scholarly journals Microneedle-Based Intradermal Delivery of the Anthrax Recombinant Protective Antigen Vaccine

2006 ◽  
Vol 74 (12) ◽  
pp. 6806-6810 ◽  
Author(s):  
John A. Mikszta ◽  
John P. Dekker ◽  
Noel G. Harvey ◽  
Cheryl H. Dean ◽  
John M. Brittingham ◽  
...  
Keyword(s):  
Immune Response ◽  
Immunoglobulin G ◽  
Protective Antigen ◽  
Neutralizing Antibody ◽  
Antigen Vaccine ◽  
Intradermal Delivery ◽  
Antibody Titers ◽  
Sparing Effect ◽  
Booster Inoculation ◽  
Recombinant Protective Antigen

ABSTRACT The recombinant protective antigen (rPA) of Bacillus anthracis is a promising anthrax vaccine. We compared serum immunoglobulin G levels and toxin-neutralizing antibody titers in rabbits following delivery of various doses of vaccine by microneedle-based intradermal (i.d.) delivery or intramuscular (i.m.) injection using conventional needles. Intradermal delivery required less antigen to induce levels of antibody similar to those produced via i.m. injection during the first 2 weeks following primary and booster inoculation. This dose-sparing effect was less evident at the later stages of the immune response. Rabbits immunized i.d. with 10 μg of rPA displayed 100% protection from aerosol spore challenge, while i.m. injection of the same dose provided slightly lower protection (71%). Groups immunized with lower antigen doses were partially protected (13 to 29%) regardless of the mode of administration. Overall, our results suggest rPA formulated with aluminum adjuvant and administered to the skin by a microneedle-based device is as efficacious as i.m. vaccination.

scholarly journals Correlation between Lethal Toxin-Neutralizing Antibody Titers and Protection from Intranasal Challenge with Bacillus anthracis Ames Strain Spores in Mice after Transcutaneous Immunization with Recombinant Anthrax Protective Antigen

2006 ◽  
Vol 74 (1) ◽  
pp. 794-797 ◽  
Author(s):  
Kristina K. Peachman ◽  
Mangala Rao ◽  
Carl R. Alving ◽  
Robert Burge ◽  
Stephen H. Leppla ◽  
...  
Keyword(s):  
Bacillus Anthracis ◽  
Protective Antigen ◽  
Neutralizing Antibody ◽  
Lethal Toxin ◽  
Vaccine Strategy ◽  
Transcutaneous Immunization ◽  
Antibody Titers ◽  
Anthrax Protective Antigen ◽  
Ames Strain ◽  
Recombinant Protective Antigen

ABSTRACT Transcutaneous immunization of mice with recombinant protective antigen (rPA) of Bacillus anthracis resulted in significantly higher lethal toxin-neutralizing antibody titers than did intramuscular injection of alum-adsorbed rPA. Immunized mice were partially protected against intranasal challenge with 235,000 (10 50% lethal doses) Ames strain B. anthracis spores. A highly significant correlation was observed between toxin-neutralizing antibody titer and survival after challenge. Future experiments with rabbits and nonhuman primates should confirm the significance of protection by this vaccine strategy.

scholarly journals Needle-Free Skin Patch Vaccination Method for Anthrax

2004 ◽  
Vol 72 (2) ◽  
pp. 1181-1183 ◽  
Author(s):  
Gary R. Matyas ◽  
Arthur M. Friedlander ◽  
Gregory M. Glenn ◽  
Stephen Little ◽  
Jianmei Yu ◽  
...  
Keyword(s):  
Protective Antigen ◽  
Neutralizing Antibody ◽  
Adjuvant Activity ◽  
Skin Patch ◽  
Transcutaneous Immunization ◽  
Antibody Titers ◽  
Recombinant Protective Antigen

ABSTRACT Three immunizations of mice with recombinant protective antigen (rPA) by transcutaneous immunization (TCI) induced long-term neutralizing antibody titers that were superior to those obtained with aluminum-adsorbed rPA. In addition, rPA alone exhibited adjuvant activity for TCI. Forty-six weeks after completion of TCI, 100% protection was observed against lethal anthrax challenge.

