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1.
Viruses ; 12(5)2020 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-32397182

RESUMO

In the midst of the ongoing COVID-19 coronavirus pandemic, influenza virus remains a major threat to public health due to its potential to cause epidemics and pandemics with significant human mortality. Cases of H7N9 human infections emerged in eastern China in 2013 and immediately raised pandemic concerns as historically, pandemics were caused by the introduction of new subtypes into immunologically naïve human populations. Highly pathogenic H7N9 cases with severe disease were reported recently, indicating the continuing public health threat and the need for a prophylactic vaccine. Here we review the development of recombinant influenza virus-like particles (VLPs) as vaccines against H7N9 virus. Several approaches to vaccine development are reviewed including the expression of VLPs in mammalian, plant and insect cell expression systems. Although considerable progress has been achieved, including demonstration of safety and immunogenicity of H7N9 VLPs in the human clinical trials, the remaining challenges need to be addressed. These challenges include improvements to the manufacturing processes, as well as enhancements to immunogenicity in order to elicit protective immunity to multiple variants and subtypes of influenza virus.


Assuntos
Subtipo H7N9 do Vírus da Influenza A/imunologia , Vacinas contra Influenza/imunologia , Vacinas de Partículas Semelhantes a Vírus/genética , Animais , Antígenos Virais/imunologia , Ensaios Clínicos como Assunto , Epitopos , Antígenos de Histocompatibilidade Classe II , Humanos
2.
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
3.
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
4.
PLoS Negl Trop Dis ; 14(3): e0008093, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32176691

RESUMO

Human leishmaniasis is a public health problem worldwide for which the development of a vaccine remains a challenge. T cell-mediated immune responses are crucial for protection. Peptide vaccines based on the identification of immunodominant T cell epitopes able to induce T cell specific immune responses constitute a promising strategy. Here, we report the identification of human leukocyte antigen class-I (HLA-I) and -II (HLA-II)-restricted multi-epitope peptides from Leishmania proteins that we have previously described as vaccine candidates. Promastigote Surface Antigen (PSA), LmlRAB (L. major large RAB GTPase) and Histone (H2B) were screened, in silico, for T cell epitopes. 6 HLA-I and 5 HLA-II-restricted multi-epitope peptides, able to bind to the most frequent HLA molecules, were designed and used as pools to stimulate PBMCs from individuals with healed cutaneous leishmaniasis. IFN-γ, IL-10, TNF-α and granzyme B (GrB) production was evaluated by ELISA/CBA. The frequency of IFN-γ-producing T cells was quantified by ELISpot. T cells secreting cytokines and memory T cells were analyzed by flow cytometry. 16 of 25 peptide pools containing HLA-I, HLA-II or HLA-I and -II peptides were able to induce specific and significant IFN-γ levels. No IL-10 was detected. 6 peptide pools were selected among those inducing the highest IFN-γ levels for further characterization. 3/6 pools were able to induce a significant increase of the percentages of CD4+IFN-γ+, CD8+IFN-γ+ and CD4+GrB+ T cells. The same pools also induced a significant increase of the percentages of bifunctional IFN-γ+/TNF-α+CD4+ and/or central memory T cells. We identified highly promiscuous HLA-I and -II restricted epitope combinations from H2B, PSA and LmlRAB proteins that stimulate both CD4+ and CD8+ T cell responses in recovered individuals. These multi-epitope peptides could be used as potential components of a polytope vaccine for human leishmaniasis.


