scholarly journals RecombinantLactococcus lactisExpressing Haemagglutinin from a Polish Avian H5N1 Isolate and Its Immunological Effect in Preliminary Animal Trials

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Agnieszka K. Szczepankowska ◽  
Katarzyna Szatraj ◽  
Przemysław Sałański ◽  
Agnieszka Rózga ◽  
Roman K. Górecki ◽  
...  
Keyword(s):  
Immune Responses ◽  
Lactococcus Lactis ◽  
Expression System ◽  
Heterologous Proteins ◽  
Specific Antibodies ◽  
Recombinant Cells ◽  
Animal Trials ◽  
Immunological Effect ◽  
H5n1 Isolate ◽  
Different Origin

Lactic acid bacteria (LAB) are Gram-positive, nonpathogenic microorganisms that are gaining much interest as antigen producers for development of live vaccine vectors. Heterologous proteins of different origin have been successfully expressed in various LAB species, includingLactococcus lactis. RecombinantL. lactisstrains have been shown to induce specific local and systemic immune responses against various antigens. Our study aimed at constructing aL. lactisstrain expressing haemagglutinin of a Polish avian H5H1 influenza isolate and examining its effect on animals. Expression of the clonedH5gene was achieved using the nisin-controlled gene expression system. Detection of the intracellular H5 antigen produced inL. lactiswas performed by Western blot analysis and confirmed using mass spectrometry. The potential ofL. lactisrecombinant cells to induce an immune response was examined by setting up preliminary immunization trials on chickens and mice. Obtained sera were tested for specific antibodies by ELISA assays. The results of these studies are a promising step toward developing a vaccine against the bird flu usingLactococcus lactiscells as bioreactors for efficient antigen production and delivery to the mucosal surface.

scholarly journals Construction and characterization of a Lactococcus lactis strain deficient in intracellular ClpP and extracellular HtrA proteases

Microbiology ◽  
2006 ◽  
Vol 152 (9) ◽  
pp. 2611-2618 ◽  
Author(s):  
N. G. Cortes-Perez ◽  
I. Poquet ◽  
M. Oliveira ◽  
J. J. Gratadoux ◽  
S. M. Madsen ◽  
...  
Keyword(s):  
Lactococcus Lactis ◽  
Heterologous Gene Expression ◽  
Expression System ◽  
Donor Strain ◽  
Heterologous Proteins ◽  
Ethanol Resistance ◽  
In The Wild ◽  
Lactis Strain ◽  
High Level

A Lactococcus lactis strain deficient in both its major proteases, intracellular (ClpP) and extracellular (HtrA), was constructed and characterized. This strain, hereafter called clpP-htrA, could be obtained only by conjugation between a clpP donor strain and an htrA recipient strain in the NZ9000 context, allowing heterologous gene expression under the control of the NICE (nisin-controlled expression) system. The clpP-htrA double mutant showed both higher stress tolerance (e.g. high temperature and ethanol resistance) and higher viability than single clpP or htrA mutant strains. In addition, the secretion rate of two heterologous proteins (staphylococcal nuclease Nuc and Nuc-E7) was also higher in clpP-htrA than in the wild-type strain. This strain should be a useful host for high-level production and quality of stable heterologous proteins.

scholarly journals Lactiplantibacillus plantarum as a Potential Adjuvant and Delivery System for the Development of SARS-CoV-2 Oral Vaccines

2021 ◽  
Vol 9 (4) ◽  
pp. 683
Author(s):  
Julio Villena ◽  
Chang Li ◽  
Maria Guadalupe Vizoso-Pinto ◽  
Jacinto Sacur ◽  
Linzhu Ren ◽  
...  
Keyword(s):  
Immune Responses ◽  
Oral Administration ◽  
Molecular Mechanisms ◽  
Spike Protein ◽  
Heterologous Proteins ◽  
Oral Vaccines ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Viral Antigens ◽  
Mucosal Infection

The most important characteristics regarding the mucosal infection and immune responses against the Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) as well as the current vaccines against coronavirus disease 2019 (COVID-19) in development or use are revised to emphasize the opportunity for lactic acid bacteria (LAB)-based vaccines to offer a valid alternative in the fight against this disease. In addition, this article revises the knowledge on: (a) the cellular and molecular mechanisms involved in the improvement of mucosal antiviral defenses by beneficial Lactiplantibacillus plantarum strains, (b) the systems for the expression of heterologous proteins in L. plantarum and (c) the successful expressions of viral antigens in L. plantarum that were capable of inducing protective immune responses in the gut and the respiratory tract after their oral administration. The ability of L. plantarum to express viral antigens, including the spike protein of SARS-CoV-2 and its capacity to differentially modulate the innate and adaptive immune responses in both the intestinal and respiratory mucosa after its oral administration, indicates the potential of this LAB to be used in the development of a mucosal COVID-19 vaccine.