scholarly journals Effect of a booster-dose of rabies vaccine on the duration of virus neutralizing antibody titers in bovines

1998 ◽  
Vol 31 (4) ◽  
pp. 367-371 ◽  
Author(s):  
Avelino Albas ◽  
Paulo Eduardo Pardo ◽  
Albério Antonio Barros Gomes ◽  
Fernanda Bernardi ◽  
Fumio Honma Ito
Keyword(s):  
Immune Response ◽  
Neutralizing Antibodies ◽  
Booster Dose ◽  
Neutralization Test ◽  
Neutralizing Antibody ◽  
Rabies Vaccine ◽  
Western Region ◽  
Humoral Immune ◽  
Paulo State ◽  
Antibody Titers

Humoral immune response using inactivated rabies vaccine was studied in 35 nelore cross-bred bovines of western region of São Paulo state. Ninety days after vaccination, 13 (92.8%) animals presented titers 30.5IU/ml, through mouse neutralization test. After 180 days, 9 (64.3%) sera showed titers 30.5IU/ml, after 270 days, only one (7.1%) showed a titer of 0.51IU/ml, and after 360 days, all animals showed titers < 0.5IU/ml. Group of animals receiving booster dose 30 days after vaccination presented, two months after, all with titers > 0.5IU/ml. At 180 days, 17 (80.9%) sera presented titers > 0.5IU/ml; at 270 days, 15 (71.4%), with titers 30.5IU/ml and at 360 days, 4 (19.0%), with titers 30.5IU/ml. Booster-dose ensured high levels of neutralizing antibodies for at least three months, and 240 days after revaccination, 71.4% of animals were found with titers 30.5IU/ml.

scholarly journals Mechanisms of Dysregulated Humoral and Cellular Immunity by SARS-CoV-2

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1027
Author(s):  
Nima Taefehshokr ◽  
Sina Taefehshokr ◽  
Bryan Heit
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Cell Function ◽  
Adaptive Immune Response ◽  
Neutralizing Antibody ◽  
Humoral And Cellular Immunity ◽  
Cell Responses ◽  
Adaptive Immune ◽  
Antibody Titers

The current coronavirus disease 2019 (COVID-19) pandemic, a disease caused by severe acute respiratory syndrome corona virus 2 (SARS-CoV-2), was first identified in December 2019 in China, and has led to thousands of mortalities globally each day. While the innate immune response serves as the first line of defense, viral clearance requires activation of adaptive immunity, which employs B and T cells to provide sanitizing immunity. SARS-CoV-2 has a potent arsenal of mechanisms used to counter this adaptive immune response through processes, such as T cells depletion and T cell exhaustion. These phenomena are most often observed in severe SARS-CoV-2 patients, pointing towards a link between T cell function and disease severity. Moreover, neutralizing antibody titers and memory B cell responses may be short lived in many SARS-CoV-2 patients, potentially exposing these patients to re-infection. In this review, we discuss our current understanding of B and T cells immune responses and activity in SARS-CoV-2 pathogenesis.

scholarly journals A multiplex serological assay for the characterization of IgG immune response to SARS-CoV-2

2021 ◽  
Author(s):  
Etienne Brochot ◽  
Vianney Souplet ◽  
Pauline Follet ◽  
Pauline Ponthieu ◽  
Christophe Olivier ◽  
...  
Keyword(s):  
Immune Response ◽  
Neutralizing Antibody ◽  
Viral Epitope ◽  
Time Period ◽  
Versatile Tool ◽  
Comprehensive Picture ◽  
Long Time ◽  
Antibody Titers ◽  
Combined Detection

