Search results for "Haptens"

Allergen-Specific Low Zone Tolerance Is Independent of MRP8/14-, TLR4-, TLR7-, and TLR9-Mediated Immune Processes.

2017

Protein-Free Hapten-Carbon Nanotube Constructs Induce the Secondary Immune Response

2017

Carbon nanotubes are novel technological tools with multiple applications. The interaction between such nanoparticles and living organisms is nowadays a matter of keen research by academic and private institutions. In this study, carbon nanotube constructs were investigated as delivery vehicles for immunostimulation and induction of the secondary immune response to a small organic molecule, namely, a hapten. Two types of nanoconstructs were prepared: on one hand, carbon nanotubes carrying a protein bioconjugate of a hapten covalently linked to the carbon surface, and on the other hand, covalent carbon nanotube constructs of the same model chemical compound without the carrier protein. Nanot…

Mepanipyrim haptens and antibodies with nanomolar affinity

2013

Mepanipyrim is an anilinopyrimidine fungicide used worldwide for crop protection. With the aim of developing useful immunoreagents for mepanipyrim immunoanalysis, two new functionalized derivatives were prepared and antibodies were generated. Affinity and specificity were assessed by direct and indirect competitive ELISA using homologous and heterologous conjugates. Although all antibodies were selective for the target analyte, the immunizing hapten structure was revealed as a determinant for high-affinity antibody production (IC50 = 3 nM). © 2013 The Royal Society of Chemistry.

Ready Access to Proquinazid Haptens via Cross-Coupling Chemistry for Antibody Generation and Immunoassay Development.

2015

17 pages, 4 tables, 5 figures.-- Publisher's PDF

Exploring alternative hapten tethering sites for high-affinity anti-picoxystrobin antibody generation

2011

The relevance of the linker tethering site in haptens was investigated for antibody generation and immunoassay development. Three derivatives of the strobilurin fungicide picoxystrobin were synthesized with the same functionalized spacer arm located at three different positions. Protein conjugates of those haptens were employed as immunogens, and novel polyclonal antibodies were produced and characterized. All haptens afforded highly specific antibodies, but different affinities to the free analyte were observed among the obtained antisera. Next, competitive enzyme-linked immunosorbent assays were studied in several formats, and site heterology was confirmed as an effective strategy for det…

Carbon nanotube-protein carriers enhance size-dependent self-adjuvant antibody response to haptens

2013

Carbon nanotubes (CNTs) are nanomaterials with interesting emerging applications. Their properties make CNTs excellent candidates for use as new nanovehicles in drug delivery, immunization and diagnostics. In the current study, we assessed the immune-response-amplifying properties of CNTs to haptens by using azoxystrobin, the first developed strobilurin fungicide, asamodel analyte. Anazoxystrobin derivative bearingacarboxylated spacer arm (hapten AZc6) was covalently coupled to bovine serum albumin (BSA), and the resulting BSA-AZc6 conjugate was covalently linked to four functionalized CNTs of different shapes and sizes, varying in diameter and length. These four types of CNT-based construc…

A class-selective immunoassay for simultaneous analysis of anilinopyrimidine fungicides using a rationally designed hapten

2017

he development of multianalyte immunoassays constitutes a main research issue in the field of bioanalytical techniques. In the present study, class-specific antibodies against the three members of the anilinopyrimidine family of fungicides (pyrimethanil, cyprodinil and mepanipyrim) were raised by using a bioconjugate of a rationally designed hapten [5-(6-methyl-2-(phenylamino)pyrimidin-4-yl)pentanoic acid]. Highly sensitive immunoassays were developed for the generic determination of these compounds, using the competitive enzyme-linked immunosorbent assay (ELISA). Particularly, a direct antibody-coated competitive ELISA afforded identical sensitivity for the three anilinopyrimidines, with I…

Combined heterologies for monoclonal antibody-based immunoanalysis of fluxapyroxad

2018

Nowadays, instrumental methodologies and rapid bioanalytical techniques complement each other for the analysis of toxic chemical compounds. Fluxapyroxad was commercialized a few years ago as a fungicide and today it is being used worldwide to control a variety of pests. In the present study, the development of monoclonal antibody-based immunochemical methods for the analysis of this chemical in food samples was evaluated for the first time. Novel haptens were synthesized and protein bioconjugates were prepared. High-affinity and specific monoclonal antibodies to fluxapyroxad were generated from two haptens with alternative linker tethering sites. Haptens with linker site heterology and a st…

Development of hapten-induced IL-4-producing CD4+ T lymphocytes requires early IL-4 production by alphabeta T lymphocytes carrying invariant V(alpha)…

1998

This paper investigates the mechanisms responsible for the generation of IL-4-producing CD4+ T cells during contact sensitization with the hapten trinitrochlorobenzene (TNCB). Lymph node cells taken 1 day after immunization spontaneously released IL-4 while lymph node cells taken 2 and 3 days after immunization did not produce IL-4. A second wave of IL-4 production that was both antigen-specific and MHC class II (I-A)-restricted was observed 4 days after immunization. The spontaneous release of IL-4 at day 1 was due to the alphabeta+ double-negative (CD4- CD8-) T lymphocytes that also expressed NK1.1 and showed V(alpha)14 rearrangement, while alphabeta+ CD4+ T lymphocytes were the source of…

Induction of CD4+/CD25+ regulatory T cells by targeting of antigens to immature dendritic cells

2003

AbstractCoupling of ovalbumin (OVA) to anti–DEC-205 monoclonal antibody (mAb) (αDEC) induced the proliferation of OVA-specific T cells in vivo. Expansion was short-lived, caused by dendritic cells (DCs), and rendered T cells anergic thereafter. Phenotypic analysis revealed the induction of CD25+/CTLA-4+ T cells suppressing proliferation and interleukin-2 (IL-2) production of effector CD4+ T cells. The findings were supported by 2 disease models: (1) CD4+ T-cell–mediated hypersensitivity reactions were suppressed by the injection of αDEC-OVA and (2) the application of hapten-coupled αDEC-205 reduced CD8+ T-cell–mediated allergic reactions. Thus, targeting of antigens to immature DCs through …