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Frontiers in Cellular and Infection... 2023Vacuolar protein sorting 29 (VPS29) is a core component of the retromer-retriever complex and is essential for recycling numerous cell-surface cargoes from endosomes....
INTRODUCTION
Vacuolar protein sorting 29 (VPS29) is a core component of the retromer-retriever complex and is essential for recycling numerous cell-surface cargoes from endosomes. However, there are no reports yet on VPS29 of spp.
METHODS
Here, we cloned and prokaryotically expressed a partial sequence of VPS29 (EtVPS29) with RT-PCR and engineered strain of respectively. The localization of the VPS29 protein in sporozoites was investigated with immunofluorescence (IFA) and overexpression assays. And its protective efficacy against infection was investigated in chickens with the animal protection test.
RESULTS
An EtVPS29 gene fragment with an ORF reading frame of 549 bp was cloned. The band size of the expressed recombinant protein, rEtVPS29, was approximately 39 kDa and was recognized by the chicken anti- positive serum. EtVPS29 protein was observed widely distributing in the cytoplasm of sporozoites in the IFA and overexpression assays. rEtVPS29 significantly increased average body weight gain and decreased mean lesion score and oocyst output in chickens. The relative weight gain rate in the rEtVPS29-immunized group was 62.9%, which was significantly higher than that in the unimmunized and challenged group (P < 0.05). The percentage of reduced oocyst output in the rEtVPS29 immunized group was 32.2%. The anticoccidial index of the rEtVPS29-immunized group was 144.2. Serum ELISA also showed that rEtVPS29 immunization induced high levels of specific antibodies in chickens.
DISCUSSION
These results suggest that rEtVPS29 can induce a specific immune response and is a potential candidate for the development of novel vaccines against infections in chickens.
Topics: Animals; Eimeria tenella; Chickens; Recombinant Proteins; Immunization; Vaccination; Oocysts; Sporozoites; Poultry Diseases; Protozoan Vaccines
PubMed: 37469602
DOI: 10.3389/fcimb.2023.1205782 -
BMC Infectious Diseases Oct 2023RTS,S/AS01 has been recommended by WHO for widespread implementation in medium to high malaria transmission settings. Previous analyses have noted lower vaccine...
Background malaria incidence and parasitemia during the three-dose RTS,S/AS01 vaccination series do not reduce magnitude of antibody response nor efficacy against the first case of malaria.
BACKGROUND
RTS,S/AS01 has been recommended by WHO for widespread implementation in medium to high malaria transmission settings. Previous analyses have noted lower vaccine efficacies in higher transmission settings, possibly due to the more rapid development of naturally acquired immunity in the control group.
METHODS
To investigate a reduced immune response to vaccination as a potential mechanism behind lower efficacy in high transmission areas, we examine initial vaccine antibody (anti-CSP IgG) response and vaccine efficacy against the first case of malaria (to exclude the effect of naturally acquired immunity) using data from three study areas (Kintampo, Ghana; Lilongwe, Malawi; Lambaréné, Gabon) from the 2009-2014 phase III trial (NCT00866619). Our key exposures are parasitemia during the vaccination series and background malaria incidence. We calculate vaccine efficacy (one minus hazard ratio) using a cox-proportional hazards model and allowing for the time-varying effect of RTS,S/AS01.
RESULTS
We find that antibody responses to the primary three-dose vaccination series were higher in Ghana than in Malawi and Gabon, but that neither antibody levels nor vaccine efficacy against the first case of malaria varied by background incidence or parasitemia during the primary vaccination series.
CONCLUSIONS
We find that vaccine efficacy is unrelated to infections during vaccination. Contributing to a conflicting literature, our results suggest that vaccine efficacy is also unrelated to infections before vaccination, meaning that control-group immunity is likely a major reason for lower efficacy in high transmission settings, not reduced immune responses to RTS,S/AS01. This may be reassuring for implementation in high transmission settings, though further studies are needed.
