Streptococcus suis Bacterin and Subunit Vaccine Immunogenicities and Protective Efficacies against Serotypes 2 and 9

ABSTRACT Streptococcus suis causes numerous diseases in pigs, most importantly, meningitis, arthritis, septicemia, and bronchopneumonia. One of the major problems in modern swine production is the lack of a vaccine protecting against more than one S. suis serotype. The objective of this study was to determine the protective efficacy of a serotype 2 murein-associated protein (MAP) fraction subunit vaccine in comparison to that of a bacterin against experimental challenge with serotype 2 (containing muramidase-released protein [MRP], extracellular factor, and suilysin [SLY]) and serotype 9 (containing MRP variant MRP* and SLY) strains. MAP was shown to include different surface-associated proteins, such as the MRP and surface antigen one (SAO) expressed by both pathotypes used for challenge. The results of this study demonstrated that the serotype 2 bacterin induced protective immunity against homologous challenge. In contrast, the protective efficacy of the MAP subunit vaccine was low, though MAP immunization resulted in high serum immunoglobulin G2 titers against MRP and SAO. Importantly, immunization with bacterin but not with MAP induced opsonizing antibody titers against the serotype 2 strain, and these antibody titers were found to correlate with protection. However, after absorption with a nonencapsulated isogenic mutant, the sera from bacterin-immunized piglets failed to facilitate neutrophil killing, indicating that antibodies directed against capsule may not have been essential for opsonophagocytosis. Furthermore, induction of opsonizing antibodies against serotype 9 was not detectable in the group receiving bacterin or in the group receiving the MAP vaccine. In agreement, protection against the heterologous serotype 9 strain was low in both groups. Thus, identification of an antigen protecting against these two important S. suis pathotypes remains an important goal of future studies.

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Evaluation of the immunoprotective effects of IF-2 GTPase and SSU05-1022 as Streptococcus suis candidate subunit vaccine

Future Microbiology ◽

10.2217/fmb-2020-0232 ◽

2021 ◽

Author(s):

Tumei Chen ◽

Chenchen Wang ◽

Linlin Hu ◽

Hao Lu ◽

Fangyu Song ◽

...

Keyword(s):

Recombinant Proteins ◽

Subunit Vaccine ◽

Streptococcus Suis ◽

Cross Protection ◽

Cytokine Levels ◽

Antibody Titers ◽

A Subunit ◽

Suis Serotype ◽

Lethal Doses ◽

Mixed Protein

Aim: This study aims to develop a subunit vaccine with high cross-protection for Streptococcus suis. Materials & methods: Four-week-old female BALB/c mice were first immunized with a single and mixed protein. Various indicators, such as antibody titers and various cytokine levels, were further analyzed. Results: The results showed that purified recombinant proteins IF-2 and 1022 had a good protective effect against lethal doses of S. suis serotype 2 and S. suis serotype 9. This study showed immunization with recombinant proteins. Conclusion: IF-2 and 1022 can enhance cross-protection against S. suis serotypes 2 and 9.

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Immunogenicity and Protective Efficacy of Recombinant Campylobacter jejuni Flagellum-Secreted Proteins in Mice

Infection and Immunity ◽

10.1128/iai.00076-08 ◽

2008 ◽

Vol 76 (7) ◽

pp. 3170-3175 ◽

Cited By ~ 21

Author(s):

Shahida Baqar ◽

Lisa A. Applebee ◽

Theron C. Gilliland ◽

Lanfong H. Lee ◽

Chad K. Porter ◽

...

Keyword(s):

Mouse Model ◽

Campylobacter Jejuni ◽

Immunoglobulin G ◽

Subunit Vaccine ◽

Vaccine Candidate ◽

Protective Efficacy ◽

Secreted Proteins ◽

Serum Immunoglobulin ◽

Heterologous Protection ◽

Homologous Challenge

ABSTRACT Immunogenicity and protective efficacy of three Campylobacter jejuni flagellum-secreted proteins, FlaC, FspA1, and FspA2, were compared by use of a mouse model. Mice were immunized intranasally with each protein with or without LTR192G as the adjuvant and challenged intranasally with C. jejuni 81-176 or CG8486. All three proteins were immunogenic, although FspA1 induced the highest levels of serum immunoglobulin G (IgG) and fecal IgA. Although immunogenic, FlaC provided only 18% protection against disease from C. jejuni 81-176. Immunization with FspA1 resulted in 57.8% protection without adjuvant or 63.8% protection with adjuvant against homologous challenge with 81-176. Alternatively, immunization with FspA2 provided 38.4% (without adjuvant) or 47.2% (with adjuvant) protection against disease from homologous challenge with CG8486. In contrast to FspA2, FspA1 provided some heterologous protection against C. jejuni CG8486 when delivered with (31.2%) or without (44.8%) LTR192G. These results suggest that FspA1 may be a good subunit vaccine candidate against C. jejuni disease.

