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1.
Front Microbiol ; 12: 725741, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34659153

RESUMO

HIV envelope glycoprotein is the most heavily glycosylated viral protein complex identified with over 20 glycans on its surface. This glycan canopy is thought to primarily shield the virus from host immune recognition as glycans are poor immunogens in general, however rare HIV neutralizing antibodies nevertheless potently recognize the glycan epitopes. While CD4 and chemokine receptors have been known as viral entry receptor and coreceptor, for many years the role of viral glycans in HIV entry was controversial. Recently, we showed that HIV envelope glycan binds to L-selectin in solution and on CD4 T lymphocytes. The viral glycan and L-selectin interaction functions to facilitate the viral adhesion and entry. Upon entry, infected CD4 T lymphocytes are stimulated to progressively shed L-selectin and suppressing this lectin receptor shedding greatly reduced HIV viral release and caused aggregation of diminutive virus-like particles within experimental infections and from infected primary T lymphocytes derived from both viremic and aviremic individuals. As shedding of L-selectin is mediated by ADAM metalloproteinases downstream of host-cell stimulation, these findings showed a novel mechanism for HIV viral release and offer a potential new class of anti-HIV compounds.

2.
J Gerontol Soc Work ; : 1-20, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34414861

RESUMO

Villages are consumer-driven organizations that promote aging-in-place. This study documents the effects of the COVID-19 pandemic on Villages and explores variation in response by age of the organization, size of the membership, staffing model, and geographic location. In summer, 2020, we distributed an online survey to executive administrators of 286 Villages in the network. During the pandemic, over 75% of Villages were seen as more or equally valuable for members. Seventy-seven percent of Villages offered virtual socialization events. Most Villages reported a decrease in service requests, given reductions in need for transportation. New services of food and medication delivery were initiated. There is much variation between organizations, but findings suggest that Villages that are older, have more members, and bigger budgets had more capacity and cushion; and although they took a negative hit in income and participation, it was a smaller hit proportionately, compared to younger and smaller Villages. Villages have demonstrated adaptability and creativity. They kept their operations running, provided services, and offered social connection. Vulnerabilities have been exposed: memberships have dropped for many and some members have not been able to participate as before the pandemic. Many lessons learned can help future developments of the Village model.

3.
NPJ Biofilms Microbiomes ; 7(1): 48, 2021 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-34078901

RESUMO

Otitis media (OM), known as a middle ear infection, is the leading cause of antibiotic prescriptions for children. With wide-spread use of antibiotics in OM, resistance to antibiotics continues to decrease the efficacy of the treatment. Furthermore, as the presence of a middle ear biofilm has contributed to this reduced susceptibility to antimicrobials, effective interventions are necessary. A miniaturized 3D-printed microplasma jet array has been developed to inactivate Pseudomonas aeruginosa, a common bacterial strain associated with OM. The experiments demonstrate the disruption of planktonic and biofilm P. aeruginosa by long-lived molecular species generated by microplasma, as well as the synergy of combining microplasma treatment with antibiotic therapy. In addition, a middle ear phantom model was developed with an excised rat eardrum to investigate the antimicrobial effects of microplasma on bacteria located behind the eardrum, as in a patient-relevant setup. These results suggest the potential for microplasma as a new treatment paradigm for OM.


Assuntos
Otite Média/microbiologia , Gases em Plasma/administração & dosagem , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/efeitos dos fármacos , Animais , Biomarcadores , Modelos Animais de Doenças , Testes de Sensibilidade Microbiana/instrumentação , Testes de Sensibilidade Microbiana/métodos , Otite Média/diagnóstico , Otite Média/tratamento farmacológico , Infecções por Pseudomonas/diagnóstico , Infecções por Pseudomonas/tratamento farmacológico , Ratos , Tomografia de Coerência Óptica
4.
Pediatr Rep ; 13(2): 197-202, 2021 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-33921315

RESUMO

Torticollis is a clinical diagnosis with heterogeneous causes. We present an unusual case of acquired torticollis in an 8-month-old female infant with a large cerebellopontine angle arachnoid cyst. Symptoms resolved after surgical fenestration. Non-traumatic acquired or new-onset torticollis requires brain imaging, and posterior fossa lesions are an important entity in the differential for pediatric clinicians.