Topics: Humans; Antibody Formation; Incidence; Malaria; Malaria Vaccines; Malaria, Falciparum; Parasitemia; Plasmodium falciparum; Vaccination; Clinical Trials, Phase III as Topic
PubMed: 37872492
DOI: 10.1186/s12879-023-08699-7 -
Health Expectations : An International... Dec 2023Malaria exists as an endemic in many countries including Bangladesh and the malaria vaccine is not yet available here. The study aimed to assess the level of knowledge...
BACKGROUND
Malaria exists as an endemic in many countries including Bangladesh and the malaria vaccine is not yet available here. The study aimed to assess the level of knowledge and acceptance of the malaria vaccination among the parents of children under the age of five in Bangladesh's malaria-endemic areas and the sociodemographic, behavioural, and household factors associated with the acceptance and knowledge of the malaria vaccine.
METHODS
From January to March 2022, a cross-sectional study was conducted in all five malaria-endemic districts of Bangladesh, involving 405 parents of children under the age of 5 who met the inclusion criteria. Multiple logistic regression was used to analyze the factor affecting parents' acceptance and knowledge of malaria vaccination in children under five and other variables.
RESULTS
Majority (54%) of the respondents were mothers. Almost half (49%) of the respondents were aged between 26 and 35 years old and around 90% were from rural areas. A small portion (20%) of the participants were housewives and 46% of them completed primary education. Overall, 70% of the study participants reported that they would accept malaria vaccination independently. About one-fourth (25%) heard about the malaria vaccine and 48% of them mentioned health professionals as the source of information. Knowledge of malaria vaccination was found associated with residence, income, and family size. Acceptance and knowledge were both associated with residence, education, occupation, income, and family size. In a multivariable analysis, housing structure, house wall, house window, knowledge of malaria, testing for malaria, and being diagnosed with malaria were all associated with knowledge of and acceptance of getting vaccinated against malaria.
CONCLUSIONS
The present study highlights the necessity of creating awareness of malaria vaccines in epidemic areas of Bangladesh. This study offers crucial data to develop a policy for a novel malaria vaccine, supporting its adoption in Bangladesh.
PUBLIC CONTRIBUTION
This study was based on interviews. The interviewees were recruited as public representatives from the malaria-endemic area to assist us in building an understanding of knowledge and acceptance of the malaria vaccine among parents of under-five children in Bangladesh.
Topics: Female; Humans; Child; Adult; Malaria Vaccines; Cross-Sectional Studies; Bangladesh; Vaccination; Parents; Malaria; Health Knowledge, Attitudes, Practice
PubMed: 37661603
DOI: 10.1111/hex.13862 -
Veterinary World Oct 2023Canine babesiosis, caused by the protozoan parasite , is characterized by clinical manifestations, including hemolytic anemia, thrombocytopenia, multiple organ failure,...
BACKGROUND AND AIM
Canine babesiosis, caused by the protozoan parasite , is characterized by clinical manifestations, including hemolytic anemia, thrombocytopenia, multiple organ failure, and may result in death. This disease is detected using conventional blood smears, which are time-consuming and have low sensitivity. This study aimed to investigate a more rapid and sensitive method for detecting infection in dogs by examining the expressed serum protein profiles using proteomics.
MATERIALS AND METHODS
We collected six sera samples from three healthy and three -infected dogs diagnosed using blood smear and polymerase chain reaction. We analyzed the proteins using two-dimensional gel electrophoresis. The candidate spots from the gel were subjected to protein identification using a nano-liquid chromatography system coupled to an ion-trap mass spectrometer equipped with an electrospray ionization nano-sprayer.
RESULTS
We found that 10 protein spots were overexpressed in the serum samples from infected dogs compared with healthy dogs, which corresponded to three proteins: serotransferrin, serotransferrin isoforms X1, and hemopexin. Furthermore, analysis of the protein-protein interaction network confirmed that they strongly interacted with each other.
