scholarly journals Dynamics of anti-M antibody response in a mouse model following intranasal infection with group A Streptococcus M-18

2005 ◽  
Vol 54 (3) ◽  
pp. 305-308 ◽  
Author(s):  
Paul Gladstone ◽  
George Varghese ◽  
K N Brahmadathan
Keyword(s):  
Mouse Model ◽  
Immune Responses ◽  
Antibody Response ◽  
Indirect Elisa ◽  
Group A Streptococcus ◽  
Swiss Albino Mouse ◽  
Intranasal Infection ◽  
Model Following ◽  
Antibody Titres ◽  
Group A

Dynamics of anti-M antibody response following intranasal infection with group A Streptococcus (GAS) M-18 were investigated in a Swiss albino mouse model. Mice arranged in three groups were inoculated intranasally with 2.0 × 107 c.f.u. ml−1 of GAS M-18 on 1, 2 alternate and 3 alternate days. Plasma collected from the retro-orbital plexus was tested for antibodies by an in-house indirect ELISA. The antibody titres of the plasma samples varied from 1 : 8 to 1 : 1024 in the 1 day dose, from 1 : 4 to 1 : 256 in the 2 day dose and from 1 : 4 to 1 : 128 in the 3 day dose. Peak titres were seen on day 42 or 56 and in all cases the titres had declined by day 84. Swiss albino mouse can thus serve as a useful animal model to study different aspects of type-specific anti-M immune responses against GAS disease when designing candidate streptococcal vaccines.

FbaA- and M protein-based multi-epitope vaccine elicits strong protective immune responses against group A streptococcus in mouse model

2014 ◽  
Vol 16 (5) ◽  
pp. 409-418 ◽  
Author(s):  
Cuiqing Ma ◽  
Zheng Liu ◽  
Wenjian Li ◽  
Xuesong Qian ◽  
Song Zhang ◽  
...  
Keyword(s):  
Mouse Model ◽  
Immune Responses ◽  
Group A Streptococcus ◽  
M Protein ◽  
Epitope Vaccine ◽  
Group A

scholarly journals Development of Polyelectrolyte Complexes for the Delivery of Peptide-Based Subunit Vaccines against Group A Streptococcus

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 823 ◽  
Author(s):  
Lili Zhao ◽  
Wanli Jin ◽  
Jazmina Gonzalez Cruz ◽  
Nirmal Marasini ◽  
Zeinab G. Khalil ◽  
...  
Keyword(s):  
Immune Responses ◽  
Subunit Vaccine ◽  
Group A Streptococcus ◽  
Vaccine Delivery ◽  
Surface Charges ◽  
Subunit Vaccines ◽  
Polyelectrolyte Complexes ◽  
Humoral Immune ◽  
Anionic Polymers ◽  
Group A

Peptide subunit vaccines hold great potential compared to traditional vaccines. However, peptides alone are poorly immunogenic. Therefore, it is of great importance that a vaccine delivery platform and/or adjuvant that enhances the immunogenicity of peptide antigens is developed. Here, we report the development of two different systems for the delivery of lipopeptide subunit vaccine (LCP-1) against group A streptococcus: polymer-coated liposomes and polyelectrolyte complexes (PECs). First, LCP-1-loaded and alginate/trimethyl chitosan (TMC)-coated liposomes (Lip-1) and LCP-1/alginate/TMC PECs (PEC-1) were examined for their ability to trigger required immune responses in outbred Swiss mice; PEC-1 induced stronger humoral immune responses than Lip-1. To further assess the adjuvanting effect of anionic polymers in PECs, a series of PECs (PEC-1 to PEC-5) were prepared by mixing LCP-1 with different anionic polymers, namely alginate, chondroitin sulfate, dextran, hyaluronic acid, and heparin, then coated with TMC. All produced PECs had similar particle sizes (around 200 nm) and surface charges (around + 30 mV). Notably, PEC-5, which contained heparin, induced higher antigen-specific systemic IgG and mucosal IgA titers than all other PECs. PEC systems, especially when containing heparin and TMC, could function as a promising platform for peptide-based subunit vaccine delivery for intranasal administration.

scholarly journals Regulatory Role of GSK-3βon NF-κB, Nitric Oxide, and TNF-αin Group A Streptococcal Infection

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Yu-Tzu Chang ◽  
Chia-Ling Chen ◽  
Chiou-Feng Lin ◽  
Shiou-Ling Lu ◽  
Miao-Huei Cheng ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Mouse Model ◽  
Group A Streptococcus ◽  
Glycogen Synthase ◽  
Critical Issue ◽  
No Production ◽  
Group A ◽  
Oxide Synthase