5.
J Appl Gerontol ; 40(9): 953-957, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33840232

RESUMO

This study explored older adults' technology use patterns and attitudes toward virtual volunteering during the COVID-19 pandemic. A 22-item survey was administered to 229 volunteers in the St. Louis region who tutor children through the Oasis Intergenerational Tutoring program. Although most respondents are familiar with technology and expressed that they are likely to volunteer virtually, their responses varied significantly by age, education, gender, income, and school districts. Some tutors expressed that virtual volunteering may eliminate barriers to in-person volunteering, while others were concerned with establishing a personal connection with students online. These findings suggest that tutors anticipate both benefits and challenges with virtual volunteering and that efforts to engage older adults during the pandemic should factor in prior use of technology and ensure that different subgroups are not marginalized.


Assuntos
Atitude , COVID-19 , Alfabetização Digital , Educação à Distância/métodos , Tecnologia Educacional/métodos , Participação Social/psicologia , Ensino , Voluntários/psicologia , Idoso , COVID-19/epidemiologia , COVID-19/prevenção & controle , COVID-19/psicologia , Feminino , Humanos , Relação entre Gerações , Relações Interpessoais , Masculino , Missouri , Ensino/psicologia , Ensino/estatística & dados numéricos , Comunicação por Videoconferência/instrumentação
6.
J Exp Med ; 218(4)2021 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-33661303

RESUMO

IgG antibodies play a role in malaria immunity, but whether and how IgM protects from malaria and the biology of Plasmodium falciparum (Pf)-specific IgM B cells is unclear. In a Mali cohort spanning infants to adults, we conducted longitudinal analyses of Pf- and influenza-specific B cells. We found that Pf-specific memory B cells (MBCs) are disproportionally IgM+ and only gradually shift to IgG+ with age, in contrast to influenza-specific MBCs that are predominantly IgG+ from infancy to adulthood. B cell receptor analysis showed Pf-specific IgM MBCs are somatically hypermutated at levels comparable to influenza-specific IgG B cells. During acute malaria, Pf-specific IgM B cells expand and upregulate activation/costimulatory markers. Finally, plasma IgM was comparable to IgG in inhibiting Pf growth and enhancing phagocytosis of Pf by monocytes in vitro. Thus, somatically hypermutated Pf-specific IgM MBCs dominate in children, expand and activate during malaria, and produce IgM that inhibits Pf through neutralization and opsonic phagocytosis.


Assuntos
Anticorpos Antiprotozoários/imunologia , Linfócitos B/imunologia , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Malária Falciparum/imunologia , Malária/imunologia , Plasmodium falciparum/imunologia , Adolescente , Adulto , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Criança , Pré-Escolar , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Memória Imunológica , Lactente , Recém-Nascido , Estudos Longitudinais , Malária/sangue , Malária/epidemiologia , Malária/parasitologia , Malária Falciparum/sangue , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Masculino , Mali/epidemiologia , Fagocitose/imunologia , Adulto Jovem
7.
Front Immunol ; 12: 639491, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33777032

