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1.
Vaccine ; 38(48): 7612-7628, 2020 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-33082015

RESUMO

SARS-CoV-2 causes a severe respiratory disease called COVID-19. Currently, global health is facing its devastating outbreak. However, there is no vaccine available against this virus up to now. In this study, a novel multi-epitope vaccine against SARS-CoV-2 was designed to provoke both innate and adaptive immune responses. The immunodominant regions of six non-structural proteins (nsp7, nsp8, nsp9, nsp10, nsp12 and nsp14) of SARS-CoV-2 were selected by multiple immunoinformatic tools to provoke T cell immune response. Also, immunodominant fragment of the functional region of SARS-CoV-2 spike (400-510 residues) protein was selected for inducing neutralizing antibodies production. The selected regions' sequences were connected to each other by furin-sensitive linker (RVRR). Moreover, the functional region of ß-defensin as a well-known agonist for the TLR-4/MD complex was added at the N-terminus of the vaccine using (EAAAK)3 linker. Also, a CD4 + T-helper epitope, PADRE, was used at the C-terminal of the vaccine by GPGPG and A(EAAAK)2A linkers to form the final vaccine construct. The physicochemical properties, allergenicity, antigenicity, functionality and population coverage of the final vaccine construct were analyzed. The final vaccine construct was an immunogenic, non-allergen and unfunctional protein which contained multiple CD8 + and CD4 + overlapping epitopes, IFN-γ inducing epitopes, linear and conformational B cell epitopes. It could form stable and significant interactions with TLR-4/MD according to molecular docking and dynamics simulations. Global population coverage of the vaccine for HLA-I and II were estimated 96.2% and 97.1%, respectively. At last, the final vaccine construct was reverse translated to design the DNA vaccine. Although the designed vaccine exhibited high efficacy in silico, further experimental validation is necessary.


Assuntos
Anticorpos Antivirais/biossíntese , Betacoronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Glicoproteína da Espícula de Coronavírus/imunologia , Proteínas não Estruturais Virais/imunologia , Vacinas Virais/biossíntese , Sequência de Aminoácidos , Betacoronavirus/patogenicidade , Biologia Computacional , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/genética , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/virologia , Epitopos de Linfócito B/química , Epitopos de Linfócito B/genética , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/química , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Antígenos de Histocompatibilidade Classe I/química , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe II/química , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Imunidade Inata/efeitos dos fármacos , Imunogenicidade da Vacina , Simulação de Acoplamento Molecular , Pneumonia Viral/epidemiologia , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Ligação Proteica , Estrutura Secundária de Proteína , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Vacinas Atenuadas , Vacinas de DNA , Vacinas de Subunidades , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/genética , Vacinas Virais/genética , Vacinas Virais/metabolismo
2.
Front Immunol ; 11: 1836, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32983097

RESUMO

Examining CD8+ and CD4+ T cell responses after primary Yellow Fever vaccination in a cohort of 210 volunteers, we have identified and tetramer-validated 92 CD8+ and 50 CD4+ T cell epitopes, many inducing strong and prevalent (i.e., immunodominant) T cell responses. Restricted by 40 and 14 HLA-class I and II allotypes, respectively, these responses have wide population coverage and might be of considerable academic, diagnostic and therapeutic interest. The broad coverage of epitopes and HLA overcame the otherwise confounding effects of HLA diversity and non-HLA background providing the first evidence of T cell immunodomination in humans. Also, double-staining of CD4+ T cells with tetramers representing the same HLA-binding core, albeit with different flanking regions, demonstrated an extensive diversification of the specificities of many CD4+ T cell responses. We suggest that this could reduce the risk of pathogen escape, and that multi-tetramer staining is required to reveal the true magnitude and diversity of CD4+ T cell responses. Our T cell epitope discovery approach uses a combination of (1) overlapping peptides representing the entire Yellow Fever virus proteome to search for peptides containing CD4+ and/or CD8+ T cell epitopes, (2) predictors of peptide-HLA binding to suggest epitopes and their restricting HLA allotypes, (3) generation of peptide-HLA tetramers to identify T cell epitopes, and (4) analysis of ex vivo T cell responses to validate the same. This approach is systematic, exhaustive, and can be done in any individual of any HLA haplotype. It is all-inclusive in the sense that it includes all protein antigens and peptide epitopes, and encompasses both CD4+ and CD8+ T cell epitopes. It is efficient and, importantly, reduces the false discovery rate. The unbiased nature of the T cell epitope discovery approach presented here should support the refinement of future peptide-HLA class I and II predictors and tetramer technologies, which eventually should cover all HLA class I and II isotypes. We believe that future investigations of emerging pathogens (e.g., SARS-CoV-2) should include population-wide T cell epitope discovery using blood samples from patients, convalescents and/or long-term survivors, who might all hold important information on T cell epitopes and responses.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Epitopos de Linfócito T/imunologia , Vacinação , Vacina contra Febre Amarela/imunologia , Febre Amarela/prevenção & controle , Vírus da Febre Amarela/imunologia , Betacoronavirus/imunologia , Estudos de Coortes , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/virologia , Voluntários Saudáveis , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Imunogenicidade da Vacina , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Pneumonia Viral/virologia , Febre Amarela/virologia
3.
PLoS Pathog ; 16(8): e1008685, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32745153