CONCLUSION
This study suggests that high levels of serotransferrin and hemopexin are related to infection, making these proteins potential candidates for the development of diagnostic molecules or vaccines.
PubMed: 38023278
DOI: 10.14202/vetworld.2023.2042-2048 -
Infection and Immunity Oct 2023In this study, we investigated how different categories of prenatal malaria exposure (PME) influence levels of maternal antibodies in cord blood samples and the...
In this study, we investigated how different categories of prenatal malaria exposure (PME) influence levels of maternal antibodies in cord blood samples and the subsequent risk of malaria in early childhood in a birth cohort study ( = 661) nested within the COSMIC clinical trial (NCT01941264) in Burkina Faso. infections during pregnancy and infants' clinical malaria episodes detected during the first year of life were recorded. The levels of maternal IgG and IgG to 15 . antigens were measured in cord blood by quantitative suspension array technology. Results showed a significant variation in the magnitude of maternal antibody levels in cord blood, depending on the PME category, with past placental malaria (PM) more frequently associated with significant increases of IgG and/or subclass levels across three groups of antigens defined as pre-erythrocytic, erythrocytic, and markers of PM, as compared to those from the cord of non-exposed control infants. High levels of antibodies to certain erythrocytic antigens (i.e., IgG to EBA140 and EBA175, IgG1 to EBA175 and MSP1, and IgG3 to EBA140 and MSP5) were independent predictors of protection from clinical malaria during the first year of life. By contrast, high levels of IgG, IgG1, and IgG2 to the VAR2CSA DBL1-2 and IgG4 to DBL3-4 were significantly associated with an increased risk of clinical malaria. These findings indicate that PME categories have different effects on the levels of maternal-derived antibodies to malaria antigens in children at birth, and this might drive heterogeneity to clinical malaria susceptibility in early childhood.
Topics: Child; Infant; Infant, Newborn; Humans; Child, Preschool; Female; Pregnancy; Plasmodium falciparum; Cohort Studies; Burkina Faso; Maternal Exposure; Placenta; Antibodies, Protozoan; Malaria, Falciparum; Malaria; Immunoglobulin G; Antigens, Protozoan
PubMed: 37754682
DOI: 10.1128/iai.00268-23 -
Microbiology Spectrum Dec 2023Avian coccidiosis caused by brings huge economic losses to the poultry industry. Although live vaccines and anti-coccidial drugs were used for a long time, infection...
Avian coccidiosis caused by brings huge economic losses to the poultry industry. Although live vaccines and anti-coccidial drugs were used for a long time, infection in chicken farms all over the world commonly occurred. The exploration of novel, effective vaccines has become a research hotspot. parasites have complex life cycles, and effective antigens are particularly critical to developing anti-coccidial vaccines. Microneme proteins (MICs), secreted from microneme organelles located at the parasite apex, are considered immunodominant antigens. microneme 3 (EtMIC3) contains four conserved repeats (MARc1, MARc2, MARc3, and MARc4) and three divergent repeats (MARa, MARb, and MARd), which play a vital role during the invasion. is a native probiotic in animal intestines and can regulate intestinal flora. In this study, BC1 and C4D domains of EtMIC3, BC1 or C4D fusing to dendritic cells targeting peptides, were surface-displyed by respectively. Oral immunizations were performed to investigate immune protective effects against infection.
Topics: Animals; Eimeria tenella; Chickens; Enterococcus faecalis; Protozoan Proteins; Microneme; Vaccines; Poultry Diseases
PubMed: 37855592
DOI: 10.1128/spectrum.02455-23 -
ACS Infectious Diseases Oct 2023Each year, approximately 50,000 children under 5 die as a result of diarrhea caused by , a protozoan parasite. There are currently no effective drugs or vaccines...