Assuntos
Antígenos de Protozoários/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Epitopos de Linfócito T/imunologia , Leishmania/imunologia , Leishmaniose Cutânea/imunologia , Proteínas Recombinantes de Fusão/imunologia , Adulto , Antígenos de Protozoários/genética , Ensaio de Imunoadsorção Enzimática , Epitopos de Linfócito T/genética , Feminino , Citometria de Fluxo , Granzimas/análise , Antígenos de Histocompatibilidade Classe I/metabolismo , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Interferon gama/análise , Interleucina-10/análise , Masculino , Pessoa de Meia-Idade , Ligação Proteica , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Fator de Necrose Tumoral alfa/análise , Voluntários , Adulto Jovem
5.
Life Sci ; 250: 117541, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32169520

RESUMO

AIM: Nontuberculous mycobacterial (NTM) infection such as endophthalmitis, dacryocystitis, and canaliculitis are pervasive across the globe and are currently managed by antibiotics. However, the recent cases of Mycobacteroides developing drug resistance reported along with the improper practice of medicine intrigued us to explore its genomic and proteomic canvas at a global scale and develop a chimeric vaccine against Mycobacteroides. MAIN METHODS: We carried out a vivid genomic study on five recently sequenced strains of Mycobacteroides and explored their Pan-core genome/proteome in three different phases. The promiscuous antigenic proteins were identified via a subtractive proteomics approach that qualified for virulence causation, resistance and essentiality factors for this notorious bacterium. An integrated pipeline was developed for the identification of B-Cell, MHC (Major histocompatibility complex) class I and II epitopes. KEY FINDINGS: Phase I identified the shreds of evidence of reductive evolution and propensity of the Pan-genome of Mycobacteroides getting closed soon. Phase II and Phase III produced 8 vaccine constructs. Our final vaccine construct, V6 qualified for all tests such as absence for allergenicity, presence of antigenicity, etc. V6 contains ß-defensin as an adjuvant, linkers, Lysosomal-associated membrane protein 1 (LAMP1) signal peptide, and PADRE (Pan HLA-DR epitopes) amino acid sequence. Besides, V6 also interacts with a maximum number of MHC molecules and the TLR4/MD2 (Toll-like receptor 4/Myeloid differentiation factor 2) complex confirmed by docking and molecular dynamics simulation studies. SIGNIFICANCE: The knowledge harnessed from the current study can help improve the current treatment regimens or in an event of an outbreak and propel further related studies.


Assuntos
Vacinas Bacterianas/química , Infecções por Bactérias Gram-Positivas/prevenção & controle , Mycobacteriaceae/genética , Vacinologia , Alelos , Linfócitos B/imunologia , Bacteriófagos , Sistemas CRISPR-Cas , Biologia Computacional , Farmacorresistência Bacteriana , Epitopos , Epitopos de Linfócito T/genética , Microbioma Gastrointestinal , Genoma Bacteriano , Genômica , Antígenos de Histocompatibilidade Classe I/metabolismo , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Imunoterapia , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Mycobacteriaceae/patogenicidade , Proteoma , Virulência
6.
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
7.
Proc Biol Sci ; 287(1922): 20200195, 2020 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-32156218

RESUMO

The impact of inbreeding on fitness has been widely studied and provides consequential inference about adaptive potential and the impact on survival for reduced and fragmented natural populations. Correlations between heterozygosity and fitness are common in the literature, but they rarely inform about the likely mechanisms. Here, we investigate a pathology with a clear impact on health in striped dolphin hosts (a nematode infection that compromises lung function). Dolphins varied with respect to their parasite burden of this highly pathogenic lung nematode (Skrjabinalius guevarai). Genetic diversity revealed by high-resolution restriction-associated DNA (43 018 RADseq single nucleotide polymorphisms) analyses showed a clear association between heterozygosity and pathogen load, but only for female dolphins, for which the more heterozygous individuals had lower Sk. guevarai burden. One locus identified by RADseq was a strong outlier in association with parasite load (heterozygous in all uninfected females, homozygous for 94% of infected females), found in an intron of the citron rho-interacting serine/threonine kinase locus (associated with milk production in mammals). Allelic variation at the Class II major histocompatability complex DQB locus was also assessed and found to be associated with both regional variation and with pathogen load. Both sex specificity and the identification of associating functional loci provide insight into the mechanisms by which more inbred individuals may be more susceptible to the infection of this parasite. This provides important insight towards our understanding of the impact of inbreeding in natural populations, relevant to both evolutionary and practical conservation considerations.