RESUMO

Smallpox and monkeypox pose severe threats to human health. Other orthopoxviruses are comparably virulent in their natural hosts, including ectromelia, the cause of mousepox. Disease severity is linked to an array of immunomodulatory proteins including the B22 family, which has homologs in all pathogenic orthopoxviruses but not attenuated vaccine strains. We demonstrate that the ectromelia B22 member, C15, is necessary and sufficient for selective inhibition of CD4+ but not CD8+ T cell activation by immunogenic peptide and superantigen. Inhibition is achieved not by down-regulation of surface MHC- II or co-stimulatory protein surface expression but rather by interference with antigen presentation. The appreciable outcome is interference with CD4+ T cell synapse formation as determined by imaging studies and lipid raft disruption. Consequently, CD4+ T cell activating stimulus shifts to uninfected antigen-presenting cells that have received antigen from infected cells. This work provides insight into the immunomodulatory strategies of orthopoxviruses by elucidating a mechanism for specific targeting of CD4+ T cell activation, reflecting the importance of this cell type in control of the virus.


Assuntos
Apresentação do Antígeno/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Vírus da Ectromelia/imunologia , Ectromelia Infecciosa/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Proteínas Virais/imunologia , Animais , Ectromelia Infecciosa/metabolismo , Ectromelia Infecciosa/virologia , Feminino , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Proteínas Virais/metabolismo , Virulência
4.
Nature ; 584(7822): 624-629, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32788723

RESUMO

Conventional type 1 dendritic cells (cDC1)1 are thought to perform antigen cross-presentation, which is required to prime CD8+ T cells2,3, whereas cDC2 are specialized for priming CD4+ T cells4,5. CD4+ T cells are also considered to help CD8+ T cell responses through a variety of mechanisms6-11, including a process whereby CD4+ T cells 'license' cDC1 for CD8+ T cell priming12. However, this model has not been directly tested in vivo or in the setting of help-dependent tumour rejection. Here we generated an Xcr1Cre mouse strain to evaluate the cellular interactions that mediate tumour rejection in a model requiring CD4+ and CD8+ T cells. As expected, tumour rejection required cDC1 and CD8+ T cell priming required the expression of major histocompatibility class I molecules by cDC1. Unexpectedly, early priming of CD4+ T cells against tumour-derived antigens also required cDC1, and this was not simply because they transport antigens to lymph nodes for processing by cDC2, as selective deletion of major histocompatibility class II molecules in cDC1 also prevented early CD4+ T cell priming. Furthermore, deletion of either major histocompatibility class II or CD40 in cDC1 impaired tumour rejection, consistent with a role for cognate CD4+ T cell interactions and CD40 signalling in cDC1 licensing. Finally, CD40 signalling in cDC1 was critical not only for CD8+ T cell priming, but also for initial CD4+ T cell activation. Thus, in the setting of tumour-derived antigens, cDC1 function as an autonomous platform capable of antigen processing and priming for both CD4+ and CD8+ T cells and of the direct orchestration of their cross-talk that is required for optimal anti-tumour immunity.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Apresentação Cruzada , Células Dendríticas/imunologia , Neoplasias/imunologia , Animais , Apresentação do Antígeno/imunologia , Linfócitos T CD4-Positivos/citologia , Antígenos CD40/imunologia , Antígenos CD40/metabolismo , Linfócitos T CD8-Positivos/imunologia , Células Dendríticas/citologia , Células Dendríticas/metabolismo , Feminino , Antígenos de Histocompatibilidade Classe II/imunologia , Camundongos , Transdução de Sinais
5.
Int J Infect Dis ; 98: 454-459, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32693089

RESUMO

Genetic factors such as the HLA type of patients may play a role in regard to disease severity and clinical outcome of patients with COVID-19. Taking the data deposited in the GISAID database, we made predictions using the IEDB analysis resource (TepiTool) to gauge how variants in the SARS-CoV-2 genome may change peptide binding to the most frequent MHC-class I and -II alleles in Africa, Asia and Europe. We caracterized how a single mutation in the wildtype sequence of of SARS-CoV-2 could influence the peptide binding of SARS-CoV-2 variants to MHC class II, but not to MHC class I alleles. Assuming the ORF8 (L84S) mutation is biologically significant, selective pressure from MHC class II alleles may select for viral varients and subsequently shape the quality and quantity of cellular immune responses aginast SARS-CoV-2. MHC 4-digit typing along with viral sequence analysis should be considered in studies examining clinical outcomes in patients with COVID-19.


