Prediction and analysis of promiscuous T cell-epitopes derived from the vaccine candidate antigens of Leishmania donovani binding to MHC class-II alleles using in silico approach

2017 ◽  
Vol 53 ◽  
pp. 107-115 ◽  
Author(s):  
Manju Kashyap ◽  
Varun Jaiswal ◽  
Umar Farooq
2006 ◽  
Vol 121 (1) ◽  
pp. 54-62 ◽  
Author(s):  
Emmanuelle Godefroy ◽  
Luigi Scotto ◽  
Naira E. Souleimanian ◽  
Gerd Ritter ◽  
Lloyd J. Old ◽  
...  

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2280-2280
Author(s):  
Katharina Nora Steinitz ◽  
Brigitte Binder ◽  
Christian Lubich ◽  
Rafi Uddin Ahmad ◽  
Markus Weiller ◽  
...  

Abstract Abstract 2280 Development of neutralizing antibodies against FVIII is the major complication in the treatment of patients with hemophilia A. Although several genetic and environmental risk factors have been identified, it remains unclear why some patients develop antibodies while others do not. Understanding the underlying mechanisms that drive the decision of the immune system whether or not to make antibodies against FVIII would help to design novel therapeutics. We used a new humanized hemophilic mouse model that expresses the human MHC-class II molecule HLA-DRB1*1501 on the background of a complete knock out of all murine MHC-class II genes. Initial studies had indicated that only a fraction of these mice developed antibodies when intravenously (i.v.) treated with human FVIII. These findings which resemble the situation in patients with severe hemophilia A, evoked the question if the lack of antibody development in non-responder mice reflects the induction of specific immune tolerance after i.v. application of FVIII or represent non-responsiveness for other reasons. We addressed this question by choosing another application route (subcutaneous, s.c.) and by combining i.v. application with a concomitant activation of the innate immune system applying LPS, a well characterized ligand for toll-like receptor 4, together with FVIII. Both strategies resulted in the development of antibodies in all mice included in the study what suggested that non-responsiveness against i.v. FVIII does not reflect an inability to develop antibodies against FVIII. Next, we asked if i.v. FVIII does induce immune tolerance in non-responder mice. We pretreated mice with i.v. FVIII, selected non-responder mice and challenged them with s.c. FVIII. None of the mice developed antibodies what indicated that i.v. pretreatment had induced immune tolerance in non-responder mice. Currently, we test the hypothesis that immune tolerance after i.v. application is induced and maintained by FVIII-specific regulatory T cells. The differences in responder rates after i.v. and s.c. application of FVIII raised the question if there are differences in FVIII T-cell epitopes involved in the initial activation of FVIII-specific CD4+ T cells. We obtained spleen cells from mice treated with either i.v. or s.c. FVIII and generated CD4+ T-cell hybridoma libraries that were tested for peptide specificities. For this purpose we used a FVIII peptide library containing 15 mers with an offset of 3 amino acids. Our results indicate that the pattern of FVIII-specific T-cell epitopes involved in the activation of FVIII-specific CD4+ T cells after i.v. and s.c. application of FVIII is almost identical and represents a small set of FVIII peptides distributed over the A1, A2, B, A3 and C1 domains. Based on our results we conclude that the new HLA-DRB1*1501 hemophilic mouse model represents an interesting opportunity to uncover the mechanisms that drive the decision of the immune system whether or not to develop antibodies against FVIII. Disclosures: Steinitz: Baxter BioScience: Employment. Binder:Baxter BioScience: Employment. Lubich:Baxter BioScience: Employment. Ahmad:Baxter BioScience: Employment. Weiller:Baxter BioScience: Employment. de la Rosa:Baxter BioScience: Employment. Schwarz:Baxter BioScience: Employment. Scheiflinger:Baxter BioScience: Employment. Reipert:Baxter Innovations GmbH: Employment.


1989 ◽  
Vol 19 (12) ◽  
pp. 2237-2242 ◽  
Author(s):  
Paola Panina-Bordignon ◽  
Agnes Tan ◽  
Annemarie Termijtelen ◽  
Stefan Demotz ◽  
Giampietro Corradin ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Class Ii ◽  

1994 ◽  
Vol 6 (5) ◽  
pp. 751-759 ◽  
Author(s):  
Irma Joosten ◽  
Marca H. M. Wauben ◽  
Monlek C. Holewijn ◽  
Konrad Reske ◽  
Lars Ø. Pedersen ◽  
...  

