Adaptive Immunity In Mice Research Articles

Lipoteichoic Acid from Heyndrickxia coagulans HOM5301 Modulates the Immune Response of RAW 264.7 Macrophages.

Heyndrickxia coagulans (formerly Bacillus coagulans) has been increasingly utilized as an immunomodulatory probiotics. Oral administration of H. coagulans HOM5301 significantly boosted both innate and adaptive immunity in mice, particularly by increasing the phagocytic capacity of monocytes/macrophages. Lipoteichoic acid (LTA), a major microbe-associated molecular pattern (MAMP) in Gram-positive bacteria, exhibits differential immunomodulatory effects due to its structural heterogeneity. We extracted, purified, and characterized LTA from H. coagulans HOM5301. The results showed that HOM5301 LTA consists of a glycerophosphate backbone. Its molecular weight is in the range of 10-16 kDa. HOM5301 LTA induced greater productions of nitric oxide, TNFα, and IL-6 in RAW 264.7 macrophages compared to Staphylococcus aureus LTA. Comparative transcriptome and proteome analyses identified the differentially expressed genes and proteins triggered by HOM5301 LTA. KEGG analyses revealed that HOM5301 LTA transcriptionally and translationally activated macrophages through two immune-related pathways: cytokine-cytokine receptor interaction and phagosome formation. Protein-protein interaction network analysis indicated that the pro-inflammatory response elicited by HOM5301 LTA was TLR2-dependent, possibly requiring the coreceptor CD14, and is mediated via the MAPK and NF-kappaB pathways. Our results demonstrate that LTA is an important MAMP of H. coagulans HOM5301 that boosts immune responses, suggesting that HOM5301 LTA may be a promising immunoadjuvant.

Study of humoral and cellular immunity following the immunization of C57Bl/6 mice with a prototype of the inactivated Chikungunya vaccine

Introduction. Chikungunya virus infection is a problem for the health care system of affected regions due to the lack of specific prevention, as well as effective antiviral drugs. The critical role of cellular immunity in viral control and clearance for the Chikungunya fever has been demonstrated in many studies. Therefore, effective stimulation of not only humoral but also cellular immunity is of undeniable importance when assessing the effectiveness of a potential vaccine for the prevention of this infection. The aim of the present study was to investigate the formation of protective immunity after administration of a drug containing inactivated Chikungunya virus (CHIKV) to C57Bl/6 mice. Materials and methods. Inactivated CHIKV (concentrations of 10 μg and 40 μg) was administered intramuscularly to C57Bl/6 mice twice with an interval of 14 days. Indicators of humoral immunity were assessed by ELISA and neutralization test (NT), cellular immunity — by the production of IFN-γ and splenocyte proliferation in vitro. The concentration of cytokines IL-1, IL-2, IL-6, IL-10, IL-12p70 and TNF was determined by ELISA. When assessing the protective immunity in animals, CHIKV was injected into the dorsal surface of the foot of the right hind paw at a dose of 2.89 ± 0.10 lg TCD50 in a volume of 20 μl. Results. The most pronounced immune response was noted to the administration of 40 μg of inactivated CHIKV, which was manifested in the balanced production of the studied cytokines, the formation of specific humoral (according to the results of ELISA and NT) and cellular — specific proliferation of splenocytes in vitro and production of IFN-γ. When assessing efficacy, the development of foot edema in immunized animals was significantly lower than in animals in the control group. Discussion. CHIKV, inactivated by beta-propiolactone, had pronounced immunogenic properties. The balance of production of pro- and anti-inflammatory cytokines, as well as the Th1/Th2 immune response, characterized the formation of adaptive immunity in mice without a pronounced inflammatory response. The formation of a specific humoral and cellular immune response has been demonstrated. A study of protection in a non-lethal animal model confirmed the efficacy of the inactivated vaccine. Conclusion. Double administration of the inactivated CHIKV vaccine at a dose of 40 μg to C57Bl/6 mice demonstrated pronounced immunogenicity, which allows us to evaluate it as a promising prophylactic vaccine.

