Global Inhibition of DC Priming Capacity in the Spleen of Self-Antigen Vaccinated Mice Requires IL-10

DC in the spleen are highly activated following intravenous vaccination with a foreign antigen, promoting expansion of effector T cells, but remain phenotypically and functionally immature after vaccination with a self-antigen. Up-regulation or suppression of expression of a cohort of pancreatic enzymes 24-72 hours post-vaccination can be used as a biomarker of stimulatory versus toleragenic DC, respectively. Here we show, using MUC1 transgenic mice (MUC1.Tg) and a vaccine based on the MUC1 peptide which these mice perceive as a self-antigen, that the difference in enzyme expression that predicts whether DC will promote immune response or immune tolerance, is seen as early as 4-8 hours following vaccination. We also identify early production of IL-10 as a predominant factor that both correlates with this early time point and controls DC function. Pre-treating mice with an antibody against the IL-10 receptor (IL-10R) prior to vaccination results in DC that up-regulate CD40, CD80, and CD86 and promote stronger IFNγ+ T cell responses. This study suggests that transient inhibition of IL-10 prior to vaccination could improve responses to cancer vaccines that utilize self-tumor antigens

Cloning and Expression of Human Membrane-Bound and Soluble Engineered T Cell Receptors for Immunotherapy

We report here the design and construction of several gene vectors for expression in mammalian cells of membrane-bound and soluble human T cell receptors (TR). We designed a vector (TR-ALPHA-IRES-TR-BETA pEF4) that encodes high-level expression of the full-length TR on the surface of T cells. Furthermore, we engineered TR that does not require the presence of endogenous CD3 molecules for surface expression and thus expression is not limited to T cells. We also constructed a vector encoding a single-chain TR (scTR) as a fusion protein of V-ALPHA-V-BETA-C-BETA with CD3Z. Since it is encoded and expressed as a single molecule, this scTR is well suited for gene therapy. Lastly, we successfully used a mammalian expression vector for generation of soluble human TR. The approaches we used here for manipulation of a human tumor-specific TR can be useful for other investigators interested in TR-based immunotherapy

Mumps and ovarian cancer: modern interpretation of an historic association

Background Epidemiologic studies found childhood mumps might protect against ovarian cancer. To explain this association, we investigated whether mumps might engender immunity to ovarian cancer through antibodies against the cancer-associated antigen MUC1 abnormally expressed in the inflamed parotid gland. Methods Through various health agencies, we obtained sera from 161 cases with mumps parotitis. Sera were obtained from 194 healthy controls. We used an ELISA to measure anti-MUC1 antibodies and electro-chemiluminescence assays to measure MUC1 and CA 125. Log-transformed measurements were analyzed by t-tests, generalized linear models, and Pearson or Spearman correlations. We also conducted a meta-analysis of all published studies regarding mumps and ovarian cancer. Results Adjusting for assay batch, age, and sex, the level of anti-MUC1 antibodies was significantly higher in mumps cases compared to controls (p = 0.002). Free circulating levels of CA 125, but not MUC1, were also higher in cases (p = 0.02). From the meta-analysis, the pooled odds ratio estimate (and 95% CI) for the mumps and ovarian cancer association was 0.81 (0.68–0.96) (p = 0.01). Conclusion Mumps parotitis may lead to expression and immune recognition of a tumor-associated form of MUC1 and create effective immune surveillance of ovarian cancer cells that express this form of MUC1

Cross-priming of cyclin B1, MUC-1 and survivin-specific CD8(+ )T cells by dendritic cells loaded with killed allogeneic breast cancer cells

