scholarly journals A T-Cell Epitope-Based Multi-Epitope Vaccine Designed Using Human HLA Specific T Cell Epitopes Induces Sterile Immunity against Experimental Visceral Leishmaniasis in Hamsters

2021 ◽  
Author(s):  
Aryandra Arya ◽  
Sunil K Arora
Keyword(s):  
T Cell ◽  
Visceral Leishmaniasis ◽  
Leishmania Donovani ◽  
Mononuclear Cells ◽  
Ex Vivo ◽  
Human Peripheral Blood ◽  
Cell Epitope ◽  
Effective Vaccine ◽  
Hamster Model ◽  
Vaccine Candidates

Visceral Leishmaniasis is a neglected tropical disease affecting 12 million people annually. Even in the second decade of the 21st century, it has remained without an effective vaccine for human use. In the current study, we have designed three multiepitope vaccine candidates by the selection of multiple IFN-γ inducing MHC-I and MHC-II binder T-cell specific epitopes from 3 previously identified antigen genes of Leishmania donovani from our lab, by immune-informatic approach using IFNepiotpe, NET-MHC-1 and NET MHC-2 webservers. We have tested the protective potential of these three multiepitope proteins as vaccine in a hamster model of visceral leishmaniasis. The immunization data revealed that the vaccine candidates induced a very high level of Th-1 biased protective immune response in-vivo in a hamster model of experimental visceral Leishmaniasis, with one of the candidates inducing a sterile immunity. The vaccinated animals displayed highly activated monocyte macrophages with the capability of clearing intracellular parasites due to increased respiratory burst. Additionally, these proteins induced activation of polyfunctional T cells secreting INF-γ, TNF-α, and IL-2 in ex-vivo stimulation of human peripheral blood mononuclear cells, further supporting the protective nature of designed candidates.

scholarly journals A T-Cell Epitope-Based Multi-Epitope Vaccine Designed Using Human HLA Specific T Cell Epitopes Induces a Near-Sterile Immunity against Experimental Visceral Leishmaniasis in Hamsters

Vaccines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1058
Author(s):  
Aryandra Arya ◽  
Sunil K. Arora
Keyword(s):  
T Cell ◽  
Visceral Leishmaniasis ◽  
Leishmania Donovani ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Cell Epitope ◽  
Effective Vaccine ◽  
T Cell Epitope ◽  
Hamster Model ◽  
Vaccine Candidates

Visceral leishmaniasis is a neglected tropical disease affecting 12 million people annually. Even in the second decade of the 21st century, it has remained without an effective vaccine for human use. In the current study, we designed three multiepitope vaccine candidates by the selection of multiple IFN-γ inducing MHC-I and MHC-II binder T-cell specific epitopes from three previously identified antigen genes of Leishmania donovani from our lab by an immuno-informatic approach using IFNepitope, the Immune Epitope Database (IEDB) T cell epitope identification tools, NET-MHC-1, and NET MHC-2 webservers. We tested the protective potential of these three multiepitope proteins as a vaccine in a hamster model of visceral leishmaniasis. The immunization data revealed that the vaccine candidates induced a very high level of Th1 biased protective immune response in-vivo in a hamster model of experimental visceral leishmaniasis, with one of the candidates inducing a near-sterile immunity. The vaccinated animals displayed highly activated monocyte macrophages with the capability of clearing intracellular parasites due to increased respiratory burst. Additionally, these proteins induced activation of polyfunctional T cells secreting INF-γ, TNF-α, and IL-2 in an ex-vivo stimulation of human peripheral blood mononuclear cells, further supporting the protective nature of the designed candidates.

scholarly journals Characterization of Plasmodium falciparum Proteome at Asexual Blood Stages for Screening of Effective Vaccine Candidates: An Immunoinformatics Approach

2015 ◽  
Vol 7 ◽  
pp. III.S24755 ◽  
Author(s):  
Satarudra Prakash Singh ◽  
Vishal Verma ◽  
Bhartendu Nath Mishra
Keyword(s):  
Plasmodium Falciparum ◽  
T Cell ◽  
Cell Epitope ◽  
Epitope Prediction ◽  
Proteome Analysis ◽  
Effective Vaccine ◽  
Secretory Proteins ◽  
Vaccine Candidates ◽  
Proteome Level

