Enhancing the Protective Immune Response against Botulism

ABSTRACTThe need for a vaccine against botulism has increased since the discontinuation of the pentavalent (ABCDE) botulinum toxoid vaccine by the Centers for Disease Control and Prevention. The botulinum toxins (BoNTs) are the primary virulence factors and vaccine components against botulism. BoNTs comprise three domains which are involved in catalysis (LC), translocation (HCT), and host receptor binding (HCR). Recombinant HCR subunits have been used to develop the next generation of BoNT vaccines. Using structural studies and the known entry properties of BoNT/A, an HCR subunit vaccine against BoNT/A that contained the point mutation W1266A within the ganglioside binding pocket was designed. HCR/A(W1266A) did not enter primary neurons, and the crystal structure of HCR/A(W1266A) was virtually identical to that of wild-type HCR/A. Using a mouse model, experiments were performed using a high-dose vaccine and a low-dose vaccine. At a high vaccine dose, HCR/A and HCR/A(W1266A) elicited a protective immune response to BoNT/A challenge. At the low-dose vaccination, HCR/A(W1266A) was a more protective vaccine than HCR/A. α-HCR IgG titers correlated with protection from BoNT challenge, although titers to block HCR/A entry were greater in serum in HCR/A-vaccinated mice than in HCR/A(W1266A)-vaccinated mice. This study shows that removal of receptor binding capacity enhances potency of the subunit HCR vaccine. Vaccines that lack receptor binding capacity have the added property of limited off-target toxicity.

Download Full-text

Immunogenicity and Neutralizing Activity Comparison of SARS-CoV-2 Spike Full-Length and Subunit Domain Proteins in Young Adult and Old-Aged Mice

Vaccines ◽

10.3390/vaccines9040316 ◽

2021 ◽

Vol 9 (4) ◽

pp. 316

Author(s):

Ki-Hye Kim ◽

Noopur Bhatnagar ◽

Subbiah Jeeva ◽

Judy Oh ◽

Bo Ryoung Park ◽

...

Keyword(s):

Young Adult ◽

Receptor Binding ◽

Vaccine Dose ◽

The Elderly ◽

Full Length ◽

High Dose ◽

Igg Antibodies ◽

Neutralizing Activity ◽

Aged Mice ◽

Adjuvant Effects

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to be expanding the pandemic disease across the globe. Although SARS-CoV-2 vaccines were rapidly developed and approved for emergency use of vaccination in humans, supply and production difficulties are slowing down the global vaccination program. The efficacy of many different versions of vaccine candidates and adjuvant effects remain unknown, particularly in the elderly. In this study, we compared the immunogenic properties of SARS-CoV-2 full-length spike (S) ectodomain in young adult and aged mice, S1 with receptor binding domain, and S2 with fusion domain. Full-length S was more immunogenic and effective in inducing IgG antibodies after low dose vaccination, compared to the S1 subunit. Old-aged mice induced SARS-CoV-2 spike-specific IgG antibodies with neutralizing activity after high dose S vaccination. With an increased vaccine dose, S1 was highly effective in inducing neutralizing and receptor-binding inhibiting antibodies, although both S1 and S2 subunit domain vaccines were similarly immunogenic. Adjuvant effects were significant for effective induction of IgG1 and IgG2a isotypes, neutralizing and receptor-binding inhibiting antibodies, and antibody-secreting B cell and interferon-γ secreting T cell immune responses. Results of this study provide information in designing SARS-CoV-2 spike vaccine antigens and effective vaccination in the elderly.

Download Full-text

Development of SARS-CoV-2 Specific IgG and Virus-Neutralizing Antibodies after Infection with Variants of Concern or Vaccination

Vaccines ◽

10.3390/vaccines9070700 ◽

2021 ◽

Vol 9 (7) ◽

pp. 700

Author(s):

Franziska Neumann ◽

Ruben Rose ◽

Janine Römpke ◽

Olaf Grobe ◽

Thomas Lorentz ◽

...

