Immune Antibodies Research Articles

Prevalence and Specificities of Immune Red Cell Antibodies in Adult Patients with Sickle Cell Anaemia and Blood Donors in Uyo, South-South Nigeria: A Case-Control Study

Background: Sickle cell anaemia (SCA) is a major public health issue in Sub-Saharan Africa, including Nigeria. Transfusion of red blood cells is an essential therapeutic modality in SCA. Repeated RBC transfusions can cause alloimmunization resulting in haemolytic transfusion reactions, transfusion refractoriness among other complications. Aims and Objectives: The study aimed to determine the prevalence and specificities of immune erythrocyte alloantibodies among adult patients with SCA compared with healthy HbAA blood donors in Uyo, South-South Nigeria. Materials and Methods: All participants were interviewed using a structured questionnaire to obtain information on bio- data, blood transfusion history and other relevant SCA history. Antibody screening and identification were carried out using tube agglutination method with commercially made panel of cells. Results: A total of 160 subjects were studied. They were made up of 80 SCA patients and 80 healthy HbAA blood donors. Prevalence of red cell alloimmunization among multi-transfused patients with SCA was observed to be 11.3%. Alloantibodies identified were mainly against Rh antigens contributing 66.7% (anti-E 22.2%, anti-C 22.2%, anti-D 11.1% and anti-e 11.1%). Antibodies directed against Kell and Lutheran blood group antigens together constituted 33.3%. No antibody was detected in the controls. Advancing age (30 years and above) and ABO blood group were statistically associated with alloimmunization (P values of 0.043 and 0.013, respectively). Conclusion: Repeated blood transfusion is associated with the development of alloantibodies. Immunohaematologic tests in transfusion care of SCA patients should be improved to include extended red cell phenotyping and routine alloantibody screening and identification.

Co-immunization with hemagglutinin stem immunogens elicits cross-group neutralizing antibodies and broad protection against influenza A viruses

Current influenza vaccines predominantly induce immunity to the hypervariable hemagglutinin (HA) head, requiring frequent vaccine reformulation. Conversely, the immunosubdominant yet conserved HA stem harbors a supersite that is targeted by broadly neutralizing antibodies (bnAbs), representing a prime target for universal vaccines. Here, we showed that the co-immunization of two HA stem immunogens derived from group 1 and 2 influenza A viruses elicits cross-group protective immunity and neutralizing antibody responses in mice, ferrets, and nonhuman primates (NHPs). Immunized mice were protected from multiple group 1 and 2 viruses, and all animal models showed broad serum-neutralizing activity. A bnAb isolated from an immunized NHP broadly neutralized and protected against diverse viruses, including H5N1 and H7N9. Genetic and structural analyses revealed strong homology between macaque and human bnAbs, illustrating common biophysical constraints for acquiring cross-group specificity. Vaccine elicitation of stem-directed cross-group-protective immunity represents a step toward the development of broadly protective influenza vaccines.

Antibody-dependent cellular cytotoxicity-null effector developed using mammalian and plant GlycoDelete platform

Cancer therapy using immune checkpoint inhibitor antibodies has markedly shifted the paradigm of cancer treatment. However, methods completely eliminating the effector function of these signal-regulating antibodies is urgently required. The heterogeneity of glycan chains in antibodies limits their use as therapeutic agents due to their variability; thus, the development of uniform glycan chains is necessary. Here, we subjected the anti-programmed cell death protein (PD)-1 antibody nivolumab, a representative immune checkpoint inhibitor, to GlycoDelete (GD) engineering to remove the antibody-dependent cellular cytotoxicity (ADCC) of the antibody, leaving only one glycan in the Fc. Glyco-engineered CHO cells were prepared by overexpressing endo-β-N-acetyl-glucosaminidase (Endo T) in CHO cells, in which N-acetyl-glucosaminyl-transferase I was knocked out using Cas9. GD IgG1 nivolumab and GD IgG4 nivolumab were produced using GD CHO cells, and glycan removal was confirmed using mass spectrometry. Target binding and PD-1 inhibition was not altered; however, ADCC decreased. Furthermore, the IgG4 form, determined to be the most suitable form of GD nivolumab, was produced in a plant GD system. The plant GD nivolumab also reduced ADCC without affecting PD-1 inhibitory function. Thus, CHO and plant GD platforms can be used to improve signal-regulating antibodies by reducing their effector function.

