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Tetanus toxin, a highly potent neurotoxin produced by Clostridium tetani, is the primary agent responsible for causing tetanus. This serious, potentially fatal disease can be effectively prevented through vaccination. Thanks to successful vaccination campaigns, tetanus has become exceedingly rare in both developed and most developing countries. However, the widespread presence of C. tetani spores in the environment means that tetanus cannot be completely eradicated, underscoring the ongoing need for vaccination. Traditionally, tetanus vaccines are produced by cultivating C. tetani, extracting a crude form of the tetanus toxin, and then chemically inactivating it for use in immunization. This method has proven clinically effective and is in widespread use. A challenge with this approach, however, is that the vaccine contains hundreds of various C. tetani proteins, with the active component making up only a variable and small fraction of the overall vaccine mass. To improve the current tetanus vaccine, there is potential in the recombinant production of a genetically inactivated tetanus vaccine. Prior studies have demonstrated the feasibility of engineering the full-length tetanus toxin in E. coli, and our current work builds on this foundation. We have successfully cloned the complete tetanus toxin open reading frame into the pMAL expression vector. This step was followed by the creation of a genetically inactivated protein, achieved through standard site-directed mutagenesis which altered 8 critical amino acid residues. These mutations have been confirmed via sequencing, ensuring that the toxin is genetically inactivated and thus does not require chemical inactivation for vaccine production. Our present focus is on optimizing the expression of this protein in E. coli. Following this, we intend to conduct thorough assessments of the biochemical and immunological properties of the recombinant tetanus toxin. This research represents a promising avenue towards enhancing

Diphtheria and tetanus, once formidable causes of morbidity and mortality worldwide, have seen their threats markedly diminished through the advent and widespread use of vaccines. This review article delves into the historical journey of diphtheria and tetanus vaccines, evaluates their current status in global immunization programs, and explores future perspectives in their evolution and implementation. The inception of diphtheria and tetanus vaccines marked a pivotal shift in infectious disease control. The development of diphtheria toxoid by Emil von Behring in the late 19th century and the subsequent creation of tetanus toxoid in the early 20th century set the stage for large-scale immunization efforts. These efforts were bolstered in the mid-20th century with the integration of these toxoids into combination vaccines, notably the DTP (diphtheria-tetanus-pertussis) vaccine, facilitating broader immunization coverage and enhanced public health outcomes. Currently, the inclusion of diphtheria and tetanus vaccines in national immunization schedules has led to a significant decline in the incidence of these diseases globally. However, challenges remain, including disparities in vaccine coverage and the emergence of non-toxigenic strains causing diphtheria. The review highlights the WHO’s strategies towards achieving higher immunization coverage and the importance of maintaining high vaccination rates to prevent resurgence. Looking forward, the review discusses the ongoing research and development aimed at improving vaccine formulations, reducing adverse reactions, and enhancing the efficacy and durability of protection. Innovations such as nanoparticle vaccines and DNA vaccines are explored as potential avenues for future advancements. Additionally, the review addresses the critical role of global health governance in addressing vaccine hesitancy, improving access in low-resource settings, and coordinating responses to outbreaks. In conclusion, while the battle again

Aging is closely related to the main aspects of multiple sclerosis (MS). The average age of the MS population is increasing and the number of elderly MS patients is expected to increase. In addition to neurons, N-methyl-D-aspartate receptors (NMDARs) are also expressed on non-neuronal cells, such as immune cells. The aim of this study was to investigate the role of NMDARs in experimental autoimmune encephalomyelitis (EAE) in young and aged rats. Memantine, a non-competitive NMDAR antagonist, was administered to young and aged Dark Agouti rats from day 7 after immunization. Antagonizing NMDARs had a more favourable effect on clinical disease, reactivation, and apoptosis of CD4+ T cells in the target organ of aged EAE rats. The expression of the fractalkine receptor CX3CR1 was increased in memantine-treated rats, but to a greater extent in aged rats. Additionally, memantine increased Nrf2 and Nrf2-regulated enzymes’ mRNA expression in brain tissue. The concentrations of superoxide anion radicals, malondialdehyde, and advanced oxidation protein products in brain tissue were consistent with previous results. Overall, our results suggest that NMDARs play a more important role in the pathogenesis of EAE in aged than in young rats.

Aging is closely related to the main aspects of multiple sclerosis (MS). The average age ofthe MS population is increasing and the number of elderly MS patients is expected to increase. Inaddition to neurons,N-methyl-D-aspartate receptors (NMDARs) are also expressed on non-neuronalcells, such as immune cells. The aim of this study was to investigate the role of NMDARs inexperimental autoimmune encephalomyelitis (EAE) in young and aged rats. Memantine, a non-competitive NMDAR antagonist, was administered to young and agedDark Agoutirats from day7 after immunization. Antagonizing NMDARs had a more favourable effect on clinical disease,reactivation, and apoptosis of CD4+T cells in the target organ of aged EAE rats. The expression ofthe fractalkine receptor CX3CR1 was increased in memantine-treated rats, but to a greater extent inaged rats. Additionally, memantine increased Nrf2 and Nrf2-regulated enzymes’ mRNA expressionin brain tissue. The concentrations of superoxide anion radicals, malondialdehyde, and advancedoxidation protein products in brain tissue were consistent with previous results. Overall, our resultssuggest that NMDARs play a more important role in the pathogenesis of EAE in aged than in young rats.