Group A streptococcus (GAS) imposes a great burden on humans. Efforts to minimize the associated morbidity and mortality represent a critical issue. Glycogen synthase kinase-3β(GSK-3β) is known to regulate inflammatory response in infectious diseases. However, the regulation of GSK-3βin GAS infection is still unknown. The present study investigates the interaction between GSK-3β, NF-κB, and possible related inflammatory mediators in vitro and in a mouse model. The results revealed that GAS could activate NF-κB, followed by an increased expression of inducible nitric oxide synthase (iNOS) and NO production in a murine macrophage cell line. Activation of GSK-3βoccurred after GAS infection, and inhibition of GSK-3βreduced iNOS expression and NO production. Furthermore, GSK-3βinhibitors reduced NF-κB activation and subsequent TNF-αproduction, which indicates that GSK-3βacts upstream of NF-κB in GAS-infected macrophages. Similar to the in vitro findings, administration of GSK-3βinhibitor in an air pouch GAS infection mouse model significantly reduced the level of serum TNF-αand improved the survival rate. The inhibition of GSK-3βto moderate the inflammatory effect might be an alternative therapeutic strategy against GAS infection.

scholarly journals Multicomponent Vaccines against Group A Streptococcus Can Effectively Target Broad Disease Presentations

Vaccines ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1025
Author(s):  
Helen A. Shaw ◽  
James Ozanne ◽  
Keira Burns ◽  
Fatme Mawas
Keyword(s):  
Immune Response ◽  
Group A Streptococcus ◽  
Specific Antigen ◽  
Binding Activity ◽  
Protein Antigens ◽  
Wide Range ◽  
Antibody Titres ◽  
Functional Immunity ◽  
Group A ◽  
Rheumatic Heart

Group A Streptococcus (GAS) is an important global human pathogen, with a wide range of disease presentations, from mild mucosal infections like pharyngitis to invasive diseases such as toxic shock syndrome. The effect on health and mortality from GAS infections is substantial worldwide, particularly from autoimmune sequelae-like rheumatic heart disease (RHD), and there is currently no licenced vaccine. We investigated protein antigens targeting a broad range of GAS disease presentations as vaccine components in individual and combination formulations. The potency and functional immunity generated were evaluated and compared between groups. Antibodies against all components were found in pooled human IgG (IVIG) and an immune response generated following the subcutaneous immunisation of mice. A combination immunisation showed a reduction in IgG response for SpyCEP but an increase for Cpa and Mac-1 (IdeS). An opsonophagocytosis assay (OPA) showed the killing of GAS with immune sera against M protein and combination groups, with a lower killing activity observed for immune sera against other individual antigens. Specific antigen assays showed functional immunity against SpyCEP and Mac-1 from both individual and combination immunisations, with the activity correlating with antibody titres. However, efficient blocking of the binding activity of Cpa to collagen I and fibronectin could not be demonstrated with immune sera or purified IgG. Our data indicate that combination immunisations, while effective at covering a broader range of virulence factors, can also affect the immune response generated. Further, our results showed that an OPA alone is inadequate for understanding protection from vaccination, particularly when considering protection from immune evasion factors and evaluation of the colonisation leading to pharyngitis.

scholarly journals Prospective Longitudinal Analysis of Immune Responses in Pediatric Subjects After Pharyngeal Acquisition of Group A Streptococci

2017 ◽  
Vol 6 (2) ◽  
pp. 187-196 ◽  
Author(s):  
Nicholas D. Hysmith ◽  
Edward L. Kaplan ◽  
P. Patrick Cleary ◽  
Dwight R. Johnson ◽  
Thomas A. Penfound ◽  
...  
Keyword(s):  
Immune Responses ◽  
Group A Streptococcus ◽  
Natural Infection ◽  
Antibody Responses ◽  
Antigen Specificity ◽  
Throat Culture ◽  
Serum Samples ◽  
Missed Opportunities ◽  
Group A ◽  
Prospective Longitudinal

