[Terminalia chebula water extract reduces joint inflammation by regulating cellular immunity in spleen cells of collagen-induced arthritis (CIA) rats through up-regulation of PD-1/PD-L1].

Objective To investigate the effect of Terminalia chebula water extract (TCWE) on the cellular immunity and PD-1/PD-L1 pathway in rats with collagen-induced arthritis (CIA). Methods SD rats were randomly divided into four groups: a control group, a CIA group, a TCWE group and a methotrexate (MTX) group, with 15 rats in each group. Except for the control group, SD rats in other groups were subcutaneously injected with type II collagen to establish the model of collagen-induced arthritis (CIA). The rats in the TCWE group were treated with 20 mg/(kg.d) TCWE and the rats in the MTX group were treated with 1.67 mg/(kg.d) MTX. After 14 days of treatment, the cartilage morphology was examined using hematoxylin-eosin (HE) staining, and splenic T lymphocyte apoptosis and Treg/Th17 cell ratio were detected by flow cytometry. The mRNA expressions of retinoid-related orphan nuclear receptor γt (RORγt), forkhead box P3 (FOXP3), PD-1 and PD-L1 in spleen were detected by reverse transcription PCR. The expression and localization of RORγt and FOXP3 were detected by immunohistochemical staining. The protein expressions of PD-1 and PD-L1 in splenic lymphocytes were detected by Western blot, and the levels of serum interleukin 17 (IL-17) and transforming growth factor ß (TGF-ß) in rats were detected by ELISA. Results Compared with CIA group, the pathological changes of cartilage and synovium were significantly alleviated in the TCWE group and the MTX group. Both the apoptosis rate of T lymphocytes in spleen and the ratio of Treg/Th17 cells increased. The expression of RORγt decreased, while the expressions of FOXP3, PD-1 and PD-L1 increased in spleen lymphocytes. The level of serum IL-17 decreased, while the level of serum TGF-ß increased. Conclusion TCWE treatment may activate PD-1/PD-L1 pathway in spleen cells to regulate cellular immunity, thus reducing cartilage injury in CIA rats.

Expression of Concern: Garlic (Allium sativum) and mushroom (Agaricus bisporus) powder: Investigation of performance, immune organs and humoural and cellular immune response in broilers.

H. Noruzi and F. Aziz-Aliabadi, "Garlic (Allium Sativum) and Mushroom (Agaricus Bisporus) Powder: Investigation of Performance, Immune Organs and Humoural and Cellular Immune Response in Broilers," Veterinary Medicine and Science 10, no. 2 (2024): e31367, https://doi.org/10.1002/vms3.1367. This Expression of Concern is for the above article, published online on 15 February 2024 in Wiley Online Library (wileyonlinelibrary.com), and has been published by agreement between the journal Editor-in-Chief, Gayle Hallowell and John Wiley & Sons Ltd. The Expression of Concern has been agreed due to concerns raised by a third party regarding the availability of an ethical approval. The authors have received Higher Degree by Research (HDR) committee approval and a bioethical course certificate. The authors and their institute confirmed that this was equivalent to an ethical approval from the Ferdowsi University of Mashhad at the time when the research was conducted but could not provide the HDR committee approval documentation. Since this does not fully comply with the ethics policy of the journal, as noted on the journal's author guidelines page, the journal has decided to issue an Expression of Concern to inform and alert the readers.

Age-Dependent Effects of Yolkin on Contact Sensitivity and Immune Phenotypes in Juvenile Mice.

Yolkin, an egg yolk immunoregulatory protein, stimulates the humoral but inhibits the cellular immune response in adult mice. The aim of this investigation was to evaluate the effects of yolkin administration on the immune response using a model of juvenile, i.e., 28-day- and 37-day-old, mice. We examined the yolkin influence on the magnitude of the cellular immune response, which was determined as contact sensitivity (CS) to oxazolone (OXA), and the humoral immune response, which was determined as the antibody response to ovalbumin (OVA). Yolkin was administered in drinking water, followed by immunization with OXA or OVA. In parallel, the phenotypic changes in the lymphoid organs were determined following yolkin treatment and prior immunization. The results showed that yolkin had a stimulatory effect on CS in the mice treated with yolkin from the 37th day of life but not from the 28th day of life. In contrast, no regulatory effect of yolkin on antibody production was found in 28-day- and 37-day-old mice. Phenotypic studies revealed significant changes in the content of B cells and T cell subpopulations, including CD4+CD25+Foxp3 regulatory T cells. The association between the effects of yolkin on the magnitude of CS and phenotypic changes in main T- and B-cell compartments, as well the importance of changes in T-regulatory and CD8+ cells in the age categories, are discussed. We conclude that the immunoregulatory effects of yolkin on the generation of CS in mice are age dependent and change from stimulation in juvenile to suppression in adult mice.

