Poly I:C elicits broader and stronger humoral and cellular responses to a Plasmodium vivax circumsporozoite protein malaria vaccine than Alhydrogel in mice.

Malaria remains a global health challenge, necessitating the development of effective vaccines. The RTS,S vaccination prevents Plasmodium falciparum (Pf) malaria but is ineffective against Plasmodium vivax (Pv) disease. Herein, we evaluated the murine immunogenicity of a recombinant PvCSP incorporating prevalent polymorphisms, adjuvanted with Alhydrogel or Poly I:C. Both formulations induced prolonged IgG responses, with IgG1 dominance by the Alhydrogel group and high titers of all IgG isotypes by the Poly I:C counterpart. Poly I:C-adjuvanted vaccination increased splenic plasma cells, terminally-differentiated memory cells (MBCs), and precursors relative to the Alhydrogel-combined immunization. Splenic B-cells from Poly I:C-vaccinated mice revealed an antibody-secreting cell- and MBC-differentiating gene expression profile. Biological processes such as antibody folding and secretion were highlighted by the Poly I:C-adjuvanted vaccination. These findings underscore the potential of Poly I:C to strengthen immune responses against Pv malaria.

Non-clinical toxicity and immunogenicity evaluation of a Plasmodium vivax malaria vaccine using Poly-ICLC (Hiltonol®) as adjuvant.

Malaria caused byPlasmodium vivaxis a pressing public health problem in tropical and subtropical areas.However, little progress has been made toward developing a P. vivaxvaccine, with only three candidates being tested in clinical studies. We previously reported that one chimeric recombinant protein (PvCSP-All epitopes) containing the conserved C-terminus of the P. vivax Circumsporozoite Protein (PvCSP), the three variant repeat domains, and aToll-like receptor-3 agonist,Poly(I:C), as an adjuvant (polyinosinic-polycytidylic acid, a dsRNA analog mimicking viral RNA), elicits strong antibody-mediated immune responses in mice to each of the three allelic forms of PvCSP. In the present study, a pre-clinical safety evaluation was performed to identify potential local and systemic toxic effects of the PvCSP-All epitopes combined with the Poly-ICLC (Poly I:C plus poly-L-lysine, Hiltonol®) or Poly-ICLC when subcutaneously injected into C57BL/6 mice and New Zealand White Rabbits followed by a 21-day recovery period. Overall, all observations were considered non-adverse and were consistent with the expected inflammatory response and immune stimulation following vaccine administration. High levels of vaccine-induced specific antibodies were detected both in mice and rabbits. Furthermore, mice that received the vaccine formulation were protected after the challenge with Plasmodium berghei sporozoites expressing CSP repeats from P. vivax sporozoites (Pb/Pv-VK210). In conclusion, in these non-clinical models, repeated dose administrations of the PvCSP-All epitopes vaccine adjuvanted with a Poly-ICLC were immunogenic, safe, and well tolerated.

Protein Arginylation Is Regulated during SARS-CoV-2 Infection.

BACKGROUND: In 2019, the world witnessed the onset of an unprecedented pandemic. By February 2022, the infection by SARS-CoV-2 has already been responsible for the death of more than 5 million people worldwide. Recently, we and other groups discovered that SARS-CoV-2 infection induces ER stress and activation of the unfolded protein response (UPR) pathway. Degradation of misfolded/unfolded proteins is an essential element of proteostasis and occurs mainly in lysosomes or proteasomes. The N-terminal arginylation of proteins is characterized as an inducer of ubiquitination and proteasomal degradation by the N-degron pathway. RESULTS: The role of protein arginylation during SARS-CoV-2 infection was elucidated. Protein arginylation was studied in Vero CCL-81, macrophage-like THP1, and Calu-3 cells infected at different times. A reanalysis of in vivo and in vitro public omics data combined with immunoblotting was performed to measure levels of arginyl-tRNA-protein transferase (ATE1) and its substrates. Dysregulation of the N-degron pathway was specifically identified during coronavirus infections compared to other respiratory viruses. We demonstrated that during SARS-CoV-2 infection, there is an increase in ATE1 expression in Calu-3 and Vero CCL-81 cells. On the other hand, infected macrophages showed no enzyme regulation. ATE1 and protein arginylation was variant-dependent, as shown using P1 and P2 viral variants and HEK 293T cells transfection with the spike protein and receptor-binding domains (RBD). In addition, we report that ATE1 inhibitors, tannic acid and merbromine (MER) reduce viral load. This finding was confirmed in ATE1-silenced cells. CONCLUSIONS: We demonstrate that ATE1 is increased during SARS-CoV-2 infection and its inhibition has potential therapeutic value.

