scholarly journals Comparative Analysis of the Mucosal Adjuvanticity of the Type II Heat-Labile Enterotoxins LT-IIa and LT-IIb

2000 ◽  
Vol 68 (1) ◽  
pp. 281-287 ◽  
Author(s):  
Michael Martin ◽  
Daniel J. Metzger ◽  
Suzanne M. Michalek ◽  
Terry D. Connell ◽  
Michael W. Russell
Keyword(s):  
Lymph Nodes ◽  
Specific Antibody ◽  
Antibody Responses ◽  
Interleukin 4 ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antibody Activity ◽  
Type I ◽  
Type Ii ◽  
Cervical Lymph Nodes ◽  
Heat Labile

ABSTRACT Cholera toxin (CT) and the heat-labile enterotoxin ofEscherichia coli (LT-I) are members of the serogroup I heat-labile enterotoxins (HLT) and can serve as systemic and mucosal adjuvants. However, information is lacking with respect to the structurally related but antigenically distinct serogroup II HLT, LT-IIa and LT-IIb, which have different binding specificities for ganglioside receptors. The purpose of this study was to assess the effectiveness of LT-IIa and LT-IIb as mucosal adjuvants in comparison to the prototypical type I HLT, CT. BALB/c mice were immunized by the intranasal (i.n.) route with the surface protein adhesin AgI/II ofStreptococcus mutans alone or supplemented with an adjuvant amount of CT, LT-IIa, or LT-IIb. Antigen-specific antibody responses in saliva, vaginal wash, and plasma were assayed by enzyme-linked immunosorbent assay. Mice given AgI/II with LT-IIa or LT-IIb by the i.n. route had significantly higher mucosal and systemic antibody responses than mice immunized with AgI/II alone. Anti-AgI/II immunoglobulin A (IgA) antibody activity in saliva and vaginal secretions of mice given AgI/II with LT-IIa or LT-IIb was statistically similar in magnitude to that seen in mice given AgI/II and CT. LT-IIb significantly enhanced the number of AgI/II-specific antibody-secreting cells in the draining superficial cervical lymph nodes compared to LT-IIa and CT. LT-IIb and CT induced significantly higher plasma anti-AgI/II IgG titers compared to LT-IIa. When LT-IIb was used as adjuvant, the proportion of plasma IgG2a relative to IgG1 anti-AgI/II antibody was elevated in contrast to the predominance of IgG1 antibodies promoted by AgI/II alone or when CT or LT-IIa was used. In vitro stimulation of AgI/II-specific cells from the superficial lymph nodes and spleen revealed that LT-IIa and LT-IIb induced secretion of interleukin-4 and significantly higher levels of gamma interferon compared to CT. These results demonstrate that the type II HLT LT-IIa and LT-IIb exhibit potent and distinct adjuvant properties for stimulating immune responses to a noncoupled protein immunogen after mucosal immunization.

scholarly journals Mutants of Type II Heat-Labile Enterotoxin LT-IIa with Altered Ganglioside-Binding Activities and Diminished Toxicity Are Potent Mucosal Adjuvants

2006 ◽  
Vol 75 (2) ◽  
pp. 621-633 ◽  
Author(s):  
Hesham F. Nawar ◽  
Sergio Arce ◽  
Michael W. Russell ◽  
Terry D. Connell
Keyword(s):  
Escherichia Coli ◽  
Immune Responses ◽  
Binding Activity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Type I ◽  
Type Ii ◽  
Heat Labile ◽  
Enhanced Expression ◽  
Adhesin Protein ◽  
And Function

