Higher Immune Response Research Articles

Bacterial expression systems based on Tymovirus-like particles for the presentation of vaccine antigens.

Virus-like particles (VLPs) are virus-derived artificial nanostructures that resemble a native virus-stimulating immune system through highly repetitive surface structures. Improved safety profiles, flexibility in vaccine construction, and the ease of VLP production and purification have highlighted VLPs as attractive candidates for universal vaccine platform generation, although exploration of different types of expression systems for their development is needed. Here, we demonstrate the construction of several simple Escherichia coli expression systems for the generation of eggplant mosaic virus (EMV) VLP-derived vaccines. We used different principles of antigen incorporation, including direct fusion of EMV coat protein (CP) with major cat allergen Feld1, coexpression of antigen containing and unmodified (mosaic) EMV CPs, and two coexpression variants of EMV VLPs and antigen using synthetic zipper pair 18/17 (SYNZIP 18/17), and coiled-coil forming peptides E and K (Ecoil/Kcoil). Recombinant Fel d 1 chemically coupled to EMV VLPs was included as control experiments. All EMV-Feld1 variants were expressed in E. coli, formed Tymovirus-like VLPs, and were used for immunological evaluation in healthy mice. The immunogenicity of these newly developed vaccine candidates demonstrated high titers of Feld1-specific Ab production; however, a comparably high immune response against carrier EMV was also observed. Antibody avidity tests revealed very specific Ab production (more than 50% specificity) for four out of the five vaccine candidates. Native Feld1 recognition and subclass-specific antibody tests suggested that the EMV-SZ18/17-Feld1 complex and chemically coupled EMV-Feld1 vaccines may possess characteristics for further development.

Evolution of antibody titers after two doses of mRNA Pfizer-BioNTech vaccine and effect of the third dose in nursing home residents.

We evaluated the IgG antibody titer against SARS-CoV-2 in 196 residents of a Spanish nursing home after the second dose of the BNT162b2 vaccine and the evolution of this titer over time. The role of the third dose of the vaccine on immune-response is also analysed in 115 of participants. Vaccine response was evaluated 1, 3 and 6 months after second dose of Pfizer-BioNTech COVID-19 Vaccine and 30 days after booster vaccination. Total anti-RBD (receptor binding domain) IgG immunoglobulins were measured to assess response. Six month after the second dose of vaccine and previously to the booster, T-cell response was also measured in 24 resident with different antibody levels. T-spot Discovery SARS-CoV-2 kit was used to identify cellular immunogenicity. As high as 99% of residents demonstrated a positive serological response after second dose. Only two patients showed no serologic response, two men without records of previous SARS-CoV-2 infection. A higher immune response was associated with prior SARS-CoV-2 infection regardless of the gender or age. The anti-S IgG titers decreased significantly in almost all the participants (98.5%) after six months of vaccination whatever previous COVID-infection. The third dose of vaccine increased antibody titers in all patients, although initial vaccination values were not restored in the majority of cases. The main conclusion of the study is that vaccine resulted in good immunogenicity in this vulnerable population. Nevertheless more data are needed on the long-term maintenance of antibody response after booster vaccination.

High expression of TARS is associated with poor prognosis of endometrial cancer.

Endometrial cancer is the second largest and most common cancer in the world. It is urgent to explore novel biomarkers. Data were obtained from The Cancer Genome Atlas (TCGA) database. The receiver operating characteristic (ROC) curves, Kaplan-Meier curves and Cox analysis, nomograms, gene set enrichment analysis (GSEA) were conducted. Cell proliferation experiments were performed in Ishikawa cell. TARS was significantly highly expressed in serous type, G3 grade, and deceased status. Significant association was between high TARS expression with poor overall survival (P = 0.0012) and poor disease specific survival (P = 0.0034). Significant differences were observed in advanced stage, G3 and G4, and old. The stage, diabetes, histologic grade, and TARS expression showed independent prognostic value for overall survival of endometrial cancer. The stage, histologic grade, and TARS expression showed independent prognostic value for disease specific survival of endometrial cancer. Activated CD4+ T cell, effector memory CD4+ T cell, memory B cell and type 2 T helper cell may participate in the high TARS expression related immune response in endometrial cancer. The CCK-8 results showed significantly inhibited cell proliferation in si-TARS (P < 0.05) and promoted cell proliferation in O-TARS (P < 0.05), confirmed by the colony formation and live/dead staining. High TARS expression was found in endometrial cancer with prognostic and predictive value. This study will provide new biomarker TARS for diagnosis and prognosis of endometrial cancer.