Trajectory of NAFLD characteristics after Roux-en-Y gastric bypass: a five-year historical cohort study

Abstract BACKGROUND: The long-term effects of bariatric surgery on the course of non-alcoholic fatty hepatopathy (NAFLD) are not fully understood. OBJECTIVE: To analyze the evolution of NAFLD characteristics through noninvasive markers after Roux-en-Y gastric bypass (RYGB) over a five-year period. DESIGN AND SETTING: Historical cohort study; tertiary-level university hospital. METHODS: The evolution of NAFLD-related characteristics was evaluated among 49 individuals who underwent RYGB, with a five-year follow-up. Steatosis was evaluated through the hepatic steatosis index (HSI), steatohepatitis through the clinical score for non-alcoholic steatohepatitis (C-NASH) and fibrosis through the NAFLD fibrosis score (NFS). RESULTS: 91.8% of the individuals were female. The mean age was 38.3 ± 10 years and average body mass index (BMI), 37.4 ± 2.3 kg/m2. HSI significantly decreased from 47.15 ± 4.27 to 36.03 ± 3.72 at 12 months (P < 0.01), without other significant changes up to 60 months. C-NASH significantly decreased from 0.75 ± 1.25 to 0.29 ± 0.7 at 12 months (P < 0.01), without other significant changes up to 60 months. NFS decreased from 1.14 ± 1.23 to 0.27 ± 0.99 at 12 months (P < 0.01), and then followed a slightly ascending course, with a marked increase by 60 months (0.82 ± 0.89), but still lower than at baseline (P < 0.05). HSI variation strongly correlated with the five-year percentage total weight loss (R = 0.8; P < 0.0001). CONCLUSION: RYGB led to significant improvement of steatosis, steatohepatitis and fibrosis after five years. Fibrosis was the most refractory abnormality, with a slightly ascending trend after two years. Steatosis improvement directly correlated with weight loss.

Trajectory of NAFLD characteristics after Roux-en-Y gastric bypass: a five-year historical cohort study.

BACKGROUND: The long-term effects of bariatric surgery on the course of non-alcoholic fatty hepatopathy (NAFLD) are not fully understood. OBJECTIVE: To analyze the evolution of NAFLD characteristics through noninvasive markers after Roux-en-Y gastric bypass (RYGB) over a five-year period. DESIGN AND SETTING: Historical cohort study; tertiary-level university hospital. METHODS: The evolution of NAFLD-related characteristics was evaluated among 49 individuals who underwent RYGB, with a five-year follow-up. Steatosis was evaluated through the hepatic steatosis index (HSI), steatohepatitis through the clinical score for non-alcoholic steatohepatitis (C-NASH) and fibrosis through the NAFLD fibrosis score (NFS). RESULTS: 91.8% of the individuals were female. The mean age was 38.3 ± 10 years and average body mass index (BMI), 37.4 ± 2.3 kg/m2. HSI significantly decreased from 47.15 ± 4.27 to 36.03 ± 3.72 at 12 months (P < 0.01), without other significant changes up to 60 months. C-NASH significantly decreased from 0.75 ± 1.25 to 0.29 ± 0.7 at 12 months (P < 0.01), without other significant changes up to 60 months. NFS decreased from 1.14 ± 1.23 to 0.27 ± 0.99 at 12 months (P < 0.01), and then followed a slightly ascending course, with a marked increase by 60 months (0.82 ± 0.89), but still lower than at baseline (P < 0.05). HSI variation strongly correlated with the five-year percentage total weight loss (R = 0.8; P < 0.0001). CONCLUSION: RYGB led to significant improvement of steatosis, steatohepatitis and fibrosis after five years. Fibrosis was the most refractory abnormality, with a slightly ascending trend after two years. Steatosis improvement directly correlated with weight loss.