The study was aimed to examine putative contribution of thymic involution to ageing-associated increase in susceptibility of Albino Oxford (AO) rats to the development of clinical EAE, and vice versa influence of the disease on the progression of thymic involution. To this end we examined (i) the parameters of thymocyte negative selection efficacy, the thymic generation of CD4+CD25+Foxp3+ T regulatory cells (Tregs) and thymic capacity to instruct/predetermine IL-17-producing T-cell differentiation, and thymopietic efficacy-associated accumulation of “inflammescent” cytotoxic CD28- T cells in the periphery, and (ii) the key underlying mechanisms in young and old non-immunised AO rats and their counterparts immunised for EAE (on the 16th day post-immunisation when the disease in old rats reached the plateau) using flow cytometry analysis and/or RT-qPCR. It was found that thymic involution impairs: (i) the efficacy of negative selection (by affecting thymocyte expression of CD90, negative regulator of selection threshold and the expression of thymic stromal cell integrity factors) and (ii) Treg generation (by diminishing expression of cytokines supporting their differentiation/maturation). Additionally, the results suggest that thymic involution facilitates CD8+ T-cell differentiation into IL-17-producing cells (previously linked to the development of clinical EAE in old AO rats). Furthermore, they confirmed that ageing-related decrease in thymic T-cell output (as indicated by diminished frequency of recent thymic emigrants in peripheral blood) resulted in the accumulation of CD28- T cells in peripheral blood and, upon immunisation, in the target organ. On the other hand, the development of EAE (most likely by increasing circulatory levels of proinflammatory cytokines) contributed to the decline in thymic output of T cells, including Tregs, and thereby to the progression/maintenance of clinical EAE. Thus, in AO rats thymic involution via multi-layered mechanisms may fa

The role of stress effector systems in the initiation and progression of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), the most commonly used experimental model of MS, has strongly been suggested. To corroborate this notion, alterations in activity of the sympathoadrenal and sympathoneural axes of sympathoadrenal system (a major communication pathway between the central nervous system and the immune system), mirrored in altered release of their end-point mediators (adrenaline and noradrenaline, respectively), are shown to precede (in MS) and/or occur during development of MS and EAE in response to immune cell activation (in early phase of disease) and disease-related damage of sympathoadrenal system neurons and their projections (in late phase of disease). To add to the complexity, innate immunity cells and T-lymphocytes synthesize noradrenaline that may be implicated in a local autocrine/paracrine self-amplifying feed-forward loop to enhance myeloid-cell synthesis of proinflammatory cytokines and inflammatory injury. Furthermore, experimental manipulations targeting noradrenaline/adrenaline action are shown to influence clinical outcome of EAE, in a disease phase-specific manner. This is partly related to the fact that virtually all types of cells involved in the instigation and progression of autoimmune inflammation and target tissue damage in EAE/MS express functional adrenoceptors. Although catecholamines exert majority of immunomodulatory effects through β2-adrenoceptor, a role for α-adrenoceptors in EAE pathogenesis has also been indicated. In this review, we summarize all aforementioned aspects of immunopathogenetic action of catecholamines in EAE/MS as possibly important for designing new strategies targeting their action to prevent/mitigate autoimmune neuroinflammation and tissue damage.

Sympathetic dysfunction is suggested to contribute to development of multiple sclerosis and experimental autoimmune encephalomyelitis (EAE) alike. Considering important role of microglia in development/resolution of neuroinflammation, contribution of noradrenaline, the key sympathetic end-point mediator, in modulation of microglial phenotypic and functional properties in rat EAE model was examined. The study showed that noradrenaline acting in neurocrine and autocrine/paracrine way might influence microglia during EAE. Propranolol treatment over the effector phase moderated EAE course. This was associated with the increased proportion of microglia expressing CX3CR1, the key molecule in their immunomodulatory/neuroprotective action, and upregulation of CX3CR1 downstream Nrf2 gene. This correlated with the increased heme oxygenase-1 (HO-1) expression and phagocytic capacity of microglia, and their phenotypic changes mirrored in increased proportion of CD163- and CD83-expressing cells. The enhanced HO-1 expression was linked with the decreased proportion of microglial cells expressing IL-1β and IL-23, and possibly IL-6, followed by increased proportion of IL- 10–expressing microglia, and downregulated MCP-1/CCL2 expression. Consistently, spinal cord infiltration with blood-borne myeloid and CD4+ T cells, as well as CD4+ T-cell reactivation/proliferation and differentiation into highly pathogenic IL-17+ cells co-producing IFN-γ and GM-CSF were decreased in propranolol-treated rats compared with saline-injected controls. The in vitro investigations of the effects of noradrenaline on microglia showed that noradrenaline through β-adrenoceptor may influence Nrf2 expression also via CX3CR1-independent route. The study suggests β-adrenoceptor–mediated neuroinflammation-promoting role of noradrenaline in EAE via modulation of microglial Nrf2 expression, and thereby forms the basis for further translational pharmacological research to improve multiple sclerosis therapy.