RESUMO

Vaccines stimulate various immune factors critical to protective immune responses. However, a comprehensive picture of vaccine-induced immune factors and pathways have not been systematically collected and analyzed. To address this issue, we developed VaximmutorDB, a web-based database system of vaccine immune factors (abbreviated as "vaximmutors") manually curated from peer-reviewed articles. VaximmutorDB currently stores 1,740 vaccine immune factors from 13 host species (e.g., human, mouse, and pig). These vaximmutors were induced by 154 vaccines for 46 pathogens. Top 10 vaximmutors include three antibodies (IgG, IgG2a and IgG1), Th1 immune factors (IFN-γ and IL-2), Th2 immune factors (IL-4 and IL-6), TNF-α, CASP-1, and TLR8. Many enriched host processes (e.g., stimulatory C-type lectin receptor signaling pathway, SRP-dependent cotranslational protein targeting to membrane) and cellular components (e.g., extracellular exosome, nucleoplasm) by all the vaximmutors were identified. Using influenza as a model, live attenuated and killed inactivated influenza vaccines stimulate many shared pathways such as signaling of many interleukins (including IL-1, IL-4, IL-6, IL-13, IL-20, and IL-27), interferon signaling, MARK1 activation, and neutrophil degranulation. However, they also present their unique response patterns. While live attenuated influenza vaccine FluMist induced significant signal transduction responses, killed inactivated influenza vaccine Fluarix induced significant metabolism of protein responses. Two different Yellow Fever vaccine (YF-Vax) studies resulted in overlapping gene lists; however, they shared more portions of pathways than gene lists. Interestingly, live attenuated YF-Vax simulates significant metabolism of protein responses, which was similar to the pattern induced by killed inactivated Fluarix. A user-friendly web interface was generated to access, browse and search the VaximmutorDB database information. As the first web-based database of vaccine immune factors, VaximmutorDB provides systematical collection, standardization, storage, and analysis of experimentally verified vaccine immune factors, supporting better understanding of protective vaccine immunity.


Assuntos
Anticorpos Antivirais/imunologia , Imunidade/imunologia , Fatores Imunológicos/imunologia , Vacinas/imunologia , Animais , Bases de Dados Factuais , Humanos , Internet , Transdução de Sinais/imunologia , Vacinação/métodos
8.
Protein Expr Purif ; 181: 105837, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33529763

RESUMO

Due to the important pathological roles of the HIV-1 gp120, the protein has been intensively used in the research of HIV. However, recombinant gp120 preparation has proven to be difficult because of extremely low expression levels. In order to facilitate gp120 expression, previous methods predominantly involved the replacement of native signal peptide with a heterologous one, resulting in very limited improvement. Currently, preparation of recombinant gp120 with native glycans relies solely on transient expression systems, which are not amendable for large scale production. In this work, we employed a different approach for gp120 expression. Besides replacing the native gp120 signal peptide with that of rat serum albumin and optimizing its codon usage, we generated a stable gp120-expressing cell line in a glutamine synthetase knockout HEK293T cell line that we established for the purpose of amplification of recombinant gene expressions. The combined usage of these techniques dramatically increased gp120 expression levels and yielded a functional product with human cell derived glycan. This method may be applicable to large scale preparation of other viral envelope proteins, such as that of the emerging SARS-CoV-2, or other glycoproteins which require the presence of authentic human glycans.


Assuntos
Glutamato-Amônia Ligase/genética , Proteína gp120 do Envelope de HIV/metabolismo , HIV-1/metabolismo , Animais , Células CHO , Sistemas CRISPR-Cas , Códon , Cricetulus , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , Sinais Direcionadores de Proteínas , Proteínas Recombinantes/metabolismo
9.
Environ Sci Technol ; 54(22): 14716-14724, 2020 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-33124800

