Newcastle disease virus suppresses antigen presentation via inhibiting IL-12 expression in dendritic cells. / æ–°åŸŽç–«ç— æ¯’é€šè¿‡æŠ‘åˆ¶æ ‘çªçŠ¶ç»†èƒžç™½ä»‹ç´ 12的表达抑制抗原递呈.

As a potential vectored vaccine, Newcastle disease virus (NDV) has been subject to various studies for vaccine development, while relatively little research has outlined the immunomodulatory effect of the virus in antigen presentation. To elucidate the key inhibitory factor in regulating the interaction of infected dendritic cells (DCs) and T cells, DCs were pretreated with the NDV vaccine strain LaSota as an inhibitor and stimulated with lipopolysaccharide (LPS) for further detection by enzyme-linked immunosorbent assay (ELISA), flow cytometry, immunoblotting, and quantitative real-time polymerase chain reaction (qRT-PCR). The results revealed that NDV infection resulted in the inhibition of interleukin (IL)-12p40 in DCs through a p38 mitogen-activated protein kinase (MAPK)|-dependent manner, thus inhibiting the synthesis of IL-12p70, leading to the reduction in T cell proliferation and the secretion of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and IL-6 induced by DCs. Consequently, downregulated cytokines accelerated the infection and viral transmission from DCs to T cells. Furthermore, several other strains of NDV also exhibited inhibitory activity. The current study reveals that NDV can modulate the intensity of the innate|‒|adaptive immune cell crosstalk critically toward viral invasion improvement, highlighting a novel mechanism of virus-induced immunosuppression and providing new perspectives on the improvement of NDV-vectored vaccine.

Photochemical inactivation as an alternative method to produce a whole-cell vaccine for uropathogenic Escherichia coli (UPEC).

Uropathogenic Escherichia coli (UPEC) is the primary causative agent of lower urinary tract infection (UTI). UTI presents a serious health risk and has considerable secondary implications including economic burden, recurring episodes, and overuse of antibiotics. A safe and effective vaccine would address this widespread health problem and emerging antibiotic resistance. Killed, whole-cell vaccines have shown limited efficacy to prevent recurrent UTI in human trials. We explored photochemical inactivation with psoralen drugs and UVA light (PUVA), which crosslinks nucleic acid, as an alternative to protein-damaging methods of inactivation to improve whole-cell UTI vaccines. Exposure of UPEC to the psoralen drug AMT and UVA light resulted in a killed but metabolically active (KBMA) state, as reported previously for other PUVA-inactivated bacteria. The immunogenicity of PUVA-UPEC as compared to formalin-inactivated UPEC was compared in mice. Both generated high UPEC-specific serum IgG titers after intramuscular delivery. However, using functional adherence as a measure of surface protein integrity, we found differences in the properties of PUVA- and formalin-inactivated UPEC. Adhesion mediated by Type-1 and P-fimbriae was severely compromised by formalin but was unaffected by PUVA, indicating that PUVA preserved the functional conformation of fimbrial proteins, which are targets of protective immune responses. In vitro assays indicated that although they retained metabolic activity, PUVA-UPEC lost virulence properties that could negatively impact vaccine safety. Our results imply the potential for PUVA to improve killed, whole-cell UTI vaccines by generating bacteria that more closely resemble their live, infectious counterparts relative to vaccines generated with protein-damaging methods. IMPORTANCE: Lower urinary tract infection (UTI), caused primarily by uropathogenic Escherichia coli, represents a significant health burden, accounting for 7 million primary care and 1 million emergency room visits annually in the United States. Women and the elderly are especially susceptible and recurrent infection (rUTI) is common in those populations. Lower UTI can lead to life-threatening systemic infection. UTI burden is manifested by healthcare dollars spent (1.5 billion annually), quality of life impact, and resistant strains emerging from antibiotic overuse. A safe and effective vaccine to prevent rUTI would address a substantial healthcare issue. Vaccines comprised of inactivated uropathogenic bacteria have yielded encouraging results in clinical trials but improvements that enhance vaccine performance are needed. To that end, we focused on inactivation methodology and provided data to support photochemical inactivation, which targets nucleic acid, as a promising alternative to conventional protein-damaging inactivation methods to improve whole-cell UTI vaccines.

PBITV3 : A robust and comprehensive tool for screening pathogenic proteomes for drug targets and prioritizing vaccine candidates.