Assuntos
Betacoronavirus/fisiologia , Infecções por Coronavirus/genética , Infecções por Coronavirus/mortalidade , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe I/genética , Pneumonia Viral/genética , Pneumonia Viral/mortalidade , África , Alelos , Ásia , Betacoronavirus/genética , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Europa (Continente) , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Pandemias , Pneumonia Viral/imunologia , Pneumonia Viral/virologia
6.
Cell Syst ; 11(2): 131-144.e6, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32721383

RESUMO

We present a combinatorial machine learning method to evaluate and optimize peptide vaccine formulations for SARS-CoV-2. Our approach optimizes the presentation likelihood of a diverse set of vaccine peptides conditioned on a target human-population HLA haplotype distribution and expected epitope drift. Our proposed SARS-CoV-2 MHC class I vaccine formulations provide 93.21% predicted population coverage with at least five vaccine peptide-HLA average hits per person (≥ 1 peptide: 99.91%) with all vaccine peptides perfectly conserved across 4,690 geographically sampled SARS-CoV-2 genomes. Our proposed MHC class II vaccine formulations provide 97.21% predicted coverage with at least five vaccine peptide-HLA average hits per person with all peptides having an observed mutation probability of ≤ 0.001. We provide an open-source implementation of our design methods (OptiVax), vaccine evaluation tool (EvalVax), as well as the data used in our design efforts here: https://github.com/gifford-lab/optivax.


Assuntos
Betacoronavirus/imunologia , Haplótipos , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe I/genética , Análise de Sequência de DNA/métodos , Vacinas de Subunidades/imunologia , Vacinas Virais/imunologia , Betacoronavirus/genética , Infecções por Coronavirus/genética , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Epitopos/química , Epitopos/genética , Epitopos/imunologia , Antígenos de Histocompatibilidade Classe I/química , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe II/química , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Aprendizado de Máquina , Análise de Sequência de DNA/normas , Vacinas de Subunidades/química , Vacinas de Subunidades/genética , Vacinas Virais/química , Vacinas Virais/genética
7.
Proc Natl Acad Sci U S A ; 117(24): 13659-13669, 2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32482872

RESUMO

T cell maturation and activation depend upon T cell receptor (TCR) interactions with a wide variety of antigenic peptides displayed in a given major histocompatibility complex (MHC) context. Complementarity-determining region 3 (CDR3) is the most variable part of the TCRα and -ß chains, which govern interactions with peptide-MHC complexes. However, it remains unclear how the CDR3 landscape is shaped by individual MHC context during thymic selection of naïve T cells. We established two mouse strains carrying distinct allelic variants of H2-A and analyzed thymic and peripheral production and TCR repertoires of naïve conventional CD4+ T (Tconv) and naïve regulatory CD4+ T (Treg) cells. Compared with tuberculosis-resistant C57BL/6 (H2-Ab) mice, the tuberculosis-susceptible H2-Aj mice had fewer CD4+ T cells of both subsets in the thymus. In the periphery, this deficiency was only apparent for Tconv and was compensated for by peripheral reconstitution for Treg We show that H2-Aj favors selection of a narrower and more convergent repertoire with more hydrophobic and strongly interacting amino acid residues in the middle of CDR3α and CDR3ß, suggesting more stringent selection against a narrower peptide-MHC-II context. H2-Aj and H2-Ab mice have prominent reciprocal differences in CDR3α and CDR3ß features, probably reflecting distinct modes of TCR fitting to MHC-II variants. These data reveal the mechanics and extent of how MHC-II shapes the naïve CD4+ T cell CDR3 landscape, which essentially defines adaptive response to infections and self-antigens.


