Preparation of a nanovaccine against Brucella melitensis M16 based on PLGA nanoparticles and oligopolysaccharide antigen

The immunostimulatory roles of gold nanoparticles in immunization and vaccination against Brucella abortus antigens

One effective antigen carrier proposed for use in immunization and vaccination is gold nanoparticles. Prior work has shown that gold nanoparticles themselves have adjuvant properties. Currently, gold nanoparticles are used to design new diagnostic tests and vaccines against viral, bacterial, and parasitic infections. We investigated the use of gold nanoparticles as immunomodulators in immunization and vaccination with an antigen isolated from Brucella abortus. Gold nanoparticles with a diameter of 15 nm were synthesized for immunization of animals and were then conjugated to the isolated antigen. The conjugates were used to immunize white BALB/c mice. As a result, high-titer (1:10240) antibodies were produced. The respiratory and proliferative activities of immune cells were increased, as were the serum interleukin concentrations. The minimum antigen amount detected with the produced antibodies was ∼ 0.5 pg. The mice immunized with gold nanoparticles complexed with the B. abortus antigen were more resistant to B. abortus strain 82 than were the mice immunized through other schemes. This fact indicates that animal immunization with this conjugate enhances the effectiveness of the immune response. The results of this study are expected to be used in further work to examine the protective effect of gold nanoparticles complexed with the B. abortus antigen on immunized animals and to develop test systems for diagnosing brucellosis in the laboratory and in the field.

Brucellosis: epidemiology, pathogenesis, diagnosis and treatment-a comprehensive review

Background: Brucellosis is a pervasive zoonotic disease caused by various Brucella species. It mainly affects livestock and wildlife and poses significant public health threats, especially in regions with suboptimal hygiene, food safety, and veterinary care standards. Human contractions occur by consuming contaminated animal products or interacting with infected animals. Objective: This study aims to provide an updated understanding of brucellosis, from its epidemiology and pathogenesis to diagnosis and treatment strategies. It emphasizes the importance of ongoing research, knowledge exchange, and interdisciplinary collaboration for effective disease control and prevention, highlighting its global health implications. Methods: Pathogenesis involves intricate interactions between bacteria and the host immune system, resulting in chronic infections characterized by diverse clinical manifestations. The diagnostic process is arduous owing to non-specific symptomatology and sampling challenges, necessitating a fusion of clinical and laboratory evaluations, including blood cultures, serological assays, and molecular methods. Management typically entails multiple antibiotics, although the rise in antibiotic-resistant Brucella strains poses a problem. Animal vaccination is a potential strategy to curb the spread of infection, particularly within livestock populations. Results: The study provides insights into the complex pathogenesis of brucellosis, the challenges in its diagnosis, and the management strategies involving antibiotic therapy and animal vaccination. It also highlights the emerging issue of antibiotic-resistant Brucella strains. Conclusions: In conclusion, brucellosis is a significant zoonotic disease with implications for public health. Efforts should be directed towards improved diagnostic methods, antibiotic stewardship to combat antibiotic resistance, and developing and implementing effective animal vaccination programs. Interdisciplinary collaboration and ongoing research are crucial for addressing the global health implications of brucellosis.

Immunization of mice with chimeric protein-loaded aluminum hydroxide and selenium nanoparticles induces reduction of Brucella melitensis infection in mice

Purpose

Due to the many problems with commercially available vaccines, the production of effective vaccines against brucellosis is a necessity. The aim of this study was to evaluate the immune responses caused by the chimeric protein consisting of trigger factor, Bp26, and Omp31 (TBO) along with aluminum hydroxide (AH/TBO) and selenium (Se/TBO) nanoparticles (NPs) as adjuvants in mouse model.

Materials and Methods

Recombinant antigen expression was induced in Escherichia coli BL21 (DE3) bacteria using IPTG (isopropyl-d-1-thiogalactopyranoside). Purification and characterization of recombinant protein was conducted through NiFe3O4 NPs, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and Western blot. NP characteristics, including morphology and particle size, were measured in vitro. The recombinant TBO was loaded on to AH and Se NPs and were administered subcutaneously. After mice immunization, measurement of antibody titter and protection assay was performed.

Results

The average sizes of AH and Se NPs were about 60 nm and 150 nm, respectively. The enzyme-linked immunosorbent assay results showed that the serum of mice immunized by subcutaneous injection with both nanovaccines produced significant immunoglobulin G (IgG) responses against the chimeric antigen. The results of TBO-specific IgG isotype (IgG2a/IgG1) analysis showed that both AH and Se NPs induced a type to T-helper immune response. In addition, the results of the challenge with the pathogenic strain of Brucella melitensis 16M showed that vaccinated mice with AH/TBO NPs indicated a higher reduction of bacterial culture than immunized mice with Se/TBO NPs and TBO alone.

Conclusion

The results showed that AH NPs carrying chimeric antigen can be a promising vaccine candidate against brucellosis by producing protective immunity.