RESUMO

Understanding the effects of biofilm structural and mechanical properties, which can influence biofilm cohesiveness and detachment under physical stress, is critical for biofilm and biofilm-associated pathogen control. In this study, we used optical coherence tomography (OCT) and nanoindentation to determine the role of silicate and tin (two experimental nonphosphate corrosion inhibitors) on the porous structure and stiffness of three types of multispecies biofilms. These biofilms were grown from groundwater (a drinking water source), and this groundwater was amended with either tin or silicate corrosion inhibitor (0.5 mg/L as Sn and 20 mg/L as SiO2). Based on the elastic moduli of these biofilms, tin biofilms and groundwater biofilms were the stiffest, followed by silicate biofilms. The thickness normalized by the growth time for silicate biofilms was highest at 38 ± 7.1 µm/month, compared to 21 ± 3.2 and 11 ± 2.4 µm/month for tin biofilms and groundwater biofilms, respectively. The silicate biofilms had the greatest overall porosities and were thickest among the three biofilms. Based on the pore network modeling (PNM) of OCT images, larger pores and connections were found in the silicate biofilms compared to those in tin and groundwater biofilms. Our analysis showed that the thicker and more porous biofilms (silicate biofilms) were potentially less resistant to deformation than the thinner and denser biofilms (tin and groundwater biofilms).


Assuntos
Água Potável , Água Subterrânea , Biofilmes , Corrosão , Dióxido de Silício
10.
J Biol Chem ; 295(52): 18579-18588, 2020 12 25.
Artigo em Inglês | MEDLINE | ID: mdl-33122196

RESUMO

The novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) has emerged to a pandemic and caused global public health crisis. Human angiotensin-converting enzyme 2(ACE2) was identified as the entry receptor for SARS-CoV-2. As a carboxypeptidase, ACE2 cleaves many biological substrates besides angiotensin II to control vasodilatation and vascular permeability. Given the nanomolar high affinity between ACE2 and SARS-CoV-2 spike protein, we investigated how this interaction would affect the enzymatic activity of ACE2. Surprisingly, SARS-CoV-2 trimeric spike protein increased ACE2 proteolytic activity ∼3-10 fold against model peptide substrates, such as caspase-1 substrate and Bradykinin-analog. The enhancement in ACE2 enzymatic function was mediated by the binding of SARS-CoV-2 spike RBD domain. These results highlighted the potential for SARS-CoV-2 infection to enhance ACE2 activity, which may be relevant to the cardiovascular symptoms associated with COVID-19.


Assuntos
Enzima de Conversão de Angiotensina 2/metabolismo , COVID-19/metabolismo , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/metabolismo , COVID-19/enzimologia , COVID-19/virologia , Humanos , Ligação Proteica , Domínios Proteicos , Proteólise , Ressonância de Plasmônio de Superfície/métodos
11.
Water Res ; 186: 116386, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32927421

RESUMO

This study evaluated the potential of a microplasma UV lamp as an alternative UV source to the current mercury-based (Hg-based) UV lamp for water disinfection. We developed a set of PCR-based molecular assays (long-range qPCR, DNase, and binding assay) to quantify the adenovirus genome, capsid, and fiber damage with a wide detection range (100.5-106.5 PFU/mL). We used these molecular assays to characterize adenovirus (AdV) inactivation kinetics by microplasma UV that produced monochromatic UV at 222 nm. We found that the inactivation rate constant (0.142 cm2/mJ) due to microplasma UV was 4.4 times higher than that of low-pressure Hg UV (0.032 cm2/mJ). This high efficacy was attributed to monochromatic UV wavelength at 222 nm damaging the AdV capsid protein. The results of these molecular assays also proved that microplasma UV and medium-pressure Hg UV with a bandpass filter at 223 nm (MPUV223nm) have a similar influence on AdV (p>0.05). We then estimated the relative energy efficiency of MPUV and microplasma UV to LPUV for 4 log reduction of the viruses. We found that the microplasma UV resulted in higher inactivation rate constants for viruses than the current Hg-based UV. Consequently, microplasma UV could be more energy efficient than low-pressure Hg UV for water disinfection if the wall-plug efficiency of the microplasma UV lamp improved to 8.4% (currently 1.5%). Therefore, the microplasma UV lamp is a promising option for water disinfection.