Immune System Modulation by the Adjuvants Poly (I:C) and Montanide ISA 720.

Adjuvants are essential for vaccine development, especially subunit-based vaccines such as those containing recombinant proteins. Increasing the knowledge of the immune response mechanisms generated by adjuvants should facilitate the formulation of vaccines in the future. The present work describes the immune phenotypes induced by Poly (I:C) and Montanide ISA 720 in the context of mice immunization with a recombinant protein based on the Plasmodium vivax circumsporozoite protein (PvCSP) sequence. Mice immunized with the recombinant protein plus Montanide ISA 720 showed an overall more robust humoral response, inducing antibodies with greater avidity to the antigen. A general trend for mixed Th1/Th2 inflammatory cytokine profile was increased in Montanide-adjuvanted mice, while a balanced profile was observed in Poly (I:C)-adjuvanted mice. Montanide ISA 720 induced a gene signature in B lymphocytes characteristic of heme biosynthesis, suggesting increased differentiation to Plasma Cells. On the other hand, Poly (I:C) provoked more perturbations in T cell transcriptome. These results extend the understanding of the modulation of specific immune responses induced by different classes of adjuvants, and could support the optimization of subunit-based vaccines.

Relationships of hepatic histopathological findings and bile microbiological aspects with bile duct injury repair surgical outcomes: A historical cohort.

Backgrounds/Aims: To analyze relationships of hepatic histopathological findings and bile microbiological profiles with perioperative outcomes and risk of late biliary stricture in individuals undergoing surgical bile duct injury (BDI) repair. Methods: A historical cohort study was carried out at a tertiary university hospital. Fifty-six individuals who underwent surgical BDI repair from 2014-2018 with a minimal follow-up of 24 months were enrolled. Liver biopsies were performed to analyze histopathology. Bile samples were collected during repair procedures. Hepatic histopathological findings and bile microbiological profiles were then correlated with perioperative and late outcomes through uni- and multi-variate analyses. Results: Forty-three individuals (76.8%) were females and average age was 47.2 ± 13.2 years; mean follow-up was 38.1 ± 18.6 months. The commonest histopathological finding was hepatic fibrosis (87.5%). Bile cultures were positive in 53.5%. The main surgical technique was Roux-en-Y hepaticojejunostomy (96.4%). Overall morbidity was 35.7%. In univariate analysis, liver fibrosis correlated with the duration of the operation (R = 0.3; p = 0.02). In multivariate analysis, fibrosis (R = 0.36; p = 0.02) and cholestasis (R = 0.34; p = 0.02) independently correlated with operative time. Strasberg classification independently correlated with estimated bleeding (R = 0.31; p = 0.049). The time elapsed between primary cholecystectomy and BDI repair correlated with hepatic fibrosis (R = 0.4; p = 0.01). Conclusions: Bacterial contamination of bile was observed in most cases. The degree of fibrosis and cholestasis correlated with operative time. The waiting time for definitive repair correlated with the severity of liver fibrosis.