Pseudorabies Virus HLJ Strain Suppresses Peripheral Blood T and B Lymphocytes in Mice

Background: Pseudorabies virus (PRV), responsible for pseudorabies, is one of the most important pathogen in swine industry. PRV infection suppresses interferon-β (IFN-β) and tumor necrosis factor-α (TNF-α) expression, which consequently results in an immune escape in the host. Methods: In this study, distribution of peripheral blood T and B cell sub-populations was analyzed by flow cytometry after infecting mice with 1×105 TCID50 PRV. Result: We found that the levels of CD3+ T, CD4+ T and CD8+ T lymphocyte in infection group were significantly decreased at 24 hpi (p less than 0.01) and remained at a low level until 72 hpi compared to the control group. Interestingly, the levels of CD19+ T lymphocyte were significantly lower after 24 hpi (p less than 0.01) and lasted until 48 hpi, then increased sharply and then dropped at 96 hpi. Collectively, these results indicated that PRV infection could play a negative role in adaptive immunity in mice by decreasing the levels of B and T lymphocytes.

POS-454 Induction of mitophagy ameliorates autoimmunity and renal infiltration of memory T lymphocytes in mice with lupus nephritis

As a common complication of systemic lupus erythematosus, lupus nephritis is evidenced by deposition of anti-dsDNA antibody complexes and sensitized T lymphocytes that cause renal injury. Accumulated evidence has supported a critical role of mitochondrial dysfunction in lupus development, and defective mitophagy has recently been identified in this disease. The current study aimed to determine the effects of pharmacological induction of mitophagy on adaptive immunity in mice with lupus nephritis(LN).

A Comprehensive Review of Vaccines against Covid-19

A Comprehensive Review of Vaccines against Covid-19

THE STATE OF THE CELLS OF THE IMMUNE SYSTEM IN EXPERIMENTAL IMMUNE-MEDIATED INFLAMMATION OF VARIOUS GENESIS

Relevance. Immune-mediated inflammation of various genesis plays a significant pathogenetic role in autoimmune, allergic, inflammatory and infectious diseases.
 The objective of the work was a comparative study of the functional status and pathways of cell death of natural and adaptive immunity in mice under the conditions of experimental hyperimmunocomplexemia and endotoxemia to identify the features and common cellular mechanisms of these pathologies.
 Materials and methods. Hyperimmunocomplexemia was simulated by six-fold immunization of female mice with increasing doses of the antigen, bovine serum albumin (BSA), once a week; the endotoxemia model was induced by the administration of lipopolysaccharide (LPS).
 Results. The use of both BSA and LPS led to a systemic inflammatory process with significant neutrophilia with a shift of the leukogram to the left. There was a significant increase in the functional and metabolic activity of nonspecific resistance cells. Genotoxic stress was observed in thymus cells and lymph nodes with significant DNA damage, decreased viability, and a significant increase in necrotic death. Violation of the plasma membrane integrity of primary alteration and the release of the cellular content outside has a strong pro-inflammatory and immunogenic effect, which can lead to further intensification of the disease and an increase in its duration with a tendency to chronicity of the pathological process.
 Conclusions. Thus, both models are characterized by the development of immune-inflammatory processes that lead to significant DNA damage and cell death, which can cause a new round of intensification of necrotic, inflammatory and autoimmune reactions in the body.

A single dose of self-transcribing and replicating RNA-based SARS-CoV-2 vaccine produces protective adaptive immunity in mice

A self-transcribing and replicating RNA (STARR)-based vaccine (LUNAR-COV19) has been developed to prevent SARS-CoV-2 infection. The vaccine encodes an alphavirus-based replicon and the SARS-CoV-2 full-length spike glycoprotein. Translation of the replicon produces a replicase complex that amplifies and prolongs SARS-CoV-2 spike glycoprotein expression. A single prime vaccination in mice led to robust antibody responses, with neutralizing antibody titers increasing up to day 60. Activation of cell-mediated immunity produced a strong viral antigen-specific CD8+ T lymphocyte response. Assaying for intracellular cytokine staining for interferon (IFN)γ and interleukin-4 (IL-4)-positive CD4+ T helper (Th) lymphocytes as well as anti-spike glycoprotein immunoglobulin G (IgG)2a/IgG1 ratios supported a strong Th1-dominant immune response. Finally, single LUNAR-COV19 vaccination at both 2 μg and 10 μg doses completely protected human ACE2 transgenic mice from both mortality and even measurable infection following wild-type SARS-CoV-2 challenge. Our findings collectively suggest the potential of LUNAR-COV19 as a single-dose vaccine.