Immunogenicity and protective activity of mRNA vaccine candidates against yellow fever virus in animal models

Despite the success of the widely used attenuated yellow fever (YF) vaccine, its global supply remains a substantial barrier to implementing vaccination campaigns in endemic regions and combating emerging epidemics. In A129 mice and rhesus macaques, we evaluated the immunogenicity and protective activity of messenger RNA (mRNA) vaccine candidates encapsulated in lipid nanoparticles, expressing the pre-membrane and envelope proteins or the non-structural protein 1 of YF virus. Vaccine constructs induced humoral and cell-mediated immune responses in mice, resulting in protection against lethal YF virus infection after passive administration of serum or splenocytes from vaccinated mice. Vaccination of macaques induced sustained high humoral and cellular immune responses for at least 5 months after the second dose. Our data demonstrate that these mRNA vaccine candidates can be considered an attractive addition to the licensed YF vaccine supply based on the induction of functional antibodies correlating with protection and T-cell responses; they could alleviate the limited supply of current YF vaccines, mitigating future YF epidemics.

Abstract P5-02-37: Multi-omics approach to identify markers of resistance to endocrine therapy + CDK4/6 inhibitors in first line HR+/HER2- metastatic breast cancer (MBC) patients

Abstract CONTEXT: Endocrine therapy combined with CDK4/6 inhibitor is the standard frontline treatment for the vast majority of HR+/HER2- MBC patients. Despite an overall survival benefit, patients eventually progress and mechanisms of resistance to this combination are not well identified. METHODS: EPICURE is an ongoing pilot prospective cohort study of heterogeneous and massive data integration, ie. multi-omics approach in MBC patients. The present study aims at identifying progression markers in patients with HR+/HER2- MBC receiving frontline endocrine therapy+iCDK4/6 by means of transcriptomics, genomics and proteomics data. All patients had a tumor biopsy at the entry in the study (B1) and a biopsy was repeated at progression if feasible (B2). Transcriptomic (RNAseq: NextSeq550, Illumina), genomic (whole exome sequencing: NextSeq550, Illumina) and proteomic (DIA mass spectrometry: TimsTOFPro2, Bruker) were performed on B1 and B2 according to available tumor tissue. RESULTS: Fifty-one patients matching inclusion criteria were included. B1 was done at inclusion for all patients (B1) (n = 51) and B2 was performed in 8 patients. (B2) (n = 8). Eight metastatic sites were biopsied: node (n = 17); liver (n = 16); bone (n = 8); breast local recurrence (n = 5); chest wall (n = 5); skin (n = 4); pleural (n = 3); ovary (n = 1). Transcriptomic, genomic and proteomic analysis of paired biopsies (B1 and B2) was performed in parallel and separately for 8, 7 and 2 patients, respectively. Exploratory data analysis of transcriptomic and proteomic data showed that liver biopsies clustered together. In order to eliminate this anatomic bias, specific genes and proteins of liver metastases were identified by means of DESeq2 analysis (12 liver vs 39 other sites) for transcriptomic data (n = 2654) and LIMMA (4 liver vs 14 other sites) for proteomic data (n = 227), and excluded for the rest of the analysis. Differential analyses (ie. gene expression, non-synonymous mutations and protein expression) between B1 and B2 were performed for each patient. These three kind of lists were finally submitted to ToppGene, DAVID and GOrilla for Gene Ontology terms enrichment analyses. Transcriptomic analyses of the 8 paired biopsies highlighted immune response (IR) in seven B1, IR in four B2 and neurogenesis in three B2. Genomics data evaluation between B1 and B2 pointed out “transposon integration” as an important pathway. Proteomic data of the 2 paired biopsies analysed underlined high immune response in B1, and muscle development/contraction and response to tumor necrosis factor in B2 for one patient. For the second one, liver metabolism in B1 and extracellular matrix and p38 MAPK cascade were emphasised. CONCLUSION: This preliminary study based on transcriptomic, genomic and proteomic data represents an encouraging first step of the EPICURE project. In a near future, additional paired biopsies and other kinds of omics data (epigenetics, radiomics, microbiomics, exposomics) will be available. Furthermore, omics data will be analysed in an integrated manner (ie. artificial intelligence), which will make it possible to detect synergies across the different omics data. Citation Format: Jean Sebastien FRENEL, Fadoua Ben Azzouz, Frederic Bigot, Jonathan Dauve, Marie Francoise Heymann, Wilfried Gouraud, Catherine Guette, Hamza Lasla, Bertrand Michel, Alain Morel, Anne Patsouris, Marie Robert, Grégoire Siekaniec, Mathilde Colombie, Pascal Jézéquel, Mario Campone. Multi-omics approach to identify markers of resistance to endocrine therapy + CDK4/6 inhibitors in first line HR+/HER2- metastatic breast cancer (MBC) patients. [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-02-37.