Assuntos
Inativação de Vírus , Purificação da Água , Adenoviridae , Desinfecção , Raios Ultravioleta
12.
Acta Neuropathol Commun ; 8(1): 151, 2020 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-32859279

RESUMO

The FGFR1 gene encoding fibroblast growth factor receptor 1 has emerged as a frequently altered oncogene in the pathogenesis of multiple low-grade neuroepithelial tumor (LGNET) subtypes including pilocytic astrocytoma, dysembryoplastic neuroepithelial tumor (DNT), rosette-forming glioneuronal tumor (RGNT), and extraventricular neurocytoma (EVN). These activating FGFR1 alterations in LGNET can include tandem duplication of the exons encoding the intracellular tyrosine kinase domain, in-frame gene fusions most often with TACC1 as the partner, or hotspot missense mutations within the tyrosine kinase domain (either at p.N546 or p.K656). However, the specificity of these different FGFR1 events for the various LGNET subtypes and accompanying genetic alterations are not well defined. Here we performed comprehensive genomic and epigenomic characterization on a diverse cohort of 30 LGNET with FGFR1 alterations. We identified that RGNT harbors a distinct epigenetic signature compared to other LGNET with FGFR1 alterations, and is uniquely characterized by FGFR1 kinase domain hotspot missense mutations in combination with either PIK3CA or PIK3R1 mutation, often with accompanying NF1 or PTPN11 mutation. In contrast, EVN harbors its own distinct epigenetic signature and is characterized by FGFR1-TACC1 fusion as the solitary pathogenic alteration. Additionally, DNT and pilocytic astrocytoma are characterized by either kinase domain tandem duplication or hotspot missense mutations, occasionally with accompanying NF1 or PTPN11 mutation, but lacking the accompanying PIK3CA or PIK3R1 mutation that characterizes RGNT. The glial component of LGNET with FGFR1 alterations typically has a predominantly oligodendroglial morphology, and many of the pilocytic astrocytomas with FGFR1 alterations lack the biphasic pattern, piloid processes, and Rosenthal fibers that characterize pilocytic astrocytomas with BRAF mutation or fusion. Together, this analysis improves the classification and histopathologic stratification of LGNET with FGFR1 alterations.


Assuntos
Neoplasias Neuroepiteliomatosas/classificação , Neoplasias Neuroepiteliomatosas/genética , Neoplasias Neuroepiteliomatosas/patologia , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Adolescente , Adulto , Idoso , Neoplasias Encefálicas/classificação , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Neoplasias da Medula Espinal/classificação , Neoplasias da Medula Espinal/genética , Neoplasias da Medula Espinal/patologia , Adulto Jovem
13.
J Neurosurg Pediatr ; : 1-9, 2020 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-32707540

RESUMO

OBJECTIVE: Ventriculoperitoneal (VP) shunt infections are common complications after shunt operations. Despite the use of intravenous antibiotics, the incidence of infections remains high. Though antibiotic-impregnated catheters (AICs) are commonly used, another method of infection prophylaxis is the use of intraventricular (IVT) antibiotics. The authors describe their single-institution experience with a standard shunt protocol utilizing prophylactic IVT and topical vancomycin administration and report the incidence of pediatric shunt infections. METHODS: Three hundred two patients undergoing VP shunt procedures with IVT and topical vancomycin between 2006 and 2016 were included. Patients were excluded if their age at surgery was greater than 18 years. Shunt operations were performed at a single institution following a standard shunt protocol implementing IVT and topical vancomycin. No AICs were used. Clinical data were retrospectively collected from the electronic health records. RESULTS: Over the 11-year study period, 593 VP shunt operations were performed with IVT and topical vancomycin, and a total of 19 infections occurred (incidence 3.2% per procedure). The majority of infections (n = 10, 52.6%) were caused by Staphylococcus epidermidis. The median time to shunt infection was 3.7 weeks. On multivariate analysis, the presence of a CSF leak (OR 31.5 [95% CI 8.8-112.6]) and age less than 6 months (OR 3.6 [95% CI 1.2-10.7]) were statistically significantly associated with the development of a shunt infection. A post hoc analysis comparing infection rates after procedures that adhered to the shunt protocol and those that did not administer IVT and topical vancomycin, plus historical controls, revealed a difference in infection rates (3.2% vs 6.9%, p = 0.03). CONCLUSIONS: The use of a standardized shunt operation technique that includes IVT and topical vancomycin is associated with a total shunt infection incidence of 3.2% per procedure, which compares favorably with the reported rates of shunt infection in the literature. The majority of infections occurred within 2 months of surgery and the most common causative organism was S. epidermidis. Young age (< 6 months) at the time of surgery and the presence of a postoperative CSF leak were statistically significantly associated with postoperative shunt infection on multivariate analysis. The results are hypothesis generating, and the authors propose that IVT and topical administration of vancomycin as part of a standardized shunt operation protocol may be an appropriate option for preventing pediatric shunt infections.