Rise of life-threatening superbugs, pandemics and epidemics warrants the need for cost-effective and novel pharmacological interventions. Availability of publicly available proteomes of pathogens supports development of high-throughput discovery platforms to prioritize potential drug-targets and develop testable hypothesis for pharmacological screening. The pipeline builder for identification of target (PBIT) was developed in 2016 and updated in 2021, with the purpose of accelerating the search for drug-targets by integration of methods like comparative and subtractive genomics, essentiality/virulence and druggability analysis. Since then, it has been used for identification of drugs and vaccine targets, safety profiling of multiepitope vaccines and mRNA vaccine construction against a broad-spectrum of pathogens. This tool has now been updated with functionalities related to systems biology and immuno-informatics and validated by analyzing 48 putative antigens of Mycobacterium tuberculosis documented in literature. PBITv3 available as both online and offline tools will enhance drug discovery against emerging drug-resistant infectious agents. PBITv3 can be freely accessed at http://pbit.bicnirrh.res.in/.

TXM peptides inhibit SARS-CoV-2 infection, syncytia formation, and lower inflammatory consequences.

After three years of the SARS-CoV-2 pandemic, the search and availability of relatively low-cost benchtop therapeutics for people not at high risk for a severe disease are still ongoing. Although vaccines and new SARS-CoV-2 variants reduce the death toll, the long COVID-19 along with neurologic symptoms can develop and persist even after a mild initial infection. Reinfections, which further increase the risk of sequelae in multiple organ systems as well as the risk of death, continue to require caution. The spike protein of SARS-CoV-2 is an important target for both vaccines and therapeutics. The presence of disulfide bonds in the receptor binding domain (RBD) of the spike protein is essential for its binding to the human ACE2 receptor and cell entry. Here, we demonstrate that thiol-reducing peptides based on the active site of oxidoreductase thioredoxin 1, called thioredoxin mimetic (TXM) peptides, can prevent syncytia formation, SARS-CoV-2 entry into cells, and infection in a mouse model. We also show that TXM peptides inhibit the redox-sensitive HIV pseudotyped viral cell entry. These results support disulfide targeting as a common therapeutic strategy for treating infections caused by viruses using redox-sensitive fusion. Furthermore, TXM peptides exert anti-inflammatory properties by lowering the activation of NF-κB and IRF signaling pathways, mitogen-activated protein kinases (MAPKs) and lipopolysaccharide (LPS)-induced cytokines in mice. The antioxidant and anti-inflammatory effects of the TXM peptides, which also cross the blood-brain barrier, in combination with prevention of viral infections, may provide a beneficial clinical strategy to lower viral infections and mitigate severe consequences of COVID-19.

Small Extracellular Vesicles Derived from Altered Peptide Ligand-Loaded Dendritic Cell Act as A Therapeutic Vaccine for Spinal Cord Injury Through Eliciting CD4+ T cell-Mediated Neuroprotective Immunity.

The balance among different CD4+ T cell subsets is crucial for repairing the injured spinal cord. Dendritic cell (DC)-derived small extracellular vesicles (DsEVs) effectively activate T-cell immunity. Altered peptide ligands (APLs), derived from myelin basic protein (MBP), have been shown to affect CD4+ T cell subsets and reduce neuroinflammation levels. However, the application of APLs is challenging because of their poor stability and associated side effects. Herein, it is demonstrate that DsEVs can act as carriers for APL MBP87-99 A91 (A91-DsEVs) to induce the activation of 2 helper T (Th2) and regulatory T (Treg) cells for spinal cord injury (SCI) in mice. These stimulated CD4+ T cells can efficiently "home" to the lesion area and establish a beneficial microenvironment through inducing the activation of M2 macrophages/microglia, inhibiting the expression of inflammatory cytokines, and increasing the release of neurotrophic factors. The microenvironment mediated by A91-DsEVs may enhance axon regrowth, protect neurons, and promote remyelination, which may support the recovery of motor function in the SCI model mice. In conclusion, using A91-DsEVs as a therapeutic vaccine may help induce neuroprotective immunity in the treatment of SCI.

Preparing for the Next Pandemic: Increased Expression of Interferon-Stimulated Genes After Local Administration of Nasalferon or HeberNasvac.