The association of immune response and colostral immunoglobulin G in Canadian and US Holstein-Friesian dairy cows

In cattle, maternal immunoglobulins are transferred through colostrum to provide passive immunity to the neonatal calf once they are absorbed into circulation. Cows can be assessed for antibody- and cell-mediated immune responses (AMIR and CMIR, respectively), and through estimated breeding values (EBV) and genomic parent averages (GPA), cows can be classified as having high, average, or low immune response (IR). The objective of this study was to identify associations of colostral IgG concentrations with IR in dairy cows. High IR dairy cows identified by GPA or EBV were hypothesized to produce higher colostral IgG concentrations than cows with average or low IR. Colostrum was collected from Holstein dairy cows from 3 large commercial herds (n = 590) in the United States and 1 research herd at the Ontario Dairy Research Centre (n = 275) in Canada. For the US herds, IR GPA were available through genotyping. For the Canadian herd, IR EBV were available through phenotyping and pedigree information. Colostral IgG concentrations were measured by radial immunodiffusion and analyzed using general linear models in SAS. Based on a prediction equation, cows in US herds with a CMIR GPA of 1 would have colostral IgG concentrations 6.3 g/L higher on average than cows with a CMIR GPA of 0. High CMIR cows produced statistically greater colostral IgG concentrations (least squares mean ± standard error of the mean, 107.5 ± 7.7 g/L) than low CMIR cows (91.4 ± 7.1 g/L), with intermediate values for average CMIR cows (105.1 ± 5.6 g/L). No differences were found among AMIR categories in US cows. The Canadian herd showed a trend for cows with high CMIR EBV (continuous variable) to produce greater colostral IgG. No differences were observed among high, average, and low AMIR EBV classifications in Canadian cows. The findings suggest that selective breeding of Holstein cows to enhance CMIR could contribute to higher-quality colostrum in succeeding generations.

Immunological depiction of synthetic B-cell epitopes of Mycobacterium tuberculosis.

To combat the tuberculosis (TB) epidemic, the development of a better and faster diagnosis or more effective vaccine is essential. Pulmonary TB (PTB) is one of the major causes of morbidity and mortality. Early diagnosis of TB is difficult. Serological assays have been performed with several antigens of laboratory strains such as Mycobacterium tuberculosis H37Rv which have not been found to be highly sensitive. In the present study, various peptides were synthesized which were predicted on the basis of immunoreactivity and differential expression in clinical isolates of M. tuberculosis compared to their expression in a laboratory strain of M. tuberculosis. Therefore, the aim of this study was to compare the antibody levels in PTB and healthy controls against these peptides. An effort was made to evaluate antibody response to peptides derived from proteins Rv2588c, Rv0512, Rv0148, Rv0896, and Rv0635 of M. tuberculosis in PTB patients and healthy individuals through enzyme-linked immunosorbent assay. Five milliliters of venous blood samples was collected from each participant, and serum was separated and stored until use. Antibody levels against these peptides, Rv2588c, Rv0512, Rv0148, Rv0896. and Rv0635 in 139 PTB patients and 52 healthy controls were evaluated. Higher immune response was observed in PTB patients when compared with healthy individuals. Strong immunoglobulin G responses with high percentage, considerable difference among patients and healthy controls was observed with P < 0.0001. In our study, we found significant statistical differences in antibody levels in PTB patients and healthy individuals against these peptides. These peptides are suggestive of being a potential new candidate (s) for early diagnosis of TB.

The Gut Microbiota Metabolite Urolithin B Prevents Colorectal Carcinogenesis by Remodeling Microbiota and PD-L1/HLA-B.