Assuntos
Stenella/parasitologia , Animais , Evolução Biológica , Feminino , Aptidão Genética , Heterozigoto , Antígenos de Histocompatibilidade Classe II , Endogamia/estatística & dados numéricos , Masculino , Infecções por Nematoides/veterinária , Seleção Genética , Stenella/fisiologia
8.
PLoS One ; 15(2): e0228658, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32012208

RESUMO

BACKGROUND: Polymorphism of major histocompatibility complex (MHC) genes ensures effective immune responses against a wide array of pathogens. However, artificial selection, as performed in the case of domestic animals, may influence MHC diversity. Here, we investigate and compare the MHC diversity of three populations of horses, for which different breeding policies were applied, to evaluate the impact of artificial selection and the environment on MHC polymorphism. METHODS: Samples of DNA were taken from 100 Polish draft horses, 38 stabled Konik Polski horses and 32 semiferal Konik Polski horses. MHC alleles and haplotype diversity within and between these populations of horses was estimated from 11 MHC microsatellite loci. RESULTS: MHC diversity measured based on allelic richness, observed heterozygosity, expected heterozygosity and polymorphism content was similar across the MHC microsatellite loci in all three populations. The highest expected heterozygosity was detected in semiferal primitive horses (He = 0.74), while the lowest was calculated for draft horses (He = 0.65). In total, 203 haplotypes were determined (111 in Polish draft horses, 43 in semiferal Konik Polski horses and 49 in stabled Konik Polski horses), and four haplotypes were shared between the two populations of Koniks. None of these haplotypes were present in any of the previously investigated horse breeds. Intra-MHC recombination events were detected in all three populations. However, the population of semiferal Konik horses showed the highest recombination frequency among the three horse populations. In addition, three recombination events were detected. CONCLUSIONS: These results showed that despite the different breeding policies, the MHC allele and haplotype diversity was similarly high in all three horse populations. Nevertheless, the proportion of new haplotypes in the offspring was the highest in semiferal Konik Polski horses, which indicates the influence of the environment on MHC diversity in horses. Thus, we speculate that the genetic makeup of the domestic horse MHC might be more strongly influenced by the environment than by artificial selection. Moreover, intra-MHC conversion, insertion, and deletion and intra-MHC recombination may be proposed as mechanisms underlying the generation of new MHC haplotypes in horses.


Assuntos
Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe I/genética , Cavalos/genética , Polimorfismo Genético , Animais , Feminino , Haplótipos , Endogamia , Masculino , Repetições de Microssatélites , Recombinação Genética
9.
PLoS Pathog ; 16(2): e1008279, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32023327

RESUMO

IFN-γ is an enigmatic cytokine that shows direct anti-viral effects, confers upregulation of MHC-II and other components relevant for antigen presentation, and that adjusts the composition and balance of complex cytokine responses. It is produced during immune responses by innate as well as adaptive immune cells and can critically affect the course and outcome of infectious diseases, autoimmunity, and cancer. To selectively analyze the function of innate immune cell-derived IFN-γ, we generated conditional IFN-γOFF mice, in which endogenous IFN-γ expression is disrupted by a loxP flanked gene trap cassette inserted into the first intron of the IFN-γ gene. IFN-γOFF mice were intercrossed with Ncr1-Cre or CD4-Cre mice that express Cre mainly in NK cells (IFN-γNcr1-ON mice) or T cells (IFN-γCD4-ON mice), respectively. Rosa26RFP reporter mice intercrossed with Ncr1-Cre mice showed selective RFP expression in more than 80% of the NK cells, while upon intercrossing with CD4-Cre mice abundant RFP expression was detected in T cells, but also to a minor extent in other immune cell subsets. Previous studies showed that IFN-γ expression is needed to promote survival of vaccinia virus (VACV) infection. Interestingly, during VACV infection of wild type and IFN-γCD4-ON mice two waves of serum IFN-γ were induced that peaked on day 1 and day 3/4 after infection. Similarly, VACV infected IFN-γNcr1-ON mice mounted two waves of IFN-γ responses, of which the first one was moderately and the second one profoundly reduced when compared with WT mice. Furthermore, IFN-γNcr1-ON as well as IFN-γCD4-ON mice survived VACV infection, whereas IFN-γOFF mice did not. As expected, ex vivo analysis of splenocytes derived from VACV infected IFN-γNcr1-ON mice showed IFN-γ expression in NK cells, but not T cells, whereas IFN-γOFF mice showed IFN-γ expression neither in NK cells nor T cells. VACV infected IFN-γNcr1-ON mice mounted normal cytokine responses, restored neutrophil accumulation, and showed normal myeloid cell distribution in blood and spleen. Additionally, in these mice normal MHC-II expression was detected on peripheral macrophages, whereas IFN-γOFF mice did not show MHC-II expression on such cells. In conclusion, upon VACV infection Ncr1 positive cells including NK cells mount two waves of early IFN-γ responses that are sufficient to promote the induction of protective anti-viral immunity.


