T‐cell epitope‐dependent immune response in inbred (C57BL/6J,SJL/J,and C3H/HeN) and transgenic P301S and Tg2576 mice

Alzheimer's disease is characterized by two pathological hallmarks, the intracellular deposition of hyperphosphorylated Tau protein and the extracellular deposition of Aβ_1–40/42, both being targets for immunotherapy. This study evaluates the immunogenic properties of three AD‐specific B‐cell epitopes (Tau_229–237[pT231/pS235], pyroGluAβ_3–8, and Aβ_{37/38–42/43}) linked to five foreign T‐cell epitopes (MVFP, TT, TBC Ag85B, PvT19, and PvT53) by immunizing inbred C57BL/6J (H‐2^b), SJL/J (H‐2^s2), and C3H/HeN (H‐2^k) mice. Two promising candidates with respect to MHC II restriction were selected, and two transgenic mouse models of AD, P301S (H‐2^b/k) and Tg2576 (H‐2^b/s) animals, were immunized with one B‐cell epitope in combination with two T‐cell epitopes. Responders displayed an enhanced immune response compared with wild‐type animals, which supports the vaccine design and the vaccination strategy. The immune response was also characterized by specific IgG subtype titers, which revealed a strong polarization toward the humoral pathway for immunization of phospho‐Tau, whereas for both Aβ vaccines, a mixed cellular/humoral pathway response was observed. Despite the diversity and unpredictability of the immunogenicity of the peptide vaccines, all three peptide vaccine formulations appear to be promising constructs for future evaluation of their therapeutic properties. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.     

Transgenic expression of n‐3 fatty acid desaturase (fat‐1) in C57/BL6 mice: Effects on glucose homeostasis and body weight

The fat‐1 gene, derived from Caenorhabditis elegans, encodes for a fatty acid n‐3 desaturase. In order to study the potential metabolic benefits of n‐3 fatty acids, independent of dietary fatty acids, we developed seven lines of fat‐1 transgenic mice (C57/BL6) controlled by the regulatory sequences of the adipocyte protein‐2 (aP2) gene for adipocyte‐specific expression (AP‐lines). We were unable to obtain homozygous fat‐1 transgenic offspring from the two highest expressing lines, suggesting that excessive expression of this enzyme may be lethal during gestation. Serum fatty acid analysis of fat‐1 transgenic mice (AP‐3) fed a high n‐6 unsaturated fat (HUSF) diet had an n‐6/n‐3 fatty acid ratio reduced by 23% (P < 0.025) and the n‐3 fatty acid eicosapentaenoic acid (EPA) concentration increased by 61% (P < 0.020). Docosahexaenoic acid (DHA) was increased by 19% (P < 0.015) in white adipose tissue. Male AP‐3‐fat‐1 line of mice had improved glucose tolerance and reduced body weight with no change in insulin sensitivity when challenged with a high‐carbohydrate (HC) diet. In contrast, the female AP‐3 mice had reduced glucose tolerance and no change in insulin sensitivity or body weight. These findings indicate that male transgenic fat‐1 mice have improved glucose tolerance likely due to increased insulin secretion while female fat‐1 mice have reduced glucose tolerance compared to wild‐type mice. Finally the inability of fat‐1 transgenic mice to generate homozygous offspring suggests that prolonged exposure to increased concentrations of n‐3 fatty acids may be detrimental to reproduction. J. Cell. Biochem. 107: 809–817, 2009. © 2009 Wiley‐Liss, Inc.     

Novel recombinant BCG coexpressing Ag85B,ESAT‐6 and mouse TNF‐α induces significantly enhanced cellular immune and antibody responses in C57BL/6 mice

The recent emergence of multidrug‐resistant and extensively drug‐resistant strains of Mtb and the epidemic of TB in populations co‐infected with human immunodeficiency virus demonstrate that TB remains a leading infectious disease. Moreover, the failure of BCG to protect against this disease indicates that new vaccines against TB are urgently needed. Experimental evidence has revealed that TNF plays a major role in host defense against Mtb in both active and latent phases of infection. Release of TNF, which would induce mycobacteria‐mediated macrophage apoptosis and thus reduce the spread of mycobacteria, is one of the most important and early responses of macrophages challenged with Mtb. In order to identify the usefulness of TNF in improving the effectiveness of TB vaccine, in the current study a novel rBCG strain expressing the fusion gene of Ag85B‐Esat6‐TNF‐α in BCG Danish strain was constructed, and its ability to induce an immune response in C57BL/6 mice evaluated. It was found that immunization with strains of rBCG‐Ag85B‐Esat6‐TNF‐α can induce a stronger immune response than does immunization with rBCG‐Ag85B‐Esat6 or parental BCG. The results indicate that rBCG‐Ag85B‐Esat6‐TNF‐α is a promising candidate for further study.     

Peptide and glycopeptide dendrimers. Part I

Recent progress in peptide and glycopeptide chemistry make the preparation of peptide and glycopeptide dendrimers of acceptable purity, with designed structural and immunochemical properties reliable. New methodologies using unprotected peptide building blocks have been developed to further increase possibilities of their design and improve their preparation and separation. Sophisticated design of peptide and glycopeptide dendrimers has led to their use as antigens and immunogens, for serodiagnosis and other biochemical uses including drug delivery. Dendrimers bearing peptide with predetermined secondary structures are useful tools in protein de novo design. This article covers synthesis and applications of multiple antigen peptides (MAPs), multiple antigen glycopeptides (MAGs), multiple antigen peptides based on sequential oligopeptide carriers (MAP‐SOCs), glycodendrimers and template‐assembled synthetic proteins (TASPs). Part I deals with the development of various structural forms of MAPs as well as their application as antigens, immunogens, and for immunodiagnostic and biochemical purposes. Copyright © 1999 European Peptide Society and John Wiley & Sons, Ltd.