Assuntos
Regiões Determinantes de Complementaridade/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T Reguladores/imunologia , Tuberculose/genética , Alelos , Animais , Linfócitos T CD4-Positivos/imunologia , Regiões Determinantes de Complementaridade/química , Regiões Determinantes de Complementaridade/genética , Antígenos de Histocompatibilidade Classe II/genética , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Antígenos de Linfócitos T/química , Receptores de Antígenos de Linfócitos T/genética , Baço/imunologia , Linfócitos T Reguladores/química , Tuberculose/imunologia
10.
J Hum Genet ; 65(7): 569-575, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: covidwho-185840

RESUMO

To control and prevent the current COVID-19 pandemic, the development of novel vaccines is an emergent issue. In addition, we need to develop tools that can measure/monitor T-cell and B-cell responses to know how our immune system is responding to this deleterious virus. However, little information is currently available about the immune target epitopes of novel coronavirus (SARS-CoV-2) to induce host immune responses. Through a comprehensive bioinformatic screening of potential epitopes derived from the SARS-CoV-2 sequences for HLAs commonly present in the Japanese population, we identified 2013 and 1399 possible peptide epitopes that are likely to have the high affinity (<0.5%- and 2%-rank, respectively) to HLA class I and II molecules, respectively, that may induce CD8+ and CD4+ T-cell responses. These epitopes distributed across the structural (spike, envelope, membrane, and nucleocapsid proteins) and the nonstructural proteins (proteins corresponding to six open reading frames); however, we found several regions where high-affinity epitopes were significantly enriched. By comparing the sequences of these predicted T cell epitopes to the other coronaviruses, we identified 781 HLA-class I and 418 HLA-class II epitopes that have high homologies to SARS-CoV. To further select commonly-available epitopes that would be applicable to larger populations, we calculated population coverages based on the allele frequencies of HLA molecules, and found 2 HLA-class I epitopes covering 83.8% of the Japanese population. The findings in the current study provide us valuable information to design widely-available vaccine epitopes against SARS-CoV-2 and also provide the useful information for monitoring T-cell responses.


Assuntos
Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Grupo com Ancestrais do Continente Asiático/genética , Sequência de Bases , Betacoronavirus/imunologia , Coronavirus/genética , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Epitopos de Linfócito T/química , Antígenos de Histocompatibilidade Classe I/química , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe II/química , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Mutação , Fases de Leitura Aberta , Vírus da SARS/imunologia , Vacinas Virais/imunologia
11.
Nat Commun ; 11(1): 2550, 2020 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-32439962

RESUMO

The inherent molecular complexity of human pathogens requires that mammals evolved an adaptive immune system equipped to handle presentation of non-conventional MHC ligands derived from disease-causing agents, such as HIV-1 envelope (Env) glycoprotein. Here, we report that a CD4+ T cell repertoire recognizes a glycopeptide epitope on gp120 presented by MHCII pathway. This glycopeptide is strongly immunogenic in eliciting glycan-dependent cellular and humoral immune responses. The glycopeptide specific CD4+ T cells display a prominent feature of Th2 and Th17 differentiation and exert high efficacy and potency to help Env trimer humoral immune responses. Glycopeptide-induced CD4+ T cell response prior to Env trimer immunization elicits neutralizing antibody development and production of antibodies facilitating uptake of immunogens by antigen-presenting cells. Our identification of gp120 glycopeptide-induced, T cell-specific immune responses offers a foundation for developing future knowledge-based vaccines that elicit strong and long-lasting protective immune responses against HIV-1 infection.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Epitopos de Linfócito T/imunologia , Proteína gp120 do Envelope de HIV/imunologia , HIV-1/imunologia , Imunidade Humoral/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Neutralizantes/imunologia , Citocinas/metabolismo , Epitopos de Linfócito T/química , Glicopeptídeos/química , Glicopeptídeos/imunologia , Anticorpos Anti-HIV/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Imunidade Celular , Imunização , Camundongos , Polissacarídeos/imunologia , Células Th17/imunologia , Células Th2/imunologia
12.
J Hum Genet ; 65(7): 569-575, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32372051

RESUMO

To control and prevent the current COVID-19 pandemic, the development of novel vaccines is an emergent issue. In addition, we need to develop tools that can measure/monitor T-cell and B-cell responses to know how our immune system is responding to this deleterious virus. However, little information is currently available about the immune target epitopes of novel coronavirus (SARS-CoV-2) to induce host immune responses. Through a comprehensive bioinformatic screening of potential epitopes derived from the SARS-CoV-2 sequences for HLAs commonly present in the Japanese population, we identified 2013 and 1399 possible peptide epitopes that are likely to have the high affinity (<0.5%- and 2%-rank, respectively) to HLA class I and II molecules, respectively, that may induce CD8+ and CD4+ T-cell responses. These epitopes distributed across the structural (spike, envelope, membrane, and nucleocapsid proteins) and the nonstructural proteins (proteins corresponding to six open reading frames); however, we found several regions where high-affinity epitopes were significantly enriched. By comparing the sequences of these predicted T cell epitopes to the other coronaviruses, we identified 781 HLA-class I and 418 HLA-class II epitopes that have high homologies to SARS-CoV. To further select commonly-available epitopes that would be applicable to larger populations, we calculated population coverages based on the allele frequencies of HLA molecules, and found 2 HLA-class I epitopes covering 83.8% of the Japanese population. The findings in the current study provide us valuable information to design widely-available vaccine epitopes against SARS-CoV-2 and also provide the useful information for monitoring T-cell responses.