Action of Bromelain and Ficin on horse anti Bothrops sp venom Antibodies

Abstract The treatment with hyperimmune sera constitute the only specific and effective therapy available against snakebite envenomation, most common in developing countries. Serum quality is an important factor on patient recovery time and in the incidence of death and permanent disability. To date, most sera consist of pepsin digested IgG antibodies harvested from hyperimmune animals. The use of animal derived enzymes, such as pepsin, to digest IgG, constitute a source of adventitious agents and contaminants, such as porcine circovirus. The present study aims to evaluate the use of the plant derived enzymes bromelain and ficin, as an alternative to pepsin. To this purpose, horse serum immunized against Bothrops venoms was purified with caprylic acid and digested with bromelain or ficin. SDS-PAGE results evidence the formation of F(ab)'2 fragments and suggest that a digestion time superior to 8 hours may be required to completely digest the antibodies with bromelain or ficin. F(ab)'2 fragments obtained by digestion with either bromelain or ficin digestion preserved the ability to recognize Bothrops sp. venom in western blotting assays. Therefore, both enzymes are suitable for use in large-scale production, minimizing contamination risks and increasing safety and efficiency of serotherapy treatments.

Action of bromelain and ficin on horse anti Bothrops sp venom antibodies

The treatment with hyperimmune sera constitute the only specific and effective therapy available against snakebite envenomation, most common in developing countries. Serum quality is an important factor on patient recovery time and in the incidence of death and permanent disability. To date, most sera consist of pepsin digested IgG antibodies harvested from hyperimmune animals. The use of animal derived enzymes, such as pepsin, to digest IgG, constitute a source of adventitious agents and contaminants, such as porcine circovirus. The present study aims to evaluate the use of the plant derived enzymes bromelain and ficin, as an alternative to pepsin. To this purpose, horse serum immunized against Bothrops venoms was purified with caprylic acid and digested with bromelain or ficin. SDS-PAGE results evidence the formation of F(ab)’2 fragments and suggest that a digestion time superior to 8 hours may be required to completely digest the antibodies with bromelain or ficin. F(ab)’2 fragments obtained by digestion with either bromelain or ficin digestion preserved the ability to recognize Bothrops sp. venom in western blotting assays. Therefore, both enzymes are suitable for use in large-scale production, minimizing contamination risks and increasing safety and efficiency of serotherapy treatments.

A universal vaccine candidate against Plasmodium vivax malaria confers protective immunity against the three PvCSP alleles.

Malaria is a highly prevalent parasitic disease in regions with tropical and subtropical climates worldwide. Among the species of Plasmodium causing human malaria, P. vivax is the second most prevalent and the most geographically widespread species. A major target of a pre-erythrocytic vaccine is the P. vivax circumsporozoite protein (PvCSP). In previous studies, we fused two recombinant proteins representing three allelic variants of PvCSP (VK210, VK247 and P. vivax-like) to the mumps virus nucleocapsid protein to enhance immune responses against PvCSP. The objective of the present study was to evaluate the protective efficacy of these recombinants in mice challenged with transgenic P. berghei parasites expressing PvCSP allelic variants. Formulations containing Poly (I:C) or Montanide ISA720 as adjuvants elicited high and long-lasting IgG antibody titers specific to each PvCSP allelic variant. Immunized mice were challenged with two existing chimeric P. berghei parasite lines expressing PvCSP-VK210 and PvCSP-VK247. We also developed a novel chimeric line expressing the third allelic variant, PvCSP-P. vivax-like, as a new murine immunization-challenge model. Our formulations conferred partial protection (significant delay in the time to reach 1% parasitemia) against challenge with the three chimeric parasites. Our results provide insights into the development of a vaccine targeting multiple strains of P. vivax.

Diagnostic Methods for Non-Falciparum Malaria.

Malaria is a serious public health problem that affects mostly the poorest countries in the world, killing more than 400,000 people per year, mainly children under 5 years old. Among the control and prevention strategies, the differential diagnosis of the Plasmodium-infecting species is an important factor for selecting a treatment and, consequently, for preventing the spread of the disease. One of the main difficulties for the detection of a specific Plasmodium sp is that most of the existing methods for malaria diagnosis focus on detecting P. falciparum. Thus, in many cases, the diagnostic methods neglect the other non-falciparum species and underestimate their prevalence and severity. Traditional methods for diagnosing malaria may present low specificity or sensitivity to non-falciparum spp. Therefore, there is high demand for new alternative methods able to differentiate Plasmodium species in a faster, cheaper and easier manner to execute. This review details the classical procedures and new perspectives of diagnostic methods for malaria non-falciparum differential detection and the possibilities of their application in different circumstances.