Current status of nano-vaccinology in veterinary medicine science

Vaccination programmes provide a safe, effective and cost-efficient strategy for maintaining population health. In veterinary medicine, vaccination not only reduces disease within animal populations but also serves to enhance public health by targeting zoonoses. Nevertheless, for many pathogens, an effective vaccine remains elusive. Recently, nanovaccines have proved to be successful for various infectious and non-infectious diseases of animals. These novel technologies, such as virus-like particles, self-assembling proteins, polymeric nanoparticles, liposomes and virosomes, offer great potential for solving many of the vaccine production challenges. Their benefits include low immunotoxicity, antigen stability, enhanced immunogenicity, flexibility sustained release and the ability to evoke both humoral and cellular immune responses. Nanovaccines are more efficient than traditional vaccines due to ease of control and plasticity in their physio-chemical properties. They use a highly targeted immunological approach which can provide strong and long-lasting immunity. This article reviews the currently available nanovaccine technology and considers its utility for both infectious diseases and non-infectious diseases such as auto-immunity and cancer. Future research opportunities and application challenges from bench to clinical usage are also discussed.

The Influence of Nanoparticle on Vaccine Responses against Bacterial Infection

Nowadays, nanovaccine is considered as an evolving method in the field of vaccination to induce immunity in the human body against various diseases, including bacterial or viral diseases as well as virulent tumors. Nanovaccines are more efficient than traditional vaccines since they could potentially induce both humoral and cellular immune reactions. Various studies have shown that nanoparticles with multiple compounds have been designed as delivery systems or as adjuvants for vaccines. Nanoparticles could function as a drug delivery tool, as an adjuvant to promote antigen processing, and as an immune modulator to induce immune responses. These nanoparticles generate immune responses through activating immune cells as well as through the production of antibody responses. Design engineering of nanoparticles (NPs) used to produce nanovaccines to induce immunity in the human body needs comprehensive information about the ways they interact with the component of immune system. Challenges remain due to the lack of sufficient and comprehensive information about the nanoparticles' mode of action. Several studies have described the interactions between various classes of nanoparticles and the immune system in the field of prevention of bacterial infections. The results of some studies conducted in recent years on the interaction between nanoparticles and biosystems have considerably affected the methods used to design nanoparticles for medical applications. In this review, NPs’ characteristics influencing their interplay with the immune system were discussed in vivo. The information obtained could lead to the development of strategies for rationalizing the design of nanovaccines in order to achieve optimum induction of immune response.

Translating the Manufacture of Immunotherapeutic PLGA Nanoparticles from Lab to Industrial Scale: Process Transfer and In Vitro Testing

Poly(lactic-co-glycolic acid) (PLGA) nanoparticle-based drug delivery systems are known to offer a plethora of potential therapeutic benefits. However, challenges related to large-scale manufacturing, such as the difficulty of reproducing complex formulations and high manufacturing costs, hinder their clinical and commercial development. In this context, a reliable manufacturing technique suitable for the scale-up production of nanoformulations without altering efficacy and safety profiles is highly needed. In this paper, we develop an inline sonication process and adapt it to the industrial scale production of immunomodulating PLGA nanovaccines developed using a batch sonication method at the laboratory scale. The investigated formulations contain three distinct synthetic peptides derived from the carcinogenic antigen New York Esophageal Squamous Cell Carcinoma-1 (NY-ESO-1) together with an invariant natural killer T-cell (iNKT) activator, threitolceramide-6 (IMM60). Process parameters were optimized to obtain polymeric nanovaccine formulations with a mean diameter of 150 ± 50 nm and a polydispersity index <0.2. Formulation characteristics, including encapsulation efficiencies, release profiles and in vitro functional and toxicological profiles, are assessed and statistically compared for each formulation. Overall, scale-up formulations obtained by inline sonication method could replicate the colloidal and functional properties of the nanovaccines developed using batch sonication at the laboratory scale. Both types of formulations induced specific T-cell and iNKT cell responses in vitro without any toxicity, highlighting the suitability of the inline sonication method for the continuous scale-up of nanomedicine formulations in terms of efficacy and safety.

Evaluation of Brucellosis Vaccines: A Comprehensive Review

Brucellosis is a bacterial zoonosis caused by Brucella spp. which can lead to heavy economic losses and severe human diseases. Thus, controlling brucellosis is very important. Due to humans easily gaining brucellosis from animals, animal brucellosis control programs can help the eradication of human brucellosis. There are two popular vaccines against animal brucellosis. Live attenuated Brucella abortus strain 19 (S19 vaccine) is the first effective and most extensively used vaccine for the prevention of brucellosis in cattle. Live attenuated Brucella melitensis strain Rev.1 (Rev.1 vaccine) is the most effective vaccine against caprine and ovine brucellosis. Although these two vaccines provide good immunity for animals against brucellosis, the expense of persistent serological responses is one of the main problems of both vaccines. The advantages and limitations of Brucella vaccines, especially new vaccine candidates, have been less studied. In addition, there is an urgent need for new strategies to control and eradicate this disease. Therefore, this narrative review aims to present an updated overview of the available different types of brucellosis vaccines.