Assuntos
Antígenos Ly/imunologia , Regulação da Expressão Gênica/imunologia , Interferon gama/imunologia , Células Matadoras Naturais/imunologia , Receptor 1 Desencadeador da Citotoxicidade Natural/imunologia , Vírus Vaccinia/imunologia , Vaccinia/imunologia , Animais , Antígenos Ly/genética , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/imunologia , Interferon gama/genética , Células Matadoras Naturais/patologia , Camundongos , Camundongos Transgênicos , Receptor 1 Desencadeador da Citotoxicidade Natural/genética , Linfócitos T/imunologia , Linfócitos T/patologia , Vaccinia/genética , Vaccinia/patologia , Vírus Vaccinia/genética
10.
J Med Virol ; 92(6): 618-631, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32108359

RESUMO

Recently, a novel coronavirus (SARS-COV-2) emerged which is responsible for the recent outbreak in Wuhan, China. Genetically, it is closely related to SARS-CoV and MERS-CoV. The situation is getting worse and worse, therefore, there is an urgent need for designing a suitable peptide vaccine component against the SARS-COV-2. Here, we characterized spike glycoprotein to obtain immunogenic epitopes. Next, we chose 13 Major Histocompatibility Complex-(MHC) I and 3 MHC-II epitopes, having antigenic properties. These epitopes are usually linked to specific linkers to build vaccine components and molecularly dock on toll-like receptor-5 to get binding affinity. Therefore, to provide a fast immunogenic profile of these epitopes, we performed immunoinformatics analysis so that the rapid development of the vaccine might bring this disastrous situation to the end earlier.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Epitopos de Linfócito B/química , Epitopos de Linfócito T/química , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Glicoproteína da Espícula de Coronavírus/química , Receptor 5 Toll-Like/química , Vacinas Virais/química , Sequência de Aminoácidos , Betacoronavirus/genética , Betacoronavirus/patogenicidade , Sítios de Ligação , Biologia Computacional/métodos , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Epitopos/química , Epitopos/genética , Epitopos/imunologia , Epitopos de Linfócito B/genética , Epitopos de Linfócito B/imunologia , 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 , Coronavírus da Síndrome Respiratória do Oriente Médio/genética , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Coronavírus da Síndrome Respiratória do Oriente Médio/patogenicidade , Simulação de Acoplamento Molecular , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Estrutura Terciária de Proteína , Vírus da SARS/genética , Vírus da SARS/imunologia , Vírus da SARS/patogenicidade , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Receptor 5 Toll-Like/genética , Receptor 5 Toll-Like/imunologia , Vacinas de Subunidades , Vacinas Virais/imunologia
11.
PLoS Biol ; 18(2): e3000590, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32069316