Keyword(s):

Immune Response ◽

Receptor Binding ◽

Neutralizing Antibodies ◽

Neutralization Test ◽

Vaccine Dose ◽

High Avidity ◽

Receptor Binding Domain ◽

Robust Immune Response ◽

Specific Igg ◽

Nucleoprotein N

The humoral immunity after SARS-CoV-2 infection or vaccination was examined. Convalescent sera after infection with variants of concern (VOCs: B.1.1.7, n = 10; B.1.351, n = 1) and sera from 100 vaccinees (Pfizer/BioNTech, BNT162b2, n = 33; Moderna, mRNA-1273, n = 11; AstraZeneca, ChAdOx1 nCoV-19/AZD1222, n = 56) were tested for the presence of immunoglobulin G (IgG) directed against the viral spike (S)-protein, its receptor-binding domain (RBD), the nucleoprotein (N) and for virus-neutralizing antibodies (VNA). For the latter, surrogate assays (sVNT) and a Vero-cell based neutralization test (cVNT) were used. Maturity of IgG was determined by measuring the avidity in an immunoblot (IB). Past VOC infection resulted in a broad reactivity of anti-S IgG (100%), anti-RBD IgG (100%), and anti-N IgG (91%), while latter were absent in 99% of vaccinees. Starting approximately two weeks after the first vaccine dose, anti-S IgG (75–100%) and particularly anti-RBD IgG (98–100%) were detectable. After the second dose, their titers increased and were higher than in the convalescents. The sVNT showed evidence of VNA in 91% of convalescents and in 80–100%/100% after first/second vaccine dose, respectively. After the second dose, an increase in VNA titer and IgGs of high avidity were demonstrated by cVNT and IB, respectively. Re-vaccination contributes to a more robust immune response.

Download Full-text

Mycobacterium tuberculosis in Chemokine Receptor 2-Deficient Mice: Influence of Dose on Disease Progression

Infection and Immunity ◽

10.1128/iai.70.11.5946-5954.2002 ◽

2002 ◽

Vol 70 (11) ◽

pp. 5946-5954 ◽

Cited By ~ 108

Author(s):

Holly M. Scott ◽

JoAnne L. Flynn

Keyword(s):

Immune Response ◽

Mycobacterium Tuberculosis ◽

Cell Migration ◽

Chemokine Receptor ◽

Chemokine Receptors ◽

Low Dose ◽

High Dose ◽

Long Term Effects ◽

Spread Of Infection ◽

Oxide Synthase

ABSTRACT Within a Mycobacterium tuberculosis-induced granuloma, lymphocytes and macrophages work together to control bacterial growth and limit the spread of infection. Chemokines and chemokine receptors are involved in cell migration and are logical candidates for a role in granuloma formation. In the present study we addressed the role of CC chemokine receptor 2 (CCR2) in M. tuberculosis infection. In previous studies (W. Peters et al., Proc. Natl. Acad. Sci. USA 98:7958-7963, 2001), CCR2−/− mice were found to be highly susceptible to a moderate or high dose of H37Rv administered intravenously (i.v.). We have expanded those studies to demonstrate that the susceptibility of CCR2−/− mice is dose dependent. After low-dose aerosol or i.v. infection of CCR2−/− mice with M. tuberculosis, there was a substantial delay in cell migration to the lungs and delayed expression of gamma interferon and inducible nitric oxide synthase. The CCR2−/− mice had a severe and prolonged deficiency in the number of macrophages in the lungs and an early increase in the number of neutrophils. Despite these deficiencies in cell migration, the CCR2−/− mice did not have increased bacterial loads in the lungs compared to wild-type (C57BL/6) mice and successfully formed granulomas. This finding is in contrast to CCR2−/− mice infected with a high dose of M. tuberculosis administered i.v. These results indicate that with low-dose infection, a delay in immune response in the lungs does not necessarily have detrimental long-term effects on the progression of the disease. The fact that CCR2−/− mice survive with substantially fewer macrophages in the low-dose models implies that the immune response to low-dose M. tuberculosis infection in mice is more robust than necessary to control the infection. Finally, these data demonstrate that, in cases of infectious disease in knockout models, clear phenotypes may not be evident when one is solely evaluating bacterial numbers and survival. Functional assays may be necessary to reveal roles for components of the multifactorial immune system.

