scholarly journals Strong off-target antibody reactivity to malarial antigens induced by RTS,S/AS01E vaccination is associated with increased protection

Author(s):  
Didac Macia ◽  
Joseph J. Campo ◽  
Gemma Moncunill ◽  
Chenjerai Jairoce ◽  
Augusto J. Nhabomba ◽  
...  

The RTS,S/AS01E vaccine targets the circumsporozoite protein (CSP) of the Plasmodium falciparum parasite. Using protein microarrays, levels of IgG to 1,000 P. falciparum antigens were measured in 2,138 infants (age 6-12 weeks) and children (age 5-17 months) from 6 African sites of the phase 3 trial, sampled before and at four longitudinal visits after vaccination. One month post-vaccination, IgG responses to 17% of all probed antigens showed differences between RTS,S/AS01E and comparator vaccination groups, whereas no prevaccination differences were found. A small subset of antigens presented IgG levels reaching 4- to 8 fold increases in the RTS,S/AS01E group, comparable in magnitude to anti-CSP IgG levels (~11-fold increase). They were strongly cross-correlated and correlated with anti CSP levels, waning similarly over time and re-increasing with the booster dose. Such an intriguing phenomenon may be due to cross-reactivity of anti-CSP antibodies with these antigens. RTS,S/AS01E vaccinees with strong off target IgG responses had an estimated lower clinical malaria incidence after adjusting for age group, site and post-vaccination anti-CSP levels. RTS,S/AS01E-induced IgG may bind strongly not only to CSP, but to unrelated malaria antigens, and this seems to either confer, or at least be a marker of, increased protection from clinical malaria.

2021 ◽  
Author(s):  
Philipe A.M. Gobeil ◽  
Stéphane Pillet ◽  
Iohann Boulay ◽  
Nathalie Charland ◽  
Aurélien Lorin ◽  
...  

As the SARS-COV-2 pandemic evolves, what is expected of vaccines extends beyond efficacy and includes evaluations of both durability and cross-reactivity to emerging variants. To complement an on-going Phase 3 efficacy study, this report expands on previously reported immunogenicity results from a Phase 1 trial of an AS03-adjuvanted, plant-based virus-like particle (VLP) displaying the spike glycoprotein of the Wuhan strain of SARS-CoV-2 virus (NCT04450004). Durability of the humoral and cellular responses against the ancestral strain was evaluated 6 months post-second dose (Day 201) at which time ~94% of vaccinated individuals remained seropositive. Interferon gamma (IFN-γ) and interleukin 4 (IL-4) responses remained detectable in ~94% and ~92% of vaccinated individuals respectively. Cross-reactivity of neutralizing antibodies to Alpha (B.1.17), Beta (B.1.351), and Gamma (P.1) variants of concern (VOC) were also measured. Twenty-one days after the second vaccination, detectable neutralizing antibodies were observed to the Alpha variant by both pseudovirion and wild-type assays for all vaccinated individuals, while 94.7% of individuals had detectable antibodies to the Beta variant in both assays. Neutralizing antibodies to the Gamma variant were detected in 100% and 94.7% of individuals using the pseudovirion and live virus neutralization assays, respectively. In all cases, the vaccine-induced neutralizing GMTs to the VOC 3 weeks post-vaccination were greater than the Wuhan-specific neutralization titers seen in individuals recovered from COVID-19.


2021 ◽  
Author(s):  
Penny Moore ◽  
Thandeka Moyo ◽  
Tandile Hermanus ◽  
Prudence Kgagudi ◽  
Frances Ayres ◽  
...  

The emergence of SARS-CoV-2 variants, such as 501Y.V2, with immune evasion mutations in the spike has resulted in reduced efficacy of several COVID-19 vaccines. However, the efficacy of the Ad26.COV2.S vaccine, when tested in South Africa after the emergence of 501Y.V2, was not adversely impacted. We therefore assessed the binding and neutralization capacity of n=120 South African sera (from Day 29, post-vaccination) from the Janssen phase 3 study, Ensemble. Spike binding assays using both the Wuhan-1 D614G and 501Y.V2 Spikes showed high levels of cross-reactivity. In contrast, in a subset of 27 sera, we observed significantly reduced neutralization of 501Y.V2 compared to Wuhan-1 D614G, with 22/27 (82%) of sera showing no detectable neutralization of 501Y.V2 at Day 29. These data suggest that even low levels of neutralizing antibodies may contribute to protection from moderate/severe disease. In addition, Fc effector function and T cells may play an important role in protection by this vaccine against 501Y.V2.