Immune responses following COVID-19 infection in multiple sclerosis patients using immunomodulatory therapy.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus type-2 (SARS-CoV-2), has quickly become a global pandemic. Most multiple sclerosis (MS) patients use disease-modifying treatments (DMTs), such as immunomodulators or immunosuppressants. By targeting different types of immune cells, DMTs affect cellular and/or humoral immunity. The potential effects of DMTs on the long-term immune response to COVID-19 is not fully known. Between 16.04.2020 and 15.07.2020, a total of 34 people, 17 of whom were diagnosed with MS according to the 2010 McDonald diagnostic criteria and a control group of 17 individuals who did not have a known systemic disease who were matched according to age, gender, and COVID-19 disease severity, where all received COVID-19 diagnosis with SARS-CoV-2 PCR positivity in nasopharyngeal swab test and immune responses were measured (SARS-CoV-2 IgM and IgG antibody levels COVID 19 ELISA kit), were included in our study. Demographic data of MS patients and the control group, SARS-CoV-2 immune responses, antibody titers and disease year of MS patients, EDSS scores, disease type, and disease duration were determined. All patients were symptomatic for COVID-19. COVID-19 disease severity was divided into three groups as mild, moderate, and severe according to the clinical condition of the patient. Demographic data of MS patients and the control group, SARS-CoV-2 immune responses, antibody titers and disease year of MS patients, EDSS scores, disease type, and disease duration were determined. All patients were symptomatic for COVID-19. COVID-19 disease severity was divided into three groups as mild, moderate, and severe according to the clinical condition of the patient. According to our study results, IgG-type long-term immune responses were lower in MS patients using DMTs than in the healthy population. We hope that our study will provide insight into the COVID-19 vaccine immune responses.

The Long-Term Healthcare Utilization and Economic Burden of RSV Infection in Children ≤5 Years in Japan: Propensity Score Matched Cohort Study.

The objective of this study was to estimate the long-term healthcare utilization and cost burden of RSV by chronological age of diagnosis (Year 1, Year 2 and Years 3-5 cohorts) as well as by gestational age at birth in Japan. The JMDC database was used to retrospectively identify RSV and control patients between February 1, 2011 and January 31, 2016 and follow them through December 31, 2017. Infants with RSV infection (n = 9028 in Year 1; n = 4929 in Year 2; n = 2004 in Years 3-5) were matched to controls (n = 17,886; n = 9351; n = 3655, respectively) based on gestational age and year and quarter of birth; controls were assigned the index date (ie, diagnosis) of their respective match. Covariate-balancing propensity score weights were employed adjusting for remaining imbalances between cohorts. The main outcomes were average cumulative rates for all-cause, asthma/wheezing, and respiratory-related hospitalizations, physician and urgent care/emergency visits and associated costs (reported as 2018 ¥JPY) over 36-months of follow-up since index. Healthcare utilization was significantly higher among RSV cases for most comparisons. All-cause average differential cost burden was higher for RSV, compared to controls, among the following cohorts: Year 1 full-term (¥277,727); Year 2 preterm (¥530,302), late preterm (¥270,797), full-term (¥238,832); Years 3-5 preterm (¥110,057), late preterm (¥486,670), full-term (¥289,986). While all-cause costs were similar for preterm and late preterm children in the Year 1 cohort, respiratory- and asthma/wheezing-related attributable costs were substantially higher for RSV. RSV infection had a significant long-term health and economic burden among children infected during their first year of life and later in life. Study findings have import for prevention strategies, currently directed at maternal immunization and monoclonal antibodies for preventing primary RSV infections in the first six months of life and beyond but also for older age not targeted currently.

Heterogeneous plasma cells and long-lived subsets in response to immunization, autoantigen and microbiota.