ABSTRACT The structure and function LT-IIa, a type II heat-labile enterotoxin of Escherichia coli, are closely related to the structures and functions of cholera toxin and LT-I, the type I heat-labile enterotoxins of Vibrio cholerae and enterotoxigenic Escherichia coli, respectively. While LT-IIa is a potent systemic and mucosal adjuvant, recent studies demonstrated that mutant LT-IIa(T34I), which exhibits no detectable binding activity as determined by an enzyme-linked immunosorbent assay, with gangliosides GD1b, GD1a, and GM1 is a very poor adjuvant. To evaluate whether other mutant LT-IIa enterotoxins that also exhibit diminished ganglioside-binding activities have greater adjuvant activities, BALB/c mice were immunized by the intranasal route with the surface adhesin protein AgI/II of Streptococcus mutans alone or in combination with LT-IIa, LT-IIa(T14S), LT-IIa(T14I), or LT-IIa(T14D). All three mutant enterotoxins potentiated strong mucosal immune responses that were equivalent to the response promulgated by wt LT-IIa. All three mutant enterotoxins augmented the systemic immune responses that correlated with their ganglioside-binding activities. Only LT-IIa and LT-IIa(T14S), however, enhanced expression of major histocompatibility complex class II and the costimulatory molecules CD40, CD80, and CD86 on splenic dendritic cells. LT-IIa(T14I) and LT-IIa(T14D) had extremely diminished toxicities in a mouse Y1 adrenal cell bioassay and reduced abilities to induce the accumulation of intracellular cyclic AMP in a macrophage cell line.

scholarly journals Biochemical and structural characterization of the novel sialic acid-binding site of Escherichia coli heat-labile enterotoxin LT-IIb

2016 ◽  
Vol 473 (21) ◽  
pp. 3923-3936 ◽  
Author(s):  
Dani Zalem ◽  
João P. Ribeiro ◽  
Annabelle Varrot ◽  
Michael Lebens ◽  
Anne Imberty ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Binding Site ◽  
Cholera Toxin ◽  
Carbohydrate Binding ◽  
Type I ◽  
Type Ii ◽  
E Coli ◽  
B Subunit ◽  
Heat Labile ◽  
B Subunits

The structurally related AB5-type heat-labile enterotoxins of Escherichia coli and Vibrio cholerae are classified into two major types. The type I group includes cholera toxin (CT) and E. coli LT-I, whereas the type II subfamily comprises LT-IIa, LT-IIb and LT-IIc. The carbohydrate-binding specificities of LT-IIa, LT-IIb and LT-IIc are distinctive from those of cholera toxin and E. coli LT-I. Whereas CT and LT-I bind primarily to the GM1 ganglioside, LT-IIa binds to gangliosides GD1a, GD1b and GM1, LT-IIb binds to the GD1a and GT1b gangliosides, and LT-IIc binds to GM1, GM2, GM3 and GD1a. These previous studies of the binding properties of type II B-subunits have been focused on ganglio core chain gangliosides. To further define the carbohydrate binding specificity of LT-IIb B-subunits, we have investigated its binding to a collection of gangliosides and non-acid glycosphingolipids with different core chains. A high-affinity binding of LT-IIb B-subunits to gangliosides with a neolacto core chain, such as Neu5Gcα3- and Neu5Acα3-neolactohexaosylceramide, and Neu5Gcα3- and Neu5Acα3-neolactooctaosylceramide was detected. An LT-IIb-binding ganglioside was isolated from human small intestine and characterized as Neu5Acα3-neolactohexaosylceramide. The crystal structure of the B-subunit of LT-IIb with the pentasaccharide moiety of Neu5Acα3-neolactotetraosylceramide (Neu5Ac-nLT: Neu5Acα3Galβ4GlcNAcβ3Galβ4Glc) was determined providing the first information for a sialic-binding site in this subfamily, with clear differences from that of CT and LT-I.

Effect of Thermal Processing during Yogurt Production upon the Detection of Staphylococcal Enterotoxin B

2009 ◽  
Vol 72 (10) ◽  
pp. 2212-2216 ◽  
Author(s):  
MARYANN PRINCIPATO ◽  
THOMAS BOYLE ◽  
JOYCE NJOROGE ◽  
ROBERT L. JONES ◽  
MICHAEL O'DONNELL
Keyword(s):  
Storage Period ◽  
Staphylococcal Enterotoxin ◽  
Enzyme Linked Immunosorbent Assay ◽  
Staphylococcal Enterotoxin B ◽  
Type I ◽  
Type Ii ◽  
Biochemical Characteristics ◽  
Enterotoxin B ◽  
Study Type ◽  
Physical Changes