Correlation Between Anthropometric Measurements and Non-alcoholic Fatty Liver Disease in Individuals With Obesity Undergoing Bariatric Surgery: Cross-Sectional Study.

BACKGROUND: We hypothesize that non-alcoholic fatty liver disease (NAFLD) may be significantly associated with waist circumference (WC), neck circumference (NC), hip circumference (HC), and waist-to-hip ratio (WHR). OBJECTIVES: To analyze correlations between anthropometric parameters and the occurrence and intensity of NAFLD aspects assessed by histopathological examination in individuals undergoing bariatric surgery. METHODS: This is a cross-sectional study carried out in a tertiary university hospital. Demographic, clinical, anthropometric, laboratory, and histopathological variables were analyzed; uni- and multivariate analyses were performed. Histopathological variables analyzed were findings of liver biopsies collected during surgical procedures. RESULTS: Of 119 individuals, 105 (88.2%) were female. The mean age was 38.8 ± 9.3 years and the mean BMI was 37.6 ± 3.1 kg/m2. The prevalence of NAFLD histopathological aspects was: steatosis (76.5%), steatohepatitis (49.6%), and fibrosis (51.3%). WC was significantly higher in individuals with steatosis (103.5 ± 9.9 vs. 99.4 ± 8.4; p = 0.03). Individuals with steatohepatitis presented significantly higher BMI (38.2 ± 3.2 vs. 36.7 ± 2.8; p = 0.01), WC (105.3 ± 10.4 vs. 99.6 ± 8.8; p = 0.002), and WHR (1 ± 0.1 vs. 0.9 ± 0.1; p = 0.02). Age (40.6 ± 9.7 vs. 37 ± 8.5; p = 0.03) and hemoglobin A1c (6.5 ± 0.5 vs. 5.6 ± 0.5; p = 0.004) were significantly higher among individuals with fibrosis. A positive correlation was observed between the steatosis intensity and WHR (R = 0.2; p = 0.04). BMI (R = 0.2; p = 0.02) and glucose (R = 0.2; p = 0.009) were independently correlated with the steatohepatitis intensity. Age (R = 0.3; p = 0.04) was independently correlated with the fibrosis intensity. CONCLUSION: There were significant associations between anthropometric parameters and NAFLD aspects. WC and WHR were associated with steatosis; BMI, WC, and WHR were associated with steatohepatitis. WHR independently correlated with steatosis intensity.

Antibodies Against the Plasmodium vivax Apical Membrane Antigen 1 From the Belem Strain Share Common Epitopes Among Other Worldwide Variants.

