The entirely carbohydrate immunogen Tn-PS A1 induces a cancer cell selective immune response and cytokine IL-17

Silva, Ravindra A. De; Appulage, Dananjaya K.; Pietraszkiewicz, Halina; Bobbitt, Kevin; Media, Joe; Shaw, J.J.; Valeriote, Fred; Andreana, Peter R.

doi:10.1007/s00262-012-1205-9

Cited by 32 publications

(27 citation statements)

References 25 publications

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“…Our results suggest that it is not the α-helical nature of the polysaccharide but the alternating charges that contribute to MHC class II activation. 17 Our data also shows how the α-helical content is diminished under physiological conditions using pH and temperature. This leads us to believe the Tn-PS A1 construct binds MHCII through electrostatics and that structural aspects do not play a critical role, contrary to what has been previously proposed.…”

Section: Discussionsupporting

confidence: 58%

“…In previous work, we conjugated the Thomsen-nouveau (Tn) 16,17 and Thomas-Friedenreich (TF) 18 tumor associated carbohydrate antigens (TACAs) to 1 and discovered an antigen specific immune response. 16,17 The Tn TACA was chosen for two main reasons: 1) it represents the simplest structure of all the known TACAs 19 rendering it readily accessible through synthetic strategies and 2) a number of reports exist detailing Tn as a glycoprotein conjugate that provides data points for comparison purposes in our own studies. Our approach involved conjugating the Tn aminooxy sugar ( 2 ) to PS A1 ( 1 ) via selective oxidative cleavage of the vicinal diol (1° 6-OH, 2° 5-OH) found on the bacterial-exclusive D-galactofuranose using 0.01 M NaIO 4 (Scheme 1).…”

Section: Resultsmentioning

confidence: 99%

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Elucidating structural features of an entirely carbohydrate cancer vaccine construct employing circular dichroism and fluorescent labeling

2014

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The zwitterionic polysaccharide PS A1 from anaerobe Bacteroides fragilis ATCC 25285/NCTC 9343 is known to elicit a T-cell-dependent, major histocompatibility complex class II (MHCII) immune response through a correspondingly similar protein-antigen-based mechanism/pathway. The biological activity of PS A1 is known to arise from alternating charged motifs on adjacent monosaccharides comprising a tetrameric repeating oligomeric unit creating an alpha-helical secondary structure. However, we have learned that this alpha-helical structural characteristic may not play a role in immune activation. Paradoxically, our current knowledge of structure - activity relationships (SARs) with electrostatically charged polysaccharides has become more clearly defined, yet a lack of tools/probes for measuring dynamic structural changes hinders progress in carbohydrate-based vaccine development. Site- and region-specific structural modifications of PS A1, followed by conjugation with a known carbohydrate cancer antigen, the Thomsen-nouveau (Tn = alpha-D-GalNAc-OSer/Thr) antigen, does not alter antibody isotype switching ability and leads to specific IgG3 antibodies in C57BL/6 mice. Circular dichroism (CD) and studies using fluorescently labeled PS A1, described herein, reveal information pertaining to structure - activity relationships and the nature of Tn conjugation to chemically modified PS A1. The CD spectra of a Tn-PS A1 construct at 8.5 ≥ pH ≤ 3.5 illustrates complete loss of alpha-helical character while spectra obtained in the 3.6 ≤ pH ≥ 8.4 range denotes minimal alpha-helicity in comparison to naturally occurring PS A1. Temperatures exceeding 60 °C reveal complete loss of helical character. Two methods for Alexa Fluor488® fluorescent labeling studies of chemically oxidized PS A1 have given rise to percent conjugation values (% loading) calculated to be on average 35 Tn molecules bound. Combined, our results argue that altering the structure of PS A1, without chemically modifying the electrostatic charge character, does not alter immune response/recognition in mice. These findings have important implications for the design of entirely carbohydrate-based vaccine constructs.