Durable antibody immunity depends on long-lived plasma cells (LLPCs) that primarily reside in the bone marrow (BM). However, due to LLPC rarity, it has not been possible to define their phenotypes or determine their heterogeneity. By single-cell mRNA sequencing, cytometry and a genetic pulse-chase mouse model, we show that IgG and IgM LLPCs display an EpCAM^hiCXCR3^- phenotype, whereas IgA LLPCs are Ly6A^hiTigit^-. While IgG and IgA LLPCs are mainly contributed by somatically hypermutated cells following immunization or infection, cells with innate properties and public antibodies are found in IgA and IgM LLPC compartments. Particularly, IgM LLPCs are highly enriched with public clones shared among different individual animals, differentiated in a T cell-independent manner and have affinity for self-antigens and microbial-derived antigens. Taken together, our work reveals different routes toward LLPC development and paves the way for deeper understanding of cellular and molecular underpinnings of long-term antibody immunity.

Efficacy of an accelerated vaccination schedule against hepatitis E virus infection in pregnant rabbits.

An important goal of the Hepatitis E virus (HEV) vaccine is to prevent adverse pregnancy outcomes caused by different HEV genotypes during pregnancy, but studies directly evaluating maternal vaccination for HEV are lacking. Here we report maternal vaccination using HEV 239 vaccine in a pregnant rabbit model. Two dose of accelerated vaccination schedule (0, 7 days) induced high titers of anti-HEV protective antibodies in a short period of time in pregnant rabbits, which could protect the pregnant rabbits from HEV infection and adverse pregnancy outcomes. In addition, the immunized rabbits transfer maternal antibodies to pups through the placenta and breast milk, which protect neonates against HEV infection. Our results suggest that, besides vaccinating nonpregnant individuals, HEV 239 vaccine may also be discreetly considered for maternal vaccination.

90Y-Labeled Gold Nanoparticle Depot (NPD) Combined with Anti-PD-L1 Antibodies Strongly Inhibits the Growth of 4T1 Tumors in Immunocompetent Mice and Induces an Abscopal Effect on a Distant Non-Irradiated Tumor.

The effectiveness and normal tissue toxicity of a novel nanoparticle depot (NPD) brachytherapy seed incorporating gold nanoparticles (AuNPs) labeled with β-particle emitting, 90Y (termed a "radiation nanomedicine"), were studied for the treatment of 4T1 triple-negative murine mammary carcinoma tumors in Balb/c mice and for inducing an abscopal effect on a distant non-irradiated tumor alone or combined with anti-PD-L1 immune checkpoint antibodies. Balb/c mice with two subcutaneous 4T1 tumors─a primary tumor and a distant secondary tumor were implanted intratumorally (i.t.) in the primary tumor with NPD incorporating 3.5 MBq of 90Y-AuNPs (1 × 1014 AuNPs) or unlabeled AuNPs, alone or combined with systemically administered anti-PD-L1 antibodies (200 μg i.p. three times/week for 2 weeks) or received anti-PD-L1 antibodies alone or no treatment. The primary tumor was strongly growth-inhibited over 14 d by NPD incorporating 90Y-AuNPs but only very modestly inhibited by NPD incorporating unlabeled AuNPs. Anti-PD-L1 antibodies alone were ineffective, and combining anti-PD-L1 antibodies with NPD incorporating 90Y-AuNPs did not further inhibit the growth of the primary tumor. Secondary tumor growth was inhibited by treatment of the primary tumor with NPD incorporating 90Y-AuNPs, and growth inhibition was enhanced by anti-PD-L1 antibodies. Treatment of the primary tumor with NPD incorporating unlabeled AuNPs or anti-PD-L1 antibodies alone had no effect on secondary tumor growth. Biodistribution studies showed high uptake of 90Y in the primary tumor [516-810% implanted dose/g (%ID/g)] but very low uptake in the secondary tumor (0.033-0.16% ID/g) and in normal tissues (<0.5% ID/g) except for kidneys (5-8% ID/g). Very high radiation absorbed doses were estimated for the primary tumor (472 Gy) but very low doses in the secondary tumor (0.13 Gy). There was highdose-heterogeneity in the primary tumor with doses as high as 9964 Gy in close proximity to the NPD, decreasing rapidly with distance from the NPD. Normal organ doses were low (<1 Gy) except for kidneys (4 Gy). No normal tissue toxicity was observed, but white blood cell counts (WBC) decreased in tumor-bearing mice treated with NPD incorporating 90Y-AuNPs. Decreased WBC counts were interpreted as tumor response and not toxicity since these were higher than that in healthy non-tumor-bearing mice, and there was a direct association between WBC counts and 4T1 tumor burden. We conclude that implantation of NPD incorporating 90Y-AuNPs into a primary 4T1 tumor in Balb/c mice strongly inhibited tumor growth and combined with anti-PD-L1 antibodies induced an abscopal effect on a distant secondary tumor. This radiation nanomedicine is promising for the local treatment of triple-negative breast cancer tumors in patients, and these therapeutic effects may extend to non-irradiated lesions, especially when combined with checkpoint immunotherapy.