Malaria is a complex parasitic disease that is currently causing great concerns globally owing to the resistance to antimalarial drugs and lack of an effective vaccine. The present study involves the characterization of extracellular secretory proteins as vaccine candidates derived from proteome analysis of Plasmodium falciparum at asexual blood stages of malaria. Among the screened 32 proteins, 31 were predicted as antigens by the VaxiJen program, and 26 proteins had less than two transmembrane spanning regions predicted using the THMMM program. Moreover, 10 and 5 proteins were predicted to contain secretory signals by SignalP and TargetP, respectively. T-cell epitope prediction using MULTIPRED2 and NetCTL programs revealed that most of the predicted antigens are immunogenic and contain more than 10% supertype and 5% promiscuous epitopes of HLA-A, -B, or -DR. We anticipate that T-cell immune responses against asexual blood stages of Plasmodium are dispersed on a relatively large number of parasite antigens. This is the first report, to the best of our knowledge, offering new insights, at the proteome level, for the putative screening of effective vaccine candidates against the malaria pathogen. The findings also suggest new ways forward for the modern omics-guided vaccine target discovery using reverse vaccinology.

scholarly journals Kinesin Motor Domain of Leishmania donovani as a Future Vaccine Candidate

2008 ◽  
Vol 15 (5) ◽  
pp. 836-842 ◽  
Author(s):  
Ayan Dey ◽  
Pawan Sharma ◽  
Naresh Singh Redhu ◽  
Sarman Singh
Keyword(s):  
Visceral Leishmaniasis ◽  
Lymphocyte Proliferation ◽  
Leishmania Donovani ◽  
Mononuclear Cells ◽  
Vaccine Candidate ◽  
Ex Vivo ◽  
Interleukin 2 ◽  
Motor Domain ◽  
Enzyme Linked Immunosorbent Assay ◽  
Kinesin Motor

ABSTRACT Visceral leishmaniasis (VL) is one of the important parasitic diseases, with approximately 350 million people at risk. Due to the nonavailability of an ideal drug, development of a safe, effective, and affordable vaccine could be a solution for control and prevention of this disease. The present study was carried out to examine the immunological potential of kinesin protein from the microtubule locus of Leishmania donovani as a suitable vaccine candidate. In silico analysis of this region revealed clusters of major histocompatibility complex class I and II binding epitopes in its motor domain region. A recombinant protein was expressed from this region and named rLvacc. The antigenicity and immunogenicity studies of this protein by Western blot analysis revealed that rLvacc is strongly recognized by sera from acute VL patients. To evaluate its immunogenicity, peripheral blood mononuclear cells from cured VL patients were separated, and a lymphocyte proliferation assay was carried out in the presence of rLvacc. After lymphocyte proliferation, the pooled culture supernatant was assayed for anti-rLvacc antibody titers using an enzyme-linked immunosorbent assay. The results showed that immunoglobulin G2 (IgG2) subtype antibodies were predominant, while IgG1 subtype antibodies were produced in very low titers. On the basis of these ex vivo preliminary findings, its immunogenicity was studied in BALB/c mice. Vaccination with the DNA construct generated a good cellular immune response with significant increases in gamma interferon and interleukin-2 (IL-2) cytokine levels (Th1), but no increase in IL-4 levels (Th2). Taken together, our findings suggest the kinesin motor domain region of L. donovani as a potential vaccine candidate against visceral leishmaniasis.

scholarly journals IL-10 and TGF-β Induced Arginase Expression Contributes to Deficient Nitric Oxide Response in Human Visceral Leishmaniasis

2021 ◽  
Vol 10 ◽  
Author(s):  
Manu Kupani ◽  
Smriti Sharma ◽  
Rajeev Kumar Pandey ◽  
Rajiv Kumar ◽  
Shyam Sundar ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Visceral Leishmaniasis ◽  
Leishmania Donovani ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
No Production ◽  
Peripheral Blood Mononuclear ◽  
Before And After ◽  
Plasma Nitrite

Nitric oxide (NO) is an anti-microbial effector of the innate immune system which plays major role in non-specific killing of various pathogens including protozoan parasites. However, due to subversion of the host’s immune processes by pathogens, suboptimal production of NO is frequently found in many infection models. Previous studies have shown suppressed NO production during Leishmania donovani infection, the causative agent of visceral leishmaniasis (VL). Availability of L-Arginine, a semi-essential amino acid is required for inducible nitric oxide synthase (iNOS) mediated NO production. However, arginase is another enzyme, which if expressed concomitantly, may strongly compete for L-Arginine, and suppress NO production by iNOS. In the present study, plasma nitrite and arginase levels were measured in VL patients before and after successful drug treatment, endemic and non-endemic healthy donors. We observed significantly lower NO levels in the plasma of VL patients as compared to endemic controls, which improved significantly post-treatment. Significantly elevated arginase activity was also observed in the plasma of VL patients, which may be associated with NO deficiency. VL patients also showed significantly higher levels of IL-10 and TGF-β, which are known to regulate expression of arginase in various immune cells. In vitro studies with human peripheral blood mononuclear cells (PBMCs) further corroborated the role of IL-10 and TGF-β in arginase mediated suppression of NO production.