Colorectal cancer has risen to the third occurring cancer in the world. Fluorouracil (5-Fu), oxaliplatin, and cisplatin are the most effective chemotherapeutic agents for clinical chemotherapy. Nevertheless, due to chemotherapeutic drug resistance, the survival rate of patients with CRC remains very low. In this study, we used the inflammation-induced or mutation-family-inherited murine CRC models to study the anticancer and immunotherapy effects of urolithin B (UB), the final metabolite of polyphenols in the gastrointestinal tract. The label-free proteomics analysis and the gene ontology (GO) classifications were used to test and analyze the proteins affected by UB. And 16S rDNA sequencing and flow cytometry were utilized to uncover gut microbiome composition and immune defense improved by UB administration. The results indicated that urolithin B prevents colorectal carcinogenesis by remodeling gut microbial and tumor immune microenvironments, such as HLA-B, NK cells, regulatory T cells, and γδ TCR cells, and decreasing the PD-L1. The combination of urolithin B with first-line therapeutic drugs improved the colorectal intestinal hematochezia by shaping gut microbiota, providing a strategy for the treatment of immunotherapy treatment for CRC treatments. UB combined with anti-PD-1 antibody could inhibit the growth of colon cancer. Urolithin B may thus contribute to anticancer treatments and provide a high immune response microenvironment for CRC patients' further immunotherapy.

Immunogenicity of Homologous Heart Valves: Mechanisms and Future Considerations.

Pediatric valvar heart disease continues to be a topic of interest due to the common and severe clinical manifestations. Problems with heart valve replacement, including lack of adaptive valve growth and accelerated structural valve degeneration, mandate morbid reoperations to serially replace valve implants. Homologous or homograft heart valves are a compelling option for valve replacement in the pediatric population but are susceptible to structural valve degeneration. The immunogenicity of homologous heart valves is not fully understood, and mechanisms explaining how implanted heart valves are attacked are unclear. It has been demonstrated that preservation methods determine homograft cell viability and there may be a direct correlation between increased cellular viability and a higher immune response. This consists of an early increase in human leukocyte antigen (HLA)-class I and II antibodies over days to months posthomograft implantation, followed by the sustained increase in HLA-class II antibodies for years after implantation. Cytotoxic T lymphocytes and T-helper lymphocytes specific to both HLA classes can infiltrate tissue almost immediately after implantation. Furthermore, increased HLA-class II mismatches result in an increased cell-mediated response and an accelerated rate of structural valve degeneration especially in younger patients. Further long-term clinical studies should be completed investigating the immunological mechanisms of heart valve rejection and their relation to structural valve degeneration as well as testing of immunosuppressant therapies to determine the needed immunosuppression for homologous heart valve implantation.

Antibody-Dependent Enhancement Activity of a Plant-Made Vaccine against West Nile Virus.

West Nile virus (WNV) causes annual outbreaks globally and is the leading cause of mosquito-borne disease in Unite States. In the absence of licensed therapeutics, there is an urgent need to develop effective and safe human vaccines against WNV. One of the major safety concerns for WNV vaccine development is the risk of increasing infection by related flaviviruses in vaccinated subjects via antibody-dependent enhancement of infection (ADE). Herein, we report the development of a plant-based vaccine candidate that provides protective immunity against a lethal WNV challenge mice, while minimizes the risk of ADE for infection by Zika (ZIKV) and dengue (DENV) virus. Specifically, a plant-produced virus-like particle (VLP) that displays the WNV Envelope protein domain III (wDIII) elicited both high neutralizing antibody titers and antigen-specific cellular immune responses in mice. Passive transfer of serum from VLP-vaccinated mice protected recipient mice from a lethal challenge of WNV infection. Notably, VLP-induced antibodies did not enhance the infection of Fc gamma receptor-expressing K562 cells by ZIKV or DENV through ADE. Thus, a plant-made wDIII-displaying VLP presents a promising WNV vaccine candidate that induces protective immunity and minimizes the concern of inducing ADE-prone antibodies to predispose vaccinees to severe infection by DENV or ZIKV.

Exploring the role of tumor stemness and the potential of stemness-related risk model in the prognosis of intrahepatic cholangiocarcinoma.