Omicron SARS-CoV-2 Spike-1 Protein’s Decreased Binding Affinity to α7nAChr: Implications for Autonomic Dysregulation of the Parasympathetic Nervous System and the Cholinergic Anti-Inflammatory Pathway—An In Silico Analysis

Omicron is the dominant strain of COVID-19 in the United States and worldwide. Although this variant is highly transmissible and may evade natural immunity, vaccines, and therapeutic antibodies, preclinical results in animal models and clinical data in humans suggest omicron causes a less severe form of infection. The molecular basis for the attenuation of virulence when compared to previous variants is currently not well understood. Using protein–ligand docking simulations to evaluate and compare the capacity of SARS-CoV-2 spike-1 proteins with the different COVID-19 variants to bind to the human α7nAChr (i.e., the core receptor under the control of the vagus nerve regulating the parasympathetic nervous system and the cholinergic anti-inflammatory pathway), we found that 10 out of the 14 mutated residues on the RBD of the B.1.1.529 (Omicron) spike, compared to between 0 and 2 in all previous variants, were present at the interaction interface of the α7nAChr. We also demonstrated, through protein–protein docking simulations, that these genetic alterations cause a dramatic decrease in the ability of the Omicron SARS-CoV-2 spike-1 protein to bind to the α7nAChr. These results suggest, for the first time, that the attenuated nature of Omicron infection in humans and animals compared to previous variants may be attributable to a particular set of genetic alterations, specifically affecting the binding site of the SARS-CoV-2 spike-1 protein to the α7nAChr.

AN AGE-STRUCTURED MODEL FOR PERTUSSIS TRANSMISSION WITH MULTIPLE INFECTIONS STUDYING THE EFFECTS OF CHILDHOOD DTAP AND ADOLESCENT TDAPVACCINES

An age-structured deterministic model with multiple infections that accounts for decaying maternal antibody, waning infection-acquired and vaccine-induced immunity is formulated to study the transmission dynamics of pertussis and the effect of childhood DTaP and adolescent Tdap vaccines. The expression of the reproduction number [Formula: see text] is derived for the ODE model in the case of proportionate mixing. Estimated age-dependent transmission probability and empirical contact data are used in the simulation of the ODE model from which the basic reproduction number [Formula: see text] is estimated to be around 15. The combination of DTaP and Tdap vaccines fails to bring [Formula: see text] under one and thus pertussis remains endemic despite sustained high coverage of vaccination. While both DTaP and Tdap vaccines have remarkable effect on reducing the incidences of the age groups being directly vaccinated, the adolescent booster dose Tdap is also found to provide some indirect protection for infants though very limited ([Formula: see text] incidence reduction).

The role of T-cells in head and neck squamous cell carcinoma: From immunity to immunotherapy.

Head and neck squamous cell carcinoma (HNSCC) encompass a group of complex entities of tumours affecting the aerodigestive upper tract. The main risk factors are strongly related to tobacco and alcohol consumption, but also HPV infection is often associated. Surgery, radiotherapy and/or chemotherapy are the standard treatments, though the 5-year overall survival is less than 50%. The advances in genomics, molecular medicine, immunology, and nanotechnology have shed a light on tumour biology which helps clinical researchers to obtain more efficacious and less toxic therapies. Head and neck tumours possess different immune escape mechanisms including diminishing the immune response through modulating immune checkpoints, in addition to the recruitment and differentiation of suppressive immune cells. The insights into the HNSCC biology and its strong interaction with the tumour microenvironment highlights the role of immunomodulating agents. Recently, the knowledge of the immunological features of these tumours has paved the way for the discovery of effective biomarkers that allow a better selection of patients with odds of improving overall survival through immunotherapy. Specially biomarkers regarding immune checkpoint inhibitors antibodies, such as anti-PD-1/PD-L1 and anti-CTLA-4 in combination with standard therapy or as monotherapy. New immunotherapies to treat head and neck cancer carcinomas, such as CAR T cells and nanoparticles have been the center of attention and in this review, we discuss the necessity of finding targets for the T cell in the cancer cells to generate CAR T cells, but also the relevance of evaluating specificity and safety of those therapies.