Abstract Background. Despite the significant burden of disease associated with infection by group A streptococcus (GAS), little is known about the human immune response to GAS antigens after natural infection. Methods. We evaluated 195 serum samples obtained prospectively over a consecutive 24-month period from 41 pediatric subjects who experienced a new pharyngeal GAS acquisition. An enzyme-linked immunoassay was used to determine the kinetics and antigen specificity of antibodies against 13 shared GAS antigens and 18 type-specific M peptides. The majority of the antigens tested are currently being considered as vaccine candidates. Results. Twelve M types of GAS were recovered from 41 subjects who experienced 51 new GAS acquisitions that elicited antibody responses against at least 1 of the 31 antigens tested (immunologically significant new GAS acquisitions). The immune responses to the 13 shared antigens were highly variable. Increases in antibody levels were detected against a mean of 3.5 shared antigens (range, 1–8). Antibody responses to the homologous M peptide were observed in 32 (63%) of the 51 episodes. Seven subjects acquired more than 1 M type of GAS. There were no new immunologically significant acquisitions of an M type against which the subject had preexisting antibodies to the homologous M peptide. Of the subjects with new GAS acquisition, 65% were asymptomatic, yet immune responses were detected against 1 or more GAS antigens. Immune responses to streptolysin O and/or deoxyribonuclease B were observed after 67% of the new GAS acquisitions. Persistently positive (>12 weeks) throat culture results were returned for 20% of the 41 subjects despite immune responses to homologous M peptides and/or shared antigens. Conclusions. The availability of throat culture results, GAS isolates, and serial serum samples collected prospectively over a 2-year period of observation provided a unique opportunity for us to assess the serologic status of pediatric subjects before and after new pharyngeal acquisitions of GAS. With the exception of antibody responses to the homologous M peptides, no clear pattern of immune responses against the remaining GAS antigens was seen. There were no new immunologically significant acquisitions ofemm types of GAS against which the subjects had preexisting elevated levels of antibodies against the homologous M peptide. The observation that 65% of new GAS acquisitions caused no symptoms yet were immunologically significant suggests that the majority of infections are not detected, which would result in missed opportunities for primary prevention of rheumatic fever and rheumatic heart disease with appropriate antimicrobial therapy.

scholarly journals Differential Regulation of Iron- and Manganese-Specific MtsABC and Heme-Specific HtsABC Transporters by the Metalloregulator MtsR of Group A Streptococcus

2006 ◽  
Vol 74 (9) ◽  
pp. 5132-5139 ◽  
Author(s):  
Tracey S. Hanks ◽  
Mengyao Liu ◽  
Michael J. McClure ◽  
Maki Fukumura ◽  
Angela Duffy ◽  
...  
Keyword(s):  
Mouse Model ◽  
Metal Ions ◽  
Promoter Region ◽  
Group A Streptococcus ◽  
Differential Regulation ◽  
Deletion Mutants ◽  
Human Pathogen ◽  
Manganese Ions ◽  
Group A ◽  
Iron And Manganese

ABSTRACT The genome of the human pathogen group A Streptococcus (GAS) encodes the transporters MtsABC, FtsABCD, and HtsABC to take up ferric and manganese ions, ferric ferrichrome, and heme, respectively. The GAS genome also encodes two metalloregulators PerR and MtsR. To understand the regulation of the expression of these transporters, the mtsR and perR deletion mutants of a GAS serotype M1 strain were generated, and the effects of the deletions and Fe3+, Mn2+, and Zn2+ on the expression of mtsA, htsA, and ftsB were examined. Mn2+ dramatically depresses mtsA transcription and levels of the MtsA protein but does not downregulate the expression of htsA and ftsB. Fe3+ decreases the expression of mtsA and htsA but has no effect on ftsB expression. Zn2+ has no effect on the expression of all three genes. The deletion of mtsR abolishes the Mn2+- and Fe3+-induced depression of mtsA expression and the Fe3+-dependent decrease in htsA expression. The deletion of mtsR does not significantly alter GAS virulence in a mouse model of subcutaneous infection. The deletion of perR does not affect the expression of the genes in response to the metal ions. MtsR binds to the mts promoter region in the presence of Mn2+ or Fe2+. The results indicate that MtsR differentially regulates the expression of mtsABC and htsABC.

scholarly journals Publisher Correction: Mucosal vaccination with pili from Group A Streptococcus expressed on Lactococcus lactis generates protective immune responses

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jacelyn M. S. Loh ◽  
Natalie Lorenz ◽  
Catherine J.-Y. Tsai ◽  
Adrina Hema J. Khemlani ◽  
Thomas Proft
Keyword(s):  
Immune Responses ◽  
Lactococcus Lactis ◽  
Group A Streptococcus ◽  
Mucosal Vaccination ◽  
Group A
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