Background: Tumor stem cells (TSCs) have been widely reported to play a critical role in tumor progression and metastasis. We explored the role of tumor stemness in intrahepatic cholangiocarcinoma (iCCA) and established a prognostic risk model related to tumor stemness for prognosis prediction and clinical treatment guidance in iCCA patients. Materials and Methods: The expression profiles of iCCA samples (E-MTAB-6389 and GSE107943 cohorts) were used in the study. One-class logistic regression algorithm calculated the mRNA stemness index (mRNAsi). The mRNAsi-related genes were used as a basis for the identification of mRNAsi-related molecular subtypes through consensus clustering. The immune characteristics and biological pathways of different subtypes were assessed. The mRNAsi-related risk model was constructed with differentially expressed genes (DEGs) between subtypes. Results: The patients with high mRNAsi had longer overall survival than that with low mRNAsi. Two subtypes were identified with that C2 had higher mRNAsi and better prognosis than C1. Tumor-related pathways such as TGF-β and epithelial-mesenchymal transition (EMT) were activated in C1. C1 had higher enrichment of cancer-associated fibroblasts and tumor-associated macrophages, as well as higher immune response and angiogenesis score than C2. We screened a total 98 prognostic DEGs between C1 and C2. Based on the prognostic DEGs, we constructed a risk model containing three genes (ANO1, CD109, and CTNND2) that could divide iCCA samples into high- and low-risk groups. The two groups had distinct prognosis and immune characteristics. Notably, the risk score was negatively associated with mRNAsi (R = -0.53). High-risk group had higher enrichment score of T cell inflamed GEP, INF-γ, and cytolytic activity, and lower score of estimated IC50 of 5-fluorouracil and cisplatin than low-risk group. Conclusions: This study clarified the important role of tumor stemness in iCCA and developed an mRNAsi-related risk model for predicting the prognosis and supporting the clinical treatment in iCCA patients. The three genes (ANO1, CD109, and CTNND2) may serve as potential targets for iCCA treatment.

Recombinant GPEHT Fusion Protein Derived from HTLV-1 Proteins with Alum Adjuvant Induces a High Immune Response in Mice.

The human T-cell leukemia virus type 1 (HTLV-1) is a positive single-stranded RNA virus that belongs to the delta retrovirus family. As a result, a vaccine candidate that can be recognized by B cells and T cells is a good candidate for generating a durable immune response. Further, the GPEHT protein is a multi-epitope protein designed based on the Gag, Pol, Env, Hbz, and Tax proteins of HTLV-1. In developing a suitable and effective vaccine against HTLV-1, the selection of a designed protein (GPEHT) with the formulation of an alum adjuvant was conducted. In this study, we assessed the potential of a multi-epitope vaccine candidate for stimulating the immune response against HTLV-1. In assessing the type of stimulated immune reaction, total IgG, IgG1, and IgG2a isotypes, as well as the cytokines associated with Th1 (IFN-γ), Th2 (IL-4), and Th17 (IL-17), were analyzed. The outcomes showed that the particular antisera (total IgG) were more elevated in mice that received the GPEHT protein with the alum adjuvant than those in the PBS+Alum control. A subcutaneous vaccination with our chimera protein promoted high levels of IgG1 and IgG2a isotypes. Additionally, IFN-γ, IL-4, and IL-17 levels were significantly increased after spleen cell stimulation in mice that received the GPEHT protein. The immunogenic analyses revealed that the GPEHT vaccine candidate could generate humoral and cell-mediated immune reactions. Ultimately, this study suggests that GPEHT proteins developed with an alum adjuvant can soon be considered as a prospective vaccine to more accurately evaluate their protective efficacy against HTLV-1.

Evaluation of immune response to single dose of quadrivalent HPV vaccine at 10-year post-vaccination.

The recent World Health Organization recommendation supporting single-dose of HPV vaccine will significantly reduce programmatic cost, mitigate the supply shortage, and simplify logistics, thus allowing more low- and middle-income countries to introduce the vaccine. From a programmatic perspective the durability of protection offered by a single-dose will be a key consideration. The primary objectives of the present study were to determine whether recipients of a single-dose of quadrivalent HPV vaccine had sustained immune response against targeted HPV types (HPV 6,11,16,18) at 10years post-vaccination and whether this response was superior to the natural antibody titres observed in unvaccinated women. Participants received at age 10-18years either one, two or three doses of the quadrivalent HPV vaccine. Serology samples were obtained at different timepoints up to 10years after vaccination from a convenience sample of vaccinated participants and from age-matched unvaccinated women at one timepoint. The evolution of the binding and neutralizing antibody response was presented by dose received. 10-year durability of immune responses induced by a single-dose was compared to that after three doses of the vaccine and in unvaccinated married women. The dynamics of antibody response among the single-dose recipients observed over 120months show stabilized levels 18months after vaccination for all four HPV types. Although the HPV type-specific (binding or neutralizing) antibody titres after a single-dose were significantly inferior to those after three doses of the vaccine (lower bounds of GMT ratios<0.5), they were all significantly higher than those observed in unvaccinated women following natural infections (GMT ratios: 2.05 to 4.04-fold higher). The results correlate well with the high vaccine efficacy of single-dose against persistent HPV 16/18 infections reported by us earlier at 10-years post-vaccination. Our study demonstrates the high and durable immune response in single-dose recipients of HPV vaccine at 10-years post vaccination.