Download Full-text

Relationship between chorionic gonadotropin immunomodulating effects and the initial functional activity of the splenocytes mediating the adoptive immune response

Problems of Endocrinology ◽

10.14341/probl11912 ◽

1993 ◽

Vol 39 (1) ◽

pp. 54-57 ◽

Cited By ~ 2

Author(s):

S. V. Shirshev ◽

N. N. Kevorkov

Keyword(s):

Immune Response ◽

Chorionic Gonadotropin ◽

Functional Activity ◽

Low Dose ◽

Interleukin 2 ◽

Prostaglandin Synthesis ◽

High Dose ◽

Transfer System ◽

Male Mice ◽

Stimulation Of

CBA and (СВАхC57BL/6) F1 male mice were used in experiments. One hour incubation of splenocytes with chorionic gonadotropin in doses 10 or 50 MU/ml statistically significantly reduced the count of antibody-producing cells detectable in the syngeneic transfer system. Addition of conA or recombinant human interleukin 2 to the splenocyte culture did not alter the processes of the formation of antibodyproducing cells. Addition of chorionic gonadotropin simultaneously with conA resulted in discontinuation of the immunosuppression induced by a low hormone dose, whereas 50 MU/ml of chorionic gonadotropin in the presence of conA had a marked immunodepressant effect. Combination of interleukin 2 with chorionic gonadotropin lead either to immunosuppression cessation (10 MU/ml) or to more than twofold stimulation of the adoptive immune response (50 MU/ml). Voltaren a cycloxygenase inhibitor, was used in some experiments to elucidate the degree of endogenic prostaglandin relationships with the mechanisms of chorionic gonadotropin immunomodulating effects. Cycloxygenase activity was found to be related to the immunosuppressive effect of chorionic gonadotropin low dose, whereas the costimulating effect of a high dose of the hormone in the presence of interleukin 2 was unrelated to endogenic prostaglandin synthesis.

Download Full-text

Ultra-low dose immunization and multi-component vaccination strategies enhance protection against malaria in mice

Scientific Reports ◽

10.1038/s41598-021-90290-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Katharine A. Collins ◽

Florian Brod ◽

Rebecca Snaith ◽

Marta Ulaszewska ◽

Rhea J. Longley ◽

...

Keyword(s):

Viral Vectors ◽

Low Dose ◽

Protective Efficacy ◽

Vaccine Dose ◽

Effective Vaccine ◽

Phase 3 ◽

Partial Protection ◽

Potential Efficacy ◽

Transgenic Parasites ◽

Dose Vaccine

AbstractAn effective vaccine would be a valuable tool for malaria control and elimination; however, the leading malaria vaccine in development, RTS,S/AS01, provided only partial protection in a Phase 3 trial. R21 is a next-generation RTS,S-like vaccine. We have previously shown in mice that R21 administered in Matrix-M is highly immunogenic, able to elicit complete protection against sporozoite challenge, and can be successfully administered with TRAP based viral-vectors resulting in enhanced protection. In this study, we developed a novel, GMP-compatible purification process for R21, and evaluated the immunogenicity and protective efficacy of ultra-low doses of both R21 and RTS,S when formulated in AS01. We demonstrated that both vaccines are highly immunogenic and also elicit comparable high levels of protection against transgenic parasites in BALB/c mice. By lowering the vaccine dose there was a trend for increased immunogenicity and sterile protection, with the highest dose vaccine groups achieving the lowest efficacy (50% sterile protection). We also evaluated the ability to combine RTS,S/AS01 with TRAP based viral-vectors and observed concurrent induction of immune responses to both antigens with minimal interference when mixing the vaccines prior to administration. These studies suggest that R21 or RTS,S could be combined with viral-vectors for a multi-component vaccination approach and indicate that low dose vaccination should be fully explored in humans to maximize potential efficacy.