The Structural Characterization of a Polysaccharide from the Dried Root of Salvia miltiorrhiza and Its Use as a Vaccine Adjuvant to Induce Humoral and Cellular Immune Responses.

In order to supplement the research gap concerning Salvia miltiorrhiza polysaccharide extracted from Danshen in NMR analysis, and to clarify its immune enhancement effect as an adjuvant, we isolated and purified SMPD-2, which is composed of nine monosaccharides such as Ara, Gal, and Glc from Danshen. Its weight average molecular weight was 37.30 ± 0.096 KDa. The main chain was mainly composed of →4)-α-D-Galp-(1→, →3,6)-ß-D-Glcp-(1→ and a small amount of α-L-Araf-(1→. After the subcutaneous injection of SMPD-2 as an adjuvant to OVA in mice, we found that it enhanced the immune response by activating DCs from lymph nodes, increasing OVA-specific antibody secretion, stimulating spleen lymphocyte activation, and showing good biosafety. In conclusion, SMPD-2 could be a promising candidate for an adjuvant.

Immunostimulant effect of dates (Phoenix dactylifera) on humoral and cellular immunity cells and their functions.

The study aimed to assess the immunomodulatory effects of Phoenix dactylifera (dates) fruit, a traditional remedy used by Moroccans to enhance immunity against pathogens. This research sought to evaluate the impacts of this fruit on immune cells and their functions. To achieve this, we conducted tests using date extracts on splenocytes, thymocytes, and macrophages, focusing on their functions: antibody production, phagocytosis, and T-lymphocyte toxicity. The results obtained demonstrated that the aqueous extract of P. dactylifera fruit exhibited significant immunostimulatory effects on humoral immunity. It achieved this by enhancing complement activity and increasing splenocyte (including B-lymphocytes) proliferation by 142.5% compared to control cells. Similarly, in the same conditions, there was notable stimulation of cellular immunity through thymocyte activity, resulting in a remarkable increase in cell proliferation (225%) and a boost in thymocyte function (245.9%), which plays a role in safeguarding against cancer. Moreover, the date extract demonstrated anti-inflammatory properties. This was evident in the increased phagocytosis activity mediated by macrophages under the ethyl acetate extract, effectively eliminating pathogens. Assessing the cosmetic potential of date extracts showed that the ethyl acetate extract possesses both anti-inflammatory and strong antioxidant effects, exhibited high photo absorption of ultraviolet-B rays. Based on these findings, we propose to study the utilization of this extract for sun protection as a sunscreen. Furthermore, the Fourier-transform infrared spectroscopy analysis indicated that the most active compounds present were flavonoids. These outcomes substantiate the traditional usage of this fruit for reinforcing immunity.

CpG adjuvant enhances humoral and cellular immunity against OVA in different degrees in BALB/c, C57BL/6J, and C57BL/6N mice.