14.
bioRxiv ; 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32637947

RESUMO

A novel coronavirus (SARS-CoV-2) has emerged to a global pandemic and caused significant damages to public health. Human angiotensin-converting enzyme 2(ACE2) was identified as the entry receptor for SARS-CoV-2. As a carboxypeptidase, ACE2 cleaves many biological substrates besides Ang II to control vasodilatation and permeability. Given the nanomolar high affinity between ACE2 and SARS-CoV-2 spike protein, we wonder how this interaction would affect the enzymatic activity of ACE2. Surprisingly, SARS-CoV-2 trimeric spike protein increased ACE2 proteolytic activity ~3-10 fold when fluorogenic caspase-1 substrate and Bradykinin-analog peptides were used to characterize ACE2 activity. In addition, the enhancement was mediated by ACE2 binding of RBD domain of SARS-CoV-2 spike. These results highlighted the altered activity of ACE2 during SARS-CoV-2 infection and would shed new lights on the pathogenesis of COVID-19 and its complications for better treatments.

15.
Front Immunol ; 11: 1216, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32612609

RESUMO

MHC-independent αßTCRs (TCRs) recognize conformational epitopes on native self-proteins and arise in mice lacking both MHC and CD4/CD8 coreceptor proteins. Although naturally generated in the thymus, these TCRs resemble re-engineered therapeutic chimeric antigen receptor (CAR) T cells in their specificity for MHC-independent ligands. Here we identify naturally arising MHC-independent TCRs reactive to three native self-proteins (CD48, CD102, and CD155) involved in cell adhesion. We report that naturally arising MHC-independent TCRs require high affinity TCR-ligand engagements in the thymus to signal positive selection and that high affinity positive selection generates a peripheral TCR repertoire with limited diversity and increased self-reactivity. We conclude that the affinity of TCR-ligand engagements required to signal positive selection in the thymus inversely determines the diversity and self-tolerance of the mature TCR repertoire that is selected.


Assuntos
Seleção Clonal Mediada por Antígeno , Complexo Principal de Histocompatibilidade/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Tolerância a Antígenos Próprios/imunologia , Especificidade do Receptor de Antígeno de Linfócitos T/imunologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Timo/fisiologia , Animais , Antígenos CD/metabolismo , Antígenos CD8/imunologia , Moléculas de Adesão Celular/metabolismo , Ligantes , Antígeno-1 Associado à Função Linfocitária/metabolismo , Complexo Principal de Histocompatibilidade/genética , Camundongos , Camundongos Knockout , Ligação Proteica , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores Virais/imunologia
16.
Proc Natl Acad Sci U S A ; 117(23): 12826-12835, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32461371