Taurine enhances the antitumor efficacy of PD-1 antibody by boosting CD8+ T cell function.

The functional state of CD8+ T cells determines the therapeutic efficacy of PD-1 blockade antibodies in tumors. Amino acids are key nutrients for maintaining T cell antitumor immunity. In this study, we used samples from lung cancer patients treated with PD-1 blockade antibodies to assay the amino acids in their serum by mass spectrometry. We found that lung cancer patients with high serum taurine levels generally responded to PD-1 blockade antibody therapy, in parallel with the secretion of high levels of cytotoxic cytokines (IFN-γ and TNF-α). CD8+ T cells cultured with exogenous taurine exhibited decreased apoptosis, enhanced proliferation, and increased secretion of cytotoxic cytokines. High SLC6A6 expression in CD8+ T cells was positively associated with an effector T cell signature. SLC6A6 knockdown limited the function and proliferation of CD8+ T cells. RNA sequencing revealed that SLC6A6 knockdown altered the calcium signaling pathway, oxidative phosphorylation, and T cell receptor signaling in CD8+ T cells. Furthermore, taurine enhanced T cell proliferation and function in vitro by stimulation of PLCγ1-mediated calcium and MAPK signaling. Taurine plus immune checkpoint blockade antibody significantly attenuated tumor growth and markedly improved the function and proliferation of CD8+ T cells in a mouse tumor model. Thus, our findings indicate that taurine is an important driver for improving CD8+ T cell immune responses and could serve as a potential therapeutic agent for cancer patients.

Evolving understanding of antibody-dependent enhancement (ADE) of SARS-CoV-2.

Since immune system and internal environment in vivo are large and complex, the interpretation of the observed immune effect from the perspective of a single immune cell or antibody seems a little feeble. Many studies have shown that specific antibodies against " former" viruses have a reduced ability to neutralize "new" mutant strains. However, there is no comprehensive and clear view of whether there will be Antibody-dependent enhancement (ADE). We review the latest relevant studies, hoping to explain the ADE of SARS-CoV-2 infection sometimes observed in some patients.

Booster vaccination is required to elicit and maintain COVID-19 vaccine-induced immunity in SIV-infected macaques

ABSTRACT Prolonged infection and possible evolution of SARS-CoV-2 in patients living with uncontrolled HIV-1 infection highlight the importance of an effective vaccination regimen, yet the immunogenicity of COVID-19 vaccines and predictive immune biomarkers have not been well investigated. Herein, we report that the magnitude and persistence of antibody and cell-mediated immunity (CMI) elicited by an Ad5-vectored COVID-19 vaccine are impaired in SIV-infected macaques with high viral loads (> 105 genome copies per ml plasma, SIVhi) but not in macaques with low viral loads (< 105, SIVlow). After a second vaccination, the immune responses are robustly enhanced in all uninfected and SIVlow macaques. These responses also show a moderate increase in 70% SIVhi macaques but decline sharply soon after. Further analysis reveals that decreased antibody and CMI responses are associated with reduced circulating follicular helper T cell (TFH) counts and aberrant CD4/CD8 ratios, respectively, indicating that dysregulation of CD4+ T cells by SIV infection impairs the COVID-19 vaccine-induced immunity. Ad5-vectored COVID-19 vaccine shows no impact on SIV loads or SIV-specific CMI responses. Our study underscores the necessity of frequent booster vaccinations in HIV-infected patients and provides indicative biomarkers for predicting vaccination effectiveness in these patients.