In lab settings, inbred mouse strains like BALB/c, C57BL/6J, and C57BL/6N are commonly used. Research in immunology and infectious diseases indicates that their Th1 and Th2 immune responses differ. However, the specific differences in the immune response to the vaccination still require investigation. In this study, ovalbumin (OVA) was used as an antigen and CpG-enriched recombinant plasmid (pUC18-CpG) as an adjuvant for immunisation. The level of serum-specific antibody IgG was detected by indirect ELISA. At 35dpi, serum cytokine levels were measured using MILLIPLEX®. T lymphocyte clusters from mouse spleen were examined using flow cytometry to investigate the immunological effects of the CPG-OVA vaccine on three different types of mice. The results showed that pUC18-CpG as an adjuvant could successfully enhance the immune response. BALB/c had the highest level of IgG antibody. In the OVA-only group, the CD4+/CD8+ ratio of the three types of mice was generally increased, and the BALB/c group had the highest ratio. After inoculation with CpG-OVA, the CD4+/CD8+ ratio of the three types of mice was lower than that of the OVA-only group, and C57BL/6J was the lowest. Compared with the CpG-OVA group of the three kinds of mice, the levels of Th2 cytokines IL-6 and IL-10 in BALB/c were increased compared with C57BL/6J and C57BL/6N. After OVA, the six cytokines secreted in C57BL/6J were higher than those in the C57BL/6N OVA group. Therefore, C57 is a better model for examining the function of the vaccine in cellular immunity, whereas BALB/c mice are more prone to humoral immunity. In addition to highlighting the CpG plasmid's ability to successfully activate the immune response of Th1 and Th2, as well as the expression of IgG in vivo and promote T cell immune typing, this study provides valuable insights into immunology and the selection of mouse models for infectious diseases, providing a valuable resource for designing more effective vaccines in the future.

Immunogenicity and safety of a self-assembling ZIKV nanoparticle vaccine in mice.

Zika virus (ZIKV) is a mosquito-borne flavivirus that highly susceptibly causes Guillain-Barré syndrome and microcephaly in newborns. Vaccination is one of the most effective measures for preventing infectious diseases. However, there is currently no approved vaccine to prevent ZIKV infection. Here, we developed nanoparticle (NP) vaccines by covalently conjugating self-assembled 24-subunit ferritin to the envelope structural protein subunit of ZIKV to achieve antigen polyaggregation. The immunogenicityof the NP vaccine was evaluated in mice. Compared to monomer vaccines, the NP vaccine achieved effective antigen presentation, promoted the differentiation of follicular T helper cells in lymph nodes, and induced significantly greater antigen-specific humoral and cellular immune responses. Moreover, the NP vaccine enhanced high-affinity antigen-specific IgG antibody levels, increased secretion of the cytokines IL-4 and IFN-γ by splenocytes, significantly activated T/B lymphocytes, and improved the generation of memory T/B cells. In addition, no significant adverse reactions occurred when NP vaccine was combined with adjuvants. Overall, ferritin-based NP vaccines are safe and effective ZIKV vaccine candidates.

Structural characterization and adjuvant activity of a water soluble polysaccharide from Poria cocos.

Adjuvants, as the essential component of vaccines, are crucial in enhancing the magnitude, breadth and durability of immune responses. Unfortunately, commonly used Alum adjuvants predominantly provoke humoral immune response, but fail to evoke cellular immune response, which is crucial for the prevention of various chronic infectious diseases and cancers. Thus, it is necessary to develop effective adjuvants to simultaneously induce humoral and cellular immune response. In this work, we obtained a water soluble polysaccharide isolated and purified from Poria cocos, named as PCP, and explored the possibility of PCP as a vaccine adjuvant. The PCP, with Mw of 20.112 kDa, primarily consisted of →6)-α-D-Galp-(1→, with a small amount of →3)-ß-D-Glcp-(1 â†’ and →4)-ß-D-Glcp-(1→. Our results demonstrated that the PCP promoted the activation of dendritic cells (DCs) and macrophages in vitro. As the adjuvant to ovalbumin, the PCP facilitated the activation of DCs in lymph nodes, and evoked strong antibody response with a combination of Th1 and Th2 immune responses. Moreover, compared to Alum adjuvant, the PCP markedly induced a potent cellular response, especially the cytotoxic T lymphocytes response. Therefore, we confirmed that the PCP has great potential to be an available adjuvant for simultaneously inducing humoral and cellular immune responses.

Aluminum oxyhydroxide-Poly(I:C) combination adjuvant with balanced immunostimulatory potentials for prophylactic vaccines.