RESUMO

Complete cancer regression occurs in a subset of patients following adoptive T cell therapy (ACT) of ex vivo expanded tumor-infiltrating lymphocytes (TILs). However, the low success rate presents a great challenge to broader clinical application. To provide insight into TIL-based immunotherapy, we studied a successful case of ACT where regression was observed against tumors carrying the hotspot mutation G12D in the KRAS oncogene. Four T cell receptors (TCRs) made up the TIL infusion and recognized two KRAS-G12D neoantigens, a nonamer and a decamer, all restricted by human leukocyte antigen (HLA) C*08:02. Three of them (TCR9a, 9b, and 9c) were nonamer-specific, while one was decamer-specific (TCR10). We show that only mutant G12D but not the wild-type peptides stabilized HLA-C*08:02 due to the formation of a critical anchor salt bridge to HLA-C. Therapeutic TCRs exhibited high affinities, ranging from nanomolar to low micromolar. Intriguingly, TCR binding affinities to HLA-C inversely correlated with their persistence in vivo, suggesting the importance of antigenic affinity in the function of therapeutic T cells. Crystal structures of TCR-HLA-C complexes revealed that TCR9a to 9c recognized G12D nonamer with multiple conserved contacts through shared CDR2ß and CDR3α. This allowed CDR3ß variation to confer different affinities via a variable HLA-C contact, generating an oligoclonal response. TCR10 recognized an induced and distinct G12D decamer conformation. Thus, this successful case of ACT included oligoclonal TCRs of high affinity recognizing distinct conformations of neoantigens. Our study revealed the potential of a structural approach to inform clinical efforts in targeting KRAS-G12D tumors by immunotherapy and has general implications for T cell-based immunotherapies.


Assuntos
Antígenos de Neoplasias/imunologia , Imunoterapia Adotiva/métodos , Proteínas Proto-Oncogênicas p21(ras)/genética , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T/imunologia , Apresentação do Antígeno , Antígenos de Neoplasias/química , Sítios de Ligação , Antígenos HLA-C/química , Antígenos HLA-C/imunologia , Humanos , Células Jurkat , Mutação de Sentido Incorreto , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/imunologia , Ligação Proteica , Proteínas Proto-Oncogênicas p21(ras)/química , Proteínas Proto-Oncogênicas p21(ras)/imunologia , Receptores de Antígenos de Linfócitos T/química
17.
J Immunol ; 204(12): 3351-3359, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32321756

RESUMO

During normal T cell development in the thymus, αß TCRs signal immature thymocytes to differentiate into mature T cells by binding to peptide-MHC ligands together with CD4/CD8 coreceptors. Conversely, in MHC and CD4/CD8 coreceptor-deficient mice, the thymus generates mature T cells expressing MHC-independent TCRs that recognize native conformational epitopes rather than linear antigenic-peptides presented by MHC. To date, no structural information of MHC-independent TCRs is available, and their structural recognition of non-MHC ligand remains unknown. To our knowledge in this study, we determined the first structures of two murine MHC-independent TCRs (A11 and B12A) that bind with high nanomolar affinities to mouse adhesion receptor CD155. Solution binding demonstrated the Vαß-domain is responsible for MHC-independent B12A recognition of its ligand. Analysis of A11 and B12A sequences against various MHC-restricted and -independent TCR sequence repertoires showed that individual V-genes of A11 and B12A did not exhibit preference against MHC-restriction. Likewise, CDR3 alone did not discriminate against MHC binding, suggesting VDJ recombination together with Vα/Vß pairing determine their MHC-independent specificity for CD155. The structures of A11 and B12A TCR are nearly identical to those of MHC-restricted TCR, including the conformations of CDR1 and 2. Mutational analysis, together with negative-staining electron microscopy images, showed that the CDR regions of A11 and B12A recognized epitopes on D1 domain of CD155, a region also involved in CD155 binding to poliovirus and Tactile in human. Taken together, MHC-independent TCRs adopt canonical TCR structures to recognize native Ags, highlighting the importance of thymic selection in determining TCR ligand specificity.


