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1.
Sci Immunol ; 6(57)2021 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-33653907

RESUMO

Pediatric COVID-19 following SARS-CoV-2 infection is associated with fewer hospitalizations and often milder disease than in adults. A subset of children, however, present with Multisystem Inflammatory Syndrome in Children (MIS-C) that can lead to vascular complications and shock, but rarely death. The immune features of MIS-C compared to pediatric COVID-19 or adult disease remain poorly understood. We analyzed peripheral blood immune responses in hospitalized SARS-CoV-2 infected pediatric patients (pediatric COVID-19) and patients with MIS-C. MIS-C patients had patterns of T cell-biased lymphopenia and T cell activation similar to severely ill adults, and all patients with MIS-C had SARS-CoV-2 spike-specific antibodies at admission. A distinct feature of MIS-C patients was robust activation of vascular patrolling CX3CR1+ CD8+ T cells that correlated with the use of vasoactive medication. Finally, whereas pediatric COVID-19 patients with acute respiratory distress syndrome (ARDS) had sustained immune activation, MIS-C patients displayed clinical improvement over time, concomitant with decreasing immune activation. Thus, non-MIS-C versus MIS-C SARS-CoV-2 associated illnesses are characterized by divergent immune signatures that are temporally distinct from one another and implicate CD8+ T cells in the clinical presentation and trajectory of MIS-C.


Assuntos
/imunologia , Ativação Linfocitária , Síndrome de Resposta Inflamatória Sistêmica/imunologia , Linfócitos T/imunologia , Adolescente , Adulto , Envelhecimento/imunologia , Criança , Pré-Escolar , Feminino , Citometria de Fluxo , Humanos , Leucopenia/imunologia , Masculino , Adulto Jovem
2.
Cell ; 184(7): 1858-1864.e10, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33631096

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread within the human population. Although SARS-CoV-2 is a novel coronavirus, most humans had been previously exposed to other antigenically distinct common seasonal human coronaviruses (hCoVs) before the coronavirus disease 2019 (COVID-19) pandemic. Here, we quantified levels of SARS-CoV-2-reactive antibodies and hCoV-reactive antibodies in serum samples collected from 431 humans before the COVID-19 pandemic. We then quantified pre-pandemic antibody levels in serum from a separate cohort of 251 individuals who became PCR-confirmed infected with SARS-CoV-2. Finally, we longitudinally measured hCoV and SARS-CoV-2 antibodies in the serum of hospitalized COVID-19 patients. Our studies indicate that most individuals possessed hCoV-reactive antibodies before the COVID-19 pandemic. We determined that ∼20% of these individuals possessed non-neutralizing antibodies that cross-reacted with SARS-CoV-2 spike and nucleocapsid proteins. These antibodies were not associated with protection against SARS-CoV-2 infections or hospitalizations, but they were boosted upon SARS-CoV-2 infection.


Assuntos
Alphacoronavirus/imunologia , Anticorpos Antivirais , Betacoronavirus/imunologia , /imunologia , Adolescente , Adulto , Animais , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Criança , Pré-Escolar , Chlorocebus aethiops , Proteção Cruzada , Reações Cruzadas , Suscetibilidade a Doenças , Células HEK293 , Humanos , Lactente , Recém-Nascido , Células Vero
3.
Cell ; 184(5): 1262-1280.e22, 2021 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-33636129

RESUMO

Improving effector activity of antigen-specific T cells is a major goal in cancer immunotherapy. Despite the identification of several effector T cell (TEFF)-driving transcription factors (TFs), the transcriptional coordination of TEFF biology remains poorly understood. We developed an in vivo T cell CRISPR screening platform and identified a key mechanism restraining TEFF biology through the ETS family TF, Fli1. Genetic deletion of Fli1 enhanced TEFF responses without compromising memory or exhaustion precursors. Fli1 restrained TEFF lineage differentiation by binding to cis-regulatory elements of effector-associated genes. Loss of Fli1 increased chromatin accessibility at ETS:RUNX motifs, allowing more efficient Runx3-driven TEFF biology. CD8+ T cells lacking Fli1 provided substantially better protection against multiple infections and tumors. These data indicate that Fli1 safeguards the developing CD8+ T cell transcriptional landscape from excessive ETS:RUNX-driven TEFF cell differentiation. Moreover, genetic deletion of Fli1 improves TEFF differentiation and protective immunity in infections and cancer.