The development of high-purity antigens promotes the urgent need of novel adjuvant with the capability to trigger high levels of immune response. Polyinosinic-polycytidylic (Poly(I:C)) is a synthetic double-stranded RNA (dsRNA) that can engage Toll-like receptor 3 (TLR3) to initiate immune responses. However, the Poly(I:C)-induced toxicity and inefficient delivery prevent its applications. In our study, combination adjuvants are formulated by aluminum oxyhydroxide nanorods (AlOOH NRs) and Poly(I:C), named Al-Poly(I:C), and the covalent interaction between the two components is further demonstrated. Al-Poly(I:C) mediates enhanced humoral and cellular immune responses in three antigen models, i.e., HBsAg virus-like particles (VLPs), human papilloma virus (HPV) VLPs and varicella-zoster virus (VZV) glycoprotein E (gE). Further mechanistic studies demonstrate that the dose and molecular weight (MW) of Poly(I:C) determine the physicochemical properties and adjuvanticity of the Al-Poly(I:C) combination adjuvants. Al-Poly(I:C) with higher Poly(I:C) dose promotes antigen-bearing dendritic cells (DCs) recruitment and B cells proliferation in lymph nodes. Al-Poly(I:C) formulated with higher MW Poly(I:C) induces higher activation of helper T cells, B cells, and CTLs. This study demonstrates that Al-Poly(I:C) potentiates the humoral and cellular responses in vaccine formulations. It offers insights for adjuvant design to meet the formulation requirements in both prophylactic and therapeutic vaccines.

Glycerides of lauric acid supplementation in the chicken diet enhances the humoral and cellular immune response to infectious bronchitis virus.

Controlling pathogenic infections while reducing antibiotic usage is an important challenge during poultry production. In addition to vaccination strategies, several solutions to enhance the immune response against pathogens are evaluated. In this study, we aim to determine the effects of the glycerides of lauric acid (GLA) supplementation in chickens' diets on humoral and cellular immune response pathogenic infections, using an in vivo model of infectious bronchitis virus (IBV). One-day-old Ross 308 broilers were vaccinated with live attenuated IBV and fed diets supplemented with or without GLA at 3 kg/ton. The levels of early (day 7) specific anti-IBV in sera were significantly increased in broilers fed GLA, compared to the control groups (P<0.05), showing a stronger primary humoral response. The secretion levels of main cytokines remained similar in spleens of all the experimental groups. However, the splenocytes from broilers fed GLA showed higher activation and effector abilities when measured by IFN-γ ELISpot in presence of N-261-280 IBV peptide or Concanavalin A (Con A), a pan T lymphocytes mitogen. In response to N-261-280 peptide, GLA group showed a 2-fold increase of spot numbers (P < 0.05) and 3-fold increase of spot surfaces (P < 0.01) compared to the control groups. Similarly, Con A stimulation showed a 2-fold increases in spot surfaces and numbers in the GLA supplemented group compared to the control group (P < 0.01). In summary, GLA supplementation in chicken feed enhances the primary humoral immune response and strengthen the T lymphocytes mediated cellular immune response. These findings demonstrate how GLA can improve chicken resilience against pathogenic challenges by enhancing their immune responses.

Controlling the speed of antigens transport in dendritic cells improves humoral and cellular immunity for vaccine.

Vaccines are an effective intervention for preventing infectious diseases. Currently many vaccine strategies are designed to improve vaccine efficacy by controlling antigen release, typically involving various approaches at the injection site. Yet, strategies for intracellular slow-release of antigens in vaccines are still unexplored. Our study showed that controlling the degradation of antigens in dendritic cells and slowing their transport from early endosomes to lysosomes markedly enhances both antigen-specific T-cell immune responses and germinal center B cell responses. This leads to the establishment of sustained humoral and cellular immunity in vivo imaging and flow cytometry indicated this method not only prolongs antigen retention at the injection site but also enhances antigen concentration in lymph nodes, surpassing traditional Aluminium (Alum) adjuvants. Additionally, we demonstrated that the slow antigen degradation induces stronger follicular helper T cell responses and increases proportions of long-lived plasma cells and memory B cells. Overall, these findings propose that controlling the speed of antigens transport in dendritic cells can significantly boost vaccine efficacy, offering an innovative avenue for developing highly immunogenic next-generation vaccines.

Immunotoxicity of 2-Acetyl-4-tetrahydroxybutylimidazole in BALB/c mice with different vitamin B6 nutritional statuses.