1996 ◽  
Vol 42 (7) ◽  
pp. 1092-1099 ◽  
Author(s):  
H M Qazzaz ◽  
S A Jortani ◽  
J M Poole ◽  
R Valdes

Abstract Digoxin-like immunoreactive factor (DLIF) from adrenal glands is an endogenous ligand structurally related to the plant-derived cardiac glycoside digoxin. Cardiac glycosides regulate the activity of the sodium pump and thus play key roles in disease processes involving regulation of ion transport. We now report the discovery of an endogenous dihydro-DLIF analogous to dihydrodigoxin. We used HPLC, ultraviolet spectrophotometry, and cross-reactivity with two antibodies, one specific for digoxin and one for dihydrodigoxin, to support the hypothesis that dihydro-DLIF contains a chemically reduced lactone ring. The spectral absorbance maximum for dihydro-DLIF is at 196 nm, identical to dihydrodigoxin. DLIF and dihydro-DLIF are 975- and 2588-fold less immunoreactive than digoxin and dihydrodigoxin for their respective antibodies. The molar ratio of dihydro-DLIF to DLIF is approximately 5.3 in bovine adrenocortical tissue and approximately 0.38 in human serum. Dihydrodigoxin (reduced lactone ring) added to microsomes isolated from bovine adrenal cortex produced a 4.5-fold increase in digoxin-like immunoreactivity (oxidized lactone ring) after 3 h of incubation. The biotransformation is likely mediated by a cytochrome P-450 NADPH-dependent process. Our findings demonstrate the presence of a dihydro-DLIF in mammals and suggest a metabolic route for synthesis of endogenous DLIF in mammalian tissue.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 839.2-840
Author(s):  
C. Vesel ◽  
A. Morton ◽  
M. Francis-Sedlak ◽  
B. Lamoreaux