RESUMO

DO (HLA-DO, in human; murine H2-O) is a highly conserved nonclassical major histocompatibility complex class II (MHC II) accessory molecule mainly expressed in the thymic medulla and B cells. Previous reports have suggested possible links between DO and autoimmunity, Hepatitis C (HCV) infection, and cancer, but the mechanism of how DO contributes to these diseases remains unclear. Here, using a combination of various in vivo approaches, including peptide elution, mixed lymphocyte reaction, T-cell receptor (TCR) deep sequencing, tetramer-guided naïve CD4 T-cell precursor enumeration, and whole-body imaging, we report that DO affects the repertoire of presented self-peptides by B cells and thymic epithelium. DO induces differential effects on epitope presentation and thymic selection, thereby altering CD4 T-cell precursor frequencies. Our findings were validated in two autoimmune disease models by demonstrating that lack of DO increases autoreactivity and susceptibility to autoimmune disease development.


Assuntos
Doenças Autoimunes/genética , Predisposição Genética para Doença/genética , Antígenos de Histocompatibilidade Classe II/genética , Animais , Células Apresentadoras de Antígenos/imunologia , Doenças Autoimunes/imunologia , Autoimunidade/genética , Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Colágeno/administração & dosagem , Colágeno/imunologia , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Glicoproteína Mielina-Oligodendrócito/imunologia , Peptídeos/imunologia , Células Precursoras de Linfócitos T/imunologia , Timo/imunologia
12.
Parasitol Res ; 119(5): 1597-1605, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32006226

RESUMO

Major histocompatibility complex class II (MHC II) is an essential molecule triggering the adaptive immune response by the presentation of pathogens to helper T cells. The association between individual MHC II variants and various parasites has become a frequent finding in studies of vertebrate populations. However, although bird ectoparasites have a significant effect on their host's fitness, and the host's immune system can regulate ectoparasitic infections, no study has yet investigated the association between MHC II polymorphism and ectoparasite infection in the populations of free-living birds. Here, we test whether an association exists between the abundance of a chewing louse (Myrsidea nesomimi) and MHC II polymorphism of its hosts, the Galápagos mockingbirds (Mimus). We have found that the presence of two MHC II supertypes (functionally differentiated clusters) was significantly associated with louse abundance. This pattern supports the theory that a co-evolutionary interaction stands behind the maintenance of MHC polymorphism. Moreover, we have found a positive correlation between louse abundance and heterophil/lymphocyte ratio (an indicator of immunological stress) that serves as an additional piece of evidence that ectoparasite burden is affected by immunological state of Galápagos mockingbirds.


Assuntos
Antígenos de Histocompatibilidade Classe II/imunologia , Infestações por Piolhos/imunologia , Passeriformes/imunologia , Passeriformes/parasitologia , Ftirápteros/imunologia , Animais , Evolução Biológica , Antígenos de Histocompatibilidade Classe II/genética , Parasitos/classificação , Parasitos/isolamento & purificação , Ftirápteros/classificação , Polimorfismo Genético/genética
13.
PLoS One ; 15(1): e0226439, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31910443

RESUMO

Although many studies have documented the effects of demographic bottlenecks on the genetic diversity of natural populations, there is conflicting evidence of the roles that genetic drift and selection may play in driving changes in genetic variation at adaptive loci. We analyzed genetic variation at microsatellite and mitochondrial loci in conjunction with an adaptive MHC class II locus in the Galápagos penguin (Spheniscus mendiculus), a species that has undergone serial demographic bottlenecks associated with El Niño events through its evolutionary history. We compared levels of variation in the Galápagos penguin to those of its congener, the Magellanic penguin (Spheniscus magellanicus), which has consistently maintained a large population size and thus was used as a non-bottlenecked control. The comparison of neutral and adaptive markers in these two demographically distinct species allowed assessment of the potential role of balancing selection in maintaining levels of MHC variation during bottleneck events. Our analysis suggests that the lack of genetic diversity at both neutral and adaptive loci in the Galápagos penguin likely resulted from its restricted range, relatively low abundance, and history of demographic bottlenecks. The Galápagos penguin revealed two MHC alleles, one mitochondrial haplotype, and six alleles across five microsatellite loci, which represents only a small fraction of the diversity detected in Magellanic penguins. Despite the decreased genetic diversity in the Galápagos penguin, results revealed signals of balancing selection at the MHC, which suggest that selection can mitigate some of the effects of genetic drift during bottleneck events. Although Galápagos penguin populations have persisted for a long time, increased frequency of El Niño events due to global climate change, as well as the low diversity exhibited at immunological loci, may put this species at further risk of extinction.