HeberNasvac, a therapeutic vaccine for chronic hepatitis B, is able to safely stimulate multiple Toll-like receptors, increasing antigen presentation in vitro and in a phase II clinical trial (Profira) in elderly volunteers who were household contacts of respiratory infection patients. Thus, a new indication as a postexposure prophylaxis or early therapy for respiratory infections has been proposed. In this study, we evaluated the expression of several interferon-stimulated genes (ISGs) after mucosal administration of HeberNasvac and compared this effect with the nasal delivery of interferon alpha 2b (Nasalferon). Molecular studies of blood samples of 50 subjects from the Profira clinical trial who were locally treated with HeberNasvac or Nasalferon and concurrent untreated individuals were compared based on their relative mRNA expression of OAS1, ISG15, ISG20, STAT1, STAT3, and DRB1-HLA II genes. In most cases, the gene expression induced by HeberNasvac was similar in profile and intensity to the expression induced by Nasalferon and significantly superior to that observed in untreated controls. The immune stimulatory effect of HeberNasvac on ISGs paved the way for its future use as an innate immunity stimulator in elderly persons and immunocompromised subjects or as part of Mambisa, a nasal vaccine to prevent severe acute respiratory syndrome coronavirus 2 infection.

In silico evidences of Mpro inhibition by a series of organochalcogen-AZT derivatives and their safety in Caenorhabditis elegans.

BACKGROUND: The new coronavirus (SARS-CoV-2) pandemic emerged in 2019 causing millions of deaths. Vaccines were quickly developed and made available in 2021. Despite the availability of vaccines, some subjects refuse to take the immunizing or present comorbities, therefore developing serious cases of COVID-19, which makes necessary the development of antiviral drugs. Previous studies have demonstrated that ebselen, a selenium-containing molecule, can inhibit SARS-CoV-2 Mpro. In addition, selenium is a trace element that has antiviral and anti-inflammatory properties. Zidovudine (AZT) has been widely used against HIV infections and its action against SARS-CoV-2 may be altered by the structural modification with organochalcogen moieties, but this hypothesis still needs to be tested. METHODS: In the present work we evaluated the Mpro inhibition capacity (in silico), the safety and antioxidant effect of six organochalcogen AZT-derivatives using the free-living nematode Caenorhabditis elegans, through acute (30 min) and chronic (48) exposure protocols. RESULTS: We observed that the molecules were safe at a concentration range of 1-500 µM and did not alter any toxicological endpoint evaluated. Furthermore, the molecules are capable to decrease the ROS formation stimulated by hydrogen peroxide, to modulate the expression of important antioxidant enzymes such superoxide-dismutase-3 and glutathione S-transferese-4 and to stimulate the translocation of the DAF-16 to the cell nucleus. In addition, the molecules did not deplete thiol groups, which reinforces their safety and contribution to oxidative stress resistance. CONCLUSIONS: We have found that compounds S116l (a Tellurium AZT-derivative) and S116h (a Selenium-AZT derivative) presented more promising effects both in silico and in vivo, being strong candidates for further in vivo studies.

Self-assembled ferritin nanoparticles displaying PcrV and OprI as an adjuvant-free Pseudomonas aeruginosa vaccine.

Introduction: Serious infections of Pseudomonas aeruginosa (PA) in hospitals and the emergence and increase of multidrug resistance have raised an urgent need for effective vaccines. However, no vaccine has been approved to date. One possible reason for this is the limited immune response due to the lack of an efficient delivery system. Self-assembled ferritin nanoparticles are good carriers of heterogeneous antigens, which enhance the activation of immunological responses. Methods: In this study, two well-studied antigen candidates, PcrV and OprI, were selected and connected to the ferritin nanoparticle by the Spytag/SpyCatcher system to generate the nanovaccine rePO-FN. Results: Compared to recombinant PcrV-OprI formulated with aluminum adjuvants, intramuscular immunization with adjuvant-free rePO-FN induced quick and efficient immunity and conferred protection against PA pneumonia in mice. In addition, intranasal immunization with adjuvant-free rePO-FN enhanced protective mucosal immunity. Moreover, rePO-FN exhibited good biocompatibility and safety. Discussion: Our results suggest that rePO-FN is a promising vaccine candidate, as well as, provide additional evidence for the success of ferritin-based nanovaccines.

A liposomal vaccine promotes strong adaptive immune responses via dendritic cell activation in draining lymph nodes.