Background:NHANES data indicate that approximately 9.2 million Americans have gout,1 with a small subset having uncontrolled disease.2 Pegloticase is a PEGylated recombinant uricase enzyme indicated for treating uncontrolled gout that markedly reduces serum uric acid levels (sUA)3 and resolves tophi in treatment responders.4 Despite pegloticase availability in the US for many years, real world demographics of pegloticase users in the treatment of uncontrolled gout have not been previously reported in a population-based cohort.Objectives:This study utilized a large US claims database to examine demographics and co-morbidities of uncontrolled gout patients treated with pegloticase. Kidney function before and after pegloticase treatment and concomitant therapy with immunomodulators were also examined.Methods:The TriNetX Diamond database includes de-identified data from 4.3 million US patients with gout (as of September 2019), including demographics, medical diagnoses, laboratory values, procedures (e.g. infusions, surgeries), and pharmacy data. Patients who had received ≥1 pegloticase infusion were included in these analyses. The number of infusions was evaluated for a subgroup of patients who were in the database ≥3 months before and ≥2 years after the first pegloticase infusion (i.e. first infusion prior to September 2017) to ensure only complete courses of therapy were captured. In this subpopulation, kidney function before and after pegloticase therapy was examined, along with the presence of immunomodulation prescriptions (methotrexate, mycophenolate mofetil, azathioprine, leflunomide) within 60 days prior to and 14 days after the first pegloticase infusion.Results:1494 patients treated with pegloticase were identified. Patients were 63.1 ± 14.0 years of age (range: 23–91), mostly male (82%), and white (76%). Mean sUA prior to pegloticase was 8.7 ± 2.4 mg/dL (n=50), indicating uncontrolled gout in the identified population. The most commonly reported comorbidities were chronic kidney disease (CKD, 48%), essential hypertension (71%), type 2 diabetes (39%), and cardiovascular disease (38%), similar to pegloticase pivotal Phase 3 trial populations. In patients with pre-therapy kidney function measures (n=134), pre-treatment eGFR averaged 61.2 ± 25.7 ml/min/1.73 m2, with 44% having Stage 3-5 CKD. In patients with complete therapy course capture and pre- and post-therapy eGFR measures (n=48), kidney function remained stable (change in eGFR: -2.9 ± 18.2 ml/min/1.73 m2) and CKD stage remained the same or improved in 81% of patients. In 791 patients with complete treatment course capture, patients had received 8.7 ± 13.8 infusions (median: 3, IQR: 2-10). Of these, 189 (24%) patients received only 1 pegloticase infusion and 173 (22%) received ≥12 infusions. As the data cut-off for this analysis pre-dated emerging data on the use of immunomodulation as co-therapy, only 19 of 791 (2%) patients received immunomodulation co-therapy with pegloticase.Conclusion:This relatively large group of patients with uncontrolled gout treated with pegloticase had similar patient characteristics of those studied in the phase 3 randomized clinical trials. Patients with uncontrolled gout are significantly burdened with systemic co-morbid diseases. The majority of patients had stable or improved kidney function following pegloticase treatment. As these results reflect patients initiating treatment prior to 2018, before co-treatment with immunomodulation was introduced, this cohort only included a small percentage of patients who were co-treated with an immunomodulator. Future studies using more current datasets are needed to evaluate real world outcomes in patients treated with pegloticase/immunomodulator co-therapy and to evaluate the impact of systemic co-morbid diseases.References:[1]Chen-Xu M, et al. Arthritis Rheumatol 2019 71:991-999.[2]Fels E, Sundy JS. Curr Opin Rheumatol 2008;20:198-202.[3]Sundy J, et al. JAMA 2011;306:711-720.[4]Mandell BF, et al. Arthritis Res Ther 2018;20:286.Disclosure of Interests:Claudia Vesel Shareholder of: Horizon Therapeutics plc, Employee of: Horizon Therapeutics plc, Allan Morton Speakers bureau: Sanofi, Amgen, and Horizon, Megan Francis-Sedlak Shareholder of: Horizon Therapeutics plc, Employee of: Horizon Therapeutics plc, Brian LaMoreaux Shareholder of: Horizon Therapeutics plc, Employee of: Horizon Therapeutics plc.


2021 ◽  
Vol 22 (15) ◽  
pp. 8030
Author(s):  
Halin Bareke ◽  
Pablo Juanes-Velasco ◽  
Alicia Landeira-Viñuela ◽  
Angela-Patricia Hernandez ◽  
Juan Jesús Cruz ◽  
...  

Specific anti-tumor immune responses have proven to be pivotal in shaping tumorigenesis and tumor progression in solid cancers. These responses can also be of an autoimmune nature, and autoantibodies can sometimes be present even before the onset of clinically overt disease. Autoantibodies can be generated due to mutated gene products, aberrant expression and post-transcriptional modification of proteins, a pro-immunogenic milieu, anti-cancer treatments, cross-reactivity of tumor-specific lymphocytes, epitope spreading, and microbiota-related and genetic factors. Understanding these responses has implications for both basic and clinical immunology. Autoantibodies in solid cancers can be used for early detection of cancer as well as for biomarkers of prognosis and treatment response. High-throughput techniques such as protein microarrays make parallel detection of multiple autoantibodies for increased specificity and sensitivity feasible, affordable, and quick. Cancer immunotherapy has revolutionized cancer treatments and has made a considerable impact on reducing cancer-associated morbidity and mortality. However, immunotherapeutic interventions such as immune checkpoint inhibition can induce immune-related toxicities, which can even be life-threatening. Uncovering the reasons for treatment-induced autoimmunity can lead to fine-tuning of cancer immunotherapy approaches to evade toxic events while inducing an effective anti-tumor immune response.


