be consistent across species.MethodsIn this study, we evaluated the innate immunostimulatory potential of mRNA vaccines in both humans and mice, using a novel mRNA-based vaccine encoding influenza A hemagglutinin of the pandemic strain H1N1pdm09 as a model. This evaluation was performed using an in vitro model of human innate immunity and in vivo in mice after intradermal injection.ResultsResults suggest that immunostimulation from the mRNA vaccine in humans is similar to that in mice and acts through cellular RNA sensors, with genes for RLRs [ddx58 (RIG-1) and ifih1 (MDA-5)], TLRs (tlr3, tlr7, and tlr8-human only), and CLRs (clec4gp1, clec2d, cledl1) all significantly up-regulated by the mRNA vaccine. The up-regulation of TLR8 and TLR7 points to the involvement of both mDCs and pDCs in the response to the mRNA vaccine in humans. In both humans and mice activation of these pathways drove maturation and activation of immune cells as well as production of cytokines and chemokines known to attract and activate key players of the innate and adaptive immune system.ConclusionThis translational approach not only allowed for identification of the basic mechanisms of self-adjuvantation from the mRNA vaccine but also for comparison of the response across species, a response that appears relatively conserved or at least convergent between the in vitro human and in vivo mouse models.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-016-1111-6) contains supplementary material, which is available to authorized users.

A 4-kilobase and a 2-kilobase cDNA clone encoding a murine macrophage colony-stimulating factor have been isolated. Except for 2 amino acid residue differences, these two clones encode the same 520 amino acid residue protein, which is preceded by a 32-amino acid residue signal peptide. The two clones, whose molecular masses correspond to the two transcripts observed in murine L929 fibroblasts, contain 3' untlated regions that are markedly different in sequence and length. Both clones can be expressed in COS cells and the recombinant protein is active in a mouse bone marrow colony assay.

A strain of Saccharomyces cerevisiae capable of simultaneous hydrolysis and fermentation of highly polymerized starch oligosaccharides was constructed. The Aspergillus awamori glucoamylase enzyme, form GAI, was expressed in Saccharomyces cerevisiae by means of the promoter and termination regions from a yeast enolase gene. Yeast transformed with plasmids containing an intron-free recombinant glucoamylase gene efficiently secreted glucoamylase into the medium, permitting growth of the transformants on starch as the sole carbon source. The natural leader sequence of the precursor of glucoamylase (preglucoamylase) was processed correctly by yeast, and the secreted enzyme was glycosylated through both N- and O-linkages at levels comparable to the native Aspergillus enzyme. The data provide evidence for the utility of yeast as an organism for the production, glycosylation, and secretion of heterologous proteins.

The filamentous ascomycete Aspergillus awamori secretes large amounts of glucoamylase upon growth in medium containing starch, glucose, or a variety of hexose sugars and sugar polymers. We examined the mechanism of this carbon source-dependent regulation of glucoamylase accumulation and found a several hundredfold increase in glucoamylase mRNA in cells grown on an inducing substrate, starch, relative to cells grown on a noninducing substrate, xylose. We postulate that induction of glucoamylase synthesis is regulated transcriptionally. Comparing total mRNA from cells grown on starch and xylose, we were able to identify an inducible 2.3-kilobase mRNA-encoding glucoamylase. The glucoamylase mRNA was purified and used to identify a molecularly cloned 3.4-kilobase EcoRI fragment containing the A. awamori glucoamylase gene. Comparison of the nucleotide sequence of the 3.4-kilobase EcoRI fragment with that of the glucoamylase I mRNA (as determined from molecularly cloned cDNA) revealed the existence of four intervening sequences within the glucoamylase gene. The 5' end of the glucoamylase mRNA was mapped to several locations within a region -52 to -73 nucleotides from the translational start. Sequence and structural features of the glucoamylase gene of the filamentous ascomycete A. awamori were examined and compared with those reported in genes of other eucaryotes.

Therapeutic mAbs that target tumor-associated Ags on the surface of malignant cells have proven to be an effective and specific option for the treatment of certain cancers. However, many of these protein markers of carcinogenesis are not expressed on the cells’ surface. Instead these tumor-associated Ags are processed into peptides that are presented at the cell surface, in the context of MHC class I molecules, where they become targets for T cells. To tap this vast source of tumor Ags, we generated a murine IgG2a mAb, 3.2G1, endowed with TCR-like binding specificity for peptide-HLA-A*0201 (HLA-A2) complex and designated this class of Ab as TCR mimics (TCRm). The 3.2G1 TCRm recognizes the GVL peptide (GVLPALPQV) from human chorionic gonadotropin β presented by the peptide-HLA-A*0201 complex. When used in immunofluorescent staining reactions using GVL peptide-loaded T2 cells, the 3.2G1 TCRm specifically stained the cells in a peptide and Ab concentration-dependent manner. Staining intensity correlated with the extent of cell lysis by complement-dependent cytotoxicity (CDC), and a peptide concentration-dependent threshold level existed for the CDC reaction. Staining of human tumor lines demonstrated that 3.2G1 TCRm was able to recognize endogenously processed peptide and that the breast cancer cell line MDA-MB-231 highly expressed the target epitope. The 3.2G1 TCRm-mediated CDC and Ab-dependent cellular cytotoxicity of a human breast carcinoma line in vitro and inhibited in vivo tumor implantation and growth in nude mice. These results provide validation for the development of novel TCRm therapeutic reagents that specifically target and kill tumors via recognition and binding to MHC-peptide epitopes.