Production of foreign proteins in the yeast Pichia pastoris

1995 ◽  
Vol 73 (S1) ◽  
pp. 891-897 ◽  
Author(s):  
James M. Cregg ◽  
David R. Higgins
Keyword(s):  
Gene Expression ◽  
Pichia Pastoris ◽  
Heterologous Gene Expression ◽  
Expression System ◽  
Methylotrophic Yeast ◽  
Culture Broth ◽  
Heterologous Gene ◽  
Foreign Gene ◽  
Heterologous Proteins ◽  
Yeast Pichia Pastoris

The methanol-utilizing yeast Pichia pastoris has been developed as a host system for the production of heterologous proteins of commercial interest. An industrial yeast selected for efficient growth on methanol for biomass generation, P. pastoris is readily grown on defined medium in continuous culture at high volume and density. A unique feature of the expression system is the promoter employed to drive heterologous gene expression, which is derived from the methanol-regulated alcohol oxidase I gene (AOX1) of P. pastoris, one of the most efficient and tightly regulated promoters known. The strength of the AOX1 promoter results in high expression levels in strains harboring only a single integrated copy of a foreign-gene expression cassette. Levels may often be further enhanced through the integration of multiple cassette copies into the P. pastoris genome and strategies to construct and select multicopy cassette strains have been devised. The system is particularly attractive for the secretion of foreign-gene products. Because P. pastoris endogenous protein secretion levels are low, foreign secreted proteins often appear to be virtually the only proteins in the culture broth, a major advantage in processing and purification. Key words: heterologous gene expression, methylotrophic yeast, Pichia pastoris, secretion, glycosylation.

An engineered Lactococcus lactis strain exerts significant immune responses through efficient expression and delivery of Helicobacter pylori Lpp20 antigen

2016 ◽  
Vol 38 (12) ◽  
pp. 2169-2175 ◽  
Author(s):  
Rongguang Zhang ◽  
Xiaoyan Peng ◽  
Guangcai Duan ◽  
Qingfeng Shi ◽  
Shuaiyin Chen ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Immune Responses ◽  
Lactococcus Lactis ◽  
Efficient Expression ◽  
Lactis Strain

scholarly journals Development and validation of an assay for detection of Japanese Encephalitis virus specific antibody responses

2020 ◽  
Author(s):  
Pradeep Darshana Pushpakumara ◽  
Chandima Jeewandara ◽  
Laksiri Gomes ◽  
Yashodha Perera ◽  
Ananda Wijewickrama ◽  
...  
Keyword(s):  
Immune Responses ◽  
Japanese Encephalitis Virus ◽  
Disease Severity ◽  
Japanese Encephalitis ◽  
Specific Antibody ◽  
Encephalitis Virus ◽  
Antibody Responses ◽  
Specific Antibodies ◽  
Dengue Disease ◽  
Conserved Regions

AbstractBackgroundAlthough immune responses to the Japanese Encephalitis virus (JEV), and the dengue viruses (DENV) have a potential to modulate the immune responses to each other, this has been poorly investigated. Therefore, we developed an ELISA to identify JEV specific, DENV non cross-reactive antibody responses by identifying JEV specific, highly conserved regions of the virus and proceeded to investigate if the presence of JEV specific antibodies associate with dengue disease severity.Methodology/Principal findings20 JEV specific peptides were identified from highly conserved regions of the virus and the immunogenicity and specificity of these peptides were assessed in individuals who were non-immune to JEV and DENV (JEV-DENV-, N=30), those who were only immune to the JEV and not DENV (JEV+DENV-, N=30), those who were only immune to DENV(JEV-DENV+, N=30) and in those who were immune to both viruses (JEV+DENV+, N=30). 7/20 peptides were found to be highly immunogenic and specific and these 7 peptides were used as a pool to further evaluate JEV-specific responses. All 30/30 JEV+DENV-and 30/30 JEV+DENV+individuals, and only 3/30 (10%) JEV-DENV+individuals responded to this pool. We further evaluated this pool of 7 peptides in patients following primary and secondary dengue infection during the convalescent period and found that the JEV-specific peptides, were unlikely to cross react with DENV IgG antibodies. We further compared this in-house ELISA developed with the peptide pool with an existing commercial JEV IgG assay to identify JEV-specific IgG following vaccination, and our in-house ELISA was found to be more sensitive. We then proceeded to investigate if the presence of JEV-specific antibodies were associated with dengue disease severity, and we found that those who had past severe dengue (n=175) were significantly more likely (p<0.0001) to have JEV-specific antibodies than those with past non-severe dengue (n=175) (OR 5.3, 95% CI 3.3 to 8.3).Conclusions/SignificanceAs our data show that this assay is highly sensitive and specific for detection of JEV-specific antibody responses, it would be an important tool to determine how JEV seropositivity modulate dengue immunity and disease severity when undertaking dengue vaccine trials.Author summaryBoth Japanese Encephalitis virus (JEV), and the dengue viruses (DENV) co-circulate in the same geographical region and have a potential to modulate the immune responses to each other. However, due to the difficulty in identifying antibody responses specific to either virus due to the highly cross-reactive nature of virus-specific antibodies, this has been poorly investigated. Therefore, we developed an ELISA to identify JEV-specific, DENV non cross-reactive antibody responses by identifying JEV-specific, highly conserved regions of the virus and proceeded to investigate if the presence of JEV-specific antibodies associates with dengue disease severity. 20 JEV-specific peptides were identified from highly conserved regions of the virus and the immunogenicity and specificity of these peptides were assessed. We found that seven peptides were highly immunogenic and specific to the JEV and we further evaluated the usefulness of an ELISA developed using these pools of peptides. We found that our in-house ELISA was found to be significantly more sensitive some of the existing commercial assays. As this assay appears to be highly sensitive and specific for detection of JEV-specific antibody responses, it would be an important tool to determine how JEV seropositivity modulate dengue immunity and disease severity when undertaking dengue vaccine trials.