Assuntos
Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Grupo com Ancestrais do Continente Asiático/genética , Sequência de Bases , Betacoronavirus/imunologia , Coronavirus/genética , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Epitopos de Linfócito T/química , Antígenos de Histocompatibilidade Classe I/química , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe II/química , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Mutação , Fases de Leitura Aberta , Vírus da SARS/imunologia , Vacinas Virais/imunologia
13.
PLoS One ; 15(5): e0233497, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32442182

RESUMO

Mixed hematopoietic chimerism enables donor-specific tolerance for solid organ grafts. This study evaluated the influence of different serological major histocompatibility complex disparities on chimerism development, graft-versus-host disease incidence and subsequently on solid organ tolerance in a rat model. For bone marrow transplantation conditioning total body irradiation was titrated using 10, 8 or 6 Gray. Bone marrow transplantation was performed across following major histocompatibility complex mismatched barriers: complete disparity, MHC class II, MHC class I or non-MHC mismatch. Recipients were clinically monitored for graft-versus-host disease and analyzed for chimerism using flow cytometry. After a reconstitution of 100 days, composition of peripheral leukocytes was determined. Mixed chimeras were challenged with heart grafts from allogeneic donor strains to define the impact of donor MHC class disparities on solid organ tolerance on the basis of stable chimerism. After myeloablation with 10 Gray of total body irradiation, chimerism after bone marrow transplantation was induced independent of MHC disparity. MHC class II disparity increased the incidence of graft-versus-host disease and reduced induction of stable chimerism upon myelosuppressive total body irradiation with 8 and 6 Gray, respectively. Stable mixed chimeras showed tolerance towards heart grafts from donors with MHC matched to either bone marrow donors or recipients. Isolated matching of MHC class II with bone marrow donors likewise led to stable tolerance as opposed to matching of MHC class I. In summary, MHC class II disparity was critically associated with the onset of graft-versus host disease and was identified as obstacle for successful development of chimerism after bone marrow transplantation and subsequent donor-specific solid organ tolerance.


Assuntos
Transplante de Medula Óssea , Antígenos de Histocompatibilidade Classe II/imunologia , Quimeras de Transplante/imunologia , Tolerância ao Transplante/imunologia , Aloenxertos , Animais , Doença Enxerto-Hospedeiro/imunologia , Transplante de Coração , Humanos , Masculino , Modelos Animais , Modelos Imunológicos , Transplante de Órgãos , Ratos , Ratos Endogâmicos BN , Ratos Endogâmicos Lew , Doadores de Tecidos , Condicionamento Pré-Transplante , Irradiação Corporal Total
14.
Transplant Proc ; 52(4): 1192-1197, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32197864

RESUMO

In 2013, the International Society of Heart and Lung Transplant (ISHLT) introduced the working classification for pathologic changes associated with antibody-mediated rejection (AMR) of the heart allograft, known as pathologic AMR (pAMR). With 2 components associated with AMR, histopathologic changes) and immunopathologic markers, the proposed classification also suggests the use of class II HLA as a marker of endothelial integrity. It is known that during allograft rejection, endothelial cells are activated, therefore, we hypothesized that endothelial class II HLA rather than a marker of mere endothelial presence, is a marker of endothelial activation and becomes upregulated in AMR. Eight hundred thirty-eight heart allograft biopsies, collected from January 2016 to September 2018 at a single institution from patients with a current or recent diagnosis of AMR, were evaluated for both histopathologic and immunopathologic changes of AMR. Biopsies were labeled with immunofluorescence with antibodies against C4d and for immunohistochemistry with antibodies against C3d, CD68, and class II HLA. ISHLT criteria were used to classify the biopsies, and for class II HLA, both the percentage and the stain intensity were evaluated. Biopsies (74.8%) from our cohort showed either histopathologic pAMR-1, immunopathologic pAMR-1, or combined histopathologic and immunopathologic pAMR-2 evidence of AMR. Expression of endothelial HLA class II was significantly correlated with the diagnosis of AMR by percentage area (P < .0001) and intensity of staining (P < .0001). The diagnosis of AMR significantly correlated with moderate (+2) and strong (+3) staining intensity for class II HLA as follows: histopathologic and immunopathologic pAMR-2 with odds ratio (OR) = 28.3 (P < .0001);histopathologic pAMR-1 alone with OR = 22.7 (P < .0001); and immunopathologic pAMR-1 alone with OR = 32.6 (P < .0001). Interestingly, our study also suggested that the inclusion of C4d focally positive cases also significantly correlates with the diagnosis of AMR (P < .003). We confirmed our hypothesis that in heart allograft biopsies, there is a spectrum of both percentage and intensity of HLA class II expression due to endothelial activation, and that class II HLA by immunohistochemistry is a marker significantly correlated with the diagnosis of AMR. In addition, the group of focally positive C4d biopsies (10%-50%) should be considered positive for the immunopathologic component of the 2013 ISHLT classification, as this group of biopsies also correlated with the diagnosis of AMR.


