scholarly journals Engineering Antigens to Assemble into Polymer Particle Vaccines for Prevention of Streptococcus suis Infection

Vaccines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1386
Author(s):  
Zennia Jean C. Gonzaga ◽  
Shuxiong Chen ◽  
Mélanie Lehoux ◽  
Mariela Segura ◽  
Bernd H. A. Rehm

Streptococcus suis is a zoonotic pathogen affecting pigs and humans. This bacterium causes severe economic losses in the swine industry and poses a serious threat to public health and food safety. There is no effective commercial vaccine available for pigs or humans. In this study, we applied the biopolymer particle (BP) vaccine technology to incorporate seven conserved S. suis antigens (38 kDa protein (38), enolase (Enol), SSU1915, SSU1355, SSU0185, SSU1215, and SSU1773 (SSU1 and SSU2)). Two combinations of these antigens (38 and Enol; all SSU antigens designated as SSU1 and SSU2) were engineered to mediate production of BPs coated with either antigens 38 and Enol or SSU1 and SSU2 inside recombinant Escherichia coli. The isolated and purified empty BPs, 38-BP-Enol and SSU1-BP-SSU2, showed size ranges of 312–428 nm and 292–344 nm with and without the QuilA® adjuvant, respectively, and all showed a negative surface charge. Further characterization of purified BPs confirmed the presence of the expected antigen-comprising fusion proteins as assessed by tryptic peptide fingerprinting analysis using quadrupole time-of-flight mass spectrometry and immunoblotting. Vaccination with 38-BP-Enol and SSU1-BP-SSU2 formulated with and without QuilA® adjuvant induced significant antigen-specific humoral immune responses in mice. Antigen-coated BPs induced significant and specific Ig (IgM + IgG) and IgG immune responses (1.0 × 106–1.0 × 107) when compared with mice vaccinated with empty BPs. Functionality of the immune response was confirmed in challenge experiments using an acute murine S. suis infection model, which showed 100% survival of the 38-BP-Enol and SSU1-BP-SSU2 vaccinated mice compared to 70% survival when vaccinated with empty BPs. Overall, our data suggest that S. suis antigen-coated BPs could be developed into particulate vaccines that induce protective immunity against S. suis infections.

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Wenchao Li ◽  
Weiwei Chen ◽  
Saisai Huang ◽  
Xiaojun Tang ◽  
Genhong Yao ◽  
...  

Infection is a common cause of hospitalization and mortality in patients with systemic lupus erythematosus (SLE). How the underlying immune dysfunctions affect the antimicrobial immunity remains largely unknown. In the present study, employing the pulmonary infection model, we determined the antimicrobial defence of lupus-prone mice. After infecting with opportunistic bacterium Haemophilus influenzae (Hi), lupus-prone mice (B6/lpr) exhibited inefficient bacterial elimination and recovered slowly. They generated severer inflammation at the early stage of infection, as excessive accumulation of neutrophils and enhanced production of proinflammatory cytokines were observed in the lung. In addition, a large number of apoptotic cells were detected in the lungs of B6/lpr mice. For adaptive immune responses, B6/lpr mice were capable to generate enough protective Hi-specific Th17 cells. They evoked stronger Hi-specific γδ T17 response in both lungs and spleens. Unexpectedly, both CD4 and γδ T cells from lupus-prone mice showed deficiency in IFN-γ production. For humoral immune responses, compared with those of WT mice, the concentrations of Hi-specific IgA, IgM, and IgG, especially IgG, were significantly higher in the B6/lpr mice. Our findings suggest that lupus mice are capable to generate antibacterial immune responses; however, the overwhelming inflammation and overactivated immune responses increase the severity of infection.


Viruses ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2264
Author(s):  
Wenqiang Sun ◽  
He Zhang ◽  
Wenhui Fan ◽  
Lihong He ◽  
Teng Chen ◽  
...  