Caramel color is a widely used food pigment, and 2-Acetyl-4-tetrahydroxybutylimidazole (THI) is a by-products of Class III caramel color. Some studies have shown that THI can reduce the number of peripheral blood lymphocytes. However, the comprehensive mechanism of THI immunotoxicity requires further study. In this study, the effects of THI on lymphocyte count, humoral immunity, cellular immunity and nonspecific immunity were determined and the effect of the nutritional status of VB6 on THI immunotoxicity was evaluated. Female BALB/c mice were divided into 3 groups and fed chow containing different doses of VB6: VB6-normal (6 mg/kg VB6), VB6-deprived (0.5 mg/kg VB6) or VB6-enhanced (12 mg/kg VB6) feed. Each group was further divided into 4 subgroups and treated with THI (0.5, 2.5 or 12.5 mg/kg bw) or the solvent control by gavage for 30 days. The thymic cortical thickness was measured with ViewPoint; the proportions of major immune cells and T cells in peripheral blood and tissues were detected via flow cytometry; the transformation and proliferation abilities of T and B cells were detected via T and B lymphocyte proliferation assays; NK cell activity was assessed via lactate dehydrogenase assays; humoral immune function was assessed via plaque-forming cell assays; and the immune function of T lymphocytes was assessed via delayed type hypersensitivity assays. The results showed that compared with those in the corresponding control group, the white blood cell count and lymphocyte count decreased significantly in all the VB6-deprived groups, in the 2.5 and 12.5 mg/kg VB6 groups, and in the 12.5 mg/kg VB6-enhanced group. With increasing THI dose, the thymic cortical layer became thinner. In the thymus, THI increased the proportions of CD3+ T cells and mature CD8+ T cells and decreased the proportions of immature double-positive, double-negative T cells and CD69-expressing lymphocytes. The proportions of naïve T cells and Tcm (central memory T) cells related to homing decreased. The proportion of mature T cells in the spleen decreased significantly. The proliferation of T cells stimulated by ConA decreased after THI exposure. VB6-deficient mice were more sensitive to THI immunotoxicity, and supplementation with VB6 had a certain protective effect on these mice. The results of the PFC and NK cell activity assays indicated that THI exposure might not affect humoral immune or innate immune function.

Peptide nanovaccine conjugated via a retro-Diels-Alder reaction linker for overcoming the obstacle in lymph node penetration and eliciting robust cellular immunity.

Nanoparticles have been regarded as a promising vaccine adjuvant due to their innate immune potentiation and enhanced antigen transport. However, the inefficient infiltration into the lymph node (LN) paracortex of nanoparticles caused by subcapsular sinus (SCS) obstruction is the main challenge in further improvement of nanovaccine immune efficacy. Herein, we propose to overcome paracortex penetration by using nanovaccine to spontaneously and continuously release antigens after retention in the SCS. In detail, we utilized a spontaneous retro-Diels-Alder (r-D-A) reaction linker to connect poly{(2-methyl-2-oxazoline)80-co-[(2-butyl-2-oxazoline)15-r-(2-thioethyl-2-oxazoline)8]} (PMBOxSH) and peptides for the peptide nanovaccine construction. The r-D-A reaction linker can spontaneously break over time, allowing the nanovaccine to release free antigens and adjuvants upon reaching the LN, thereby facilitating the entry of released antigens and adjuvants into the interior of the LNs. We showed that the efficacy of the peptide nanovaccine constructed using this dynamic linker could be significantly improved, thus greatly enhancing the tumor inhibition efficacy in the B16-OVA model. This dynamic-covalent-chemistry-based vaccine strategy may inspire designing more efficient therapeutic vaccines, especially those that require eliciting high-amount T cell responses.

Effect of Immunosuppression on the Immune Response to SARS-CoV-2 Infection and Vaccination.

Immunosuppressive treatment in patients with rheumatic diseases can maintain disease remission but also increase risk of infection. Their response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination is frequently blunted. In this study we evaluated the effect of immunosuppression exposure on humoral and T cell immune responses to SARS-CoV-2 infection and vaccination in two distinct cohorts of patients; one during acute SARS-CoV-2 infection and 3 months later during convalescence, and another prior to SARS-CoV-2 vaccination, with follow up sampling 6 weeks after vaccination. Results were compared between rituximab-exposed (in previous 6 months), immunosuppression-exposed (in previous 3 months), and non-immunosuppressed groups. The immune cell phenotype was defined by flow cytometry and ELISA. Antigen specific T cell responses were estimated using a whole blood stimulation interferon-γ release assay. A focused post-vaccine assessment of rituximab-treated patients using high dimensional spectral cytometry was conducted. Acute SARS-CoV-2 infection was characterised by T cell lymphopenia, and a reduction in NK cells and naïve CD4 and CD8 cells, without any significant differences between immunosuppressed and non-immunosuppressed patient groups. Conversely, activated CD4 and CD8 cell counts increased in non-immunosuppressed patients with acute SARS-CoV-2 infection but this response was blunted in the presence of immunosuppression. In rituximab-treated patients, antigen-specific T cell responses were preserved in SARS-CoV-2 vaccination, but patients were unable to mount an appropriate humoral response.