Subunit proteins provide a safe source of antigens for vaccine development especially for intracellular infections which require the induction of strong cellular immune responses. However, those antigens are often limited by their low immunogenicity. In order to achieve effective immune responses, they should be encapsulated into a stable antigen delivery system combined with an appropriate adjuvant. As such cationic liposomes provide an efficient platform for antigen delivery. In the present study, we describe a liposomal vaccine platform for co-delivery of antigens and adjuvants able to elicit strong antigen-specific adaptive immune responses. Liposomes are composed of the cationic lipid dimethyl dioctadecylammonium bromide (DDAB), cholesterol (CHOL) and oleic acid (OA). Physicochemical characterization of the formulations showed that their size was in the range of ∼250 nm with a positive zeta potential which was affected in some cases by the enviromental pH facilitating endosomal escape of potential vaccine cargo. In vitro, liposomes were effectively taken up by bone marrow dendritic cells (BMDCs) and when encapsulated IMQ they promoted BMDCs maturation and activation. Upon in vivo intramuscular administration, liposomes' active drainage to lymph nodes was mediated by DCs, B cells and macrophages. Thus, mice immunization with liposomes having encapsulated LiChimera, a previously characterized anti-leishmanial antigen, and IMQ elicited infiltration of CD11blow DCs populations in draining LNs followed by increased antigen-specific IgG, IgG2a and IgG1 levels production as well as indcution of antigen-specific CD4+ and CD8+ T cells. Collectively, the present work provides a proof-of-concept that cationic liposomes composed of DDAB, CHOL and OA adjuvanted with IMQ provide an efficient delivery platform for protein antigens able to induce strong adaptive immune responses via DCs targeting and induction of maturation.

Characterization of the Human Immunodeficiency Virus (HIV-1) Envelope Glycoprotein Conformational States on Infectious Virus Particles.

Human immunodeficiency virus (HIV-1) entry into cells involves triggering of the viral envelope glycoprotein (Env) trimer ([gp120/gp41]3) by the primary receptor, CD4, and coreceptors, CCR5 or CXCR4. The pretriggered (State-1) conformation of the mature (cleaved) Env is targeted by broadly neutralizing antibodies (bNAbs), which are inefficiently elicited compared with poorly neutralizing antibodies (pNAbs). Here, we characterize variants of the moderately triggerable HIV-1AD8 Env on virions produced by an infectious molecular proviral clone; such virions contain more cleaved Env than pseudotyped viruses. We identified three types of cleaved wild-type AD8 Env trimers on virions: (i) State-1-like trimers preferentially recognized by bNAbs and exhibiting strong subunit association; (ii) trimers recognized by pNAbs directed against the gp120 coreceptor-binding region and exhibiting weak, detergent-sensitive subunit association; and (iii) a minor gp41-only population. The first Env population was enriched and the other Env populations reduced by introducing State-1-stabilizing changes in the AD8 Env or by treatment of the virions with crosslinker or the State-1-preferring entry inhibitor, BMS-806. These stabilized AD8 Envs were also more resistant to gp120 shedding induced by a CD4-mimetic compound or by incubation on ice. Conversely, a State-1-destabilized, CD4-independent AD8 Env variant exhibited weaker bNAb recognition and stronger pNAb recognition. Similar relationships between Env triggerability and antigenicity/shedding propensity on virions were observed for other HIV-1 strains. State-1 Envs on virions can be significantly enriched by minimizing the adventitious incorporation of uncleaved Env; stabilizing the pretriggered conformation by Env modification, crosslinking or BMS-806 treatment; strengthening Env subunit interactions; and using CD4-negative producer cells. IMPORTANCE Efforts to develop an effective HIV-1 vaccine have been frustrated by the inability to elicit broad neutralizing antibodies that recognize multiple virus strains. Such antibodies can bind a particular shape of the HIV-1 envelope glycoprotein trimer, as it exists on a viral membrane but before engaging receptors on the host cell. Here, we establish simple yet powerful assays to characterize the envelope glycoproteins in a natural context on virus particles. We find that, depending on the HIV-1 strain, some envelope glycoproteins change shape and fall apart, creating decoys that can potentially divert the host immune response. We identify requirements to keep the relevant envelope glycoprotein target for broad neutralizing antibodies intact on virus-like particles. These studies suggest strategies that should facilitate efforts to produce and use virus-like particles as vaccine immunogens.