Design, creation and in vitro testing of a reduced immunogenicity humanized anti-CD25 monoclonal antibody that retains functional activity

2019 ◽  
Vol 32 (12) ◽  
pp. 543-554
Author(s):  
Marcia Stickler ◽  
Anita Reddy ◽  
Joanna M Xiong ◽  
Melanie H Wong ◽  
Yoshiko Akamatsu ◽  
...  
Keyword(s):  
T Cell ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Cell Epitope ◽  
Cd4 T Cell ◽  
Peripheral Blood Mononuclear ◽  
Epitope Region ◽  
Human Sequence ◽  
Amino Acid Mutations

Abstract Humanized and fully human sequence-derived therapeutic antibodies retain the capacity to induce anti-drug antibodies. Daclizumab (humanized version of the murine anti-Tac antibody; E.HAT) was selected for a proof of concept application of engineering approaches to reduce potential immunogenicity due to its demonstrated immunogenicity in the clinic. Reduced immunogenicity variants of E.HAT were created by identifying and modifying a CD4+ T cell epitope region in the VH region. Variant epitope region peptides were selected for their reduced capacity to induce CD4+ T cell proliferative responses in vitro. Variant antibody molecules were created, and CD25 affinity and potency were similar to the unmodified parent antibody. Fab fragments from the variant antibodies induced a lower frequency and magnitude of responses in human peripheral blood mononuclear cells proliferation tests. By the empirical selection of two amino acid mutations, fully functional humanized E.HAT antibodies with reduced potential to induce immune responses in vitro were created.

scholarly journals Human Interleukin-32γ Plays a Protective Role in an Experimental Model of Visceral Leishmaniasis in Mice

2018 ◽  
Vol 86 (5) ◽  
Author(s):  
Rodrigo Saar Gomes ◽  
Muriel Vilela Teodoro Silva ◽  
Jéssica Cristina dos Santos ◽  
Christine van Linge ◽  
Juliana Machado Reis ◽  
...  
Keyword(s):  
Immune Response ◽  
Visceral Leishmaniasis ◽  
Proinflammatory Cytokines ◽  
Mononuclear Cells ◽  
Ex Vivo ◽  
Human Peripheral Blood ◽  
No Production ◽  
Content Type ◽  
Splenic Cells ◽  
Ifn Γ

ABSTRACTVisceral leishmaniasis (VL) is a chronic parasitic disease caused byLeishmania infantumin the Americas. During VL, several proinflammatory cytokines are produced in spleen, liver, and bone marrow. However, the role of interleukin-32 (IL-32) has not been explored in this disease. IL-32 can induce production of proinflammatory cytokines in innate immune cells and polarize the adaptive immune response. Herein, we discovered thatL. infantumantigens induced expression of mRNA mainly for the IL-32γ isoform but also induced low levels of the IL-32β transcript in human peripheral blood mononuclear cells. Furthermore, infection of human IL-32γ transgenic mice (IL-32γTg mice) withL. infantumpromastigote forms increased IL-32γ expression in the spleen and liver. Interestingly, IL-32γTg mice harbored less parasitism in the spleen and liver than wild-type (WT) mice. In addition, IL-32γTg mice showed increased granuloma formation in the liver compared to WT mice. The protection against VL was associated with increased production of nitric oxide (NO), interferon gamma (IFN-γ), IL-17A, and tumor necrosis factor alpha by splenic cells restimulatedex vivowithL. infantumantigens. In parallel, there was an increase in the number of Th1 and Th17 T cells in the spleens of IL-32γTg mice infected withL. infantum. IL-32γ induction of IFN-γ and IL-17A expression was found to be essential for NO production by splenic cells of infected animals. These data indicate that IL-32γ potentiates the Th1/Th17 immune response during experimental VL, thus contributing to the control ofL. infantuminfection.

scholarly journals Members of the 30- to 32-Kilodalton Mycolyl Transferase Family (Ag85) from Culture Filtrate of Mycobacterium avium subsp. paratuberculosis Are Immunodominant Th1-Type Antigens Recognized Early upon Infection in Mice and Cattle

