• Title/Summary/Keyword: Epitope

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In silico Design of Discontinuous Peptides Representative of B and T-cell Epitopes from HER2-ECD as Potential Novel Cancer Peptide Vaccines

  • Manijeh, Mahdavi;Mehrnaz, Keyhanfar;Violaine, Moreau;Hassan, Mohabatkar;Abbas, Jafarian;Mohammad, Rabbani
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5973-5981
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    • 2013
  • At present, the most common cause of cancer-related death in women is breast cancer. In a large proportion of breast cancers, there is the overexpression of human epidermal growth factor receptor 2 (HER2). This receptor is a 185 KDa growth factor glycoprotein, also known as the first tumor-associated antigen for different types of breast cancers. Moreover, HER2 is an appropriate cell-surface specific antigen for passive immunotherapy, which relies on the repeated application of monoclonal antibodies that are transferred to the patient. However, vaccination is preferable because it would stimulate a patient's own immune system to actively respond to a disease. In the current study, several bioinformatics tools were used for designing synthetic peptide vaccines. PEPOP was used to predict peptides from HER2 ECD subdomain III in the form of discontinuous-continuous B-cell epitopes. Then, T-cell epitope prediction web servers MHCPred, SYFPEITHI, HLA peptide motif search, Propred, and SVMHC were used to identify class-I and II MHC peptides. In this way, PEPOP selected 12 discontinuous peptides from the 3D structure of the HER2 ECD subdomain III. Furthermore, T-cell epitope prediction analyses identified four peptides containing the segments 77 (384-391) and 99 (495-503) for both B and T-cell epitopes. This work is the only study to our knowledge focusing on design of in silico potential novel cancer peptide vaccines of the HER2 ECD subdomain III that contain epitopes for both B and T-cells. These findings based on bioinformatics analyses may be used in vaccine design and cancer therapy; saving time and minimizing the number of tests needed to select the best possible epitopes.

Identification of a conservative site in the African swine fever virus p54 protein and its preliminary application in a serological assay

  • Xu, Lingyu;Cao, Chenfu;Yang, Zhiyi;Jia, Weixin
    • Journal of Veterinary Science
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    • v.23 no.4
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    • pp.55.1-55.12
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    • 2022
  • Background: ASF was first reported in Kenya in 1910 in 1921. In China, ASF spread to 31 provinces including Henan and Jiangsu within six months after it was first reported on August 3, 2018. The epidemic almost affected the whole China, causing direct economic losses of tens of billions of yuan. Cause great loss to our pig industry. As ELISA is cheap and easy to operate, OIE regards it as the preferred serological method for ASF detection. P54 protein has good antigenicity and is an ideal antigen for detection. Objective: To identify a conservative site in the African swine fever virus (ASFV) p54 protein and perform a Cloth-enzyme-linked immunosorbent assay (ELISA) for detecting the ASFV antibody in order to reduce risks posed by using the live virus in diagnostic assays. Method: We used bioinformatics methods to predict the antigen epitope of the ASFV p54 protein in combination with the antigenic index and artificially synthesized the predicted antigen epitope peptides. Using ASFV-positive serum and specific monoclonal antibodies (mAbs), we performed indirect ELISA and blocking ELISA to verify the immunological properties of the predicted epitope polypeptide. Results: The results of our prediction revealed that the possible antigen epitope regions were A23-29, A36-45, A72-94, A114-120, A124-130, and A137-150. The indirect ELISA showed that the peptides A23-29, A36-45, A72-94, A114-120, and A137-150 have good antigenicity. Moreover, the A36-45 polypeptide can react specifically with the mAb secreted by hybridoma cells, and its binding site contains a minimum number of essential amino acids in the sequence 37DIQFINPY44. Conclusions: Our study confirmed a conservative antigenic site in the ASFV p54 protein and its amino acid sequence. A competitive ELISA method for detecting ASFV antibodies was established based on recombinant p54 and matching mAb. Moreover, testing the protein sequence alignment verified that the method can theoretically detect antibodies produced by pigs affected by nearly all ASFVs worldwide.