4.
Artigo em Inglês | MEDLINE | ID: mdl-33263756

RESUMO

SARS-CoV-2 antibody responses in children remain poorly characterized. Here, we show that pediatric patients with multisystem inflammatory syndrome in children (MIS-C) possess higher SARS-CoV-2 spike IgG titers compared to those with severe coronavirus disease 2019 (COVID-19), likely reflecting a longer time since onset of infection in MIS-C patients.

5.
medRxiv ; 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33200143

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread within the human population. Although SARS-CoV-2 is a novel coronavirus, most humans had been previously exposed to other antigenically distinct common seasonal human coronaviruses (hCoVs) before the COVID-19 pandemic. Here, we quantified levels of SARS-CoV-2-reactive antibodies and hCoV-reactive antibodies in serum samples collected from 204 humans before the COVID-19 pandemic. We then quantified pre-pandemic antibody levels in serum from a separate cohort of 252 individuals who became PCR-confirmed infected with SARS-CoV-2. Finally, we longitudinally measured hCoV and SARS-CoV-2 antibodies in the serum of hospitalized COVID-19 patients. Our studies indicate that most individuals possessed hCoV-reactive antibodies before the COVID-19 pandemic. We determined that ∼23% of these individuals possessed non-neutralizing antibodies that cross-reacted with SARS-CoV-2 spike and nucleocapsid proteins. These antibodies were not associated with protection against SARS-CoV-2 infections or hospitalizations, but paradoxically these hCoV cross-reactive antibodies were boosted upon SARS-CoV-2 infection.

6.
medRxiv ; 2020 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-32995826

RESUMO

Pediatric COVID-19 following SARS-CoV-2 infection is associated with fewer hospitalizations and often milder disease than in adults. A subset of children, however, present with Multisystem Inflammatory Syndrome in Children (MIS-C) that can lead to vascular complications and shock, but rarely death. The immune features of MIS-C compared to pediatric COVID-19 or adult disease remain poorly understood. We analyzed peripheral blood immune responses in hospitalized SARS-CoV-2 infected pediatric patients (pediatric COVID-19) and patients with MIS-C. MIS-C patients had patterns of T cell-biased lymphopenia and T cell activation similar to severely ill adults, and all patients with MIS-C had SARS-CoV-2 spike-specific antibodies at admission. A distinct feature of MIS-C patients was robust activation of vascular patrolling CX3CR1+ CD8 T cells that correlated with use of vasoactive medication. Finally, whereas pediatric COVID-19 patients with acute respiratory distress syndrome (ARDS) had sustained immune activation, MIS-C patients displayed clinical improvement over time, concomitant with decreasing immune activation. Thus, non-MIS-C versus MIS-C SARS-CoV-2 associated illnesses are characterized by divergent immune signatures that are temporally distinct and implicate CD8 T cells in clinical presentation and trajectory of MIS-C.

7.
medRxiv ; 2020 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-32839782

RESUMO

SARS-CoV-2 antibody responses in children remain poorly characterized. Here, we show that pediatric patients with multisystem inflammatory syndrome in children (MIS-C) possess higher SARS-CoV-2 spike IgG titers compared to those with severe coronavirus disease 2019 (COVID-19), likely reflecting a longer time since onset of infection in MIS-C patients.

8.
Sci Immunol ; 5(49)2020 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-32727884

RESUMO

Limited data are available for pregnant women affected by SARS-CoV-2. Serological tests are critically important for determining SARS-CoV-2 exposures within both individuals and populations. We validated a SARS-CoV-2 spike receptor binding domain serological test using 834 pre-pandemic samples and 31 samples from COVID-19 recovered donors. We then completed SARS-CoV-2 serological testing of 1,293 parturient women at two centers in Philadelphia from April 4 to June 3, 2020. We found 80/1,293 (6.2%) of parturient women possessed IgG and/or IgM SARS-CoV-2-specific antibodies. We found race/ethnicity differences in seroprevalence rates, with higher rates in Black/non-Hispanic and Hispanic/Latino women. Of the 72 seropositive women who also received nasopharyngeal polymerase chain reaction testing during pregnancy, 46 (64%) were positive. Continued serologic surveillance among pregnant women may inform perinatal clinical practices and can potentially be used to estimate exposure to SARS-CoV-2 within the community.