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Sterilizing immunity against SARS-CoV-2 in hamsters conferred by a novel recombinant subunit vaccine

10.1101/2020.12.18.423552 ◽

2020 ◽

Author(s):

Yangtao Wu ◽

Xiaofen Huang ◽

Lunzhi Yuan ◽

Shaojuan Wang ◽

Yali Zhang ◽

...

Keyword(s):

T Cell ◽

Subunit Vaccine ◽

Vaccine Candidate ◽

Protective Efficacy ◽

Humoral Response ◽

Neutralizing Antibody ◽

Cell Immune Response ◽

Antibody Titers ◽

A Subunit ◽

Sterilizing Immunity

AbstractA safe and effective SARS-CoV-2 vaccine is essential to avert the on-going COVID-19 pandemic. Here, we developed a subunit vaccine, which is comprised of CHO-expressed spike ectodomain protein (StriFK) and nitrogen bisphosphonates-modified zinc-aluminum hybrid adjuvant (FH002C). This vaccine candidate rapidly elicited the robust humoral response, Th1/Th2 balanced helper CD4 T cell and CD8 T cell immune response in animal models. In mice, hamsters, and non-human primates, 2-shot and 3-shot immunization of StriFK-FH002C generated 28- to 38-fold and 47- to 269-fold higher neutralizing antibody titers than the human COVID-19 convalescent plasmas, respectively. More importantly, the StriFK-FH002C immunization conferred sterilizing immunity to prevent SARS-CoV-2 infection and transmission, which also protected animals from virus-induced weight loss, COVID-19-like symptoms, and pneumonia in hamsters. Vaccine-induced neutralizing and cell-based receptor-blocking antibody titers correlated well with protective efficacy in hamsters, suggesting vaccine-elicited protection is immune-associated. The StriFK-FH002C provided a promising SARS-CoV-2 vaccine candidate for further clinical evaluation.

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A Live Attenuated Severe Acute Respiratory Syndrome Coronavirus Is Immunogenic and Efficacious in Golden Syrian Hamsters

Journal of Virology ◽

10.1128/jvi.00304-08 ◽

2008 ◽

Vol 82 (15) ◽

pp. 7721-7724 ◽

Cited By ~ 73

Author(s):

Elaine W. Lamirande ◽

Marta L. DeDiego ◽

Anjeanette Roberts ◽

Jadon P. Jackson ◽

Enrique Alvarez ◽

...

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Respiratory Tract ◽

Protective Efficacy ◽

Neutralizing Antibody ◽

High Serum ◽

Wild Type Virus ◽

Live Attenuated Vaccine ◽

Virus Challenge ◽

Antibody Titers ◽

Efficacious Vaccine

ABSTRACT The immunogenicity and protective efficacy of a live attenuated vaccine consisting of a recombinant severe acute respiratory syndrome (SARS) coronavirus lacking the E gene (rSARS-CoV-ΔE) were studied using hamsters. Hamsters immunized with rSARS-CoV-ΔE developed high serum-neutralizing antibody titers and were protected from replication of homologous (SARS-CoV Urbani) and heterologous (GD03) SARS-CoV in the upper and lower respiratory tract. rSARS-CoV-ΔE-immunized hamsters remained active following wild-type virus challenge, while mock-immunized hamsters displayed decreased activity. Despite being attenuated in replication in the respiratory tract, rSARS-CoV-ΔE is an immunogenic and efficacious vaccine in hamsters.

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Evaluation of the protective efficacy of four novel identified membrane associated proteins of Streptococcus suis serotype 2

Vaccine ◽

10.1016/j.vaccine.2015.03.038 ◽

2015 ◽

Vol 33 (19) ◽

pp. 2254-2260 ◽

Cited By ~ 8

Author(s):

Yang Zhou ◽

Yan Wang ◽

Limei Deng ◽

Chengkun Zheng ◽

Fangyan Yuan ◽

...

Keyword(s):

Protective Efficacy ◽

Streptococcus Suis ◽

Associated Proteins ◽

Suis Serotype ◽

Streptococcus Suis Serotype 2

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Use of Proteins Identified through a Functional Genomic Screen To Develop a Protein Subunit Vaccine That Provides Significant Protection against Virulent Streptococcus suis in Pigs

Infection and Immunity ◽

10.1128/iai.00559-17 ◽

2017 ◽

Vol 86 (3) ◽

Cited By ~ 3

Author(s):

Susan L. Brockmeier ◽

Crystal L. Loving ◽

Tracy L. Nicholson ◽

Jinhong Wang ◽

Sarah E. Peters ◽

...