CD8α+ dendritic cells potentiate antitumor and immune activities against murine ovarian cancers.

Dendritic cell (DC)-based immunotherapies have been shown to be a potential treatment option for various cancers; however, the exact strategies in ovarian cancer remain unknown. Here, we report the effectiveness of mouse CD8α+ DCs derived from bone marrow hematopoietic stem cells (BM-HSCs), equivalent to human CD141+ DCs, which have proven to be a highly superior subset. Mono-DCs from monocytes and stem-DCs from HSCs were characterized by CD11c+ CD80+ CD86+ and CD8α+ Clec9a+ expression, respectively. Despite a lower dose compared with Mono-DCs, mice treated with pulsed Stem-DCs showed a reduced amount of ascitic fluid and lower body weights compared with those of vehicle-treated mice. These mice treated with pulsed stem-DCs appeared to have fewer tumor implants, which were usually confined in the epithelium of tumor-invaded organs. All mice treated with DCs showed longer survival than the vehicle group, especially in the medium/high dose pulsed Stem-DC treatment groups. Moreover, the stem-DC-treated group demonstrated a low proportion of myeloid-derived suppressor cells and regulatory T cells, high interleukin-12 and interferon-γ levels, and accumulation of several tumor-infiltrating lymphocytes. Together, these results indicate that mouse CD8α+ DCs derived from BM-HSCs decrease tumor progression and enhance antitumor immune responses against murine ovarian cancer, suggesting that better DC vaccines can be used as an effective immunotherapy in EOC treatment. Further studies are necessary to develop potent DC vaccines using human CD141+ DCs.

Effect of in ovo administration of Newcastle disease vaccine conjugated with Astragalus polysaccharide on growth performance, intestinal development, and mucosal immunity in broiler chickens.

This study was conducted to investigate the effect of in ovo administration of a mixture of Astragalus polysaccharide (APS) and Newcastle disease vaccine (NDV) on growth performance, intestinal development, and mucosal immunity in newly hatched chicks. Six hundred specific-pathogen-free (SPF) Leghorn fertilised eggs were incubated in a commercial hatchery and divided into four groups: (a) control group injected with 1 ml of 0.9% physiological saline, (b) APS group injected with 1 ml of 1 mg/ml APS solution, and (c) NDV group injected with 1 ml of 104.0 EID50 /dose of NDV solution, and (d) APS + NDV group injected with a mixture of 0.5 ml of 2 mg/ml APS plus 0.5 ml 104.0 EID50 /dose ND vaccine (NDV) on Day 18.5 of incubation. The results showed that in ovo injection of APS or the mixture of APS and NDV increased the body weight at 1 day (IW) and final weight (FW) at 28 days and increased the feed conversion ratio (FCR) at 1-7, 8-14, 15-21, and 1-28 days of age. The villus height (VH) was increased (p < 0.05), and the crypt depth (CD) was decreased (p < 0.05) in the duodenum compared with the control group. The VH/CD ratios were increased (p < 0.05) in the APS + NDV group compared with controls, NDV group, and APS group on d3. The levels of slgA in washings were increased (p < 0.05) on Days 3, 7, 14, 21, and 28, and the number of IgA+ cells in the duodenum was increased on Days 7, 14, 21, and 28. In addition, the IgA+ cells were promoted from the villus root to the apex in the APS + NDV group. It can be concluded that in ovo administration of NDV conjugated with APS compared with NDV alone may be more effective in promoting growth performance and intestinal mucosal immunity.

Humoral immunity is not altered in overweight pregnant Crioulo mares / Imunidade humoral não é alterada em éguas Crioulas gestantes com sobrepeso

Both pregnancy and obesity can influence significant changes in the immune system. On this basis, the present study proposes to evaluate the humoral immune response of overweight pregnant mares in response to a commercial vaccine. Thirty pregnant Crioulo mares were separated according to body condition score (BCS) into overweight (BCS≥7/9) or lean-control (BCS= 5-6/9). In each group, the animals were subdivided into vaccinated and controls. The mares were vaccinated against EHV-1 in two doses spaced 21 days apart and had their blood collected monthly, for five months, for antibody evaluation. Both vaccinated groups had an increase in specific neutralizing antibodies after the vaccine. However, after the second dose, there was no increase in antibodies in any of the groups. Vaccinated overweight and lean-control mares did not differ at any time point. Therefore, this study demonstrated that obesity does not influence the humoral immune response in pregnant Crioulo mares.(AU)