INTRODUCTION: The ability of dendritic cells (DCs) to take up whole tumor cells and process their antigens for presentation to T cells ('cross-priming') is an important mechanism for induction of tumor specific immunity. METHODS: In vitro generated DCs were loaded with killed allogeneic breast cancer cells and offered to autologous naïve CD8(+ )T cells in 2-week and/or 3-week cultures. CD8(+ )T cell differentiation was measured by their capacity to secrete effector cytokines (interferon-γ) and kill breast cancer cells. Specificity was measured using peptides derived from defined breast cancer antigens. RESULTS: We found that DCs loaded with killed breast cancer cells can prime naïve CD8(+ )T cells to differentiate into effector cytotoxic T lymphocytes (CTLs). Importantly, these CTLs primed by DCs loaded with killed HLA-A*0201(- )breast cancer cells can kill HLA-A*0201(+ )breast cancer cells. Among the tumor specific CTLs, we found that CTLs specific for HLA-A2 restricted peptides derived from three well known shared breast tumor antigens, namely cyclin B1, MUC-1 and survivin. CONCLUSION: This ability of DCs loaded with killed allogeneic breast cancer cells to elicit multiantigen specific immunity supports their use as vaccines in patients with breast cancer

Evolution of the Cytosolic Iron/Sulfur cluster Assembly machinery in Blastocystis sp. and other microbial eukaryotes

The Cytosolic Iron/Sulfur cluster Assembly (CIA) machinery is responsible for the assembly of cytosolic and nuclear iron/sulfur clusters, cofactors that are vital for all living cells. This machinery is uniquely found in eukaryotes and consists of at least eight proteins in opisthokont lineages such as animals and yeast. We sought to identify and characterize homologues of the CIA system proteins in the anaerobic stramenopile parasite Blastocystis sp. NandII strain. We identified transcripts encoding six of the components - Cia1, Cia2, MMS19, Nbp35, Nar1, and a putative Tah18 - and showed that the last three of them localized to the cytoplasm of the cell using immuno-fluorescence microscopy, immuno-electron microscopy and subcellular fractionation. We then used comparative genomic and phylogenetic approaches to investigate the evolutionary history of these proteins. While most Blastocystis homologues branch with their eukaryotic counterparts, the putative Blastocystis Tah18 seems to have a separate evolutionary origin and therefore possibly a different function. Furthermore, our phylogenomic analyses revealed that all eight CIA components described in opisthokonts originated before the diversification of extant eukaryotic lineages and were likely already present in the Last Eukaryotic Common Ancestor (LECA). Nbp35, Nar1 Cia1 and Cia2 proteins have been conserved during the subsequent evolutionary diversification of eukaryotes and are present in virtually all extant lineages, whereas the other CIA proteins have patchy phylogenetic distributions. Cia2 appears to be homologous to SufT, a component of the prokaryotic SUF system, making this the first reported evolutionary link between the CIA and any other Fe/S biogenesis pathway. All of our results suggest that the CIA machinery is an ubiquitous biosynthetic pathway in eukaryotes, but its apparent plasticity in composition raises questions regarding how it functions in non-model organisms and how it interfaces with various iron/sulfur cluster systems (i.e., ISC, NIF and/or SUF) found in eukaryotic cells

Stem rust resistance in wheat is suppressed by a subunit of the mediator complex

Stem rust is an important disease of wheat that can be controlled using resistance genes. The gene SuSr-D1 identified in cultivar 'Canthatch' suppresses stem rust resistance. SuSr-D1 mutants are resistant to several races of stem rust that are virulent on wild-type plants. Here we identify SuSr-D1 by sequencing flow-sorted chromosomes, mutagenesis, and map-based cloning. The gene encodes Med15, a subunit of the Mediator Complex, a conserved protein complex in eukaryotes that regulates expression of protein-coding genes. Nonsense mutations in Med15b.D result in expression of stem rust resistance. Time-course RNAseq analysis show a significant reduction or complete loss of differential gene expression at 24h post inoculation in med15b.D mutants, suggesting that transcriptional reprogramming at this time point is not required for immunity to stem rust. Suppression is a common phenomenon and this study provides novel insight into suppression of rust resistance in wheat. Stem rust is an important disease of wheat and resistance present in some cultivars can be suppressed by the SuSr-D1 locus. Here the authors show that SuSr-D1 encodes a subunit of the Mediator Complex and that nonsense mutations are sufficient to abolish suppression and confer stem rust resistance