Применение адоптивной иммунотерапии для лечения герпесвирусной инфекции

Given the ability of the herpes simplex virus to persist for a long time, leading to a decrease in the specific immune response, the treatment of cancer patients with concomitant herpesvirus infection (HVI) is a difficult task. In the 1980s, progress was made in the study of HVI related to the development of the first drug from the group of acyclic nucleosides. Usually, the treatment of HVI includes antiviral agents, analgesics, antipyretics, local drugs with antiviral components and anesthetics. However, wellknown treatment for the disease does not provide complete elimination of the virus, and often after drug withdrawal, the symptoms occur, which causes problems in providing the medical care. Thus, the search for new ways to treat HVI, including in patients with a cancer, is relevant and necessary. The article describes the method for treating patients with HVI using in vitro activated autologous lymphocytes. Six clinical cases of successful treatment of genital herpes infection in patients were considered. Two patients had cancer, in the first case – cervical cancer, in the second – anal cancer. The conducted study allows to conclude that the uing of the method of adoptive immunotherapy for the treatment of patients with HVI improves the quality of life of the patient, induces the high immune response, which manifests itself in the duration of the relapse-free period from 8 to 45 months. Key words: adoptive immunotherapy, autologous lymphocytes, herpes virus infection, cancer patient

LB746. Safety and Immunogenicity of a Booster Dose of Novavax COVID-19 Vaccine, Adjuvanted (NVX-CoV2373) in Adults from the PREVENT-19 Trial in the United States

Abstract Background Novavax COVID-19 Vaccine, Adjuvanted (5 µg recombinant spike protein/50 µg Matrix-MTM adjuvant; NVX-CoV2373) has received regulatory authorizations for use in adults ≥ 18 years globally. Methods Participants from PREVENT-19 (NCT04611802), a phase 3, randomized, observer-blinded, placebo-controlled trial that evaluated the efficacy, safety, and immunogenicity of a primary series of 2 doses of NVX-CoV2373 given 21 days apart, in adults ≥ 18 years in the United States and Mexico, were eligible to receive a booster dose at least 6 months after the initial vaccination series. Short-term safety and immunogenicity of the booster dose was assessed in an ad hoc analysis of 298 participants. Results There was an incremental increase compared to the initial vaccination series in local and systemic reactogenicity, which was transient and mostly mild-to-moderate in intensity. Most unsolicited adverse events were also mild-to-moderate in severity; there were no deaths or treatment-related SAEs and 2/298 booster recipients in this analysis reported unrelated SAEs. Neutralizing, anti-S IgG, and hACE2 receptor binding inhibiting antibodies against the ancestral (Wuhan) strain 28 days after booster were higher than those 14 days after primary vaccination (Table). Overall, humoral responses were high regardless of interval between priming and booster vaccination, but a longer interval yielded stronger responses. Higher immune responses against the Omicron BA.1, BA.2, and BA.5 variants were also observed after the booster dose than after the primary series in a subset of 14-18 participants tested. Overall, humoral responses were high and broad regardless of age after any vaccination, but higher responses were observed in adults &amp;lt; 65 years after initial and booster vaccinations. A booster dose induced more robust antibody responses compared with the primary series in adults ≥ 65 years. Conclusion A single booster dose of NVX-CoV2373 demonstrated a satisfactory safety profile, and high levels of neutralizing, anti-S IgG, and hACE2 inhibition antibody responses against the SARS-CoV-2 prototype Wuhan as well as against the Omicron variant including recently emerged sub-variants. Disclosures Germán Áñez, MD, Novavax Inc.: employer|Novavax Inc.: Stocks/Bonds Lisa M. Dunkle, MD, Novavax, Inc: Employee|Novavax, Inc: Stocks/Bonds Nita Patel, MS, CRP, Novavax, Inc.: employer|Novavax, Inc.: Stocks/Bonds Joyce S. Plested, PhD, Novavax Inc.: employer|Novavax Inc.: Stocks/Bonds|Novavax Inc.: Stocks/Bonds Alice McGarry, MPH, Novavax: Employee|Novavax: Stocks/Bonds Wayne Woo, MS, Novavax: Employee|Novavax: Stocks/Bonds Rongman Cai, PhD, Novavax Inc.: employer|Novavax Inc.: Stocks/Bonds Iksung Cho, MS, Novavax, Inc.: employer|Novavax, Inc.: Stocks/Bonds.