scholarly journals Genetic diversity and immunogenicity of the merozoite surface protein 1 C-terminal 19-kDa fragment of Plasmodium ovale imported from Africa into China

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Qinwen Xu ◽  
Sihong Liu ◽  
Kokouvi Kassegne ◽  
Bo Yang ◽  
Jiachen Lu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Immune Responses ◽  
Expression System ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
High Avidity ◽  
Plasmodium Ovale ◽  
Merozoite Surface Protein 1 ◽  
Proliferation Assays

Abstract Background Merozoite surface protein 1 (MSP1) plays an essential role in erythrocyte invasion by malaria parasites. The C-terminal 19-kDa region of MSP1 has long been considered one of the major candidate antigens for a malaria blood-stage vaccine against Plasmodium falciparum. However, there is limited information on the C-terminal 19-kDa region of Plasmodium ovale MSP1 (PoMSP119). This study aims to analyze the genetic diversity and immunogenicity of PoMSP119. Methods A total of 37 clinical Plasmodium ovale isolates including Plasmodium ovale curtisi and Plasmodium ovale wallikeri imported from Africa into China and collected during the period 2012–2016 were used. Genomic DNA was used to amplify P. ovale curtisi (poc) msp119 (pocmsp119) and P. ovale wallikeri (pow) msp119 (powmsp119) genes by polymerase chain reaction. The genetic diversity of pomsp119 was analyzed using the GeneDoc version 6 programs. Recombinant PoMSP119 (rPoMSP119)-glutathione S-transferase (GST) proteins were expressed in an Escherichia coli expression system and analyzed by western blot. Immune responses in BALB/c mice immunized with rPoMSP119-GST were determined using enzyme-linked immunosorbent assay. In addition, antigen-specific T cell responses were assessed by lymphocyte proliferation assays. A total of 49 serum samples from healthy individuals and individuals infected with P. ovale were used for the evaluation of natural immune responses by using protein microarrays. Results Sequences of pomsp119 were found to be thoroughly conserved in all the clinical isolates. rPoMSP119 proteins were efficiently expressed and purified as ~ 37-kDa proteins. High antibody responses in mice immunized with rPoMSP119-GST were observed. rPoMSP119-GST induced high avidity indexes, with an average of 92.57% and 85.32% for rPocMSP119 and rPowMSP119, respectively. Cross-reactivity between rPocMSP119 and rPowMSP119 was observed. Cellular immune responses to rPocMSP119 (69.51%) and rPowMSP119 (52.17%) induced in rPocMSP119- and rPowMSP119-immunized mice were found in the splenocyte proliferation assays. The sensitivity and specificity of rPoMSP119-GST proteins for the detection of natural immune responses in patients infected with P. ovale were 89.96% and 75%, respectively. Conclusions This study revealed highly conserved gene sequences of pomsp119. In addition, naturally acquired humoral immune responses against rPoMSP1 were observed in P. ovale infections, and high immunogenicity of rPoMSP119 in mice was also identified. These instructive findings should encourage further testing of PoMSP119 for rational vaccine design. Graphical abstract

scholarly journals Induction of GLUTAMINE DUMPER1 reveals a link between amino acid export, abscisic acid, and immune responses