Optimized production and immunogenicity of an insect virus-based chikungunya virus candidate vaccine in cell culture and animal models

ABSTRACT A chimeric Eilat/ Chikungunya virus (EILV/CHIKV) was previously reported to replicate only in mosquito cells but capable of inducing robust adaptive immunity in animals. Here, we initially selected C7/10 cells to optimize the production of the chimeric virus. A two-step procedure produced highly purified virus stocks, which was shown to not cause hypersensitive reactions in a mouse sensitization study. We further optimized the dose and characterized the kinetics of EILV/CHIKV-induced immunity. A single dose of 108 PFU was sufficient for induction of high levels of CHIKV-specific IgM and IgG antibodies, memory B cell and CD8+ T cell responses. Compared to the live-attenuated CHIKV vaccine 181/25, EILV/CHIKV induced similar levels of CHIKV-specific memory B cells, but higher CD8+ T cell responses at day 28. It also induced stronger CD8+, but lower CD4+ T cell responses than another live-attenuated CHIKV strain (CHIKV/IRES) at day 55 post-vaccination. Lastly, the purified EILV/CHIKV triggered antiviral cytokine responses and activation of antigen presenting cell (APC)s in vivo, but did not induce APCs alone upon in vitro exposure. Overall, our results demonstrate that the EILV/CHIKV vaccine candidate is safe, inexpensive to produce and a potent inducer of both innate and adaptive immunity in mice.

Mucosal Vaccination for Influenza Protection Enhanced by Catalytic Immune-Adjuvant.

Influenza poses a severe threat to global health. Despite the whole inactivated virus (WIV)‐based nasal vaccine being a promising strategy for influenza protection, the mucosal barrier is still a bottleneck of the nasal vaccine. Here, a catalytic mucosal adjuvant strategy for an influenza WIV nasal vaccine based on chitosan (CS) functionalized iron oxide nanozyme (IONzyme) is developed. The results reveal that CS‐IONzyme increases antigen adhesion to nasal mucosa by 30‐fold compared to H1N1 WIV alone. Next, CS‐IONzyme facilitates H1N1 WIV to enhance CCL20‐driven submucosal dendritic cell (DC) recruitment and transepithelial dendrite(TED) formation for viral uptake via the toll‐like receptor(TLR) 2/4‐dependent pathway. Moreover, IONzyme with enhanced peroxidase (POD)‐like activity by CS modification catalyzes a reactive oxygen species (ROS)‐dependent DC maturation, which further enhances the migration of H1N1 WIV‐loaded DCs into the draining lymph nodes for antigen presentation. Finally, CS‐IONzyme‐based nasal vaccine triggers an 8.9‐fold increase of IgA‐mucosal adaptive immunity in mice, which provides a 100% protection against influenza, while only a 30% protection by H1N1 WIV alone. This work provides an antiviral alternative for designing nasal vaccines based on IONzyme to combat influenza infection.

Nitroglycerin ameliorates liver injury and regulates adaptive immunity in mice.

This study aimed to assess the protective effect of nitroglycerin, a commonly used drug in cardiovascular diseases, on mice with acute liver injury induced by carbon tetrachloride (CCl4 ). The mice were randomly divided into three groups: control, CCl4 , and CCl4 + nitroglycerin. They were killed at 0, 6, 12, 24, and 48 h after treatment. Blood and liver tissue samples were collected for analysis. Analysis of the amounts of serum alanine aminotransferase (ALT)/aspartate aminotransferase (AST), hepatic glutathione (GSH), and malondialdehyde (MDA) showed that nitroglycerin protected against CCl4 -induced acute liver injury. Liver histological analysis provided further evidence of the protective effect of nitroglycerin. Furthermore, we found that nitroglycerin suppressed the increase of T helper 17 (Th17) cells in CCl4 -induced acute liver injury mice. The results indicate that nitroglycerin is a potential candidate for hepatic disease.

Microbiome Modulation of the Host Adaptive Immunity through Bile Acid Modification

The microbiome is well known to influence the immune response of the host. Song etal. now show that the microbiome modulates adaptive immunity in mice through formation of bile acid species acting on RORγ+ regulatory Tcells via the Vitamin D Receptor, thereby lowering the vulnerability for chemically induced colitis.