Each year, approximately 50,000 children under 5 die as a result of diarrhea caused by , a protozoan parasite. There are currently no effective drugs or vaccines available to cure or prevent infection, and there are limited tools for identifying and validating targets for drug or vaccine development. We previously reported a high throughput screening (HTS) of a large compound library against -myristoyltransferase (NMT), a validated drug target in multiple protozoan parasite species. To identify molecules that could be effective against , we counter-screened hits from the NMT HTS against NMT. We identified two potential hit compounds and validated them against NMT to determine if NMT might be an attractive drug target also for . We tested the compounds against using both cell-based and NMT enzymatic assays. We then determined the crystal structure of NMT bound to Myristoyl-Coenzyme A (MyrCoA) and structures of ternary complexes with MyrCoA and the hit compounds to identify the ligand binding modes. The binding site architectures display different conformational states in the presence of the two inhibitors and provide a basis for rational design of selective inhibitors.
Topics: Child; Humans; Cryptosporidiosis; Cryptosporidium; Plasmodium; Drug Development
PubMed: 37722671
DOI: 10.1021/acsinfecdis.3c00151 -
Frontiers in Cellular and Infection... 2023Toxoplasma gondii is an apicomplexan parasite that affects the health of humans and livestock, and an effective vaccine is urgently required. Nanoparticles can modulate...
BACKGROUND
Toxoplasma gondii is an apicomplexan parasite that affects the health of humans and livestock, and an effective vaccine is urgently required. Nanoparticles can modulate and improve cellular and humoral immune responses.
METHODS
In the current study, poly (D, L-lactic-co-glycolic acid) (PLGA) nanoparticles were used as a delivery system for the T. gondii dense granule antigens GRA12 and GRA7. BALB/c mice were injected with the vaccines and protective efficacy was evaluated.
RESULTS
Mice immunized with PLGA+GRA12 exhibited significantly higher IgG, and a noticeable predominance of IgG2a over IgG1 was also observed. There was a 1.5-fold higher level of lymphocyte proliferation in PLGA+GRA12-injected mice compared to Alum+GRA12-immunized mice. Higher levels of IFN-g and IL-10 and a lower level of IL-4 were detected, indicating that Th1 and Th2 immune responses were induced but the predominant response was Th1. There were no significant differences between Alum+GRA7-immunized and PLGA+GRA7-immunized groups. Immunization with these four vaccines resulted in significantly reduced parasite loads, but they were lowest in PLGA+GRA12-immunized mice. The survival times of mice immunized with PLGA+GRA12 were also significantly longer than those of mice in the other vaccinated groups.
CONCLUSION
The current study indicated that T. gondii GRA12 recombinant protein encapsulated in PLGA nanoparticles is a promising vaccine against acute toxoplasmosis, but PLGA is almost useless for enhancing the immune response induced by T. gondii GRA7 recombinant protein.
Topics: Humans; Animals; Mice; Toxoplasma; Protozoan Proteins; Antigens, Protozoan; Toxoplasmosis; Recombinant Proteins; Lactic Acid; Nanoparticles; Mice, Inbred BALB C; Protozoan Vaccines; Antibodies, Protozoan
PubMed: 37502604
DOI: 10.3389/fcimb.2023.1209755 -
Vaccines Nov 2023Toxoplasmosis is a major worldwide protozoan zoonosis. The surface antigen 1 (SAG1) of () has always been recognized as an ideal vaccine candidate antigen. However, the...