Assuntos
Células Endoteliais/metabolismo , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/imunologia , Transplante de Coração/efeitos adversos , Antígenos de Histocompatibilidade Classe II/metabolismo , Adulto , Aloenxertos/imunologia , Biomarcadores/metabolismo , Biópsia , Estudos de Coortes , Feminino , Antígenos de Histocompatibilidade Classe II/análise , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Regulação para Cima , Adulto Jovem
15.
PLoS Pathog ; 16(3): e1008243, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32203551

RESUMO

Trichuris trichiura is a parasite that infects 500 million people worldwide, leading to colitis, growth retardation and Trichuris dysentery syndrome. There are no licensed vaccines available to prevent Trichuris infection and current treatments are of limited efficacy. Trichuris infections are linked to poverty, reducing children's educational performance and the economic productivity of adults. We employed a systematic, multi-stage process to identify a candidate vaccine against trichuriasis based on the incorporation of selected T-cell epitopes into virus-like particles. We conducted a systematic review to identify the most appropriate in silico prediction tools to predict histocompatibility complex class II (MHC-II) molecule T-cell epitopes. These tools were used to identify candidate MHC-II epitopes from predicted ORFs in the Trichuris genome, selected using inclusion and exclusion criteria. Selected epitopes were incorporated into Hepatitis B core antigen virus-like particles (VLPs). Bone marrow-derived dendritic cells and bone marrow-derived macrophages responded in vitro to VLPs irrespective of whether the VLP also included T-cell epitopes. The VLPs were internalized and co-localized in the antigen presenting cell lysosomes. Upon challenge infection, mice vaccinated with the VLPs+T-cell epitopes showed a significantly reduced worm burden, and mounted Trichuris-specific IgM and IgG2c antibody responses. The protection of mice by VLPs+T-cell epitopes was characterised by the production of mesenteric lymph node (MLN)-derived Th2 cytokines and goblet cell hyperplasia. Collectively our data establishes that a combination of in silico genome-based CD4+ T-cell epitope prediction, combined with VLP delivery, offers a promising pipeline for the development of an effective, safe and affordable helminth vaccine.


Assuntos
Epitopos de Linfócito T/imunologia , Tricuríase/prevenção & controle , Trichuris/imunologia , Vacinas/imunologia , Animais , Anticorpos Anti-Helmínticos/imunologia , Simulação por Computador , Células Dendríticas/imunologia , Epitopos de Linfócito T/administração & dosagem , Epitopos de Linfócito T/genética , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Imunogenicidade da Vacina , Macrófagos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Tricuríase/imunologia , Tricuríase/parasitologia , Trichuris/genética , Vacinas/administração & dosagem , Vacinas/genética
16.
Cancer Invest ; 38(4): 228-239, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32208057

RESUMO

The aim of this study was to characterize both by flow cytometry analysis and immunohistochemistry cervix uteri cells of nulliparous women screened for cervical intraepithelial neoplasia (CIN) in comparison to a group without CIN by using mesenchymal stem cell-like and hematopoietic lineage markers. A significant expression for CD29, CD38, HLA-I, and HLA-II was correlated positively to the CIN degree and it was more relevant in patients positive for human papilloma virus (HPV). Thus, identification and detailed characterization of pluripotent resident in uteri cells could be a promising therapeutic target.


Assuntos
Neoplasia Intraepitelial Cervical/patologia , Colo do Útero/citologia , Células-Tronco Neoplásicas/patologia , Infecções por Papillomavirus/patologia , Neoplasias do Colo do Útero/patologia , ADP-Ribosil Ciclase 1/análise , ADP-Ribosil Ciclase 1/imunologia , ADP-Ribosil Ciclase 1/metabolismo , Adulto , Biópsia , Neoplasia Intraepitelial Cervical/imunologia , Neoplasia Intraepitelial Cervical/virologia , Colo do Útero/imunologia , Colo do Útero/patologia , Colo do Útero/virologia , Inibidor p16 de Quinase Dependente de Ciclina/análise , Inibidor p16 de Quinase Dependente de Ciclina/imunologia , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Feminino , Citometria de Fluxo , Antígenos de Histocompatibilidade Classe I/análise , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Antígenos de Histocompatibilidade Classe II/análise , Antígenos de Histocompatibilidade Classe II/imunologia , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Imuno-Histoquímica , Imunofenotipagem , Integrina beta1/análise , Integrina beta1/imunologia , Integrina beta1/metabolismo , Glicoproteínas de Membrana/análise , Glicoproteínas de Membrana/imunologia , Glicoproteínas de Membrana/metabolismo , Gradação de Tumores , Células-Tronco Neoplásicas/imunologia , Células-Tronco Neoplásicas/virologia , Papillomaviridae/imunologia , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/imunologia , Infecções por Papillomavirus/virologia , Estudos Prospectivos , Neoplasias do Colo do Útero/imunologia , Neoplasias do Colo do Útero/prevenção & controle , Neoplasias do Colo do Útero/virologia
17.
Cancer Res ; 80(12): 2575-2585, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32107211