Prenatal Maternal Stress Causes Preterm Birth and Affects Neonatal Adaptive Immunity in Mice.

Maternal stress is a well-established risk factor for preterm birth and has been associated with adverse neonatal outcomes in the first and subsequent generations, including increased susceptibility to disease and lasting immunological changes. However, a causal link between prenatal maternal stress and preterm birth, as well as compromised neonatal immunity, has yet to be established. To fill this gap in knowledge, we used a murine model of prenatal maternal stress across three generations and high-dimensional flow cytometry to evaluate neonatal adaptive immunity. We report that recurrent prenatal maternal stress induced preterm birth in the first and second filial generations and negatively impacted early neonatal growth. Strikingly, prenatal maternal stress induced a systematic reduction in T cells and B cells, the former including regulatory CD4+ T cells as well as IL-4- and IL-17A-producing T cells, in the second generation. Yet, neonatal adaptive immunity gained resilience against prenatal maternal stress by the third generation. We also show that the rate of prenatal maternal stress-induced preterm birth can be reduced upon cessation of stress, though neonatal growth impairments persisted. These findings provide evidence that prenatal maternal stress causes preterm birth and affects neonatal immunity across generations, adverse effects that can be ameliorated upon cessation.

An Efficient Combination Immunotherapy for Primary Liver Cancer by Harmonized Activation of Innate and Adaptive Immunity in Mice

Immunotherapy with checkpoint inhibitors for liver cancer, while active in many clinical trials worldwide, may have uncertain outcomes due to the unique immunotolerant microenvironment of the liver. In previous experiments, we unexpectedly identified a robust liver tumor-preventive effect of a synthetic double-stranded RNA, polyinosinic-polycytidylic acid (polyIC), in mice. Herein we further demonstrate that polyIC given at the precancer stage effectively prevented liver tumorigenesis by activating natural killer cells, macrophages, and some T-cell subsets; no inhibitory effect was observed on tumor progression if injected after tumor initiation. Nevertheless, polyIC administration potently induced programmed death ligand 1 (PD-L1) expression in liver sinusoid endothelial cells, which prompted us to test a combined treatment of polyIC and PD-L1 antibody (Ab). Although injecting PD-L1 Ab alone did not show any therapeutic effect, injection of polyIC sensitized the hepatic response to PD-L1 blockade. Combination of polyIC and PD-L1 Ab resulted in sustained accumulation of active cluster of differentiation 8 cytotoxic T cells and robust liver tumor suppression and conferred a survival advantage in mice. These preclinical data in animal models suggest that, despite the low efficacy of PD-L1/PD-1 blockade alone, careful design of mechanism-based combinatorial immunotherapeutic protocols may shift the paradigm in liver cancer treatment by coordinating maximal activation of multiple innate and adaptive immune functions. Conclusion: We provide proof of principle for the development of an efficient prevention strategy of liver tumorigenesis and a powerful combination immunotherapy for primary liver cancer.

Histone deacetylase 6 inhibitor enhances resistance to Mycobacterium tuberculosis infection through innate and adaptive immunity in mice.

Interleukin (IL)-10 plays a key role in immune response following mycobacterial infection, which can be inhibited by histone deacetylase (HDAC) 6. In this study, we explored whether Tubastatin A, a HDAC6 inhibitor, could enhance immune response and restrain mycobacterial growth. We established a mouse model using attenuated Mycobacterium tuberculosis (M.tbH37Ra) infection. The growth of mycobacteria was evaluated using colony form unit assays. Immune response statues were investigated using flow cytometry. Chromatin immunoprecipitation was used to study the influence of HDAC6 on IL10 transcription. Tubastatin A significantly inhibited the growth of M.tbH37Ra in the lungs of mice. In parallel, the levels of tumor necrosis factor-α, IL-12p40 and interferon-γ were up-regulated, while the level of IL-10 was down-regulated. Tubastatin A accelerated the delayed innate cellular immune response by recruiting more macrophages, dendritic cells (DCs) and neutrophils into the lungs. More antigen-bearing DCs and primed Th1 cells were observed in the draining lymph nodes in mice treated with Tubastatin A. Tubastatin A reduced HDCA6 recruitment on IL10 promoter. Tubastatin A enhanced innate and adaptive immune responses against the mycobacteria by suppressing IL-10 expression and consequently delayed mycobacterial growth. The experiments were extended to the H37Rv strain on the insistence of the Editor.