Keyword(s):

Immune Response ◽

Vaccine Trial ◽

Streptococcus Suis ◽

Protein Subunit ◽

Content Type ◽

Degree Of Protection ◽

Wide Range ◽

Associated Proteins ◽

Clinical Protection ◽

Cellular Immune

ABSTRACT Streptococcus suis is a bacterium that is commonly carried in the respiratory tract and that is also one of the most important invasive pathogens of swine, commonly causing meningitis, arthritis, and septicemia. Due to the existence of many serotypes and a wide range of immune evasion capabilities, efficacious vaccines are not readily available. The selection of S. suis protein candidates for inclusion in a vaccine was accomplished by identifying fitness genes through a functional genomics screen and selecting conserved predicted surface-associated proteins. Five candidate proteins were selected for evaluation in a vaccine trial and administered both intranasally and intramuscularly with one of two different adjuvant formulations. Clinical protection was evaluated by subsequent intranasal challenge with virulent S. suis . While subunit vaccination with the S. suis proteins induced IgG antibodies to each individual protein and a cellular immune response to the pool of proteins and provided substantial protection from challenge with virulent S. suis , the immune response elicited and the degree of protection were dependent on the parenteral adjuvant given. Subunit vaccination induced IgG reactive against different S. suis serotypes, indicating a potential for cross protection.

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Efficacy of Eimeria tenella rhomboid-like protein as a subunit vaccine in protective immunity against homologous challenge

Parasitology Research ◽

10.1007/s00436-011-2603-1 ◽

2011 ◽

Vol 110 (3) ◽

pp. 1139-1145 ◽

Cited By ~ 22

Author(s):

Jianhua Li ◽

Jun Zheng ◽

Pengtao Gong ◽

Xichen Zhang

Keyword(s):

Protective Immunity ◽

Subunit Vaccine ◽

Eimeria Tenella ◽

A Subunit ◽

Homologous Challenge

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BACTERIAL AND VIRAL COPROANTIBODIES IN BREAST-FED INFANTS

PEDIATRICS ◽

10.1542/peds.39.2.202 ◽

1967 ◽

Vol 39 (2) ◽

pp. 202-213

Author(s):

Jean F. Kenny ◽

Mary I. Boesman ◽

Richard H. Michaels

Keyword(s):

Serum Antibody ◽

Neutralizing Antibody ◽

High Serum ◽

Maternal Milk ◽

Neutralizing Activity ◽

E Coli ◽

Immune Globulins ◽

Antibody Titers ◽

Human Immune ◽

Breast Fed

Stools of newborn breast-fed infants may contain significant amounts of hemagglutinating antibody to enteropathogenic E. coli and neutralizing antibody to polioviruses. Stool titers averaged only fourfold lower than maternal milk titers for antibacterial and less than twofold lower for antiviral activity. Similar ratios of stool:milk activity were also found for paired specimens obtained during the second and third postpartum months. The stool antibodies were stable at 56°C and exhibited definite specificity. Bacterial hemagglutinins in feces were more sensitive to mercaptoethanol than the poliovirus neutralizing activity. Stools from breast-fed infants contained gamma-1 globulins similar to those in milk, including IgA and small amounts of IgM. Meconium from bottle-fed infants with high serum antibody titers to polioviruses contained traces of homotypic neutralizing antibody. Antiviral and antibacterial activity were not detected in transitional and later stools from artificially fed infants, nor were human immune globulins. Milk bacterial hemagglutinating antibodies were more resistant to acid and to pepsin than those in serum. Furthermore, acid had a less deleterious effect on virus neutralizing activity in milk than it had on that in serum, and it also had less effect on the milk antiviral than on the milk antibacterial antibodies.

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Study of Antibody Levels in Children with Purulent Otitis Media

Annals of Otology Rhinology & Laryngology ◽

10.1177/00034894800890s331 ◽

1980 ◽

Vol 89 (3_suppl) ◽

pp. 117-120 ◽

Cited By ~ 2

Author(s):

P. Branefors ◽

T. Dahlberg ◽

O. Nylén

Keyword(s):

Otitis Media ◽

Serum Antibody ◽

Acute Otitis Media ◽

High Serum ◽

Haemophilus Influenzae Type ◽

Enzyme Linked Immunosorbent Assay ◽

Polysaccharide Antigens ◽

Antibody Titers ◽

Iga Antibody ◽

Antibody Levels

A series of episodes of acute otitis media were studied with reference to the bacterial findings in the nasopharynx and the specific antibody response in a group of children nine months to ten years of age, with previous frequent episodes of acute otitis media, Serum IgG, IgM and IgA antibody levels against five polysaccharide antigens, namely Haemophilus influenzae type b and Streptococcus pneumoniae types 3, 6, 19 and 23, were studied by means of an enzyme-linked immunosorbent assay. The selection of polysaccharide antigens was based on isolation frequency. The sera to be tested were tenfold serially diluted. An extinction of 0.2 over the base was taken as the end-point titer and expressed as in-log10. The results showed that most children including those under three years of age showed increasing homologous antibody titers at an infection, or had already initially very high antibody titers, especially of the IgG class. The titers reached levels of 104 to 105. In some cases, however, it could be shown that high serum antibody titers did not give protection against a new infection with the same serological type of bacteria. It was also demonstrated that most children, regardless of age, had IgG and IgM titers against the heterologous antigens. In some cases the levels were quite high (103 to 104). However, the IgA antibody levels were lower and in a considerable number of samples antibodies were not even detectable.

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