This research was conducted to examine the inherent properties of yogurt contaminated with staphylococcal enterotoxin B (SEB). Two types of yogurts were produced for this study. Type I yogurts were produced by adding SEB at the start of yogurt production, and type II yogurts were produced by adding SEB after the milk base had been boiled. Biochemical characteristics inherent to yogurt, including pH, lactic acid and acetaldehyde concentrations, were analyzed weekly for each batch beginning at a time just after production and throughout a storage period of at least 4 weeks. The presence of toxin during yogurt production did not result in any significant biochemical or physical changes in yogurt. However, we were unable to detect SEB toxin in type I yogurt using a commercially available enzyme-linked immunosorbent assay (ELISA). In contrast, SEB was easily detectable by our ELISA in type II yogurt samples. Higher levels of SEB were recovered from type II yogurt that had been stored for 1 week than from type II yogurt that had been stored for any other length of time. These results indicate that the biochemical characteristics of yogurt did not change significantly (relative to control yogurt) in the presence of either thermally processed SEB or native SEB. However, the ability to detect SEB by ELISA was dependent on whether the toxin had been processed.

Interferon activation status underlies higher antibody response to viral antigens in patients with systemic lupus erythematosus receiving no or light treatment

Rheumatology ◽  
2020 ◽  
Author(s):  
Albin Björk ◽  
Rui Da Silva Rodrigues ◽  
Elina Richardsdotter Andersson ◽  
Jorge I Ramírez Sepúlveda ◽  
Johannes Mofors ◽  
...  
Keyword(s):  
Antibody Response ◽  
Specific Antibody ◽  
Lupus Erythematosus ◽  
Serum Proteins ◽  
Light Treatment ◽  
Antibody Responses ◽  
Type I ◽  
Specific Antibody Response ◽  
Viral Antigens

Abstract Objectives Infections have been proposed as an environmental risk factor for autoimmune disease. Responses to microbial antigens may be studied in vivo during vaccination. We therefore followed patients with SLE and controls during split-virion influenza vaccination to quantify antibody responses against viral antigens and associated cellular and proteome parameters. Methods Blood samples and clinical data were collected from female patients with SLE with no or HCQ and/or low-dose prednisolone treatment (n = 29) and age- and sex-matched healthy controls (n = 17). Vaccine-specific antibody titres were measured by ELISA and IFN-induced gene expression in monocytes by quantitative PCR. Serum proteins were measured by proximity extension assay and disease-associated symptoms were followed by questionnaires. Results The vaccine-specific antibody response was significantly higher in patients compared with controls and titres of IgG targeting the viral proteins were higher in patients than controls at both 1 and 3 months after immunization. Clinical disease symptoms and autoantibody titres remained unchanged throughout the study. Notably, a positive pre-vaccination mRNA-based IFN score was associated with a significantly higher vaccine-specific antibody response and with a broader profile of autoantibody specificities. Screening of serum protein biomarkers revealed higher levels of IFN-regulated proteins in patients compared with controls and that levels of such proteins correlated with the vaccine-specific IgG response, with C-C motif chemokine ligand 3 exhibiting the strongest association. Conclusion Augmented antibody responses to viral antigens develop in patients with SLE on no or light treatment and associate with markers of type I IFN system activation at the RNA and protein levels.

scholarly journals Distinctive Immunomodulatory and Inflammatory Properties of the Escherichia coli Type II Heat-Labile Enterotoxin LT-IIa and Its B Pentamer following Intradermal Administration

2011 ◽  
Vol 18 (8) ◽  
pp. 1243-1251 ◽  
Author(s):  
Camila Mathias-Santos ◽  
Juliana F. Rodrigues ◽  
Maria Elisabete Sbrogio-Almeida ◽  
Terry D. Connell ◽  
Luís C. S. Ferreira
Keyword(s):  
T Cell ◽  
Present Report ◽  
Type I ◽  
Type Ii ◽  
Vaccine Adjuvants ◽  
Local Skin ◽  
Inflammatory Reactions ◽  
Heat Labile ◽  
Intradermal Administration ◽  
Adjuvant Effects