Background: In the fight against SARS-COV-2, the development of serological assays based on different antigenic domains represent a versatile tool to get a comprehensive picture of the immune response or differentiate infection from vaccination beyond simple diagnosis. Objectives: Here we use a combination of the Nucleoprotein (NP), the Spike 1 (S1) and Spike 2 (S2) subunits, and the receptor binding domain (RBD) and N-terminal domain (NTD) of the Spike antigens from the Syrius-CoViDiag multiplex IgG assay, to follow the immune response to SARS-CoV-2 infection over a long time period and depending on disease severity. Results: Using a panel of 209 sera collected from 61 patients up to eight months after infection, we observed that most patients develop an immune response against multiple viral epitope, but anti-S2 antibodies seemed to last longer. For all the tested IgGs, we have found higher titers for hospitalized patients than for non-hospitalized ones. Moreover the combination of the five different IgG titers increased the correlation to the neutralizing antibody titers than if considered individually. Conclusion: Multiplex immunoassays have the potential to improve diagnostic performances, especially for ancient infection or mild form of the disease presenting weaker antibody titers. Also the combined detection of anti-NP and anti-Spike-derived domains can be useful to differentiate vaccination from viral infection and accurately assess the antibody potential to neutralize the virus.

scholarly journals SARS-CoV-2 seroprevalence and neutralizing activity in donor and patient blood from the San Francisco Bay Area

2020 ◽  
Author(s):  
Dianna L. Ng ◽  
Gregory M. Goldgof ◽  
Brian R. Shy ◽  
Andrew G. Levine ◽  
Joanna Balcerek ◽  
...  
Keyword(s):  
San Francisco ◽  
Immunoglobulin G ◽  
Neutralizing Antibodies ◽  
San Francisco Bay ◽  
San Francisco Bay Area ◽  
Neutralizing Antibody ◽  
Immunoglobulin M ◽  
Bay Area ◽  
Antibody Titers

ABSTRACTWe report very low SARS-CoV-2 seroprevalence in two San Francisco Bay Area populations. Seropositivity was 0.26% in 387 hospitalized patients admitted for non-respiratory indications and 0.1% in 1,000 blood donors. We additionally describe the longitudinal dynamics of immunoglobulin-G, immunoglobulin-M, and in vitro neutralizing antibody titers in COVID-19 patients. Neutralizing antibodies rise in tandem with immunoglobulin levels following symptom onset, exhibiting median time to seroconversion within one day of each other, and there is >93% positive percent agreement between detection of immunoglobulin-G and neutralizing titers.

scholarly journals Structural and Immunological Analysis of Anthrax Recombinant Protective Antigen Adsorbed to Aluminum Hydroxide Adjuvant

2012 ◽  
Vol 19 (9) ◽  
pp. 1465-1473 ◽  
Author(s):  
Leslie Wagner ◽  
Anita Verma ◽  
Bruce D. Meade ◽  
Karine Reiter ◽  
David L. Narum ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Neutralizing Antibodies ◽  
Tertiary Structure ◽  
Protective Antigen ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Neutralizing Antibody ◽  
Fluorescence Emission Spectra ◽  
Recombinant Protective Antigen

ABSTRACTNew anthrax vaccines currently under development are based on recombinant protective antigen (rPA) and formulated with aluminum adjuvant. Because long-term stability is a desired characteristic of these vaccines, an understanding of the effects of adsorption to aluminum adjuvants on the structure of rPA is important. Using both biophysical and immunological techniques, we compared the structure and immunogenicity of freshly prepared rPA-Alhydrogel formulations to that of formulations stored for 3 weeks at either room temperature or 37°C in order to assess the changes in rPA structure that might occur upon long-term storage on aluminum adjuvant. Intrinsic fluorescence emission spectra of tryptophan residues indicated that some tertiary structure alterations of rPA occurred during storage on Alhydrogel. Using anti-PA monoclonal antibodies to probe specific regions of the adsorbed rPA molecule, we found that two monoclonal antibodies that recognize epitopes located in domain 1 of PA exhibited greater reactivity to the stored formulations than to freshly prepared formulations. Immunogenicity of rPA-Alhydrogel formulations in mice was assessed by measuring the induction of toxin-neutralizing antibodies, as well as antibodies reactive to 12-mer peptides spanning the length of PA. Mice immunized with freshly prepared formulations developed significantly higher toxin-neutralizing antibody titers than mice immunized with the stored preparations. In contrast, sera from mice immunized with stored preparations exhibited increased reactivity to nine 12-mer peptides corresponding to sequences located throughout the rPA molecule. These results demonstrate that storage of rPA-Alhydrogel formulations can lead to structural alteration of the protein and loss of the ability to elicit toxin-neutralizing antibodies.