2006 ◽  
Vol 74 (1) ◽  
pp. 202-212 ◽  
Author(s):  
Valérie Rosseels ◽  
Sylvie Marché ◽  
Virginie Roupie ◽  
Marc Govaerts ◽  
Jacques Godfroid ◽  
...  
Keyword(s):  
T Cell ◽  
Mycobacterium Avium ◽  
Culture Filtrate ◽  
Mononuclear Cells ◽  
Ex Vivo ◽  
Natural Infection ◽  
Cell Epitope ◽  
Major Protein ◽  
Protective Antigens ◽  
Ifn Γ

ABSTRACT The characterization of protective antigens is essential for the development of an effective, subunit-based vaccine against paratuberculosis. Surface-exposed and secreted antigens, present abundantly in mycobacterial culture filtrate (CF), are among the well-known protective antigens of Mycobacterium tuberculosis and Mycobacterium bovis. Culture filtrate, prepared from Mycobacterium avium subsp. paratuberculosis ATCC 19698 grown as a surface pellicle on synthetic Sauton medium, was strongly and early recognized in experimentally infected B6 bg/bg beige mice and cattle, as indicated by elevated spleen cell gamma interferon (IFN-γ) secretion and lymphoproliferative responses of peripheral blood mononuclear cells, respectively. Strong proliferative and ex vivo IFN-γ responses against antigen 85 (Ag85) complex (a major protein component from M. bovis BCG culture filtrate) could be detected in cattle as early as 10 weeks after oral M. avium subsp. paratuberculosis infection. Synthetic peptides from the Ag85A and Ag85B components of this complex were strongly recognized, whereas T-cell responses were weaker against peptides from the Ag85C protein. A promiscuous T-cell epitope spanning amino acids 145 to 162 of Ag85B (identical sequence in M. bovis and M. avium subsp. paratuberculosis) was identified in experimentally infected cattle. Finally, young calves, born from cows with confirmed paratuberculosis, demonstrated proliferative responses to purified, recombinant Ag85A and Ag85B from M. avium subsp. paratuberculosis. These results indicate that the M. avium subsp. paratuberculosis Ag85 homologues are immunodominant T-cell antigens that are recognized early in experimental and natural infection of cattle.

scholarly journals Targeting CD38 is lethal to Breg-like chronic lymphocytic leukemia cells and Tregs, but restores CD8+ T-cell responses

2020 ◽  
Vol 4 (10) ◽  
pp. 2143-2157 ◽  
Author(s):  
Alak Manna ◽  
Timothy Kellett ◽  
Sonikpreet Aulakh ◽  
Laura J. Lewis-Tuffin ◽  
Navnita Dutta ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
Cd8 T Cells ◽  
Mononuclear Cells ◽  
Transforming Growth Factor ◽  
Ex Vivo ◽  
Xenograft Model ◽  
Lymphocytic Leukemia ◽  
Dependent Manner

Abstract Patients with chronic lymphocytic leukemia (CLL) are characterized by monoclonal expansion of CD5+CD23+CD27+CD19+κ/λ+ B lymphocytes and are clinically noted to have profound immune suppression. In these patients, it has been recently shown that a subset of B cells possesses regulatory functions and secretes high levels of interleukin 10 (IL-10). Our investigation identified that CLL cells with a CD19+CD24+CD38hi immunophenotype (B regulatory cell [Breg]–like CLL cells) produce high amounts of IL-10 and transforming growth factor β (TGF-β) and are capable of transforming naive T helper cells into CD4+CD25+FoxP3+ T regulatory cells (Tregs) in an IL-10/TGF-β-dependent manner. A strong correlation between the percentage of CD38+ CLL cells and Tregs was observed. CD38hi Tregs comprised more than 50% of Tregs in peripheral blood mononuclear cells (PBMCs) in patients with CLL. Anti-CD38 targeting agents resulted in lethality of both Breg-like CLL and Treg cells via apoptosis. Ex vivo, use of anti-CD38 monoclonal antibody (mAb) therapy was associated with a reduction in IL-10 and CLL patient-derived Tregs, but an increase in interferon-γ and proliferation of cytotoxic CD8+ T cells with an activated phenotype, which showed an improved ability to lyse patient-autologous CLL cells. Finally, effects of anti-CD38 mAb therapy were validated in a CLL–patient-derived xenograft model in vivo, which showed decreased percentage of Bregs, Tregs, and PD1+CD38hiCD8+ T cells, but increased Th17 and CD8+ T cells (vs vehicle). Altogether, our results demonstrate that targeting CD38 in CLL can modulate the tumor microenvironment; skewing T-cell populations from an immunosuppressive to immune-reactive milieu, thus promoting immune reconstitution for enhanced anti-CLL response.