A xanthan gum and carbomer-codispersed divalent manganese ion-loaded tannic acid nanoparticle adjuvanted inactivated pseudorabies virus vaccine induces balanced humoral and cellular immune responses.

Adjuvants including aluminum adjuvant (Alum) and oil-water emulsion have been widely used in inactivated pseudorabies virus (PRV) vaccines to improve their performance, however, they are not sufficient to protect from PRV infection because of the weak immune response and poor Th1-type immune response. Divalent manganese ion (Mn2+) has been reported to increase the cellular immune response significantly. In this work, a xanthan gum and carbomer-dispersed Mn2+-loaded tannic acid-polyethylene glycol (TPMnXC) nanoparticle colloid is developed and used as an adjuvant to improve the performance of the inactivated PRV vaccine. The good in vitro and in vivo biocompatibility of the developed TPMnXC colloid has been confirmed by the cell viability assay, erythrocyte hemolysis, blood routine analysis, and histological analysis of mouse organs and injection site. The TPMnXC-adjuvanted inactivated PRV vaccine (TPMnXC@PRV) significantly promotes higher and more balanced immune responses indicating with an increased specific total IgG antibody and IgG2a/IgG1 ratio, efficient splenocytes proliferation, and elevated Th1- and Th2-type cytokine secretion than those of control groups. Wild PRV challenge experiment is performed using mice as a model animal, achieving a protection rate of up to 86.67 %, which is much higher than those observed from the commercial Alum. This work not only demonstrates the high potentiality of TPMnXC in practical applications but also provides a new way to develop the Mn2+-loaded nanoadjuvant for veterinary vaccines.

Ganoderma lucidum Polysaccharide Supplementation Significantly Activates T-Cell-Mediated Antitumor Immunity and Enhances Anti-PD-1 Immunotherapy Efficacy in Colorectal Cancer.

Ganoderma lucidum polysaccharide (GLP) is a prebiotic with immunomodulatory effects. However, the therapeutic potential of GLP in tumor immunotherapy has not been fully explored, especially in T cell-mediated antitumor immunity. In this study, we found that GLP significantly inhibited tumor growth and activated antitumor immunity in colorectal cancer (CRC). In the spleens and tumor tissues, the proportion of cytotoxic CD8+T cells and Th1 helper cells increased, while immunosuppressive Tregs decreased. Additionally, microbiota dysbiosis was alleviated by GLP, and short-chain fatty acid production was increased. Meanwhile, GLP decreased the ratio of kynurenine and tryptophan (Kyn/Trp) in the serum, which contributed to antitumor immunity of T cells. More importantly, the combination of GLP and the immune checkpoint inhibitor anti-PD-1 monoclonal antibody further enhanced the efficacy of anti-PD-1 immunotherapy. Thus, GLP as a prebiotic has the potential to be used in tumor immunotherapy.

Longitudinal study of immunity to SARS-CoV2 in ocrelizumab-treated MS patients up to 2 years after COVID-19 vaccination.