ABSTRACTThe type I and type II heat-labile enterotoxins (LT-I and LT-II) are strong mucosal adjuvants when they are coadministered with soluble antigens. Nonetheless, data on the parenteral adjuvant activities of LT-II are still limited. Particularly, no previous study has evaluated the adjuvant effects and induced inflammatory reactions of LT-II holotoxins or their B pentameric subunits after delivery via the intradermal (i.d.) route to mice. In the present report, the adjuvant and local skin inflammatory effects of LT-IIa and its B subunit pentamer (LT-IIaB5) were determined. When coadministered with ovalbumin (OVA), LT-IIa and, to a lesser extent, LT-IIaB5exhibited serum IgG adjuvant effects. In addition, LT-IIa but not LT-IIaB5induced T cell-specific anti-OVA responses, particularly in respect to induction of antigen-specific cytotoxic CD8+T cell responses. LT-IIa and LT-IIaB5induced differential tissue permeability and local inflammatory reactions after i.d. injection. Of particular interest was the reduced or complete lack of local reactions, such as edema and tissue induration, in mice i.d. inoculated with LT-IIa and LT-IIaB5,respectively, compared with mice immunized with LT-I. In conclusion, the present results show that LT-IIa and, to a lesser extent, LT-IIaB5exert adjuvant effects when they are delivered via the i.d. route. In addition, the low inflammatory effects of LT-IIa and LT-IIaB5in comparison to those of LT-I support the usefulness of LT-IIa and LT-IIaB5as parenterally delivered vaccine adjuvants.

Obinutuzumab (GA101) More Potently Engages Phagocytic-Lineage Cells Resulting In Enhanced Monocyte and Macrophage Activity When Compared To Rituximab and Ofatumumab

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 5136-5136 ◽  
Author(s):  
Sylvia Herter ◽  
Christian Klein ◽  
Pablo Umana ◽  
Marina Bacac
Keyword(s):  
Cell Death ◽  
Tumor Cell ◽  
Nk Cell ◽  
Antibody Activity ◽  
Type I ◽  
Type Ii ◽  
Therapeutic Antibodies ◽  
Tumor Cell Death ◽  
Macrophage Activity ◽  
Anti Cd20

Abstract Therapeutic antibodies possess several clinically relevant mechanisms of action including cell death induction, perturbation of tumor cell signaling, activation of complement dependent cytotoxicity (CDC), antibody dependent cellular cytotoxicity (ADCC), antibody dependent cellular phagocytosis (ADCP) and induction of adaptive immunity. Obinutuzumab (GA101) is a novel humanized, glycoengineered Type II anti-CD20 monoclonal antibody engineered for displaying enhanced FcγRIIIa (CD16) binding affinity and characterized by stronger induction of ADCC and direct tumor cell death when compared to wild-type, Type I anti-CD20 antibodies rituximab and ofatumumab. In light of the important role of phagocytic lineage cells in the mechanism of action of therapeutic antibodies, we compared GA101, rituximab and ofatumumab for their ability to trigger FcγR-dependent monocyte and macrophage effector functions. We show that, due to glycoengineering, GA101 displays superior CD16-dependent binding to monocytes, M1 and M2c macrophages in presence of nonspecific, competing, human endogenous IgGs, a situation that more closely mimics physiological conditions. Subsequently, GA101 more strongly engages monocytes and macrophages and leads to significantly higher elimination of CD20-expressing tumor cells as shown by assays detecting total antibody activity (ADCP, ADCC and direct effects). In support of the stronger GA101 activity, higher nitric-oxide (NO) levels are also detected in supernatants of tumor/macrophage co-cultures treated with antibody. Taken together, our data show that in addition to stronger NK-cell mediated ADCC and direct cell death induction due to Type II CD20 binding, GA101 more potently engages phagocytic-lineage cells resulting in enhanced monocyte and macrophage activity under conditions that more closely resemble physiological settings. Disclosures: Herter: Roche: Employment. Klein:Roche Glycart AG: Employment. Umana:Roche: Employment, Equity Ownership. Bacac:Roche: Employment.