Assuntos
Deriva Genética , Variação Genética , Genética Populacional , Antígenos de Histocompatibilidade Classe II/genética , Seleção Genética , Spheniscidae/genética , Animais , DNA Mitocondrial/genética , Demografia , Evolução Molecular , Genótipo , Repetições de Microssatélites , Spheniscidae/classificação
14.
Nat Commun ; 11(1): 313, 2020 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-31949143

RESUMO

Langerhans cells (LC) can prime tolerogenic as well as immunogenic responses in skin, but the genomic states and transcription factors (TF) regulating these context-specific responses are unclear. Bulk and single-cell transcriptional profiling demonstrates that human migratory LCs are robustly programmed for MHC-I and MHC-II antigen presentation. Chromatin analysis reveals enrichment of ETS-IRF and AP1-IRF composite regulatory elements in antigen-presentation genes, coinciding with expression of the TFs, PU.1, IRF4 and BATF3 but not IRF8. Migration of LCs from the epidermis is accompanied by upregulation of IRF4, antigen processing components and co-stimulatory molecules. TNF stimulation augments LC cross-presentation while attenuating IRF4 expression. CRISPR-mediated editing reveals IRF4 to positively regulate the LC activation programme, but repress NF2EL2 and NF-kB pathway genes that promote responsiveness to oxidative stress and inflammatory cytokines. Thus, IRF4-dependent genomic programming of human migratory LCs appears to enable LC maturation while attenuating excessive inflammatory and immunogenic responses in the epidermis.


Assuntos
Genômica , Fatores Reguladores de Interferon/genética , Fatores Reguladores de Interferon/metabolismo , Células de Langerhans/metabolismo , Apresentação do Antígeno/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Sistemas CRISPR-Cas , Movimento Celular , Citocinas/metabolismo , Edição de Genes , Perfilação da Expressão Gênica , Antígenos de Histocompatibilidade Classe I , Antígenos de Histocompatibilidade Classe II , Humanos , Células de Langerhans/imunologia , NF-kappa B/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Repressoras/metabolismo , Transativadores/metabolismo , Transcrição Genética , Ativação Transcricional , Regulação para Cima
15.
Immunohorizons ; 4(1): 1-13, 2020 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-31896555

RESUMO

CD4+ helper T cells play important roles in providing help to B cells, macrophages, and cytotoxic CD8+ T cells, but also exhibit direct effector functions against a variety of different pathogens. In contrast to CD8+ T cells, CD4+ T cells typically exhibit broader specificities and undergo less clonal expansion during many types of viral infections, which often makes the identification of virus-specific CD4+ T cells technically challenging. In this study, we have generated recombinant vaccinia virus (VacV) vectors that target I-Ab-restricted peptides for MHC class II (MHC-II) presentation to activate CD4+ T cells in mice. Conjugating the lymphocytic choriomeningitis virus immunodominant epitope GP61-80 to either LAMP1 to facilitate lysosomal targeting or to the MHC-II invariant chain (Ii) significantly increased the activation of Ag-specific CD4+ T cells in vivo. Immunization with VacV-Ii-GP61-80 activated endogenous Ag-specific CD4+ T cells that formed memory and rapidly re-expanded following heterologous challenge. Notably, immunization of mice with VacV expressing an MHC-II-restricted peptide from Leishmania species (PEPCK335-351) conjugated to either LAMP1 or Ii also generated Ag-specific memory CD4+ T cells that underwent robust secondary expansion following a visceral leishmaniasis infection, suggesting this approach could be used to generate Ag-specific memory CD4+ T cells against a variety of different pathogens. Overall, our data show that VacV vectors targeting peptides for MHC-II presentation is an effective strategy to activate Ag-specific CD4+ T cells in vivo and could be used to study Ag-specific effector and memory CD4+ T cell responses against a variety of viral, bacterial, or parasitic infections.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Vírus Vaccinia/imunologia , Imunidade Adaptativa , Animais , Antígenos , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/virologia , Epitopos de Linfócito T , Epitopos Imunodominantes , Camundongos , Camundongos Endogâmicos C57BL , Peptídeos
16.
Cancer Immunol Immunother ; 69(5): 859-865, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31915853