Assuntos
Complexo Principal de Histocompatibilidade/fisiologia , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Receptores Virais/metabolismo , Animais , Células HEK293 , Humanos , Ligantes , Camundongos , Peptídeos/metabolismo , Poliovirus/metabolismo , Ligação Proteica , Domínios Proteicos , Timócitos/metabolismo , Recombinação V(D)J/fisiologia
19.
Brain Pathol ; 30(3): 479-494, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31609499

RESUMO

"Myxoid glioneuronal tumor, PDGFRA p.K385-mutant" is a recently described tumor entity of the central nervous system with a predilection for origin in the septum pellucidum and a defining dinucleotide mutation at codon 385 of the PDGFRA oncogene replacing lysine with either leucine or isoleucine (p.K385L/I). Clinical outcomes and optimal treatment for this new tumor entity have yet to be defined. Here, we report a comprehensive clinical, radiologic, and histopathologic assessment of eight cases. In addition to its stereotypic location in the septum pellucidum, we identify that this tumor can also occur in the corpus callosum and periventricular white matter of the lateral ventricle. Tumors centered in the septum pellucidum uniformly were associated with obstructive hydrocephalus, whereas tumors centered in the corpus callosum and periventricular white matter did not demonstrate hydrocephalus. While multiple patients were found to have ventricular dissemination or local recurrence/progression, all patients in this series remain alive at last clinical follow-up despite only biopsy or subtotal resection without adjuvant therapy in most cases. Our study further supports "myxoid glioneuronal tumor, PDGFRA p.K385-mutant" as a distinct CNS tumor entity and expands the spectrum of clinicopathologic and radiologic features of this neoplasm.


Assuntos
Neoplasias Encefálicas/patologia , Corpo Caloso/patologia , Glioma/patologia , Ventrículos Laterais/patologia , Mutação , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Adolescente , Adulto , Idoso , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/genética , Neoplasias do Ventrículo Cerebral/diagnóstico por imagem , Neoplasias do Ventrículo Cerebral/genética , Neoplasias do Ventrículo Cerebral/patologia , Criança , Corpo Caloso/diagnóstico por imagem , Feminino , Glioma/diagnóstico por imagem , Glioma/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Ventrículos Laterais/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Septo Pelúcido/patologia , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Adulto Jovem
20.
BMC Bioinformatics ; 20(Suppl 21): 704, 2019 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-31865910

RESUMO

BACKGROUND: Different human responses to the same vaccine were frequently observed. For example, independent studies identified overlapping but different transcriptomic gene expression profiles in Yellow Fever vaccine 17D (YF-17D) immunized human subjects. Different experimental and analysis conditions were likely contributed to the observed differences. To investigate this issue, we developed a Vaccine Investigation Ontology (VIO), and applied VIO to classify the different variables and relations among these variables systematically. We then evaluated whether the ontological VIO modeling and VIO-based statistical analysis would contribute to the enhanced vaccine investigation studies and a better understanding of vaccine response mechanisms. RESULTS: Our VIO modeling identified many variables related to data processing and analysis such as normalization method, cut-off criteria, software settings including software version. The datasets from two previous studies on human responses to YF-17D vaccine, reported by Gaucher et al. (2008) and Querec et al. (2009), were re-analyzed. We first applied the same LIMMA statistical method to re-analyze the Gaucher data set and identified a big difference in terms of significantly differentiated gene lists compared to the original study. The different results were likely due to the LIMMA version and software package differences. Our second study re-analyzed both Gaucher and Querec data sets but with the same data processing and analysis pipeline. Significant differences in differential gene lists were also identified. In both studies, we found that Gene Ontology (GO) enrichment results had more overlapping than the gene lists and enriched pathway lists. The visualization of the identified GO hierarchical structures among the enriched GO terms and their associated ancestor terms using GOfox allowed us to find more associations among enriched but often different GO terms, demonstrating the usage of GO hierarchical relations enhance data analysis. CONCLUSIONS: The ontology-based analysis framework supports standardized representation, integration, and analysis of heterogeneous data of host responses to vaccines. Our study also showed that differences in specific variables might explain different results drawn from similar studies.


Assuntos
Vacinas , Ontologias Biológicas , Humanos , Software
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