2020 ◽  
Author(s):  
Shi Yu ◽  
Delasa Aghamirzaie ◽  
Kim Harich ◽  
Eva Collakova ◽  
Ruth Grene ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Amino Acid ◽  
Immune Responses ◽  
Transmembrane Domain ◽  
Induced Defense ◽  
Expression System ◽  
Amino Acid Content ◽  
Defense Responses ◽  
Developmental Needs ◽  
Amino Acid Homeostasis

ABSTRACTAmino acid homeostasis in plants is finely tuned to match developmental needs and response to adverse environments. Over-expression of the single-transmembrane domain protein GLUTAMINE DUMPER1 (GDU1) leads to increased amino acid export, reduced growth and constitutive induction of immune responses. We used an inducible gene expression system to tease apart the primary and secondary effects caused by GDU1, and demonstrated that the primary effect is increasing amino acid export, followed by increased amino acid content and abscisic acid (ABA) response, and a subsequent activation of defense responses. The GDU1-mediated hypersensitivity to ABA partially depended on the E3 ubiquitin ligase LOSS-OF-GDU1 2 (LOG2), a known GDU1 interactor. More importantly, the lysine catabolite pipecolic acid played a pivotal role in the GDU1-induced defense responses. This work unravels a novel relationship between amino acid transport, ABA and defense responses, potentially mediated by the GDU1-LOG2 complex, critical for understanding how plants respond to amino acid imbalance.ONE SENTENCE SUMMARYGenetically induced disturbance of amino acid homeostasis sequentially triggers responses to abiotic stresses and plant defenses to pathogens in Arabidopsis through undefined sensing mechanisms

scholarly journals Differential antibody dynamics to SARS-CoV-2 infection and vaccination

2021 ◽  
Author(s):  
Yuezhou Chen ◽  
Pei Tong ◽  
Noah B. Whiteman ◽  
Ali Sanjari Moghaddam ◽  
Adam Zuiani ◽  
...  
Keyword(s):  
Immune Responses ◽  
B Cell ◽  
Somatic Mutation ◽  
Post Infection ◽  
Vaccine Strategy ◽  
Specific Antibodies ◽  
Antibody Dynamics ◽  
Induced Immunity ◽  
Original Virus

ABSTRACTOptimal immune responses furnish long-lasting (durable) antibodies protective across dynamically mutating viral variants (broad). To assess robustness of mRNA vaccine-induced immunity, we compared antibody durability and breadth after SARS-CoV-2 infection and vaccination. While vaccination delivered robust initial virus-specific antibodies with some cross-variant coverage, pre-variant SARS-CoV-2 infection-induced antibodies, while modest in magnitude, showed highly stable long-term antibody dynamics. Vaccination after infection induced maximal antibody magnitudes with enhanced longitudinal stability while infection-naïve vaccinee antibodies fell with time to post-infection-alone levels. The composition of antibody neutralizing activity to variant relative to original virus also differed between groups, with infection-induced antibodies demonstrating greater relative breadth. Differential antibody durability trajectories favored COVID-19-recovered subjects with dual memory B cell features of greater early antibody somatic mutation and cross-coronavirus reactivity. By illuminating an infection-mediated antibody breadth advantage and an anti-SARS-CoV-2 antibody durability-enhancing function conferred by recalled immunity, these findings may serve as guides for ongoing vaccine strategy improvement.

Immunogenicity and protective efficacy of orally administered recombinant Lactococcus lactis expressing surface-bound HIV Env

Blood ◽  
2003 ◽  
Vol 102 (1) ◽  
pp. 223-228 ◽  
Author(s):  
Ke-Qin Xin ◽  
Yuka Hoshino ◽  
Yoshihiko Toda ◽  
Shizunobu Igimi ◽  
Yoshitsugu Kojima ◽  
...  
Keyword(s):  
Immune Responses ◽  
Lactococcus Lactis ◽  
Potential Role ◽  
Protective Efficacy ◽  
Oral Immunization ◽  
Vaccine Strategy ◽  
Regional Lymph Nodes ◽  
Viral Loads ◽  
Recombinant Lactococcus Lactis ◽  
Further Development

Abstract This study investigates whether genetically modified orally administered Lactococcus lactis (L lactis) could be used as an HIV vaccine. L lactis is immunogenic and extremely safe when delivered orally. We created a recombinant L lactis vector expressing the envelope protein of HIV on its cell surface. Oral immunization with this vector induced high levels of HIV-specific serum IgG and fecal IgA antibodies. Cell-mediated immune responses also were generated in both the regional lymph nodes and the spleen. Dendritic cells are readily infected by L lactis and appear to play a potential role in mediating the development of these immune responses. The protective efficacy of this vaccine strategy was demonstrated by challenging mice intraperitoneally with an HIV Env–expressing vaccinia virus. Their viral loads were 350-fold lower than those of control mice. These findings support the further development of L lactis–based HIV vaccines. (Blood. 2003; 102:223-228)

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