African swine fever virus (ASFV) causes acute hemorrhagic fever in domestic pigs and wild boars, resulting in incalculable economic losses to the pig industry. As the mechanism of viral infection is not clear, protective antigens have not been discovered or identified. In this study, we determined that the p30, pp62, p72, and CD2v proteins were all involved in the T cell immune response of live pigs infected with ASFV, among which p72 and pp62 proteins were the strongest. Panoramic scanning was performed on T cell epitopes of the p72 protein, and three high-frequency positive epitopes were selected to construct a swine leukocyte antigen (SLA)-tetramer, and ASFV-specific T cells were detected. Subsequently, the specific T cell and humoral immune responses of ASFV-infected pigs and surviving pigs were compared. The results demonstrate that the specific T cellular immunity responses gradually increased during the infection and were higher than that in the surviving pigs in the late stages of infection. The same trend was observed in specific humoral immune responses, which were highest in surviving pigs. In general, our study provides key information for the exploration of ASFV-specific immune responses and the development of an ASFV vaccine.


1997 ◽  
Vol 27 (11) ◽  
pp. 1285-1291 ◽  
Author(s):  
M. N. KOLOPP-SARDA ◽  
D. A. MONERET-VAUTRIN ◽  
B. GOBERT ◽  
G. KANNY ◽  
M. BRODSCHII ◽  
...  

2021 ◽  
Author(s):  
Michael Whitehead ◽  
Andrew Osborne ◽  
Patrick Yu‐Wai‐Man ◽  
Keith Martin

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 271-272
Author(s):  
Janna Shapiro ◽  
Helen Kuo ◽  
Rosemary Morgan ◽  
Huifen Li ◽  
Sabra Klein ◽  
...  

Abstract Older adults bear the highest burden of severe disease and complications associated with seasonal influenza, with annual vaccination serving as the best option for protection. Variability in vaccine efficacy exists, yet the host factors that affect immune responses to inactivated influenza vaccines (IIV) are incompletely understood. We hypothesized that sex and frailty interact to affect vaccine-induced humoral responses among older adults. To test this hypothesis, community-dwelling adults above 75 years of age were recruited yearly, assessed for frailty (as defined by the Cardiovascular Health Study criteria), and vaccinated with the high-dose trivalent IIV. Humoral immune responses were evaluated via hemagglutination inhibition titers. The study began during the 2014-2015 influenza season, with yearly cohorts ranging from 76-163 individuals. A total of 617 vaccinations were delivered from 2014-2019. In preliminary analyses, the outcome of interest was seroconversion, defined as ≥ 4-fold rise in titers. Crude odds ratios suggest that females are more likely to seroconvert to influenza A strains (H1N1: OR = 1.39, (0.98-1.96) ; H3N2: 1.17 (0.85 – 1.62)), while males are more likely to seroconvert to the B strain (OR = 0.85 (0.60 – 1.22)). Furthermore, this sex difference was modified by frailty – for example, the odds of seroconversion to H1N1 were 65% higher for females than males among those who were nonfrail, and only 30% higher among females who were frail. Together, these results suggest that sex and frailty interact to impact immune responses to influenza vaccines. These findings may be leveraged to better protect vulnerable populations.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Qiuting Fu ◽  
Qiankun Cui ◽  
Yi Yang ◽  
Xinghong Zhao ◽  
Xu Song ◽  
...  

Resveratrol, a polyphenolic plant antitoxin, has a wide range of pharmacological activities. In this study, we systematically evaluated the effects of resveratrol dry suspension (RDS) on immune function in piglets that were treated with different doses of RDS for 2 weeks. The results showed that the RDS has significant effects on the development, maturation, proliferation, and transformation of T lymphocytes. RDS could regulate humoral immune responses by upregulating the release of IFN-γ and downregulating the release of TNF-α. After piglets were vaccinated against classical swine fever virus and foot-and-mouth disease virus, the antibody titers were significantly increased. RDS treatment showed an excellent resistance to enhance T-SOD activity. Values of blood routine and blood biochemistry showed no toxicity. These results suggested that RDS could be considered as an adjuvant to enhance immune responses to vaccines, as well as dietary additives for animals to enhance humoral and cellular immunity.


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