High Immune Response Rate to the Fourth Boost of the BNT162b2 Vaccine against the Omicron Variants of Concern among Liver Transplant Recipients.

The immune response of liver transplant (LT) recipients to a third dose of the BNT162b2 mRNA vaccine significantly waned after four months. We aimed to evaluate the immune response and breakthrough infection rates of a fourth dose against the Omicron variants among LT recipients. LT recipients who had no past or active SARS-CoV-2 infection and received three doses of the BNT162b2mRNA vaccine were included. Of the 73 LT recipients, 50 (68.5%) received a fourth dose. The fourth dose was associated with a significantly higher positive immune response than the third dose. Receptor-binding domain (RBD) IgG and Omicron BA.1 and BA.2 neutralizing antibodies were determined at a median of 132 and 29 days after the third and fourth vaccines. They were 345 binding antibody units per milliliter (BAU/mL) vs. 2118 BAU/mL (p < 0.0001), 10 vs. 87 (p < 0.0001), and 15 vs. 149 (p = 0.001), respectively. Breakthrough infections were documented among nine (18%) LT recipients after the fourth dose and among seven (30.4%) patients following the third dose (p = 0.2); 93.5% of breakthrough infections were mild. The infection rate after the fourth dose was higher among diabetic vs. nondiabetic recipients (33.3% vs. 6.9%, respectively; p = 0.02). Further studies are needed to evaluate additional factors influencing the breakthrough infection rate among LT recipients.

Comparing the Immunogenicity and Protective Effects of Three MERS-CoV Inactivation Methods in Mice.

The Middle East respiratory syndrome (MERS) is a fatal acute viral respiratory disease caused by MERS-coronavirus (MERS-CoV) infection. To date, no vaccine has been approved for MERS-CoV despite continuing outbreaks. Inactivated vaccines are a viable option when developed using the appropriate inactivation methods and adjuvants. In this study, we evaluated the immunogenicity and protective effects of MERS-CoV vaccine candidates inactivated by three different chemical agents. MERS-CoV was effectively inactivated by formaldehyde, hydrogen peroxide, and binary ethylene imine and induced humoral and cellular immunity in mice. Although inflammatory cell infiltration was observed in the lungs four days after the challenge, the immunized hDPP4-transgenic mouse group showed 100% protection against a challenge with MERS-CoV (100 LD50). In particular, the immune response was highly stimulated by MERS-CoV inactivated with formaldehyde, and all mice survived a challenge with the minimum dose. In the adjuvant comparison test, the group immunized with inactivated MERS-CoV and AddaVax had a higher immune response than the group immunized with aluminum potassium sulfate (alum). In conclusion, our study indicates that the three methods of MERS-CoV inactivation are highly immunogenic and protective in mice and show strong potential as vaccine candidates when used with an appropriate adjuvant.

Immune Response After Vaccination against SARS-CoV-2 in the Elderly in the Czech Republic