scholarly journals Contribution of Immunological Memory to Protective Immunity Conferred by a Bacillus anthracis Protective Antigen-Based Vaccine

2004 ◽  
Vol 72 (6) ◽  
pp. 3471-3477 ◽  
Author(s):  
Hadar Marcus ◽  
Rachel Danieli ◽  
Eyal Epstein ◽  
Baruch Velan ◽  
Avigdor Shafferman ◽  
...  
Keyword(s):  
Bacillus Anthracis ◽  
Protective Antigen ◽  
Lethal Dose ◽  
Neutralizing Antibody ◽  
Immunological Memory ◽  
Antimicrobial Treatment ◽  
Secondary Response ◽  
Primary Immunization ◽  
Protective Capacity ◽  
Antibody Titers

ABSTRACT Protective antigen (PA)-based vaccination is an effective countermeasure to anthrax infection. While neutralizing anti-PA antibody titers elicited by this vaccine serve as good correlates for protection against anthrax (S. Reuveny, M. D. White, Y. Y. Adar, Y. Kafri, Z. Altboum, Y. Gozes, D. Kobiler, A. Shafferman, and B. Velan, Infect. Immun. 69:2888-2893, 2001), no data are available on the contribution of the immunological memory for PA itself to protection. We therefore developed a guinea pig model in which a primary immunization with threshold levels of PA can induce a long-term T-cell immunological memory response without inducing detectable anti-PA antibodies. A revaccination of primed animals with the same threshold PA levels was effective for memory activation, yielding a robust and rapid secondary response. A challenge with a lethal dose (40 50% lethal doses; 2,000 spores) of spores after the booster vaccinations indicated that animals were not protected at days 2, 4, and 6 postboosting. Protection was achieved only from the 8th day postboosting, concomitant with the detection of protective levels of neutralizing antibody titers in the circulation. The practical implications from the studies reported herein are that, as expected, the protective capacity of memory depends on the PA dose used for the primary immunization and that the effectiveness of booster immunizations for the postexposure treatment of anthrax may be very limited when no detectable antibodies are present in primed animals prior to Bacillus anthracis spore exposure. Therefore, to allow for the establishment of memory-dependent protection prior to the expected onset of disease, booster immunizations should not be used without concomitant antimicrobial treatment in postexposure scenarios.

scholarly journals Recombinant Protective Antigen Anthrax Vaccine Improves Survival when Administered as a Postexposure Prophylaxis Countermeasure with Antibiotic in the New Zealand White Rabbit Model of Inhalation Anthrax

2012 ◽  
Vol 19 (8) ◽  
pp. 1158-1164 ◽  
Author(s):  
Elizabeth K. Leffel ◽  
James S. Bourdage ◽  
E. Diane Williamson ◽  
Matthew Duchars ◽  
Thomas R. Fuerst ◽  
...  
Keyword(s):  
Immune Response ◽  
New Zealand ◽  
Survival Rate ◽  
Protective Antigen ◽  
Zealand White Rabbit ◽  
Postexposure Prophylaxis ◽  
Content Type ◽  
New Zealand White Rabbit ◽  
Inhalation Anthrax ◽  
Recombinant Protective Antigen