Nano drug delivery in intracellular bacterial infection treatments

The present work aimed to review the potential mechanisms used by macrophages to kill intracellular bacteria, their entrance to the cell, and mechanisms of escape of cellular immunity and applications of various nanoparticles. Since intracellular bacteria such as Mycobacterium and Brucella can survive in host cells and can resist the lethal power of macrophages, they can cause chronic disease or recur in 10-30% of cases in improved patients Nano drug-based therapeutics are promising tools for treating intracellular bacteria and preventing recurrence of the disease caused by these bacteria. In addition, among their unique features, we can mention the small size and the ability of these compounds to purposefully reach the target location.

Nanovaccines against Animal Pathogens: The Latest Findings

Nowadays, safe and efficacious vaccines represent powerful and cost-effective tools for global health and economic growth. In the veterinary field, these are undoubtedly key tools for improving productivity and fighting zoonoses. However, cases of persistent infections, rapidly evolving pathogens having high variability or emerging/re-emerging pathogens for which no effective vaccines have been developed point out the continuing need for new vaccine alternatives to control outbreaks. Most licensed vaccines have been successfully used for many years now; however, they have intrinsic limitations, such as variable efficacy, adverse effects, and some shortcomings. More effective adjuvants and novel delivery systems may foster real vaccine effectiveness and timely implementation. Emerging vaccine technologies involving nanoparticles such as self-assembling proteins, virus-like particles, liposomes, virosomes, and polymeric nanoparticles offer novel, safe, and high-potential approaches to address many vaccine development-related challenges. Nanotechnology is accelerating the evolution of vaccines because nanomaterials having encapsulation ability and very advantageous properties due to their size and surface area serve as effective vehicles for antigen delivery and immunostimulatory agents. This review discusses the requirements for an effective, broad-coverage-elicited immune response, the main nanoplatforms for producing it, and the latest nanovaccine applications for fighting animal pathogens.

Immunization effect of lipopolysaccharide antigen in conjugation with PLGA nanoparticles as a nanovaccine against Brucella melitensis infection

Brucella is an infectious disease with difficult treatment faced with drug resistance and recurrence of infection. Despite advances in the development of effective vaccines against brucellosis infections, there is still a need for more effective vaccine against brucellosis. In this study, we developed a nanovaccine for delivery of lipopolysaccharide Brucella melitensis antigen to the immune system using PLGA nanoparticles to prevent Brucella infection, which is associated with the stimulation of both humoral and cellular immune systems. In particular, we determined the rate of produced immunoglobulines and their functional effectiveness on the immune system by carring out opsonophagocytosis and challenge tests. According to the results, it was determined that PLGA improve the delivery of LPS antigen to the immune system to enhance the production of immunoglobulins levels and their efficiency to remove Brucella bacteria.

Topical review on nano-vaccinology: Biochemical promises and key challenges

Nanomaterials have wide-ranging biomedical applications in prevention, treatment and control of diseases. Nanoparticle based vaccines have proven prodigious prophylaxis of various infectious and non-infectious diseases of human and animal concern. Nano-vaccines outnumber the conventional vaccines by virtue of plasticity in physio-chemical properties and ease of administration. The efficacy of nano-based vaccines may be attributed to the improved antigen stability, minimum immuno-toxicity, sustained release, enhanced immunogenicity and the flexibility of physical features of nanoparticles. Based on these, the nano-based vaccines have potential to evoke both cellular and humoral immune responses. Targeted and highly specific immunological pathways required for solid and long lasting immunity may be achieved with specially engineered nano-vaccines. This review presents an insight into the prevention of infectious diseases (of bacterial, viral and parasitic origin) and non-infectious diseases (cancer, auto-immune diseases) using nano-vaccinology. Additionally, key challenges to the effective utilization of nano-vaccines from bench to clinical settings have been highlighted as research domains for future.

Applications of Nanovaccines for Disease Prevention in Cattle

Vaccines are one of the most important tools available to prevent and reduce the incidence of infectious diseases in cattle. Despite their availability and widespread use to combat many important pathogens impacting cattle, several of these products demonstrate variable efficacy and safety in the field, require multiple doses, or are unstable under field conditions. Recently, nanoparticle-based vaccine platforms (nanovaccines) have emerged as promising alternatives to more traditional vaccine platforms. In particular, polymer-based nanovaccines provide sustained release of antigen payloads, stabilize such payloads, and induce enhanced antibod- and cell-mediated immune responses, both systemically and locally. To improve vaccine administrative strategies and efficacy, they can be formulated to contain multiple antigenic payloads and have the ability to protect fragile proteins from degradation. Nanovaccines are also stable at room temperature, minimizing the need for cold chain storage. Nanoparticle platforms can be synthesized for targeted delivery through intranasal, aerosol, or oral administration to induce desired mucosal immunity. In recent years, several nanovaccine platforms have emerged, based on biodegradable and biocompatible polymers, liposomes, and virus-like particles. While most nanovaccine candidates have not yet advanced beyond testing in rodent models, a growing number have shown promise for use against cattle infectious diseases. This review will highlight recent advancements in polymeric nanovaccine development and the mechanisms by which nanovaccines may interact with the bovine immune system. We will also discuss the positive implications of nanovaccines use for combating several important viral and bacterial disease syndromes and consider important future directions for nanovaccine development in beef and dairy cattle.