Requirement of CD4 Help for Induction of CD8 T Cell Response Specific for Virally Derived H60

  • Ryu, Su-Jeong;Kang, Bo-Ra;Kim, Seok-Ho;Kim, Tae-Woo;Chang, Jun;Choi, Eun-Young
    • IMMUNE NETWORK
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    • v.12 no.3
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    • pp.118-125
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    • 2012
  • CD40-CD40L-mediated help from CD4 T cells is essential to induce primary CD8 T cell responses specific to the non-inflammatory cell-based antigen H60. In this study, using H60 as a model antigen, we generated recombinant vaccinia viruses (rVVs) expressing the H60 CD8 epitope and investigated whether CD4 help was required to activate the CD8 T cell response specific to the virally expressed H60. The immune response after infection with rVVs expressing H60 was similar to that after immunization with H60 congenic splenocytes, with a peak frequency of H60-specific CD8 T cells detected in the blood on day 10 post-infection. A CD8 T cell response specific for virally derived H60 was not induced in CD4-depleted mice, but was in CD40-deficient mice. These results provide insights into the characterization of the CD8 T cell response specifically for antigens originating from cellular sources compared to viral sources.

Identifying Novel B Cell Epitopes within Toxoplasma gondii GRA6

  • Wang, Yanhua;Wang, Guangxiang;Cai, Jian Ping
    • Parasites, Hosts and Diseases
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    • v.54 no.4
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    • pp.431-437
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    • 2016
  • The study of antigenic epitopes from Toxoplasma gondii has not only enhanced our understanding of the structure and function of antigens, the reactions between antigens and antibodies, and many other aspects of immunology, but it also plays a significant role in the development of new diagnostic reagents and vaccines. In the present study, T. gondii GRA6 epitopes were identified using bioinformatics tools and a synthetic peptide technique. The potential B cell epitopes of GRA6 predicted by bioinformatics tools concentrated upon 3 regions of GRA6, 1-20 aa, 44-103 aa, and 172-221 aa. Ten shorter peptides from the 3 regions were synthesized and assessed by ELISA using pig sera from different time points after infection. Three of the 10 peptides (amino acids 44-63, 172-191, and 192-211) tested were recognized by all sera and determined to be immunodominant B-cell epitopes of GRA6. The results indicated that we precisely and accurately located the T. gondii GRA6 epitopes using pig sera collected at different time points after infection. The identified epitopes may be very useful for further studies of epitope-based vaccines and diagnostic reagents.

Prediction of Promiscuous Epitopes in the E6 Protein of Three High Risk Human Papilloma Viruses: A Computational Approach

  • Nirmala, Subramanian;Sudandiradoss, Chinnappan
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.7
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    • pp.4167-4175
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    • 2013
  • A najor current challenge and constraint in cervical cancer research is the development of vaccines against human papilloma virus (HPV) epitopes. Although many studies are done on epitope identification on HPVs, no computational work has been carried out for high risk forms which are considered to cause cervical cancer. Of all the high risk HPVs, HPV 16, HPV 18 and HPV 45 are responsible for 94% of cervical cancers in women worldwide. In this work, we computationally predicted the promiscuous epitopes among the E6 proteins of high risk HPVs. We identified the conserved residues, HLA class I, HLA class II and B-cell epitopes along with their corresponding secondary structure conformations. We used extremely precise bioinformatics tools like ClustalW2, MAPPP, NetMHC, Epi,Jen, EpiTop 1.0, ABCpred, BCpred and PSIPred for achieving this task. Our study identified specific regions 'FAFR(K)DL' followed by 'KLPD(Q)LCTEL' fragments which proved to be promiscuous epitopes present in both human leukocyte antigen (HLA) class I, class II molecules and B cells as well. These fragments also follow every suitable character to be considered as promiscuous epitopes with supporting evidences of previously reported experimental results. Thus, we conclude that these regions should be considered as the important for design of specific therapeutic vaccines for cervical cancer.