ABSTRACTInhalation anthrax is a potentially lethal form of disease resulting from exposure to aerosolizedBacillus anthracisspores. Over the last decade, incidents spanning from the deliberate mailing ofB. anthracisspores to incidental exposures in users of illegal drugs have highlighted the importance of developing new medical countermeasures to protect people who have been exposed to “anthrax spores” and are at risk of developing disease. The New Zealand White rabbit (NZWR) is a well-characterized model that has a pathogenesis and clinical presentation similar to those seen in humans. This article reports how the NZWR model was adapted to evaluate postexposure prophylaxis using a recombinant protective antigen (rPA) vaccine in combination with an oral antibiotic, levofloxacin. NZWRs were exposed to multiples of the 50% lethal dose (LD50) ofB. anthracisspores and then vaccinated immediately (day 0) and again on day 7 postexposure. Levofloxacin was administered daily beginning at 6 to 12 h postexposure for 7 treatments. Rabbits were evaluated for clinical signs of disease, fever, bacteremia, immune response, and survival. A robust immune response (IgG anti-rPA and toxin-neutralizing antibodies) was observed in all vaccinated groups on days 10 to 12. Levofloxacin plus either 30 or 100 μg rPA vaccine resulted in a 100% survival rate (18 of 18 per group), and a vaccine dose as low as 10 μg rPA resulted in an 89% survival rate (16 of 18) when used in combination with levofloxacin. In NZWRs that received antibiotic alone, the survival rate was 56% (10 of 18). There was no adverse effect on the development of a specific IgG response to rPA in unchallenged NZWRs that received the combination treatment of vaccine plus antibiotic. This study demonstrated that an accelerated two-dose regimen of rPA vaccine coadministered on days 0 and 7 with 7 days of levofloxacin therapy results in a significantly greater survival rate than with antibiotic treatment alone. Combination of vaccine administration and antibiotic treatment may be an effective strategy for treating a population exposed to aerosolizedB. anthracisspores.

scholarly journals Immunogenicity of Bacillus anthracis Protective Antigen Domains and Efficacy of Elicited Antibody Responses Depend on Host Genetic Background

2008 ◽  
Vol 15 (7) ◽  
pp. 1115-1123 ◽  
Author(s):  
Nareen Abboud ◽  
Arturo Casadevall
Keyword(s):  
Bacillus Anthracis ◽  
Antibody Titer ◽  
Genetic Background ◽  
Protective Antigen ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Full Length ◽  
Mouse Strains ◽  
Neutralizing Capacity ◽  
Antibody Titers

ABSTRACT Neutralizing antibodies to Bacillus anthracis protective antigen (PA), a component of anthrax toxin, mediate protection against anthrax. PA is antigenically complex and can elicit protective and nonprotective antibodies. Furthermore, vaccinated individuals demonstrate considerable variability in their antibody responses to PA. To explore the relationship between PA structure and antigenicity, we produced Escherichia coli strains expressing full-length PA (PA1-4), domains 2 to 4 (PA2-4), domain 1, (PA1), and domain 4 (PA4) and evaluated the immunogenicities and protective efficacies of the protein fractions in four mouse strains (strains A/J, BALB/c, C57BL/6, and Swiss Webster). Immunization with PA1-4 resulted in significantly higher lethal toxin-neutralizing antibody titers than immunization with any recombinant protein (rPA) fraction of PA. The magnitude and neutralizing capacity of the antibody response to full-length PA and its fragments varied depending on the mouse strain. We found no correlation between the antibody titer and the neutralizing antibody titer for A/J and Swiss Webster mice. In C57BL/6 mice, antibody titers and neutralization capacity correlated for two of four rPA domain proteins tested, while BALB/c mice displayed a similar correlation with only one rPA. By correlating the reactivity of immune sera with solvent-exposed linear peptide segments of PA, we tentatively assign the presence of four new linear B-cell epitopes in PA amino acids 121 to 150, 143 to 158, 339 to 359, and 421 to 440. We conclude that the genetic background of the host determines the relative efficacy of the antitoxin response. The results suggest that the variability observed in vaccination studies with PA-derived vaccines is a result of host heterogeneity and implies a need to develop other antigens as vaccine candidates.

Sign in / Sign up

Export Citation Format

Share Document