RESUMO

Because of the high coverage of international vaccination programs, most people worldwide have been vaccinated against common pathogens, leading to acquired pathogen-specific immunity with a robust memory T-cell repertoire. Although CD8+ antitumor cytotoxic T lymphocytes (CTL) are the preferred effectors of cancer immunotherapy, CD4+ T-cell help is also required for an optimal antitumor immune response to occur. Hence, we investigated whether the pathogen-related CD4+ T-cell memory populations could be reengaged to support the CTLs, converting a weak primary antitumor immune response into a stronger secondary one. To this end, we used our PeptiCRAd technology that consists of an oncolytic adenovirus coated with MHC-I-restricted tumor-specific peptides and developed it further by introducing pathogen-specific MHC-II-restricted peptides. Mice preimmunized with tetanus vaccine were challenged with B16.OVA tumors and treated with the newly developed hybrid TT-OVA-PeptiCRAd containing both tetanus toxoid- and tumor-specific peptides. Treatment with the hybrid PeptiCRAd significantly enhanced antitumor efficacy and induced TT-specific, CD40 ligand-expressing CD4+ T helper cells and maturation of antigen-presenting cells. Importantly, this approach could be extended to naturally occurring tumor peptides (both tumor-associated antigens and neoantigens), as well as to other pathogens beyond tetanus, highlighting the usefulness of this technique to take full advantage of CD4+ memory T-cell repertoires when designing immunotherapeutic treatment regimens. Finally, the antitumor effect was even more prominent when combined with the immune checkpoint inhibitor anti-PD-1, strengthening the rationale behind combination therapy with oncolytic viruses. SIGNIFICANCE: These findings establish a novel technology that enhances oncolytic cancer immunotherapy by capitalizing on pre-acquired immunity to pathogens to convert a weak antitumor immune response into a much stronger one.


Assuntos
Vacinas Anticâncer/administração & dosagem , Vacina contra Difteria, Tétano e Coqueluche/administração & dosagem , Memória Imunológica , Imunoterapia/métodos , Melanoma Experimental/terapia , Vacina Antipólio de Vírus Inativado/administração & dosagem , Adenoviridae/genética , Adenoviridae/imunologia , Animais , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Antineoplásicos Imunológicos/administração & dosagem , Linfócitos T CD4-Positivos/imunologia , Vacinas Anticâncer/imunologia , Linhagem Celular Tumoral/transplante , Vacina contra Difteria, Tétano e Coqueluche/imunologia , Feminino , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Melanoma Experimental/imunologia , Melanoma Experimental/patologia , Camundongos , Vírus Oncolíticos/genética , Vírus Oncolíticos/imunologia , Vacina Antipólio de Vírus Inativado/imunologia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia , Linfócitos T Citotóxicos/imunologia , Vacinas Combinadas/administração & dosagem , Vacinas Combinadas/imunologia
18.
Infect Immun ; 88(5)2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32071068

RESUMO

Brucella spp. are facultative intracellular bacteria notorious for their ability to induce a chronic, and often lifelong, infection known as brucellosis. To date, no licensed vaccine exists for prevention of human disease, and mechanisms underlying chronic illness and immune evasion remain elusive. We and others have observed that B cell-deficient mice challenged with Brucella display reduced bacterial burden following infection, but the underlying mechanism has not been clearly defined. Here, we show that at 1 month postinfection, B cell deficiency alone enhanced resistance to splenic infection ∼100-fold; however, combined B and T cell deficiency did not impact bacterial burden, indicating that B cells only enhance susceptibility to infection when T cells are present. Therefore, we investigated whether B cells inhibit T cell-mediated protection against Brucella Using B and T cell-deficient Rag1-/- animals as recipients, we demonstrate that adoptive transfer of CD4+ T cells alone confers marked protection against Brucella melitensis that is abrogated by cotransfer of B cells. Interestingly, depletion of CD4+ T cells from B cell-deficient, but not wild-type, mice enhanced susceptibility to infection, further confirming that CD4+ T cell-mediated immunity against Brucella is inhibited by B cells. In addition, we found that the ability of B cells to suppress CD4+ T cell-mediated immunity and modulate CD4+ T cell effector responses during infection was major histocompatibility complex class II (MHCII)-dependent. Collectively, these findings indicate that B cells modulate CD4+ T cell function through an MHCII-dependent mechanism which enhances susceptibility to Brucella infection.