Abstract Background and Aims Elderly, especially those with chronic diseases, are a population at high risk of a severe course of the SARS-CoV-2 infection. The study aimed to investigate the complex immune response after vaccination in nursing home residents older than 65 years depending on the previous COVID-19 status and vaccine brand. Methods 375 participants participated in the study in September-October 2021. IgG antibodies against spike protein and nucleocapsid protein, the titer of virus neutralization antibodies, and cellular immunity (interferon-gamma release assay) were tested in elderly nursing home residents vaccinated with Pfizer, Moderna 30-31 weeks after the completion of vaccination and in those vaccinated with AstraZeneca 23 weeks before sampling. The prevalence with 95% confidence intervals (CI) was evaluated in Stata version 17. Results In total, 95.2% (95% CI: 92.5%-97.1%) of samples had positive results of anti-S IgG, 92.8% (95% CI: 89.7%-95.2%) were positive in virus neutralization assay and 89.0% (95% CI: 84.5%-92.5%) in the interferon-gamma-releasing assay (indicator of cellular immunity). Even though the immune response to the Pfizer and Moderna vaccines were evaluated after a longer period than AstraZeneca, the immune response in residents vaccinated with these vaccines were superior. All immune parameters in vaccinated individuals were significantly higher in convalescent residents than in those who had not been infected with COVID. No case of COVID-19 occurred during the vaccination-to-test period. Conclusions High immune response was found in elderly nursing homes residents (65 years and older) after 5-7 months after vaccination against SARS-CoV-2. In particular, vaccinated convalescents showed high immune responses. It appears that such residents are much better protected from COVID-19 than those who are only vaccinated. Key messages

Effect of heat stress amelioration during dry period on biological responses, proinflammatory cytokines and milk production in subsequent lactation of Surti buffaloes

Present study was conducted on 12 dry Surti buffaloes to assess the effect of heat stress amelioration during dry period on their biological responses and milk production in subsequent lactation. Buffaloes were divided into control (n=6) and treatment (n=6) groups. Treatment buffaloes were housed only during their dry period in shed having wall-mounted fans, roof whitewashed with microfine lime powder and open paddock covered with 75% green net. At -8, -3, +1 and +3 weeks of calving, blood collection and recording of observations (physiological, skin thermography and BCS) were done. Milk composition and daily milk yield were recorded at every 2 weeks up to 11 weeks of lactation, respectively. Shed modification was successful in lowereing air temperature and THI indicating thermal comfort for treatment buffaloes as also revealed by lower temperatures of rectum, tympanic membrane, surface like forehead, eye, udder, coronet and lower respiration rate. Treatment group maintained significantly higher BCS, glucose, total protein, GSH, TAS, in vitro lymphocyte proliferation, neutrophil phagocytic activity and lower levels of urea, creatinine, NEFA, BHBA, SOD, MDA, cortisol, TNF-α, IL-1β, IL-6 and HSP70. These results are indicative of minimum negative energy balance, stress and higher immune response. Milk yield and fat were higher in treatment group. Providing thermal comfort to buffaloes in dry period helped in abating the negative effects of heat stress not only during dry period but also during subsequent lactation along with improved milk yield.

Construction of an immune-related signature for predicting the ischemic events in patients undergoing carotid endarterectomy.

Background: Inflammatory responses have drawn more attention to atherosclerosis; however, the immune-related genes (IRGs) as a prognostic factor in atherosclerotic plaque remain to be fully elucidated. Here, the purpose of this study was to investigate whether the IRGs could be identified as a reliable biomarker for predicting ischemic events in patients undergoing carotid endarterectomy (CEA). Methods: Two datasets GSE97210 and GSE21545 were downloaded from the Gene Expression Omnibus (GEO) database. The dataset GSE97210 was used to explore the significant pathways and differentially expressed IRGs (DEIRGs) between plaques and controls, which were further screened to identify the prognostic DEIRGs in the GSE21545 dataset. The identification of molecular subgroups with the prognostic gene expression patterns was achieved through nonnegative matrix factorization (NMF) clustering. Functional analyses including GO, KEGG, GSVA, and GSEA analyses, and immune analyses including xCell and ssGSEA algorithms were conducted to elucidate the underlying mechanisms. The prognostic risk model was constructed using the LASSO algorithm and multivariate Cox regression analysis. Results: A total of 796 DEIRGs (including 588 upregulated and 208 downregulated) were identified. Nine prognostic DEIRGs were further screened with univariate Cox regression analysis. Two clusters with different prognosis were grouped based on the prognostic DEIRGs. Immune infiltration analysis shows that cluster 2 with a better prognosis presented with a higher immune response than cluster 1. A prognostic model based on seven IRGs (IL2RA, NR4A2, DES, ERAP2, SLPI, RASGRP1, and AGTR2) was developed and verified. Consistent with the immune analysis of the cluster, the immune infiltration in the low-risk group with a better prognosis was also more active than that in the high-risk group. Finally, a nomogram based on the seven genes was constructed, which might have future implications in clinical care. Conclusion: The expression of immune-related genes is correlated with the immune microenvironment of atherosclerotic patients and could be applied to predict the ischemic events in patients undergoing CEA accurately.