Download Full-text

25. Effectiveness of High Dose Influenza Vaccine in HIV-positive Patients for the Winter 2017–2018 Season

Open Forum Infectious Diseases ◽

10.1093/ofid/ofaa439.070 ◽

2020 ◽

Vol 7 (Supplement_1) ◽

pp. S36-S37

Author(s):

Mikiro Kato ◽

Tori Kunkel ◽

David Bram ◽

Jessica Newman ◽

Angela Lopez ◽

...

Keyword(s):

Influenza Vaccine ◽

Sore Throat ◽

Standard Dose ◽

Winter Season ◽

Panel Member ◽

Vaccine Dose ◽

Quadrivalent Vaccine ◽

High Dose ◽

Vaccine Type ◽

Dose Vaccine

Abstract Background Antibody response after high dose influenza vaccine (HDIV) approved for age ≥ 65 years, is superior to a standard-dose vaccine in HIV-infected persons. We report the effectiveness data of HDIV compared to the standard dose quadrivalent vaccine (SDIV) in our HIV clinic. Methods We conducted a retrospective cohort study at the University of Kansas Medical Center to evaluate the effectiveness of HDIV in HIV-infected patients during the 2017–2018 influenza season. A phone survey was utilized to verify vaccination status and interval development of influenza-like illness (ILI). A modified CDC definition of ILI (mCDC ILI = fever and cough, sore throat or shortness of breath (SOB)) and a broader protocol defined ILI (PD ILI = sore throat, cough or SOB with either fever, chills, headache or myalgia) were utilized. The electronic medical record was reviewed to confirm vaccine type and influenza testing when available. Results Of 560 HIV-infected patients in the clinic, 219 (39.1%) were available and willing to participate (197 males, 21 females, 1 transgender female). The median age was 53 years and BMI 27.2 kg/m2. Five percent had CD4< 200 cells/uL, and 13.7% had an HIV viral load > 40 copies/mL. HDIV was given to 119 (54.3%), SDIV to 77 (35.2%) and 23 (10.5%) were not vaccinated (Table 1). A mCDC ILI occurred in 8 (10.4%) in the SDIV group compared to 6 (5.0%) in the HDIV group (p=0.16). A PD ILI was reported in 16 (20.8%) in the SDIV group compared to 12 (10.1%) in the HDIV group (p=0.04). There was no difference in confirmed influenza cases between the two groups (Table 2). On logistic regression only vaccine dose (SDIV OR 2.34 95% CI 1.04–5.37, p=0.04) and age in years (OR 0.97, 95% CI 0.94–1.0, p=0.045) were associated with PD ILI. HDIV remained protective after adjustment for age. Vaccine side effects were mild and occurred in 11/77 (14.3%) in the SDIV group compared to 13/119 (10.9%) in the HDIV group (p=0.5). Conclusion During the 2017–2018 winter season, the CDC reported an influenza attack rate of 14.7% in adults in the US and overall vaccine effectiveness of 38%. Our study demonstrated a 50% reduction in ILI with the HDIV compared to the standard-dose vaccine in HIV-infected patients. A larger prospective randomized control trial is warranted. Disclosures Wissam El Atrouni, MD, ViiV (Advisor or Review Panel member)

Download Full-text

Aldosterone secretion and adrenal angiotensin II receptors in the Brattleboro rat

Journal of Endocrinology ◽

10.1677/joe.0.1170215 ◽

1988 ◽

Vol 117 (2) ◽

pp. 215-221 ◽

Cited By ~ 4

Author(s):

J. P. Laulin ◽

G. Simonnet ◽

R. Brudieux ◽

A. Carayon ◽

J. D. Vincent

Keyword(s):