Assuntos
Linfócitos B/imunologia , Brucella melitensis/imunologia , Brucelose/imunologia , Linfócitos T CD4-Positivos/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Transferência Adotiva/métodos , Animais , Vacina contra Brucelose/imunologia , Proteínas de Homeodomínio/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Baço/imunologia
19.
Sci Rep ; 10(1): 2367, 2020 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-32047235

RESUMO

The effect of donor-specific anti-human leukocyte antigen (HLA) antibodies (DSAs) has been recognized as a factor in graft failure (GF) in patients who underwent umbilical cord blood transplantation (UBT), matched unrelated donor transplantation (MUDT), or haploidentical stem cell transplantation (haplo-SCT). Presently, we know little about the prevalence of and risk factors for having anti-HLA antibodies among older transplant candidates. Therefore, we analyzed 273 older patients with hematologic disease who were waiting for haplo-SCT. Among all patients, 73 (26.7%) patients had a positive panel-reactive antibody (PRA) result for class I, 38 (13.9%) for class II, and 32 (11.7%) for both. Multivariate analysis showed that females were at a higher risk for having a PRA result for class II (P = 0.001) and for having antibodies against HLA-C and HLA-DQ. Prior pregnancy was a risk factor for having a PRA result for class I (P < 0.001) and for having antibodies against HLA-A, HLA-B and HLA-DQ. Platelet transfusions were risk factors for the following: having a positive PRA result for class I (P = 0.014) and class II (P < 0.001); having antibodies against HLA-A, HLA-B, HLA-C, HLA-DP, HLA-DQ, and HLA-DR; and having higher mean fluorescence intensity (MFI) of PRA for class I (P = 0.042). In addition, previous total transfusions were at high risk for having higher numbers of antibodies to specific HLA loci (P = 0.005), and disease course (7.5 months or more) (P = 0.020) were related to higher MFI of PRAs for class I. Our findings indicated that female sex, prior pregnancy, platelet transfusions and disease courses are independent risk factors for older patients with hematologic disease for having anti-HLA antibodies, which could guide anti-HLA antibody monitoring and be helpful for donor selection.


Assuntos
Doenças Autoimunes/epidemiologia , Transplante de Medula Óssea/efeitos adversos , Doença Enxerto-Hospedeiro/epidemiologia , Antígenos de Histocompatibilidade Classe II/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Fatores Etários , Idoso , Feminino , Haplótipos , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe II/genética , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores Sexuais , Transplante Homólogo
20.
J Immunol ; 204(6): 1630-1640, 2020 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-32034060

RESUMO

MHC class II (MHC-II) molecules play a crucial role in cellular and humoral immunity by forming peptide-MHC-II (pMHC-II) complexes. The three-dimensional structures of pMHC-II complexes have been well resolved in humans and mice. However, there is no structural information for pMHC-II complexes in nonmammals. In chickens, there are two closely related and highly polymorphic ß-chains and one monomorphic α-chain, and the mechanism by which one monomorphic α-chain combines with two polymorphic ß-chains to form a functional heterodimer remains unknown. In this study, we report the crystal structure of a chicken pMHC-II complex (pBL2*019:01) at 1.9-Å resolution as the first nonmammalian structure of a pMHC-II complex. The structure reveals an increase in hydrogen bonding between the α and ß main chains at the central interface that is introduced by the insertion of four residues in the α-chain. The residues in the ß-chain that form hydrogen bonds with the α-chain are conserved among all ß alleles. These structural characteristics explain the phenomenon of only one BLA allele without sequence variation pairing with highly diverse BLB alleles from two loci in the genome. Additionally, the characteristics of the peptide in the peptide-binding groove were confirmed. These results provide a new understanding of the pairing mechanism of the α- and ß-chains in a pMHC-II complex and establish a structural principle to design epitope-related vaccines for the prevention of chicken diseases.


Assuntos
Galinhas/imunologia , Genes MHC da Classe II/genética , Antígenos de Histocompatibilidade Classe II/ultraestrutura , Multimerização Proteica/imunologia , Estrutura Quaternária de Proteína , Animais , Apresentação do Antígeno/imunologia , Galinhas/genética , Cristalografia por Raios X , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Evolução Molecular , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/imunologia , Domínios Proteicos/genética , Domínios Proteicos/imunologia , Multimerização Proteica/genética
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