Limited cross-variant immune response from SARS-CoV-2 Omicron BA.2 in naïve but not previously infected outpatients

Omicron is currently the dominant SARS-CoV-2 variant and several sublineages have emerged. Questions remain about the impact of previous SARS-CoV-2 exposure on cross-variant immune responses elicited by the SARS-CoV-2 Omicron sublineage BA.2 compared to BA.1. Here we show that without previous history of COVID-19, BA.2 infection induces a reduced immune response against all variants of concern (VOC) compared to BA.1 infection. The absence of ACE2 binding in sera of previously naïve BA.1 and BA.2 patients indicates a lack of meaningful neutralization. In contrast, anti-spike antibody levels and neutralizing activity greatly increased in the BA.1 and BA.2 patients with a previous history of COVID-19. Transcriptome analyses of peripheral immune cells showed significant differences in immune response and specific antibody generation between BA.1 and BA.2 patients as well as significant differences in the expression of specific immune genes. In summary, prior infection status significantly impacts the innate and adaptive immune response against VOC following BA.2 infection.

Inflammatory responses and obesity: Nutrition as an epigenetic modulator

The onset of inflammation takes place in a human body due to an injury or infection during which the tissue becomes inflamed/reddened, swollen, hot, and painful. Basically, it is a collection of host defenses that occurs during an injury and infection in which the white blood cells protect the body from infection from bacteria, fungi, parasites, or viruses. Innate immunity provides the first challenging defense against the diverse foreign harmful invaders, while adaptive immunity, also known as acquired immunity, utilizes specialized immune cells and antibodies, which provide a counterattack and destroy these diverse foreign invaders. Moreover, they can prevent infections/diseases in the future by recognizing those invaders and providing a new immune response. However, when an immune system responds too aggressively to an infection, a condition termed a cytokine storm takes place, which may lead to multi-organ failure and even death. Inflammatory response in advancing age and obesity is intricately associated. Obesity has been identified as a low-grade systemic inflammatory response. Particularly, elevated levels of serum C-reactive protein, interleukin-6, tumor necrosis factor-α, and leptin, well characterized biomarkers of inflammation, are observed predominantly in obese individuals.

Safety and Immunogenicity of a Heterologous Booster of Protein Subunit Vaccine MVC-COV1901 after Two Doses of Adenoviral Vector Vaccine AZD1222.

We report the safety and immunogenicity results in participants administrated with a booster dose of protein subunit vaccine MVC-COV1901 at 12 (Group A) or 24 (Group B) weeks after two doses of AZD1222 (ChAdOx1 nCoV-19). The administration of the MVC-COV1901 vaccine as a booster dose in both groups was generally safe. There were no serious adverse events related to the intervention as adverse events reported were “mild” or “moderate” in nature. In subjects fully vaccinated with two doses of AZD1222, waning antibody immunity was apparent within six months of the second dose of AZD1222. At one month after the MVC-COV1901 booster dose, those who were vaccinated within 12 weeks after the last AZD1222 dose (Group A) had anti-SARS-CoV-2 spike IgG antibody titers and neutralizing antibody titers which were 14- and 6.5-fold increased, respectively, when compared to the titer levels on the day of the booster dose. On the other hand, fold-increase a month post-booster in people who had a booster 24 weeks after the last AZD1222 dose (Group B) were 19.5 and 14.0 times for anti-SARS-CoV-2 spike IgG antibody titers and neutralizing antibody titers, respectively. Among those who were vaccinated within 12 weeks after the last AZD1222 dose, we also observed 5.2- and 5.6-fold increases in neutralizing titer levels against ancestral strain and Omicron variant pseudovirus after the booster dose, respectively. These results support the use of MVC-COV1901 as a heterologous booster for individuals vaccinated with AZD1222. Furthermore, regardless of the dosing schedule, the combination of AZD1222 primary series and MVC-COV1901 booster can be cost-effective and suitably applied to low- and middle-income countries (LMIC).