Tanto a gestação quanto a obesidade podem influenciar o desenvolvimento de alterações significativas no sistema imune, portanto, o presente estudo teve como objetivo avaliar a resposta imune humoral de éguas gestantes com sobrepeso em resposta a uma vacina comercial. Trinta éguas Crioulas gestantes foram separadas de acordo com o escore de condição corporal (ECC) em éguas com sobrepeso (ECC≥7/9) e éguas controles (ECC=5-6/9) e, ainda, em cada grupo, os animais também foram separados em vacinados e controles. As éguas foram vacinadas contra o EHV-1 em duas doses com intervalo de 21 dias, sendo realizadas coletas de sangue mensalmente durante cinco meses para avaliação de anticorpos neutralizantes. Ambos os grupos vacinados tiveram aumento de anticorpos neutralizantes específicos após a vacina, porém, após a segunda dose, não foi observado aumento de anticorpos em nenhum dos grupos. Nenhuma diferença foi observada entre éguas vacinadas com sobrepeso e as éguas controles em nenhum momento. Assim, este estudo demonstrou que a obesidade não é um fator que influencia a resposta imune humoral de éguas Crioulas gestantes.(AU)

Available evidence and potential for vaccines for reduction in antibiotic prescriptions.

Bacterial antibiotic resistance is a public health issue. It means that drugs become ineffective, infections persist and have a huge impact on the health of patients and their spreading increases. To address a complex threat such as bacterial antibiotic resistance different and integrated approaches are needed including discovery of new antibiotics, improvement of diagnostics tools and improvement of antibiotic stewardship. Absolutely relevant are prevention of infections as well as decrease in the use of antibiotics. Vaccines are an important tool in the fight against bacterial antibiotic resistance and can help prevent it in several ways. Indeed, vaccines are highly effective in preventing diseases that might otherwise require the use of antibiotics to treat symptoms and associated complications. Preventing infections through vaccination helps reduce the need for and widespread and inappropriate use of antibiotics, including for secondary bacterial infections.

Praziquantel: An update on the mechanism of its action against schistosomiasis and new therapeutic perspectives.

Praziquantel (PZQ) is the drug of choice for the treatment of all forms of schistosomiasis, although its mechanisms of action are not completely understood. PZQ acts largely on adult worms. This narrative literature review describes what is known about the mechanisms of action of PZQ against schistosomes from in vitro and in vivo studies and highlights the molecular targets in parasites and immune responses induced in definitive hosts by this drug. Moreover, new therapeutic uses of PZQ are discussed. Studies have demonstrated that in addition to impacting voltage-operated Ca2 + channels, PZQ may interact with other schistosome molecules, such as myosin regulatory light chain, glutathione S-transferase, and transient receptor potential channels. Following PZQ administration, increased T regulatory type 1 (Tr1) cell differentiation and decreased inflammation were observed, indicating that PZQ promotes immunoregulatory pathways. Although PZQ is widely used in mass drug administration schemes, the existence of resistant parasites has not been proven; however, it is a concern that should be constantly investigated in human populations. In addition, we discuss studies that evaluate health applications of PZQ (other than helminth infection), such as its effect in cancer therapy and its adjuvant action in vaccines against viruses.

Red blood cell-based vaccines for ameliorating cancer chemoimmunotherapy.