RESUMO

We have established a platform for the isolation of tumour-specific TCR from T cells of patients who experienced clinical benefit from cancer vaccination. In this review we will present the rationale behind this strategy and discuss the advantages of working with "natural" wild type TCRs. Indeed, the general trend in the field has been to use various modifications to enhance the affinity of such therapeutic TCRs. This was done to obtain stronger T cell responses, often at the cost of safety. We further describe antigen targets and recent in vitro and in vivo results obtained to validate them. We finally discuss the use of MHC class II-restricted TCR in immunotherapy. Typically cellular anti-tumour immune responses have been attributed to CD8 T cells; however, we isolated mainly CD4 T cells. Importantly, these MHC class II-restricted TCRs have the potential to induce broad, long lasting immune responses that enable cancer control. The use of CD4 T cell-derived TCRs for adoptive immunotherapy has so far been limited and we will here discuss their therapeutic potential.


Assuntos
Linfócitos T CD4-Positivos/transplante , Sobreviventes de Câncer , Imunoterapia Adotiva/métodos , Neoplasias/terapia , Receptores de Antígenos de Linfócitos T/isolamento & purificação , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Vacinas Anticâncer/administração & dosagem , Ensaios Clínicos como Assunto , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Imunoterapia Adotiva/tendências , Neoplasias/sangue , Neoplasias/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo
18.
Am J Pathol ; 190(1): 25-32, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31669415

RESUMO

The major histocompatibility complex class II (MHC II)-CD4 immunologic synapse is classically described between the T-cell receptor of CD4-positive lymphocytes and MHC II on antigen-presenting cells. This interaction and others between surrounding costimulatory and checkpoint molecules promote differentiation of naïve CD4 T lymphocytes into helper T cells subtypes, including types 1, 2, and 17 helper T cells, that have more tailored immunologic responses. Although MHC II is mainly produced by professional antigen-presenting cells, it can be aberrantly produced by other cell types, including hepatocytes in various liver pathologies, such as autoimmune hepatitis and alcoholic hepatitis. This can lead to direct targeting of hepatocytes by CD4-positive lymphocytes, which form an immunologic synapse with the hepatocyte. The lymphocytes internalize the MHC II-CD4 complexes in a phagocytosis-like mechanism and in the process eat the hepatocyte piece by piece. We review the evidence for this mechanism and the role of these autoimmune responses in various liver diseases, including alcoholic hepatitis, autoimmune hepatitis, and primary biliary cirrhosis. The role of aberrant MHC II in malignancy, including hepatocellular carcinoma, is also reviewed. Further understanding of this mechanism can lead to better understanding of the immune mechanisms involved in these liver pathologies, with potential diagnostic and therapeutic applications.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Doenças Autoimunes/imunologia , Linfócitos T CD4-Positivos/imunologia , Hepatite Alcoólica/imunologia , Hepatócitos/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Animais , Doenças Autoimunes/patologia , Hepatite Alcoólica/patologia , Humanos
19.
World Neurosurg ; 134: 215-220, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31605845