Synergistic Internal Ribosome Entry Site/MicroRNA-Based Approach for Flavivirus Attenuation and Live Vaccine Development.

ABSTRACTThe recent emergence of Zika virus underscores the need for new strategies for a rapid development of safe flavivirus vaccines. Using another flavivirus (Langat virus [LGTV]) that belongs to the group of tick-borne flaviviruses as a model, we describe a dual strategy for virus attenuation which synergistically accesses the specificity of microRNA (miRNA) genome targeting and the effectiveness of internal ribosome entry site (IRES) insertion. To increase the stability and immunogenicity of bicistronic LGTVs, we developed a novel approach in which the capsid (C) protein gene was relocated into the 3′ noncoding region (NCR) and expressed under translational control from an IRES. Engineered bicistronic LGTVs carrying multiple target sequences for brain-specific miRNAs were stable in Vero cells and induced adaptive immunity in mice. Importantly, miRNA-targeted bicistronic LGTVs were not pathogenic for either newborn mice after intracranial inoculation or adult immunocompromised mice (SCID or type I interferon receptor knockout) after intraperitoneal injection. Moreover, bicistronic LGTVs were restricted for replication in tick-derived cells, suggesting an interruption of viral transmission in nature by arthropod vectors. This approach is suitable for reliable attenuation of many flaviviruses and may enable development of live attenuated flavivirus vaccines.

Immunization of Mice with a Live Transconjugant Shigella Hybrid Strain Induced Th1 and Th17 Cell-Mediated Immune Responses and Confirmed Passive Protection Against Heterologous Shigellae.

An avirulent, live transconjugant Shigella hybrid (LTSHΔstx) strain was constructed in our earlier study by introducing a plasmid vector, pPR1347, into a Shiga toxin gene deleted Shigella dysenteriae 1. Three successive oral administrations of LTSHΔstx to female adult mice produced comprehensive passive heterologous protection in their offspring against challenge with wild-type shigellae. Production of NO and different cytokines such asIL-12p70, IL-1β and IL-23 in peritoneal mice macrophages indicated that LTSHΔstx induced innate and adaptive immunity in mice. Furthermore, production of IFN-γ, IL-10 and IL-17 in LTSH-primed splenic CD4+ T cell suggested that LTSHΔstx may induce Th1 and Th17 cell-mediated immune responses. Exponential increase of the serum IgG and IgA titre against whole shigellae was observed in immunized adult mice during and after the immunization with the highest peak on day 35. Antigen-specific sIgA was also determined from intestinal lavage of immunized mice. The stomach extracts of neonates from immunized mice, mainly containing mother's milk, contained significant levels of anti-LTSHΔstx immunoglobulin. These studies suggest that the LTSHΔstx could be a new live oral vaccine candidate against shigellosis in the near future.

A Novel Live Pichinde Virus-Based Vaccine Vector Induces Enhanced Humoral and Cellular Immunity after a Booster Dose.

Pichinde virus (PICV) is a bisegmented enveloped RNA virus that targets macrophages and dendritic cells (DCs) early in infection and induces strong innate and adaptive immunity in mice. We have developed a reverse genetics system to produce live recombinant PICV (strain P18) with a trisegmented RNA genome (rP18tri), which encodes all four PICV gene products and as many as two foreign genes. We have engineered the vector to express the green fluorescent protein (GFP) reporter gene (abbreviated as G in virus designations) and either the hemagglutination (HA [H]) or the nucleoprotein (NP [P]) gene of the influenza A/PR8 virus. The trisegmented viruses rP18tri-G/H and rP18tri-G/P showed slightly reduced growth in vitro and expressed HA and NP, respectively. Mice immunized with rP18tri-G/H were completely protected against lethal influenza virus challenge even 120 days after immunization. These rP18tri-based vectors could efficiently induce both neutralizing antibodies and antigen-specific T cell responses via different immunization routes. Interestingly, the immune responses were significantly increased upon a booster dose and remained at high levels even after three booster doses. In summary, we have developed a novel PICV-based live vaccine vector that can express foreign antigens to induce strong humoral and cell-mediated immunity and is ideal for a prime-and-boost vaccination strategy. We have developed a novel Pichinde virus (PICV)-based live viral vector, rP18tri, that packages three RNA segments and encodes as many as two foreign genes. Using the influenza virus HA and NP genes as model antigens, we show that this rP18tri vector can induce strong humoral and cellular immunity via different immunization routes and can lead to protection in mice. Interestingly, a booster dose further enhances the immune responses, a feature that distinguishes this from other known live viral vectors. In summary, our study demonstrates a unique feature of this live rP18tri vector to be used as a novel vaccine platform for a prime-and-boost vaccination strategy.