Immune checkpoint blockade (ICB) therapy has shown promising antitumor effects, but its immune response rate remains unsatisfactory. In recent years, chemotherapy has been proven to have synergistic effects with ICB therapy because some chemotherapeutic agents can enhance the immunogenicity of tumor cells by inducing immunogenic cell death (ICD). However, it cannot be ignored that chemotherapy often shows limited therapeutic efficacy due to high cytotoxicity, drug resistance, and some other side effects. Herein, we report a strategy to improve cancer immunotherapy by utilizing red blood cell-based vaccines (RBC-vaccines) where chemotherapy-induced tumor antigens (cAgs) are anchored onto red blood cells (RBCs) via the EDC/NHS-mediated amine coupling reaction. In this work, RBC-vaccines administered subcutaneously are primarily devoured by dendritic cells (DCs) and significantly improve the efficacy of αPD-1 (anti-programmed cell death 1) treatment by increasing the infiltration of intratumoral CD8+ and CD4+ T cells and elevating the intratumoral ratio of CD8+ T cells to regulatory T cells in the CT-26 colon cancer model. Finally, based on the rejection of tumor rechallenge in cured mice, the combination therapy of RBC-vaccines and αPD-1 can induce the expansion of memory T cells and thereby establish a long-term antitumor immune response. Taken together, the proposed RBC-vaccines have great potential to improve chemoimmunotherapy. STATEMENT OF SIGNIFICANCE: Immunotherapy, especially immune checkpoint blockade therapy, has made great contributions to the treatment of some advanced cancers. Unfortunately, the great majority of patients with cancer do not benefit from immunotherapy. To enhance the response rate of immunotherapy, we developed red blood cell-based vaccines (RBC-vaccines) against cancers where antigens were harvested from chemotherapy-treated cancer cells and then attached to erythrocytes via covalent surface modification. Such RBC-vaccines could provide a wide variety of tumor antigens and damage-associated molecular patterns without the use of any extra ingredients to trigger a stronger antitumor immune response. More importantly, the combination of RBC-vaccines with PD-1 blockade could significantly improve the efficacy of cancer immunotherapy and induce durable antitumor immunity.

Modulation of dendritic cell metabolism by an MPLA-adjuvanted allergen product for specific immunotherapy.

Background: Recently, bacterial components were shown to enhance immune responses by shifting immune cell metabolism towards glycolysis and lactic acid production, also known as the Warburg Effect. Currently, the effect of allergen products for immunotherapy (AIT) and commercial vaccines on immune cell metabolism is mostly unknown. Objective: To investigate the effect of AIT products (adjuvanted with either MPLA or Alum) on myeloid dendritic cell (mDC) metabolism and activation. Methods: Bone marrow-derived mDCs were stimulated with five allergoid-based AIT products (one adjuvanted with MPLA, four adjuvanted with Alum) and two MPLA-adjuvanted vaccines and analyzed for their metabolic activation, expression of cell surface markers, and cytokine secretion by ELISA. mDCs were pre-incubated with either immunological or metabolic inhibitors or cultured in glucose- or glutamine-free culture media and subsequently stimulated with the MPLA-containing AIT product (AIT product 1). mDCs were co-cultured with allergen-specific CD4+ T cells to investigate the contribution of metabolic pathways to the T cell priming capacity of mDCs stimulated with AIT product 1. Results: Both the MPLA-containing AIT product 1 and commercial vaccines, but not the Alum-adjuvanted AIT products, activated Warburg metabolism and TNF-α secretion in mDCs. Further experiments focused on AIT product 1. Metabolic analysis showed that AIT product 1 increased glycolytic activity while also inducing the secretion of IL-1ß, IL-10, IL-12, and TNF-α. Both rapamycin (mTOR-inhibitor) and SP600125 (SAP/JNK MAPK-inhibitor) dose-dependently suppressed the AIT product 1-induced Warburg Effect, glucose consumption, IL-10-, and TNF-α secretion. Moreover, both glucose- and glutamine deficiency suppressed secretion of all investigated cytokines (IL-1ß, IL-10, and TNF-α). Glucose metabolism in mDCs was also critical for the (Th1-biased) T cell priming capacity of AIT product 1-stimulated mDCs, as inhibition of mTOR signaling abrogated their ability to induce Th1-responses. Conclusion: The AIT product and commercial vaccines containing the adjuvant MPLA were shown to modulate the induction of immune responses by changing the metabolic state of mDCs. Better understanding the mechanisms underlying the interactions between cell metabolism and immune responses will allow us to further improve vaccine development and AIT.

Chemical composition and adjuvant properties of the macromolecules from cultivated Cistanche deserticola Y. C. Ma as an immunopotentiator.