The role of stress effector systems in the initiation and progression of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), the most commonly used experimental model of MS, has strongly been suggested. To corroborate this notion, alterations in activity of the sympathoadrenal and sympathoneural axes of sympathoadrenal system (a major communication pathway between the central nervous system and the immune system), mirrored in altered release of their end-point mediators (adrenaline and noradrenaline, respectively), are shown to precede (in MS) and/or occur during development of MS and EAE in response to immune cell activation (in early phase of disease) and disease-related damage of sympathoadrenal system neurons and their projections (in late phase of disease). To add to the complexity, innate immunity cells and T-lymphocytes synthesize noradrenaline that may be implicated in a local autocrine/paracrine self-amplifying feed-forward loop to enhance myeloid-cell synthesis of proinflammatory cytokines and inflammatory injury. Furthermore, experimental manipulations targeting noradrenaline/adrenaline action are shown to influence clinical outcome of EAE, in a disease phase-specific manner. This is partly related to the fact that virtually all types of cells involved in the instigation and progression of autoimmune inflammation and target tissue damage in EAE/MS express functional adrenoceptors. Although catecholamines exert majority of immunomodulatory effects through beta(2)-adrenoceptor, a role for alpha-adrenoceptors in EAE pathogenesis has also been indicated. In this review, we summarize all aforementioned aspects of immunopathogenetic action of catecholamines in EAE/MS as possibly important for designing new strategies targeting their action to prevent/mitigate autoimmune neuroinflammation and tissue damage.

Clinical and animal trials show that early life probiotic consumption provides health benefits in adult life by modulating the immune response. We tested the effects of early life oral consumption of the probiotic Lactobacillus rhamnosus on the function and phenotype of rat peritoneal cavity cells in a model of induced colitis. For the first month of their lives, rats were either fed with an aqueous probiotic bacteria suspension (LB group) or tap water (control group). When the rats grew to 3 months old, we studied the response of their peritoneal macrophages to autologous fecal bacteria stimulation in vitro, both before and after colitis induction (TNBS 40mg/kg of body mass in 50% ethanol). Compared to the controls, the peritoneal cavity cells of the LB group produced less nitric oxide (NO) and had an increased proportion of CD163+ cells. The rats in the LB group have shown milder symptoms of colitis (shorter length of colon under necrosis, less severe submucosal infiltration, lesser degree of colonic wall thickening), along with a diminished increase of peritoneal proinflammatory CCR7+ cells and blunted NO production in response to stimulation by autologous fecal bacteria. Our results may indicate that early oral probiotic administration attenuates macrophage responses to fecal bacteria, which are the primary cause of tissue inflammation and necrosis in chemically induced colitis models, and that this attenuation may be involved in improving the health of colitic rats.

The systemic and extra- gonadal levels of 17 beta-estradiol (E2) change during aging, and affect the expression of estrogen receptors (ERs) in the immune cells of both females and males. The age-related cessation of ovarian function in females, as well as the tissue-specific expression of enzyme aromatase (estrogen synthase which significantly rises with the advancing age) in both males and females, both determine the concentration of E2 to which immune cells may be exposed. The present study was set up to investigate the direct influence of E2 in vitro on the secretory profile of peritoneal macrophages from young and naturally menopausal female rats, and from young and middle-aged male rats. The involvement of receptor(s) responsible for mediating the effects of E2 in vitro was examined by use of antagonists specific for ERa or ER beta. Whereas in macrophages from young female rats E2 treatment diminished interleukin (IL)-1 beta secretion, it increased it in young males, and the middleaged females. The in vitro E2 treatment increased tumor necrosis factor (TNF)-alpha release by macrophages from young rats of both sexes, while it increased macrophage IL-6 release independently of both sex and age. At the same time, E2 decreased hydrogen peroxide (H2O2) production in macrophages from females, and increased it in male rats of both ages, whereas it diminished nitric oxide (NO) release in all experimental groups. Inspite of the sex-and age-specific effects of E2 on macrophage urea release, E2 did not affect the NO/urea ratio in macrophages from female rats, and diminished it in macrophages from both young and middle-aged male rats. Independently of the sex and age, E2 stimulated the release of inflammatory cytokines predominantly via macrophage ER alpha, and inhibited the IL-1 beta release in young females via ER beta. In contrast, E2 increased macrophage H2O2 and urea production by activating ER beta, but diminished their release via ER alpha. Our study may contribute