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/epidemiologia , Disparidades nos Níveis de Saúde , Pneumonia Viral/epidemiologia , Complicações Infecciosas na Gravidez/epidemiologia , Adulto , Afro-Americanos/estatística & dados numéricos , Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico/métodos , Técnicas de Laboratório Clínico/estatística & dados numéricos , Estudos de Coortes , Infecções por Coronavirus/sangue , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Feminino , Hispano-Americanos/estatística & dados numéricos , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Pandemias , Philadelphia/epidemiologia , Pneumonia Viral/sangue , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Gravidez , Complicações Infecciosas na Gravidez/sangue , Complicações Infecciosas na Gravidez/imunologia , Complicações Infecciosas na Gravidez/virologia , Domínios Proteicos/imunologia , Estudos Soroepidemiológicos , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto Jovem
9.
Sci Immunol ; 5(49)2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32669287

RESUMO

Although critical illness has been associated with SARS-CoV-2-induced hyperinflammation, the immune correlates of severe COVID-19 remain unclear. Here, we comprehensively analyzed peripheral blood immune perturbations in 42 SARS-CoV-2 infected and recovered individuals. We identified extensive induction and activation of multiple immune lineages, including T cell activation, oligoclonal plasmablast expansion, and Fc and trafficking receptor modulation on innate lymphocytes and granulocytes, that distinguished severe COVID-19 cases from healthy donors or SARS-CoV-2-recovered or moderate severity patients. We found the neutrophil to lymphocyte ratio to be a prognostic biomarker of disease severity and organ failure. Our findings demonstrate broad innate and adaptive leukocyte perturbations that distinguish dysregulated host responses in severe SARS-CoV-2 infection and warrant therapeutic investigation.


Assuntos
Subpopulações de Linfócitos B/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Neutrófilos/imunologia , Pneumonia Viral/imunologia , Linfócitos T/imunologia , Idoso , Seleção Clonal Mediada por Antígeno/imunologia , Infecções por Coronavirus/patologia , Citocinas/metabolismo , Feminino , Humanos , Imunidade Inata/imunologia , Memória Imunológica/imunologia , Ativação Linfocitária/imunologia , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/patologia
10.
Science ; 369(6508)2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32669297

RESUMO

Coronavirus disease 2019 (COVID-19) is currently a global pandemic, but human immune responses to the virus remain poorly understood. We used high-dimensional cytometry to analyze 125 COVID-19 patients and compare them with recovered and healthy individuals. Integrated analysis of ~200 immune and ~50 clinical features revealed activation of T cell and B cell subsets in a proportion of patients. A subgroup of patients had T cell activation characteristic of acute viral infection and plasmablast responses reaching >30% of circulating B cells. However, another subgroup had lymphocyte activation comparable with that in uninfected individuals. Stable versus dynamic immunological signatures were identified and linked to trajectories of disease severity change. Our analyses identified three immunotypes associated with poor clinical trajectories versus improving health. These immunotypes may have implications for the design of therapeutics and vaccines for COVID-19.


Assuntos
Linfócitos B/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Pneumonia Viral/imunologia , Linfócitos T/imunologia , Imunidade Adaptativa , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/sangue , Subpopulações de Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Citocinas/sangue , Feminino , Humanos , Memória Imunológica , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Pandemias , Plasmócitos/imunologia , Índice de Gravidade de Doença , Subpopulações de Linfócitos T/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Fatores de Tempo , Adulto Jovem
11.
medRxiv ; 2020 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-32676623

RESUMO

Limited data are available for pregnant women affected by SARS-CoV-2. Serological tests are critically important to determine exposure and immunity to SARS-CoV-2 within both individuals and populations. We completed SARS-CoV-2 serological testing of 1,293 parturient women at two centers in Philadelphia from April 4 to June 3, 2020. We tested 834 pre-pandemic samples collected in 2019 and 15 samples from COVID-19 recovered donors to validate our assay, which has a ~1% false positive rate. We found 80/1,293 (6.2%) of parturient women possessed IgG and/or IgM SARS-CoV-2-specific antibodies. We found race/ethnicity differences in seroprevalence rates, with higher rates in Black/non-Hispanic and Hispanic/Latino women. Of the 72 seropositive women who also received nasopharyngeal polymerase chain reaction testing during pregnancy, 46 (64%) were positive. Continued serologic surveillance among pregnant women may inform perinatal clinical practices and can potentially be used to estimate seroprevalence within the community.