Malaria is a human parasitic disease distributed in many tropical countries and caused by various Plasmodium species. Plasmodium vivax has the largest geographical distribution of the Plasmodium species and is predominant in the Americas, including Brazil. Only a small number of P. vivax vaccine formulations have successfully reached clinical trials relative to their P. falciparum counterparts. One of the candidate antigens for a blood-stage P. vivax vaccine is apical membrane antigen 1 (PvAMA-1). Due to the worldwide distribution of Plasmodium parasites, a high degree of variability has been detected in this antigen sequence, representing a considerable challenge to the development of a universal vaccine against malaria. In this study, we evaluated how PvAMA-1 polymorphisms influence vaccine-derived immune responses in P. vivax malaria. To this end, we expressed 9 recombinant protein representatives of different PvAMA-1 allelic variants in the yeast Pichia pastoris: Belem, Chesson I, Sal-1, Indonesia XIX, SK0814, TC103, PNG_05_ESP, PNG_62_MU, and PNG_68_MAS. After protein expression and purification, we evaluated the breadth of the immune responses derived from malaria-exposed individuals from the Amazon region. From 611 serum samples of malaria-exposed individuals, 53.68% of them reacted against the PvAMA-1 Belem through ELISA. Positive samples were further tested against recombinant proteins representing the other PvAMA-1 allelic variants. Whereas Sal-1, Chesson I and SK0814 variants were highly recognized by tested serum samples, Indonesia XIX, TC103, PNG_05_ESP, PNG_62_MU, and PNG_68_MAS were only slightly recognized. Moreover, polyclonal sera derived from C57BL/6 mice immunized with the PvAMA-1 Belem protein predominantly recognized Belem, Sal-1, Chesson I, SK0814, and Indonesia XIX through ELISA. Last, ELISA-based competition assays demonstrated that a previous interaction between anti-Belem polyclonal serum and Sal-1, Chesson I, SK0814, or Indonesia XIX proteins could further inhibit antibody binding to the Belem variant. Our human and mouse data suggest the presence of common epitopes or cross-reactivity between Belem, Sal-1, Chesson I, and SK0814 variants. Although the PvAMA-1 Belem variant induces strain-transcendent antibodies, PvAMA-1 variants from Thailand and Papua New Guinea may need to be included in a universal vaccine formulation to achieve protection against P. vivax malaria.

Caracterização imunológica da formulação vacinal baseada em VLP (Virus Like Particle) da Proteína Circumsporozoíta de Plasmodium vivax / Immunological characterization of the VLP (Virus Like Particle) vaccine formulation fused to Circumsporozoite Protein of Plasmodium vivax

O Plasmodium vivax é a espécie mais comum de parasita causador da malária humana encontrada fora da África, com maior endemicidade na Ásia, América Central e do Sul e Oceania. Embora o Plasmodium falciparum cause a maioria do número de mortes, o P. vivax pode levar à malária grave e resultar em morbimortalidade significativa. O desenvolvimento de uma vacina protetora será um passo importante para a eliminação da malária. Recentemente, uma formulação contendo as três variantes alélicas da proteína circumsporozoíta de P. vivax (PvCSP - All epitopes) induziu proteção parcial em camundongos após desafio com esporozoíto híbrido Plasmodium berghei (Pb), no qual as repetições centrais do PbCSP foram substituídas por repetições PvCSP-VK210 (esporozoítos Pb/Pv). No presente estudo, a proteína quimérica PvCSP contendo as variantes alélicas (VK210, VK247 e P. vivax-like) fusionadas com a proteína de nucleocapsídeo do vírus da caxumba (formando partículas semelhantes a nucleocapsídeos ou do inglês, NLP - Núcleo Like Particles) na ausência (NLP-CSPR) ou na presença do domínio C-terminal (CT) conservado da PvCSP (NLP-CSPCT). Para a realização do estudo selecionamos os adjuvantes Poly (I:C), um RNA sintético de dupla fita, agonista do receptor Toll do tipo 3 (TLR3) ou o adjuvante Montanide ISA 720, uma emulação óleo em agua. Para obter uma forte resposta imune, a levedura Pichia pastoris foi usada para expressar as proteínas recombinantes na forma de NLPs. Camundongos foram imunizados com cada uma das proteínas recombinantes em combinação com os adjuvantes citados. Embora ambas as NLPs tenham sido capazes de gerar uma forte resposta imune, com altos níveis de títulos e longevidade, apenas a formulação contendo a proteína NLP-CSPCT na presença do adjuvante Poly (I:C) foi selecionada para ser explorada em experimentos futuros. Esta proteína em combinação com o adjuvante Poly (I:C) induziu alta frequência de células secretoras de anticorpos específicas para o antígeno homólogo nos dias 5 e 30, no baço e na medula óssea, respectivamente. Altos títulos de IgG contra as 3 variantes de PvCSP foram detectados nos soros. Posteriormente camundongos imunizados com NLP-CSPCT foram desafiados com esporozoítos Pb/Pv e a parasitemia no 5º dia demonstrou proteção estéril em 30% dos camundongos desafiados. Portanto, a formulação vacinal gerada neste estudo tem potencial para ser explorada no desenvolvimento de uma vacina universal contra a malária causada por P. vivax