scholarly journals Adult Renal Stem/Progenitor Cells Can Modulate T Regulatory Cells and Double Negative T Cells

2020 ◽  
Vol 22 (1) ◽  
pp. 274
Author(s):  
Claudia Curci ◽  
Angela Picerno ◽  
Nada Chaoul ◽  
Alessandra Stasi ◽  
Giuseppe De Palma ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Progenitor Cells ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Double Negative ◽  
Chronic Injury ◽  
Peripheral Blood Mononuclear ◽  
Cell Subpopulations ◽  
T Cell Subpopulations

Adult Renal Stem/Progenitor Cells (ARPCs) have been recently identified in the human kidney and several studies show their active role in kidney repair processes during acute or chronic injury. However, little is known about their immunomodulatory properties and their capacity to regulate specific T cell subpopulations. We co-cultured ARPCs activated by triggering Toll-Like Receptor 2 (TLR2) with human peripheral blood mononuclear cells for 5 days and 15 days and studied their immunomodulatory capacity on T cell subpopulations. We found that activated-ARPCs were able to decrease T cell proliferation but did not affect CD8+ and CD4+ T cells. Instead, Tregs and CD3+ CD4- CD8- double-negative (DN) T cells decreased after 5 days and increased after 15 days of co-culture. In addition, we found that PAI1, MCP1, GM-CSF, and CXCL1 were significantly expressed by TLR2-activated ARPCs alone and were up-regulated in T cells co-cultured with activated ARPCs. The exogenous cocktail of cytokines was able to reproduce the immunomodulatory effects of the co-culture with activated ARPCs. These data showed that ARPCs can regulate immune response by inducing Tregs and DN T cells cell modulation, which are involved in the balance between immune tolerance and autoimmunity.

scholarly journals Analysis of CD4+ T-Cell Responses to Human Papillomavirus (HPV) Type 11 L1 in Healthy Adults Reveals a High Degree of Responsiveness and Cross-Reactivity with Other HPV Types

2002 ◽  
Vol 76 (15) ◽  
pp. 7418-7429 ◽  
Author(s):  
O. Martin Williams ◽  
Keith W. Hart ◽  
Eddie C. Y. Wang ◽  
Colin M. Gelder
Keyword(s):  
Human Papillomavirus ◽  
T Cell ◽  
In Vitro Selection ◽  
Mononuclear Cells ◽  
Ex Vivo ◽  
T Cell Responses ◽  
Cross Reactivity ◽  
Peripheral Blood Mononuclear ◽  
Cell Responses ◽  
Hpv Types

ABSTRACT Human papillomavirus type 11 (HPV-11) infection causes genital warts and recurrent respiratory papillomatosis. While there is compelling evidence that CD4+ T cells play an important role in immune surveillance of HPV-associated diseases, little is known about human CD4+ T-cell recognition of HPV-11. We have investigated the CD4+ T-cell responses of 25 unrelated healthy donors to HPV-11 L1 virus-like particles (VLP). CD4+ T-cell lines from 21 of 25 donors were established. Cell sorting experiments carried out on cells from six donors demonstrated that the response was located in the CD45RAlow CD45ROhigh memory T-cell population. To determine the peptide specificity of these responses, epitope selection was analyzed by using 95 15-mer peptides spanning the entire HPV-11 L1 protein. No single region of L1 was immunodominant; responders recognized between 1 and 10 peptides, located throughout the protein, and peptide responses fell into clear HLA class II restricted patterns. Panels of L1 peptides specific for skin and genital HPV were used to show that the L1 CD4+ T-cell responses were cross-reactive. The degree of cross-reactivity was inversely related to the degree of L1 sequence diversity between these viruses. Finally, responses to HPV-11 L1 peptides were elicited from ex vivo CD45RO+ peripheral blood mononuclear cells, demonstrating that recognition of HPV-11 was a specific memory response and not due to in vitro selection during tissue culture. This is the first study of CD4+ T-cell responses to HPV-11 in healthy subjects and demonstrates marked cross-reactivity with other skin and genital HPV types. This cross-reactivity may be of significance for vaccine strategies against HPV-associated clinical diseases.

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