OBJECTIVES: (1) To plot the trajectory of humoral and cellular immune responses to the primary (two-dose) COVID-19 mRNA series and the third/booster dose in B-cell-depleted multiple sclerosis (MS) patients up to 2 years post-vaccination; (2) to identify predictors of immune responses to vaccination; and (3) to assess the impact of intercurrent COVID-19 infections on SARS CoV-2-specific immunity. METHODS: Sixty ocrelizumab-treated MS patients were enrolled from NYU (New York) and University of Colorado (Anschutz) MS Centers. Samples were collected pre-vaccination, and then 4, 12, 24, and 48 weeks post-primary series, and 4, 12, 24, and 48 weeks post-booster. Binding anti-Spike antibody responses were assessed with multiplex bead-based immunoassay (MBI) and electrochemiluminescence (Elecsys®, Roche Diagnostics), and neutralizing antibody responses with live-virus immunofluorescence-based microneutralization assay. Spike-specific cellular responses were assessed with IFNγ/IL-2 ELISpot (Invitrogen) and, in a subset, by sequencing complementarity determining regions (CDR)-3 within T-cell receptors (Adaptive Biotechnologies). A linear mixed-effect model was used to compare antibody and cytokine levels across time points. Multivariate analyses identified predictors of immune responses. RESULTS: The primary vaccination induced an 11- to 208-fold increase in binding and neutralizing antibody levels and a 3- to 4-fold increase in IFNγ/IL-2 responses, followed by a modest decline in antibody but not cytokine responses. Booster dose induced a further 3- to 5-fold increase in binding antibodies and 4- to 5-fold increase in IFNγ/IL-2, which were maintained for up to 1 year. Infections had a variable impact on immunity. INTERPRETATION: Humoral and cellular benefits of COVID-19 vaccination in B-cell-depleted MS patients were sustained for up to 2 years when booster doses were administered.

Boosting humoral and cellular immunity with enhanced STING activation by hierarchical mesoporous metal-organic framework adjuvants.

Vaccination is essential for preventing and controlling infectious diseases, along with reducing mortality. Developing safe and versatile adjuvants to enhance humoral and cellular immune responses to vaccines remains a key challenge in vaccine development. Here, we designed hierarchical mesoporous MOF-801 (HM801) using a Cocamidopropyl betaine (CAPB) and a Pluronics F127 in an aqueous phase system. Meanwhile, we synthesized a novel SARS-CoV-2 nanovaccine (R@M@HM801) with a high loading capacity for both the STING agonist (MSA-2) and the Delta receptor binding domain (Delta-RBD) antigen. R@M@HM801 enhanced MSA-2 and RBD utilization and effectively co-delivered MSA-2 and RBD antigens to antigen-presenting cells in the draining lymph nodes, thereby promoting the activation of both T and B cells. Lymphocyte single-cell analysis showed that R@M@HM801 stimulated robust CD11b+CD4+ T cells, CXCR5+CD4+ T follicular helper (Tfh), and durable CD4+CD44+CD62L-, CD8+CD44+CD62L- effector memory T cell (TEM) immune responses, and promoted the proliferative activation of CD26+ B cells in vivo. Meanwhile, R@M@HM801 induced stronger specific antibodies and neutralization of pseudovirus against Delta compared to the RBD + MAS-2 and RBD + MAS-2 + Alum vaccines. Our study demonstrated the efficacy of a hierarchical mesoporous HM801 and its potential immune activation mechanism in enhancing adaptive immune responses against viruses and other diseases.

A rational designed multi-epitope vaccine elicited robust protective efficacy against Klebsiella pneumoniae lung infection.

BACKGROUND: The emergence of drug-resistant strains of Klebsiella pneumoniae (K. pneumoniae) has become a significant challenge in the field of infectious diseases, posing an urgent need for the development of highly protective vaccines against this pathogen. METHODS AND RESULTS: In this study, we identified three immunogenic extracellular loops based on the structure of five candidate antigens using sera from K. pneumoniae infected mice. The sequences of these loops were linked to the C-terminal of an alpha-hemolysin mutant (mHla) from Staphylococcus aureus to generate a heptamer, termed mHla-EpiVac. In vivo studies confirmed that fusion with mHla significantly augmented the immunogenicity of EpiVac, and it elicited both humoral and cellular immune responses in mice, which could be further enhanced by formulation with aluminum adjuvant. Furthermore, immunization with mHla-EpiVac demonstrated enhanced protective efficacy against K. pneumoniae channeling compared to EpiVac alone, resulting in reduced bacterial burden, secretion of inflammatory factors, histopathology and lung injury. Moreover, mHla fusion facilitated antigen uptake by mouse bone marrow-derived cells (BMDCs) and provided sustained activation of these cells. CONCLUSIONS: These findings suggest that mHla-EpiVac is a promising vaccine candidate against K. pneumoniae, and further validate the potential of mHla as a versatile carrier protein and adjuvant for antigen design.