Plasmodium vivax is the most common species of human malaria parasite found outside Africa, with high endemicity in Asia, Central and South America, and Oceania. Although Plasmodium falciparum causes the majority of deaths, P. vivax can lead to severe malaria and result in significant morbidity and mortality. The development of a protective vaccine will be a major step toward malaria elimination. Recently, a formulation containing the three allelic variants of the P. vivax circumsporozoite protein (PvCSP--All epitopes) showed partial protection in mice after a challenge with the hybrid Plasmodium berghei (Pb) sporozoite, in which the PbCSP central repeats were replaced by the VK210 PvCSP repeats (Pb/Pv sporozoite). In the present study, the chimeric PvCSP allelic variants (VK210, VK247, and P. vivax-like) were fused with the mumps virus nucleocapsid protein (assembling into nucleo like particles - NLP) in the absence (NLP-CSPR) or presence of the conserved C-terminal (CT) domain of PvCSP (NLP-CSPCT). To carry out the study, we selected the adjuvants Poly (I:C), a synthetic double-stranded RNA, Toll-like receptor 3 (TLR3) agonist or Montanide ISA 720 adjuvant, an oil-water emulation. To elicit stronger immune response, Pichia pastoris yeast was used to produce the NLPs. Mice were immunized with each recombinant protein in combination with above. Although both NLPs were able to generate stronger immune response, with high antibodies titer levels and longevity, formulation containing NLP-CSPCT in the presence of Poly (I:C) was selected to be explored in future experiments. NLP-CSPCT with Poly (I:C) adjuvant presented a high frequency of antigen-specific antibody-secreting cells (ASCs) on days 5 and 30, respectively, in the spleen and bone marrow. Moreover, high IgG titers against all PvCSP variants were detected in the sera. Later, immunized mice with NLP-CSPCT were challenged with Pb/Pv sporozoites. Sterile protection was observed in 30% of the challenged mice. Therefore, this vaccine formulation use has the potential to be a good candidate for the development of a universal vaccine against P. vivax malaria.

Prevalence and Factors Associated with Hepatic Iron Overload in Obese Individuals Undergoing Bariatric Surgery: a Cross-Sectional Study.

BACKGROUND: Slight to moderate hepatic iron overload (HIO) can be found in cases of liver disease, including non-alcoholic fatty liver disease (NAFLD), but the mechanism is not completely understood, as well as its relationship with obesity. OBJECTIVE: To determine the prevalence of HIO assessed through histopathological examination in obese individuals undergoing bariatric surgery and to identify correlations between this condition and demographic, anthropometric, clinical, laboratory, and NAFLD-related aspects. METHODS: This is a cross-sectional study which enrolled individuals undergoing bariatric surgery from January 2018 to February 2019 at a tertiary university hospital. NAFLD and HIO were assessed through histological examination. RESULTS: Of 125 individuals, 87.2% were female and the average age was 38.8 ± 9.2 years. The average BMI was 37.2 ± 3.1 kg/m2. NAFLD was present in 66.4% and HIO in 17.6%, with 63.6% of patients with overload classified as mild (grade I) and 22.7% moderate (grade II). HIO was significantly more frequent in males (p = 0.003) and was significantly associated with higher levels of glucose (92.1 ± 28.4 vs. 80.7 ± 39.6; p = 0.02), ferritin (385.5 ± 290.9 vs. 131.6 ± 99.7; p < 0.0001), serum iron (82.4 ± 35.7 vs. 66.6 ± 25.1; p = 0.03), glutamic-oxaloacetic transaminase (27.3 ± 19.5 vs. 20.6 ± 8.8; p = 0.02), and glutamic-pyruvic transaminase (37.6 ± 36.4 vs. 24.6 ± 16.3; p = 0.01). Multivariate analysis showed that HIO intensity was significant and independently associated with ferritin levels (R = 0.19; p = 0.01), serum iron (R = 0.25; p < 0.0001), blood glucose (R = 0.16; p = 0.001), and total cholesterol (R = - 0.17; p < 0.0001). CONCLUSION: In obese individuals, HIO presented a high prevalence and was associated with higher levels of ferritin, serum iron, glucose, and transaminases; lower levels of total cholesterol; and male gender.