Prediction of HLA-A*0201-Restricted Antigenic Epitopes Targeting Multiple Myeloma (다발성 골수종 적용을 위한 HLA-A*0201 제한 항원성 펩타이드 예측)

  • Kang, Yoon Joong
    • Journal of Convergence for Information Technology
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    • v.10 no.6
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    • pp.209-216
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    • 2020
  • Protein antigens and their epitopes are targets for epitope based vaccines. There are many prediction servers which can be used for identification of binding peptides to MHC molecules. However, choosing of appropriate prediction servers is difficult. This study compared data obtained from prediction servers and evaluate them in scope of binding affinity to MHC-I molecules. Here we predicted HLA-A2-restricted cytotoxic T lymphocyte epitopes from survivin as a potential target for multiple myeloma. We suggest a procedure for prediction of antigenic peptides which could bind to MHC-I molecule. The results of this study will assist researchers in selection and prediction of noble antigenic peptides.

Adoptive transfer of Porphyromonas gingivalis heat shock protein epitope-specific T-cell lines into SCID mice in experimental atherosclerosis (실험적 동맥경화증에서 Porphyromonas gingivalis 열충격단백-항원결정부위-특이성 T-세포주의 SCID mice내로의 주입효과에 대한 연구)

  • Choi, Jeom-Il;Witztum, Joseph
    • Journal of Periodontal and Implant Science
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    • v.35 no.1
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    • pp.1-8
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    • 2005
  • Bacterial heat shock protein has been one of the components that are responsible to induce autoimmune disease mechanisms in the pathogenesis of atherosclerosis due to high level of homology in sequence with human counterpart. This mechanism may explain how bacterial infectious disease, such as periodontal disease, might contribute to the acceleration of the disease process of atherosclerosis. Porphyromonas gingivalis which is a major periodontal pathogenic bacterial species, has been implicated as one of the pathogenic bacteria playing the role in this context. The present study has been performed to evaluate the anti-atherosclerotic effect of adoptive transfer of Porphyromonas gingivalis heat shock protein epitope-specific T cell lines into severe combined immunodeficiency (SCID) mice. Peptide no. 15 with amino acid sequence VKEVASKTND-specific T cell line was selected for the transfer. When experimental atherosclerosis was induced in SCID mice adoptively transferred either by the T cell lines (experimental group) or by non-specific mouse T cells (control group), there was no significant difference in the severity and extent of the atherosclerosis induced by hypercholesterol diet.

Prediction of Common Peptide Vaccine forHuman Infective Major Flavivirus by Using Bioinformatics (생물정보학을 이용한 인체 감염주요 플라비바이러스 공통백신 후보군 도출)

  • Kim, Min Jung;Jo, Byung-Gwan;Heo, Jae-Rin;Choi, Jae-Won;Kim, Hak Yong
    • Proceedings of the Korea Contents Association Conference
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    • 2017.05a
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    • pp.297-298
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    • 2017
  • 플라비바이러스(Flavivirus)는 모기와 같은 곤충을 매개로 하여 인체에 감염된다고 잘 알려져 있다. 그 대표적인 예로 지카 바이러스(Zika virus), 뎅기 바이러스(Dengue virus), 황열 바이러스(Yellow fever virus), 일본 뇌염 바이러스(Japanese encephalitis virus) 등을 들 수 있다. 본 연구에서는 생물정보학을 기반으로 인체 감염 주요 플라비바이러스인 지카 바이러스, 뎅기 바이러스. 황열 바이러스, 일본 뇌염 바이러스의 총 4종류 플라비바이러스에 공통적으로 적용 가능한 펩타이드 백신 후보를 제시하고자 한다. 먼저 UniProt (The Universal Protein Resource)의 유전자 서열정보를 이용하여 4종류의 바이러스가 가진 단백질 중 백신으로써 적합한 단백질을 선정하였다. 선정된 단백질의 아미노산 서열정보를 바탕으로 IEDB (Immune Epitope Database And Analysis Resource)를 활용한 에피토프(epitope) 분석을 통해 에피토프로 작용하는 4 종류 바이러스의 공통적인 서열을 도출하였다.

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