Evaluation of immunogenicity and protection mediated by Lawsonia intracellularis subunit vaccines

To date, vaccination has become one of the most effective strategies to control and reduce infectious diseases, preventing millions of deaths worldwide. The earliest vaccines were developed as live-attenuated or inactivated pathogens, and, although they still represent the most extended human vaccine types, they also face some issues, such as the potential to revert to a pathogenic form of live-attenuated formulations or the weaker immune response associated with inactivated vaccines. Advances in genetic engineering have enabled improvements in vaccine design and strategies, such as recombinant subunit vaccines, have emerged, expanding the number of diseases that can be prevented. Moreover, antigen display systems such as VLPs or those designed by nanotechnology have improved the efficacy of subunit vaccines. Platforms for the production of recombinant vaccines have also evolved from the first hosts, Escherichia coli and Saccharomyces cerevisiae, to insect or mammalian cells. Traditional bacterial and yeast systems have been improved by engineering and new systems based on plants or insect larvae have emerged as alternative, low-cost platforms. Vaccine development is still time-consuming and costly, and alternative systems that can offer cost-effective and faster processes are demanding to address infectious diseases that still do not have a treatment and to face possible future pandemics.

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An evidence-based systematic review on emerging therapeutic and preventive strategies to treat novel coronavirus (SARS-CoV-2) during an outbreak scenario

Journal of Basic and Clinical Physiology and Pharmacology ◽

10.1515/jbcpp-2020-0113 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Anupama M. Gudadappanavar ◽

Jyoti Benni

Keyword(s):

Antiviral Drug ◽

Drug Repurposing ◽

Respiratory Illness ◽

World Health ◽

Recombinant Vaccines ◽

Subunit Vaccines ◽

Coronavirus Infection ◽

Novel Coronavirus ◽

Health Organization ◽

Full Length Genome

AbstractA novel coronavirus infection coronavirus disease 2019 (COVID-19) emerged from Wuhan, Hubei Province of China, in December 2019 caused by SARS-CoV-2 is believed to be originated from bats in the local wet markets. Later, animal to human and human-to-human transmission of the virus began and resulting in widespread respiratory illness worldwide to around more than 180 countries. The World Health Organization declared this disease as a pandemic in March 2020. There is no clinically approved antiviral drug or vaccine available to be used against COVID-19. Nevertheless, few broad-spectrum antiviral drugs have been studied against COVID-19 in clinical trials with clinical recovery. In the current review, we summarize the morphology and pathogenesis of COVID-19 infection. A strong rational groundwork was made keeping the focus on current development of therapeutic agents and vaccines for SARS-CoV-2. Among the proposed therapeutic regimen, hydroxychloroquine, chloroquine, remdisevir, azithromycin, toclizumab and cromostat mesylate have shown promising results, and limited benefit was seen with lopinavir–ritonavir treatment in hospitalized adult patients with severe COVID-19. Early development of SARS-CoV-2 vaccine started based on the full-length genome analysis of severe acute respiratory syndrome coronavirus. Several subunit vaccines, peptides, nucleic acids, plant-derived, recombinant vaccines are under pipeline. This article concludes and highlights ongoing advances in drug repurposing, therapeutics and vaccines to counter COVID-19, which collectively could enable efforts to halt the pandemic virus infection.

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Lawsonia intracellularis infected enterocytes lack sucrase-isomaltase which contributes to reduced pig digestive capacity

Veterinary Research ◽

10.1186/s13567-021-00958-2 ◽

2021 ◽

Vol 52 (1) ◽

Author(s):

Emma T. Helm ◽

Eric R. Burrough ◽

Fernando L. Leite ◽

Nicholas K. Gabler

Keyword(s):

Dry Matter ◽

Post Inoculation ◽

Intestinal Function ◽

Lawsonia Intracellularis ◽

Sample Collection ◽

Treatment Groups ◽

Swine Herds ◽

The Impact ◽

Lesion Severity

AbstractLawsonia intracellularis is endemic to swine herds worldwide, however much is still unknown regarding its impact on intestinal function. Thus, this study aimed to characterize the impact of L. intracellularis on digestive function, and how vaccination mitigates these impacts. Thirty-six L. intracellularis negative barrows were assigned to treatment groups (n = 12/trt): (1) nonvaccinated, L. intracellularis negative (NC); (2) nonvaccinated, L intracellularis challenged (PC); and (3) L. intracellularis challenged, vaccinated (Enterisol® Ileitis, Boehringer Ingelheim) 7 weeks pre-challenge (VAC). On days post-inoculation (dpi) 0 PC and VAC pigs were inoculated with L. intracellularis. From dpi 19–21 fecal samples were collected for apparent total tract digestibility (ATTD) and at dpi 21, pigs were euthanized for sample collection. Post-inoculation, ADG was reduced in PC pigs compared with NC (41%, P < 0.001) and VAC (25%, P < 0.001) pigs. Ileal gross lesion severity was greater in PC pigs compared with NC (P = 0.003) and VAC (P = 0.018) pigs. Dry matter, organic matter, nitrogen, and energy ATTD were reduced in PC pigs compared with NC pigs (P ≤ 0.001 for all). RNAscope in situ hybridization revealed abolition of sucrase-isomaltase transcript in the ileum of PC pigs compared with NC and VAC pigs (P < 0.01). Conversely, abundance of stem cell signaling markers Wnt3, Hes1, and p27Kip1 were increased in PC pigs compared with NC pigs (P ≤ 0.085). Taken together, these data demonstrate that reduced digestibility during L. intracellularis challenge is partially driven by abolition of digestive machinery in lesioned tissue. Further, vaccination mitigated several of these effects, likely from lower bacterial burden and reduced disease severity.

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Immune Response to Herpes Simplex Virus Infection and Vaccine Development

Vaccines ◽

10.3390/vaccines8020302 ◽

2020 ◽

Vol 8 (2) ◽

pp. 302 ◽

Cited By ~ 1

Author(s):

Anthony C. Ike ◽

Chisom J. Onu ◽

Chukwuebuka M. Ononugbo ◽

Eleazar E. Reward ◽

Sophia O. Muo

Keyword(s):

Herpes Simplex Virus ◽

Herpes Simplex ◽

Viral Infections ◽

Recombinant Dna ◽

Vaccine Development ◽

The Body ◽

Effective Vaccine ◽

Subunit Vaccines ◽

Simplex Virus ◽

Hsv Infections

Herpes simplex virus (HSV) infections are among the most common viral infections and usually last for a lifetime. The virus can potentially be controlled with vaccines since humans are the only known host. However, despite the development and trial of many vaccines, this has not yet been possible. This is normally attributed to the high latency potential of the virus. Numerous immune cells, particularly the natural killer cells and interferon gamma and pathways that are used by the body to fight HSV infections have been identified. On the other hand, the virus has developed different mechanisms, including using different microRNAs to inhibit apoptosis and autophagy to avoid clearance and aid latency induction. Both traditional and new methods of vaccine development, including the use of live attenuated vaccines, replication incompetent vaccines, subunit vaccines and recombinant DNA vaccines are now being employed to develop an effective vaccine against the virus. We conclude that this review has contributed to a better understanding of the interplay between the immune system and the virus, which is necessary for the development of an effective vaccine against HSV.

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