2020 ◽  
Author(s):  
Fatou thiam ◽  
Gora Diop ◽  
Cedric Coulanges ◽  
Celine Derbois ◽  
Babacar Mbengue ◽  
...  

Abstract Background Several genetic polymorphisms were reported to be prevalent among populations living in tropical endemic regions and induce protection against malaria. In this study, we investigated the prevalence of key malaria-protective polymorphisms in G6PD and HBB genes in a Senegalese population. Methods We performed a retrospective study in 323 samples from patients recruited in hospitals located in three different endemic areas where malaria episodes were confirmed. Patients enrolled were classified in two groups: severe (153 patients) and uncomplicated malaria (170 patients). PCR and DNA sequencing assessed host genetic polymorphisms in HBB and G6PD. Using a multivariate regression and additive model, estimates the impact of human HBB and G6PD polymorphisms on malaria incidence were performed. Results We identified 12 SNPs in HBB gene. Among them, 6 SNPs (rs7946748, rs7480526, rs10768683, rs35209591, HbS (rs334) and rs713040) were detected with high frequencies in global population. The MAF of the sickle cell HbS polymorphism was estimated to 0.026, 0.069 and 0.035; and HbC polymorphism was estimated to be 0, 0.009, 0.029, in SM, UM and CTR group respectively. The MAF of G6PD deficiency polymorphisms such as G6PD-202 G>A were 0.022, 0.032 and 0.018 in SM, UM and CTR, respectively. Analysis of selected HbS polymorphism showed significant association with protection against severe malaria with a significant p-value = 0.033 (OR 0.38, 95%CI: 0.16–0.91). Surprisingly, HbC polymorphism is not a protective variant in our population. Finally, we found that the selected SNPs were associated to biological parameters such as PNE, PNB and lymphocytes. Conclusion Our data report at the first time the prevalence of HBB and G6PD mutations in senegalese population. These deficiencies are very common in West Africa endemic regions such as Gambia, Mali and Burkina Faso. Our findings show the important role of genetic factors in malaria outcome and these genetic markers could be good tools for malaria diagnosis and prognosis. Keywords : severe malaria, HBB, G6PD, Polymorphisms, Senegal, severe malaria.


Author(s):  
Jia-Qian Cao ◽  
Peng-Fei Jin ◽  
Zhao-Zhun Zeng ◽  
Li Zhang ◽  
Fan-Yue Meng ◽  
...  

Abstract Background To investigate effects of prior influenza exposure on vaccine-elicited humor immune responses to circulating influenza variants. Method We randomly selected 360 participants in previous clinical trials stratified by age. Blood samples before and 28 days after vaccination were collected and tested by hemagglutination-inhibition tests against both vaccine strains and circulating variants during the 2015–2016 influenza seasons in China. The antigenic map was plotted and antigenic distance was calculated. Results Subjects with H1-priming had higher cross-reactive antibodies titers against A/JiangsuTinghu/11019/2015(H3N2) compared with subjects with B-priming did (Padjusted=0.038). Subjects with H1-priming also had higher cross-reactive antibodies titers against A/Jiangsu Qinhuai/11059/2015(H3N2) than subjects with both H1 and B priming did (Padjusted=0.036). Nevertheless, subjects with no H1 and B-priming had higher cross-reactive antibodies titers against A/Jiangsu Qinhuai/11059/2015(H3N2) than subjects with both H1 and B priming did (Padjusted=0.012). Antigenic distance was well-matched with serological results. Besides, age-specific differences in human post-vaccination responses against the identical circulating strain was noted. And children had most cross-reactive response to both H3N2 and B-yamagata subtypes. Conclusion Our results suggest that prior exposure to H1 or B influenza virus may influence cross-reactivity of H3-specific post-vaccination responses and consequently could influence the vaccine effectiveness. Our findings also support that there are age-specific differences in human post-vaccination responses.


2006 ◽  
Vol 14 (1-2) ◽  
pp. 7-15 ◽  
Author(s):  
Paul F. Predki ◽  
Dawn Mattoon ◽  
Rhonda Bangham ◽  
Barry Schweitzer ◽  
Gregory Michaud

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