Abstract 481: Diabetic Hyperglycemia Accelerates Atherosclerosis by Driving Adaptive Immunity in Mice with Similar Hyperlipidemia

Hyperglycemia is recognized to accelerate atherosclerosis and its complications among human diabetic individuals. Although the participation of monocytes and macrophages in the pathogenesis of diabetic atherosclerosis is well established, a role for adaptive immunity is not well understood. Unfortunately, hyperglycemia raises plasma lipids in mice fed a high-fat diet that can independently activate immune cells to enhance atherosclerosis. We have overcome this impediment with studies of hypomorphic apoE (Apoeh/h) mice deficient in LDL receptor expression. Apoeh/hLdlr-/- mice fed a chow diet display plasma cholesterol levels of 650+/-50 mg/dl by 4 months of age, and do not display significantly more hyperlipidemia when they are made hyperglycemic with streptozotocin. Our studies show that 4 weeks of hyperglycemia with an average blood glucose level of 400 mg/dl results in marked leukocytosis among 24 week-old Apoeh/hLdlr-/- mice continually fed a chow diet. Levels of blood Ly6Chigh monocytes increased by two fold and displayed enhanced cellular oxidative stress similar to primary macrophages cultured in high glucose that displayed increased NF-kB activation. Interestingly, we also noted that levels of circulating CD4+ T cells increased by twofold. A similar pattern of leukocyte expansion was also noted in the spleen, including a twofold expansion in CD11c+ dendritic cells (DC) and CD4+ T cells. We also noted evidence of DC activation as revealed by increased cell surface expression of the co-stimulatory molecule CD80 that participates in the activation and expansion of T cells. At the level of the vessel wall, we noted that 4 weeks of hyperglycemia resulted in a substantial increase in atherosclerosis in the aortic root as revealed by Oil Red O staining. Using the aorta digest method, we noted a 4-fold increase in macrophages and 3-fold increase in CD3+ T cells in the abdominal aorta. Collectively, our results show that hyperglycemia accelerates atherosclerosis in hyperlipidemic mice by enhancing adaptive immune cell-driven inflammation, and ongoing studies are exploring mechanisms responsible for this effect.

Self-adjuvanted RNActive® vaccine induces local immune responses at the injection site leading to potent adaptive immunity in mice and humans

Meeting abstracts Two-component mRNA-based vaccine (RNActive®) combines high antigen expression with strong immune stimulation. We have previously shown that intradermal administration of RNActive® vaccines induced balanced, potent and long-lasting immune responses in both mice and humans. Here,

Highly immunostimulatory RNA derived from a Sendai virus defective viral genome

Defective viral genomes (DVGs) are generated during virus replication. DVGs bearing complementary ends are strong inducers of dendritic cell (DC) maturation and of the expression of antiviral and pro-inflammatory cytokines by triggering signaling of the RIG-I family of intracellular pattern recognition receptors. Our data show that DCs stimulated with virus containing DVGs have an enhanced ability to activate human T cells and can induce adaptive immunity in mice. In addition, we describe the generation of a short Sendai virus (SeV)-derived DVG RNA (DVG-324) that maintains strong immunostimulatory activity in vitro and in vivo. DVG-324 induced high levels of Ifnb expression when transfected into cells and triggered fast expression of pro-inflammatory cytokines and mobilization of dendritic cells when injected into the footpad of mice. Importantly, DVG-324 enhanced the production of antibodies to a prototypic vaccine after a single intramuscular immunization in mice. Notably, the pro-inflammatory cytokine profile induced by DVG-324 was different from that induced by poly I:C, the only viral RNA analog currently used as an immunostimulant in vivo, suggesting a distinct mechanism of action. SeV-derived oligonucleotides represent novel alternatives to be harnessed as potent adjuvants for vaccination.