A type II anti-CD20 monoclonal antibody efficiently depletes CNS B cells in a mouse model of multiple sclerosis

2021 ◽  
Author(s):  
Sabine Tacke ◽  
Rittika Chunder ◽  
Verena Schropp ◽  
Philipp Kirchner ◽  
Arif B. Ekici ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
B Cells ◽  
B Cell ◽  
Single Cell ◽  
Total Serum ◽  
Enzyme Linked Immunosorbent Assay ◽  
Type I ◽  
Type Ii ◽  
Cns Pathology ◽  
Anti Cd20

Abstract BackgroundSuccessful therapy with anti-CD20 monoclonal antibodies (mAbs) has reinforced the key role of B cells in the immunopathology of multiple sclerosis. While treatment with currently available anti-CD20 mAbs results in rapid and robust elimination of vascular B cells, B cells residing within compartments of the central nervous system (CNS) are not well targeted. The aim of this study was to determine the effects of a novel class of anti-CD20 mAbs on vascular and extravascular CNS-infiltrating B cells in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. MethodsMale double transgenic hCD20xhIgR3 mice and male wild-type C57BL/6 (B6) mice were injected with human myelin oligodendrocyte glycoprotein (MOG)1–125 to induce chronic EAE. On days 19, 22, and 25 after immunization, the hCD20xhIgR3 mice were injected intravenously with an anti-human CD20 mAb (5 mg/kg), either rituximab (a type I anti-CD20 mAb) or obinutuzumab (a type II humanized anti-CD20 mAb). The B6 mice received a dose of the murine anti-mouse CD20 antibody 18B12. Development of EAE was assessed daily. Seven days after the last injection, mice were euthanized, splenic B-cell subsets were analyzed by flow cytometry, and differential gene expression determined by single-cell RNA sequencing. Total serum immunoglobulin (Ig)G and anti-MOG1–125 IgG titers were measured by enzyme-linked immunosorbent assay. Reduction in CNS-infiltrated CD19+ and CD3+ cells was analyzed by immunohistochemistry, and ultrastructural CNS pathology was studied by transmission electron microscopy. ResultsTreatment with either anti-CD20 mAb had no effect on the clinical course of the disease, animal weight, or serum antibody levels. Obinutuzumab was superior to rituximab in reducing both splenic and CNS-infiltrated B cells. At the single-cell level, obinutuzumab showed pronounced effects on germinal center B cells as well as on CD4+ T cells, which acquired a regulatory-gene signature. In addition, obinutuzumab had beneficial effects on spinal cord myelination. B-cell depletion rates in the 18B12/B6 model were comparable with those observed in obinutuzumab-treated hCD20xhIgR3 mice. ConclusionsOur results demonstrate differential effects of anti-CD20 mAbs on peripheral immune response and CNS pathology, with type II antibodies potentially being superior to type I in the depletion of tissue-infiltrating B cells.

scholarly journals Limitations of Pneumovax® as a detection antigen in the measurement of serotype-specific antibodies by enzyme-linked immunosorbent assay

2002 ◽  
Vol 39 (4) ◽  
pp. 398-403 ◽  
Author(s):  
ZM Huo ◽  
J Miles ◽  
PG Riches ◽  
T Harris
Keyword(s):  
Immunosorbent Assay ◽  
Specific Antibody ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Carbohydrate Antigens ◽  
Specific Antibodies ◽  
Elisa System ◽  
Background Measurement ◽  
Polysaccharide Antigens ◽  
The Individual

Background: Measurement of antibody responses to polysaccharide antigens is regarded as an important assessment of an individual's ability to respond to carbohydrate antigens. The currently used assays for the measurement of pneumococcal-specific antibody use the multi-serotype vaccine Pneumovax® as the detection antigen. Methods: An equal potency enzyme-linked immunosorbent assay (ELISA) system was used to compare the measurement of serotype-specific antibody with the multi-serotype assay. Results: Our results show that the concentration of specific antibody to Pneumovax is not related to the concentration of antibody to the individual serotypes. Neither is any correlation found between the antibody concentrations to any of the three single serotypes investigated, to the mixture of the three serotypes or to Pneumovax. Conclusion: We conclude that the measurement of the concentration of the specific antibody to the mixed serotypes present in Pneumovax has serious limitations when used to evaluate the protection acquired from Pneumovax immunization against any specific serotype.

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