RESUMO

Primary central nervous system (CNS) diffuse large B-cell lymphoma (DLBCL) represents less than 1% of non-Hodgkin lymphomas and 2%-3% of brain tumors. Primary CNS DLBCL occurs sporadically in healthy patients. Tumor development and progression have been associated with reduced/absent expression of human leukocyte antigen class I and II proteins; increased expression of CXCR4, CXCL12, CXCR5, and CCR7; mutations of VH4/34, BCL6, MYC, and PAX5 genes; and rearrangement of immunoglobulin heavy and light chain genes. Generally, DLBCL is a single supratentorial lesion (60%-70%), and stereotactic biopsy and intraoperative examination are the main diagnostic methods. Distinctive histologic features are a diffuse growth pattern and angioinvasiveness. Most neoplastic cells resemble centroblasts and exhibit positive CD20, CD22, PAX5, CD79a, and MUM1 expression. The prognosis of primary CNS DLBCL is less favorable than that of nodal DLBCL, and DLBCL subtype, strong FOXP1 immunoreactivity, MYC and BCL2 overexpression, and BCL6 translocations are associated with poor prognosis.


Assuntos
Neoplasias Encefálicas/genética , Linfoma Difuso de Grandes Células B/genética , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Neoplasias do Sistema Nervoso Central/genética , Neoplasias do Sistema Nervoso Central/imunologia , Neoplasias do Sistema Nervoso Central/metabolismo , Neoplasias do Sistema Nervoso Central/patologia , Quimiocina CXCL12/genética , Quimiocina CXCL12/metabolismo , Rearranjo Gênico do Linfócito B , Antígenos de Histocompatibilidade Classe I/metabolismo , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Imunocompetência , Imunofenotipagem , Linfoma Difuso de Grandes Células B/imunologia , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma Difuso de Grandes Células B/patologia , Mutação , Fator de Transcrição PAX5/genética , Prognóstico , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-bcl-6/genética , Proteínas Proto-Oncogênicas c-myc/genética , Receptores CCR7/genética , Receptores CCR7/metabolismo , Receptores CXCR4/genética , Receptores CXCR4/metabolismo , Receptores CXCR5/genética , Receptores CXCR5/metabolismo , Transcriptoma , Translocação Genética
20.
Microbiol Immunol ; 64(1): 63-71, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31552680

RESUMO

Specific tumor microenvironment signaling might prevent the maturation of dendritic cells (DCs) with tolerogenic and immunosuppressive potential accounting for antigen-specific unresponsiveness in the lymphoid organs and in the periphery. In the present study, dendritic cells treated with LLC lung cancer cell or 4T1 breast cancer cell culture supernatants significantly down-regulated the expression of co-stimulatory molecules MHC-II, CD40, CD80, but up-regulated the inhibitory molecule PD-L1/L2, VISTA, and increased the messengerRNA levels of interleukin (IL)-6, arginase I, and IL-10, but decreased tumor necrosis factor-α and IL-12a. RNA was isolated from the dendritic cells with or without tumor supernatant stimulation and RNA sequencing was done. Then the differential expression genes were sorted, the candidate genes were analyzed and pathway enrichment analysis was done, and the associated protein-protein interaction network (PPI) was established. After integrated bioinformatical analysis, 405 (279 up-regulated and 126 down-regulated) consistently differential expression genes were identified. Using gene ontology and pathway analysis, it was found that differential expression genes were mainly enriched in the immune response, cell-cell interaction, hemostasis, and cell surface interactions with the vascular wall. The PPI data demonstrated that 236 nodes were classified with 1072 edges, and the most remarkable three modules involved 53 central node genes associated with cell survival, cell-substrate adhesion, chemotaxis, migration, immune response, and complement receptor mediated signaling pathway. These findings revealed the immune status of dendritic cells in the tumor environment.


Assuntos
Biologia Computacional , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Microambiente Tumoral/imunologia , Antígenos B7/metabolismo , Antígeno B7-1/metabolismo , Antígeno B7-H1/metabolismo , Neoplasias da Mama , Antígenos CD40/metabolismo , Linhagem Celular Tumoral , Regulação para Baixo , Feminino , Regulação Neoplásica da Expressão Gênica , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Interleucina-10/metabolismo , Interleucina-12 , Neoplasias Pulmonares , Proteína 2 Ligante de Morte Celular Programada 1/metabolismo , Mapas de Interação de Proteínas , RNA Mensageiro/metabolismo , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo
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