Author(s):  
Muhammad Tahir ul Qamar ◽  
Farah Shahid ◽  
Usman Ali Ashfaq ◽  
Sidra Aslam ◽  
Israr Fatima ◽  
...  

Abstract Background: Coronavirus disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Corona virus 2 (SARS-COV-2) was first diagnosed in December 2019, Wuhan, China. Little is known about this new virus and it has the potential to cause severe illness and pneumonia in some people, therefore the development of an effective vaccine is highly desired.Methods: Immunoinformatics and statistical approaches were used in this study to forecast B- and T- cell epitopes for the SARS-COV-2 structural proteins (Surface glycoprotein, Envelope protein, and Membrane glycoprotein) that may play a key role in eliciting immune response against COVID-19. Different types of B cell epitopes (linear as well as discontinuous) and T cell (MHC class I and MHC class II) were determined. Moreover, their antigenicity and allergenicity were also estimated.Results: The antigenic B-cell epitopes exposed to the outer surface were screened out and 23 linear B cell epitopes were selected. “SPTKLNDLCFTNVY” had the highest antigenicity score among B cell epitopes. The T-cell epitopes bound to multiple alleles, antigenic, non-allergen, non-toxic, and conserved in the protein sequence were shortlisted. In total, 16 epitopes (9 from MHC class I and 7 from MHC class II) were selected. Among the T-cell epitopes, MHC class I (IPFAMQMAYRFN) and MHC class II (VTLACFVLAAVYRIN) were classified as strongly antigenic. Digestion analysis verified the safety and stability of the peptides predicted during this study. Furthermore, docking analyses of predicted peptides showed significant interactions with the HLA-B7 allele.Conclusion: The putative antigen epitopes identified in this study may serve as vaccine candidates and can help to eliminate/control growing health threat of COVID-19.


2020 ◽  
Author(s):  
Kathrin Balz ◽  
Meng Chen ◽  
Abhinav Kaushik ◽  
Franz Cemic ◽  
Vanessa Heger ◽  
...  

Abstract The outbreak of the new Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is a public health emergency. Asthma does not represent a risk factor for COVID-19 in several published cohorts. We hypothesized that the SARS-CoV-2 proteome contains T cell epitopes, which are potentially cross-reactive to allergen epitopes. We aimed at identifying homologous peptide sequences by means of two distinct complementary bioinformatics approaches. Pipeline 1 included prediction of MHC Class I and Class II epitopes contained in the SARS-CoV-2 proteome and allergens along with alignment and elaborate ranking approaches. Pipeline 2 involved alignment of SARS-CoV-2 overlapping peptides with known allergen-derived T cell epitopes. Our results indicate a large number of MHC Class I epitope pairs including known as well as de novo predicted allergen T cell epitopes with high probability for cross-reactivity. Allergen sources, such as Aspergillus fumigatus, Phleum pratense and Dermatophagoides species are of particular interest due to their association with multiple cross-reactive candidate peptides, independently of the applied bioinformatic approach. In contrast, peptides derived from food allergens, as well as MHC class II epitopes did not achieve high in silico ranking and were therefore not further investigated. Our findings warrant further experimental confirmation along with examination of the functional importance of such cross-reactive responses.


1998 ◽  
Vol 188 (5) ◽  
pp. 819-831 ◽  
Author(s):  
Danielle Lankar ◽  
Volker Briken ◽  
Kristin Adler ◽  
Peter Weiser ◽  
Sylvanie Cassard ◽  
...  

Stimulation of CD4+ helper T lymphocytes by antigen-presenting cells requires the degradation of exogenous antigens into antigenic peptides which associate with major histocompatibility complex (MHC) class II molecules in endosomal or lysosomal compartments. B lymphocytes mediate efficient antigen presentation first by capturing soluble antigens through clonally distributed antigen receptors (BCRs), composed of membrane immunoglobulin (Ig) associated with Ig-α/Ig-β heterodimers which, second, target antigens to MHC class II–containing compartments. We report that antigen internalization and antigen targeting through the BCR or its Ig-α–associated subunit to newly synthesized class II lead to the presentation of a large spectrum of T cell epitopes, including some cryptic T cell epitopes. To further characterize the intracellular mechanisms of BCR-mediated antigen presentation, we used two complementary experimental approaches: mutational analysis of the Ig-α cytoplasmic tail, and overexpression in B cells of dominant negative syk mutants. Thus, we found that the syk tyrosine kinase, an effector of the BCR signal transduction pathway, is involved in the presentation of peptide– MHC class II complexes through antigen targeting by BCR subunits.


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