A Multistage Formulation Based on Full-Length CSP and AMA-1 Ectodomain of Plasmodium vivax Induces High Antibody Titers and T-cells and Partially Protects Mice Challenged with a Transgenic Plasmodium berghei Parasite.

Infections with Plasmodium vivax are predominant in the Americas, representing 75% of malaria cases. Previously perceived as benign, malaria vivax is, in fact, a highly debilitating and economically important disease. Considering the high complexity of the malaria parasite life cycle, it has been hypothesized that an effective vaccine formulation against Plasmodium should contain multiple antigens expressed in different parasite stages. Based on that, we analyzed a recombinant P. vivax vaccine formulation mixing the apical membrane antigen 1 ectodomain (PvAMA-1) and a full-length circumsporozoite protein (PvCSP-AllFL) previously studied by our group, which elicits a potent antibody response in mice. Genetically distinct strains of mice (C57BL/6 and BALB/c) were immunized with the proteins, alone or in combination, in the presence of poly(I:C) adjuvant, a TLR3 agonist. In C57BL/6, high-antibody titers were induced against PvAMA-1 and the three PvCSP variants (VK210, VK247, and P. vivax-like). Meanwhile, mixing PvAMA-1 with PvCSP-AllFL had no impact on total IgG antibody titers, which were long-lasting. Moreover, antibodies from immunized mice recognized VK210 sporozoites and blood-stage parasites by immunofluorescence assay. However, in the BALB/c model, the antibody response against PvCSP-AllFL was relatively low. PvAMA-1-specific CD3+CD4+ and CD3+CD8+ T-cell responses were observed in C57BL/6 mice, and the cellular response was impaired by PvCSP-AllFL combination. More relevant, the multistage vaccine formulation provided partial protection in mice challenged with a transgenic Plasmodium berghei sporozoite expressing the homologous PvCSP protein.

Protective Malaria Vaccine in Mice Based on the Plasmodium vivax Circumsporozoite Protein Fused with the Mumps Nucleocapsid Protein.

Plasmodium vivax is the most common species of human malaria parasite found outside Africa, with high endemicity in Asia, Central and South America, and Oceania. Although Plasmodium falciparum causes the majority of deaths, P. vivax can lead to severe malaria and result in significant morbidity and mortality. The development of a protective vaccine will be a major step toward malaria elimination. Recently, a formulation containing the three allelic variants of the P. vivax circumsporozoite protein (PvCSP-All epitopes) showed partial protection in mice after a challenge with the hybrid Plasmodium berghei (Pb) sporozoite, in which the PbCSP central repeats were replaced by the VK210 PvCSP repeats (Pb/Pv sporozoite). In the present study, the chimeric PvCSP allelic variants (VK210, VK247, and P. vivax-like) were fused with the mumps virus nucleocapsid protein in the absence (NLP-CSPR) or presence of the conserved C-terminal (CT) domain of PvCSP (NLP-CSPCT). To elicit stronger humoral and cellular responses, Pichia pastoris yeast was used to assemble them as nucleocapsid-like particles (NLPs). Mice were immunized with each recombinant protein adjuvanted with Poly (I:C) and presented a high frequency of antigen-specific antibody-secreting cells (ASCs) on days 5 and 30, respectively, in the spleen and bone marrow. Moreover, high IgG titers against all PvCSP variants were detected in the sera. Later, these immunized mice with NLP-CSPCT were challenged with Pb/Pv sporozoites. Sterile protection was observed in 30% of the challenged mice. Therefore, this vaccine formulation use has the potential to be a good candidate for the development of a universal vaccine against P. vivax malaria.