Angiotensin Ii ◽

Time Course ◽

Low Dose ◽

Binding Capacity ◽

Venous Blood ◽

Zona Glomerulosa ◽

High Dose ◽

Brattleboro Rats ◽

Angiotensin Ii Receptor ◽

Long Evans

ABSTRACT The basal secretion of aldosterone, measured in adrenal venous blood, was three- to fourfold lower in Brattleboro than in Long–Evans rats used as controls. Infusion of a low dose of angiotensin II (1 ng/min per 100 g body/wt) to Long–Evans rats caused a fourfold increase in aldosterone release but neither the low dose nor a tenfold higher dose changed the rate of release in Brattleboro rats. Only a very high dose (300 ng/min per 100 g body wt) succeeded in increasing the secretion of aldosterone in Brattleboro rats but throughout the time-course of the infusion, secretion remained about fivefold lower than in Long-Evans rats and the incremental response was reduced by 74·9%. Adrenal zona glomerulosa angiotensin II receptor sites had similar affinity and maximum binding capacity in the two groups of rats. It is suggested that the reduced corticosteroidogenic capacity of the adrenal cortex of Brattleboro rats results from an impairment of the post-receptor mechanisms involved in the biosynthesis of aldosterone. J. Endocr. (1988) 117, 215–221

Download Full-text

STUDIES ON THE REGULATION OF AVIDITY AT THE LEVEL OF THE SINGLE ANTIBODY-FORMING CELL

Journal of Experimental Medicine ◽

10.1084/jem.132.1.77 ◽

1970 ◽

Vol 132 (1) ◽

pp. 77-88 ◽

Cited By ~ 117

Author(s):

Birger Andersson

Keyword(s):

Immune Response ◽

Present Method ◽

Low Dose ◽

Cellular Level ◽

Plaque Formation ◽

High Dose ◽

High Avidity ◽

Specific Inhibition ◽

Cellular Events ◽

Free Antigen

The hemolytic plaque formation of cells producing antibody against heterologous albumins was tested for sensitivity to specific inhibition by free antigen. The inhibition characteristics of plaques in this system were found to be a measure for the avidity of the antibody produced by the plaque-forming cells (PFC:s). High avidity-producing PFC:s were more sensitive to inhibition than low avidity PFC:s. Immunization with a high dose of antigen induced PFC:s that produced antibody with a lower avidity as compared to PFC:s from animals immunized with a low dose. The avidity was increased with time. Determinations of avidity at the serum level were also made, and the results were in agreement with the findings at the cellular level. The present method made it possible to demonstrate differences in avidity of antibody at the level of the single antibody-forming cell. It may also constitute a useful tool for the analysis of the cellular events leading to the production of antibodies with varying affinities during the immune response.

Download Full-text

A dual-role of SARS-CoV-2 nucleocapsid protein in regulating innate immune response

Signal Transduction and Targeted Therapy ◽

10.1038/s41392-021-00742-w ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Yinghua Zhao ◽

Liyan Sui ◽

Ping Wu ◽

Wenfang Wang ◽

Zedong Wang ◽

...

Keyword(s):

Immune Response ◽

Immune Responses ◽

Inflammatory Cytokines ◽

Low Dose ◽

Nuclear Translocation ◽

Innate Immune ◽

High Dose ◽

Type I ◽

Innate Immune Responses ◽

N Protein

AbstractThe recently emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the causative agent of ongoing global pandemic of COVID-19, may trigger immunosuppression in the early stage and overactive immune response in the late stage of infection; However, the underlying mechanisms are not well understood. Here we demonstrated that the SARS-CoV-2 nucleocapsid (N) protein dually regulated innate immune responses, i.e., the low-dose N protein suppressed type I interferon (IFN-I) signaling and inflammatory cytokines, whereas high-dose N protein promoted IFN-I signaling and inflammatory cytokines. Mechanistically, the SARS-CoV-2 N protein dually regulated the phosphorylation and nuclear translocation of IRF3, STAT1, and STAT2. Additionally, low-dose N protein combined with TRIM25 could suppress the ubiquitination and activation of retinoic acid-inducible gene I (RIG-I). Our findings revealed a regulatory mechanism of innate immune responses by the SARS-CoV-2 N protein, which would contribute to understanding the pathogenesis of SARS-CoV-2 and other SARS-like coronaviruses, and development of more effective strategies for controlling COVID-19.

Download Full-text