Parental knowledge about respiratory syncytial virus (RSV) and attitudes to infant immunization with monoclonal antibodies

Background Ninety percent of all children are infected with respiratory syncytial virus (RSV) within their first two years of life. RSV is the main cause behind hospitalization of infants with lower respiratory tract infections. A new monoclonal antibody (mAb) immunization may prevent RSV in all infants. This cross-national study aimed to examine parental knowledge about RSV and attitudes to such RSV immunization. Research design and methods Based on a literature study, a questionnaire was designed and applied in a survey carried out in China, France, Germany, Italy, Japan, Spain, the UK, and the US. Eligible respondents were expecting their first baby or parents of children <24 months old who were open to vaccination. Results Parental acceptance of immunizations relies on perceptions of the preventable disease. In 5627 parents, only 35% reported basic or good level of knowledge about RSV. Recommendation from health care professionals and inclusion in immunization programs were crucial to their acceptance of RSV immunization. If recommended and informed about its efficacy and safety, most parents would accept RSV mAb immunization for their infants. Conclusions Infant RSV infections are highly prevalent, yet parental awareness of RSV is poor. Country variations call for targeted communication about RSV and immunization.

Metabolomics-based investigation of SARS-CoV-2 vaccination (Sinovac) reveals an immune-dependent metabolite biomarker.

SARS-CoV-2 and its mutant strains continue to rapidly spread with high infection and fatality. Large-scale SARS-CoV-2 vaccination provides an important guarantee for effective resistance to existing or mutated SARS-CoV-2 virus infection. However, whether the host metabolite levels respond to SARS-CoV-2 vaccine-influenced host immunity remains unclear. To help delineate the serum metabolome profile of SARS-CoV-2 vaccinated volunteers and determine that the metabolites tightly respond to host immune antibodies and cytokines, in this study, a total of 59 sera samples were collected from 30 individuals before SARS-CoV-2 vaccination and from 29 COVID-19 vaccines 2 weeks after the two-dose vaccination. Next, untargeted metabolomics was performed and a distinct metabolic composition was revealed between the pre-vaccination (VB) group and two-dose vaccination (SV) group by partial least squares-discriminant and principal component analyses. Based on the criteria: FDR < 0.05, absolute log2 fold change greater than 0.25, and VIP >1, we found that L-glutamic acid, gamma-aminobutyric acid (GABA), succinic acid, and taurine showed increasing trends from SV to VB. Furthermore, SV-associated metabolites were mainly annotated to butanoate metabolism and glutamate metabolism pathways. Moreover, two metabolite biomarkers classified SV from VB individuals with an area under the curve (AUC) of 0.96. Correlation analysis identified a positive association between four metabolites enriched in glutamate metabolism and serum antibodies in relation to IgG, IgM, and IgA. These results suggest that the contents of gamma-aminobutyric acid and indole in serum could be applied as biomarkers in distinguishing vaccinated volunteers from the unvaccinated. What’s more, metabolites such as GABA and taurine may serve as a metabolic target for adjuvant vaccines to boost the ability of the individuals to improve immunity.

A novel method for in vitro culture and expansion of nonhuman primate B cells

BackgroundGiven the role of B cells in sensitization and antibody-mediated rejection pathogenesis, the ability to identify, isolate, and study B cells in vitro is critical for understanding these processes and developing novel therapeutics. While in vivo nonhuman primate models have been used to this end, an in vitro nonhuman primate model of B cell activation and proliferation has not been developed. MethodsCD20+ B cells and CD3+ T cells were isolated using magnetic bead separation from the peripheral blood of naive and skin allograft sensitized nonhuman primates. Allogeneic B and T cells were co-cultured in plates pre-coated with murine stromal cells engineered to express human CD40L and stimulated with cytokines. Cells and supernatants were harvested every 2 days for immune phenotyping and donor specific antibody quantification by flow cytometry. ResultsThe optimized culture system consisted of MS40L cells co-cultured with B and allogenic T cells and stimulated with cytokines. This culture system resulted in increased memory cells and plasmablasts over time compared to other culture systems. Comparison of culture of naïve and sensitized nonhuman primate samples revealed faster B cell exhaustion and marginally increased plasmablast differentiation in sensitized culture. Donor-specific antibody production was not observed in either culture group. ConclusionsThis study describes the first in vitro nonhuman primate model of B cell activation and proliferation using both naïve and allosensitized samples. This model provides an opportunity for exploration of B cell mechanisms and novel therapeutics and is a preliminary step in the development of an in vitro germinal center model.