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Section: Discussionsupporting

confidence: 58%

Section: Resultsmentioning

confidence: 99%

Elucidating structural features of an entirely carbohydrate cancer vaccine construct employing circular dichroism and fluorescent labeling

2014

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“…44 Por outro lado, os C-glicosídeos estão envolvidos em muitos processos de reconhecimento biológicos, como por exemplo, comunicação entre células, 45,46 transdução de sinal, [47][48][49] adesão bacteriana e viral, [50][51][52] e respostas do sistema imune. [53][54][55][56][57] Esse tipo de comportamento imunológico, nos últimos anos, vem levando ao desenvolvimento de pesquisa inovadoras para vacinas antitumorais. 58…”

Section: Figura 4 Estrutura Da Ambruticina Sunclassified

Recent Advances in C-Glycoside Chemistry: Application, Synthesis and Reactions

et al. 2018

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The synthesis of C-glycosides, sugar analogs in which glycosidic oxygen is substituted by a carbon atom, is of particular interest due to their usefulness as key intermediates for assembling biologically active molecules and natural products. Despite their challenging chemistry, due to their versatility, C-glycosides play a pivotal role in the development of the chemistry of novel materials and bioactive molecules. In this review, we present of various synthetic methodologies, mechanistic proposal and application for 2,3-unsaturated C-glycosides in the last twenty years.

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“…PS A1 is a zwitterionic polysaccharide (ZPS) isolated from the commensal bacteria Bacteroides fragilis (ATCC 25285/NCTC 9343) capable of activating CD4+ T cells in a major histocompatibility complex-II (MHC-II) dependent mechanism [20,21]. PS A1 is an effective immunogenic carrier for TACAs and is evidenced by our previous work with Tn-PS A1 and STn-PS A1 [17,18,22]. These PS A1 conjugates were able to induce protective immune responses that consisted of potent antibody production, cellular immunity, and the production of proinflammatory markers such as T helper 17 (Th17) cells and IL-17, which are essential in the protection against cancer [23,24].…”

Section: Introductionmentioning

confidence: 96%

Enhanced Immune Response Against the Thomsen-Friedenreich Tumor Antigen Using a Bivalent Entirely Carbohydrate Conjugate

et al. 2020

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The Thomsen-Friedenreich (TF) antigen is a key target for the development of anticancer vaccines, and this ongoing challenge remains relevant due to the poor immunogenicity of the TF antigen. To overcome this challenge, we adopted a bivalent conjugate design which introduced both the TF antigen and the Thomsen-nouveau (Tn) antigen onto the immunologically relevant polysaccharide A1 (PS A1). The immunological results in C57BL/6 mice revealed that the bivalent, Tn-TF-PS A1 conjugate increased the immune response towards the TF antigen as compared to the monovalent TF-PS A1. This phenomenon was first observed with enzyme-linked immunosorbent assay (ELISA) where the bivalent conjugate generated high titers of IgG antibodies where the monovalent conjugate generated an exclusive IgM response. Fluorescence-activated cell sorting (FACS) analysis also revealed increased binding events to the tumor cell lines MCF-7 and OVCAR-5, which are consistent with the enhanced tumor cell lysis observed in a complement dependent cytotoxicity (CDC) assay. The cytokine profile generated by the bivalent construct revealed increased pro-inflammatory cytokines IL-17 and IFN-γ. This increase in cytokine concentration was matched with an increase in cytokine producing cells as observed by ELISpot. We hypothesized the mechanisms for this phenomenon to involve the macrophage galactose N-acetylgalactosamine specific lectin 2 (MGL2). This hypothesis was supported by using biotinylated probes and recombinant MGL2 to measure carbohydrate-protein interactions.

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The entirely carbohydrate immunogen Tn-PS A1 induces a cancer cell selective immune response and cytokine IL-17

Cited by 32 publications

References 25 publications

Elucidating structural features of an entirely carbohydrate cancer vaccine construct employing circular dichroism and fluorescent labeling

Elucidating structural features of an entirely carbohydrate cancer vaccine construct employing circular dichroism and fluorescent labeling

Recent Advances in C-Glycoside Chemistry: Application, Synthesis and Reactions

Enhanced Immune Response Against the Thomsen-Friedenreich Tumor Antigen Using a Bivalent Entirely Carbohydrate Conjugate

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