The study aims to investigate the constituents, adjuvant effects, and underlying mechanisms of purified polysaccharides from cultivated Cistanche deserticola (C. deserticola). Two macromolecules designated as CCDP-1 (26.5 kDa) and CCDP-2 (32.3 kDa) from C. deserticola were respectively identified as carbohydrate-lignin complexes with 44.1 % and 43.8 % lignin. CCDP-1 and CCDP-2 were composed of glucose, rhamnose, galactose, arabinose, and mannose respectively in the molar ratios of 7.22: 5.98:2.51:1.81:1.00 and 6.57:8.48:4.20:2.72:1.00. An in vitro experiment revealed that endotoxin-free CCDP-1 and CCDP-2 promoted splenocyte proliferation without cytotoxicity, but CCDP-2 induced dendritic cell (DC) maturation more efficiently than CCDP-1. An in vivo experiment suggested that CCDP-2 enhanced OVA-specific antibody production, antigen-specific T-cell activation, IFN-γ production, IL-4 production, and DC activation. Notably, CCDP-2 elicited a Th1-biased response. Mechanically, CCDP-2 upregulated CD40, CD80, CD86, and MHC II, facilitated allogeneic T-cell proliferation and Th1/Th2 cytokines, improved IFN-γ, IL-12, IL-6, and TNF-α production, and decreased endocytosis from DCs in vitro. Blocking assays indicated that TLR2 and TLR4 were the membrane receptor candidates of DCs. Western blot implied that CCDP-2 with the immune-enhancing activities were involved in the activation of MAPKs and NF-κB pathways in a dose-/time-related manner and could be employed as a more balanced Th1/Th2 adjuvant for vaccine exploitation.

Serological Response to BNT162b2 Anti-SARS-CoV-2 Vaccination in Patients with Inflammatory Rheumatic Diseases: Results From the RHEUVAX Cohort.

Objective: In the light of the current COVID-19 epidemic and the availability of effective vaccines, this study aims to identify factors associated with non-response to anti-SARS-CoV-2 vaccines as immunological alteration associated with immune rheumatic diseases (IRD) and immunosuppressive medications may impair the response to vaccination. Methods: Volunteers in the health profession community with IRD, age, and sex-matched controls (CTRL) who underwent vaccination with two doses of BNT162b2 were recruited for this study. Anti-Trimeric Spike protein antibodies were assayed eight ± one weeks after the second vaccine dose. Univariate and logistic regression analyses were performed to identify factors independently associated with non-response and low antibody titers. Results: Samples were obtained from 237 IRD patients (m/f 73/164, mean age 57, CI 95% [56-59]): 4 autoinflammatory diseases (AI), 62 connective tissue diseases (CTD), 86 rheumatoid arthritis (RA), 71 spondylarthritis (SpA) and 14 vasculitis (Vsc). 232 CTRL were recruited (m/f 71/161, mean age 57, CI 95% [56-58]). Globally, IRD had a lower seroconversion rate (88.6% vs 99.6%, CI 95% OR [1.61-5.73], p<0.001) and lower antibody titer compared to controls (median (IQR) 403 (131.5-1012) versus 1160 (702.5-1675), p<0.001). After logistic regression, age, corticosteroid (CCS), Abatacept and Mycophenolate Mofetil (MMF) use were associated with non-response. Lower antibody titer was associated with the use of MMF, ABA, CCS, Rituximab, tumor necrosis factor inhibitor, JAK inhibitors, and higher age. Conclusion: The response to anti-SARS-CoV-2 vaccines is often impaired in IRD patients under treatment and may pose them at higher risk of severe COVID-19. Specific vaccination protocols are desirable for these patients.

Nanomedicine in leishmaniasis: A promising tool for diagnosis, treatment and prevention of disease - An update overview.

Leishmaniasis is a neglected tropical disease that has a wide spectrum of clinical manifestations, ranging from visceral to cutaneous, with millions of new cases and thousands of deaths notified every year. The severity of the disease and its various clinical forms are determined by the species of the causative agent, Leishmania, as well as the host's immune response. Major challenges still exist in the diagnosis and treatment of leishmaniasis, and there is no vaccine available to prevent this disease in humans. Nanotechnology has emerged as a promising tool in a variety of fields. In this review, we highlight the main and most recent advances in nanomedicine to improve the diagnosis and treatment, as well as for the development of vaccines, for leishmaniasis. Nanomaterials are nanometric in size and can be produced by a variety of materials, including lipids, polymers, ceramics, and metals, with varying structures and morphologies. Nanotechnology can be used as biosensors to detect antibodies or antigens, thus improving the sensitivity and specificity of such immunological and molecular diagnostic tests. While in treatment, nanomaterials can act as drug carriers or, be used directly, to reduce any toxic effects of drug compounds to the host and to be more selective towards the parasite. Furthermore, preclinical studies show that different nanomaterials can carry different Leishmania antigens, or even act as adjuvants to improve a Th1 immune response in an attempt to produce an effective vaccine.