Toxoplasmosis is a major worldwide protozoan zoonosis. The surface antigen 1 (SAG1) of () has always been recognized as an ideal vaccine candidate antigen. However, the intact and soluble SAG1 protein is usually difficult to acquire in vitro, which is unfavorable for employing the recombinant protein as a vaccine candidate antigen. In the present study, we obtained the full-length SAG1 recombinant protein in soluble form by Transetta (DE3) cells under optimized expression conditions. The immunogenicity and protective ability of this recombinant protein against acute infection were evaluated in a mouse model. Monitoring changes in serum antibody levels and types, the presence of cytokines, and the rate of lymphocyte proliferation in vaccinated mice were used to assess humoral and cellular immune responses. Additional assessments were performed to determine the protective potency of the recombinant protein in combating RH tachyzoites. It was found that the titers of both IgG2a and IgG2b were considerably greater in the immunized mice compared to the titers of IgG1 and IgG3. The levels of Th1-type cytokines (IFN-γ, IL-12p70, IL-2, and TNF-α) and Th2-type cytokines (IL-10) significantly increased when splenocytes from immunological group mice were treated with lysate antigen. Compared to the control group, a recombinant protein substantially increased the longevity of infected mice, with an average death time prolonged by 14.50 ± 0.34 days ( < 0.0001). These findings suggest that the full-length and soluble SAG1 recombinant protein produced potent immune responses in mice and could be a preferred subunit vaccine candidate for , offering a feasible option for vaccination against acute toxoplasmosis.
PubMed: 38006011
DOI: 10.3390/vaccines11111678 -
Frontiers in Cellular and Infection... 2023can cause congenital infection and abortion in humans and warm-blooded animals. dense granule proteins, GRA35, GRA42, and GRA43, play a critical role in the...
BACKGROUND
can cause congenital infection and abortion in humans and warm-blooded animals. dense granule proteins, GRA35, GRA42, and GRA43, play a critical role in the establishment of chronic infection. However, their potential to induce protective immunity against infection remains unexplored.
OBJECTIVE
This study aimed to test the efficacy of a DNA vaccine encompassing GRA35, GRA42, and GRA43 in inducing protective immunity against the highly virulent RH strain (type I) and the brain cyst-forming PRU strain (type II).
METHODS
The eukaryotic plasmids pVAX-GRA35, pVAX-GRA42, and pVAX-GRA43 were constructed and formulated into two- or three-gene cocktail DNA vaccines. The indirect immunofluorescence assay (IFA) was used to analyze their expression and immunogenicity. Mice were immunized with a single-gene, two-genes, or multicomponent eukaryotic plasmid, intramuscularly. We assessed antibody levels, cytotoxic T-cell (CTL) responses, cytokines, and lymphocyte surface markers by using flow cytometry. Additionally, mouse survival and cyst numbers in the brain of mice challenged 1 to 2 months postvaccination were determined.
RESULTS
Specific humoral and cellular immune responses were elicited in mice immunized with single-, two-, or three-gene cocktail DNA vaccine, as indicated by significant increases in serum antibody concentrations of total IgG, IgG2a/IgG1 ratio, cytokine levels (IFN-γ, IL-2, IL-12, IL-4, and IL-10), lymphocyte proliferation, lymphocyte populations (CD4 and CD8 T lymphocytes), CTL activities, and survival, as well as decreased brain cysts, in comparison with control mice. Moreover, compared with pVAX-GRA35 + pVAX-GRA42, pVAX-GRA42 + pVAX-GRA43, or pVAX-GRA35 + pVAX-GRA43, multicomponent DNA vaccine with three genes (pVAX-GRA35 + pVAX-GRA42 + pVAX-GRA43) induced the higher humoral and cellular immune responses, including serum antibody concentrations, cytokine levels, lymphocyte proliferation, lymphocyte populations, CTL activities and survival, resulting in prolonged survival time and reduced brain cyst loads. Furthermore, mice immunized with pVAX-GRA35 + pVAX-GRA42, pVAX-GRA42 + pVAX-GRA43, or pVAX-GRA35 + pVAX-GRA43 showed greater Th1 immune responses and protective efficacy than the single-gene-vaccinated groups.
CONCLUSION
These results demonstrate that Tg, Tg, or Tg are vaccine candidates against infection, and the three-gene DNA vaccine cocktail conferred the strongest protection against infection.
Topics: Mice; Humans; Animals; Vaccines, DNA; Protozoan Proteins; Toxoplasmosis; Toxoplasma; Cytokines; Protozoan Vaccines; Antibodies, Protozoan; Mice, Inbred BALB C
PubMed: 38029261
DOI: 10.3389/fcimb.2023.1236130