12.
bioRxiv ; 2020 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-32511371

RESUMO

COVID-19 has become a global pandemic. Immune dysregulation has been implicated, but immune responses remain poorly understood. We analyzed 71 COVID-19 patients compared to recovered and healthy subjects using high dimensional cytometry. Integrated analysis of ~200 immune and >30 clinical features revealed activation of T cell and B cell subsets, but only in some patients. A subgroup of patients had T cell activation characteristic of acute viral infection and plasmablast responses could reach >30% of circulating B cells. However, another subgroup had lymphocyte activation comparable to uninfected subjects. Stable versus dynamic immunological signatures were identified and linked to trajectories of disease severity change. These analyses identified three "immunotypes" associated with poor clinical trajectories versus improving health. These immunotypes may have implications for therapeutics and vaccines.

13.
bioRxiv ; 2020 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-32511394

RESUMO

Although critical illness has been associated with SARS-CoV-2-induced hyperinflammation, the immune correlates of severe COVID-19 remain unclear. Here, we comprehensively analyzed peripheral blood immune perturbations in 42 SARS-CoV-2 infected and recovered individuals. We identified broad changes in neutrophils, NK cells, and monocytes during severe COVID-19, suggesting excessive mobilization of innate lineages. We found marked activation within T and B cells, highly oligoclonal B cell populations, profound plasmablast expansion, and SARS-CoV-2-specific antibodies in many, but not all, severe COVID-19 cases. Despite this heterogeneity, we found selective clustering of severe COVID-19 cases through unbiased analysis of the aggregated immunological phenotypes. Our findings demonstrate broad immune perturbations spanning both innate and adaptive leukocytes that distinguish dysregulated host responses in severe SARS-CoV-2 infection and warrant therapeutic investigation. One Sentence Summary: Broad immune perturbations in severe COVID-19.

14.
EBioMedicine ; 54: 102727, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32268275

RESUMO

BACKGROUND: Untreated HIV infection leads to alterations in HIV-specific CD4+ T cells including increased expression of co-inhibitory receptors (IRs) and skewing toward a T follicular helper cell (Tfh) signature. However, which changes are maintained after suppression of viral replication with antiretroviral therapy (ART) is poorly known. METHODS: We analyzed blood CD4+ T cells specific to HIV and comparative viral antigens in ART-treated people using a cytokine-independent activation-induced marker assay alone or in combination with functional readouts. FINDINGS: In intra-individual comparisons, HIV-specific CD4+ T cells were characterized by a larger fraction of circulating Tfh (cTfh) cells than CMV- and HBV-specific cells and preferentially expressed multiple IRs and showed elevated production of the Tfh cytokines CXCL13 and IL-21. In addition, HIV-specific cTfh exhibited a predominant Th1-like phenotype and function when compared to cTfh of other specificities, contrasting with a reduction in Th1-functions in HIV-specific non-cTfh. Using longitudinal samples, we demonstrate that this distinct HIV-specific cTfh profile was induced during chronic untreated HIV infection, persisted on ART and correlated with the translation-competent HIV reservoir but not with the total HIV DNA reservoir. INTERPRETATION: Expansion and altered features of HIV-specific cTfh cells are maintained during ART and may be driven by persistent HIV antigen expression. FUNDING: This work was supported by the National Institutes of Health (NIH), the Canadian Institutes of Health Research (CIHR) and the FRQS AIDS and Infectious Diseases Network.

15.
Nat Med ; 26(2): 222-227, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32015556

RESUMO

Combination antiretroviral therapy (ART) is highly effective in controlling human immunodeficiency virus (HIV)-1 but requires lifelong medication due to the existence of a latent viral reservoir1,2. Potent broadly neutralizing antibodies (bNAbs) represent a potential alternative or adjuvant to ART. In addition to suppressing viremia, bNAbs may have T cell immunomodulatory effects as seen for other forms of immunotherapy3. However, this has not been established in individuals who are infected with HIV-1. Here, we document increased HIV-1 Gag-specific CD8+ T cell responses in the peripheral blood of all nine study participants who were infected with HIV-1 with suppressed blood viremia, while receiving bNAb therapy during ART interruption4. Increased CD4+ T cell responses were detected in eight individuals. The increased T cell responses were due both to newly detectable reactivity to HIV-1 Gag epitopes and the expansion of pre-existing measurable responses. These data demonstrate that bNAb therapy during ART interruption is associated with enhanced HIV-1-specific T cell responses. Whether these augmented T cell responses can contribute to bNAb-mediated viral control remains to be determined.


Assuntos
Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , Infecções por HIV/terapia , Imunoterapia/métodos , Linfócitos T/imunologia , Adulto , Anticorpos Neutralizantes/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Epitopos/imunologia , Feminino , Produtos do Gene gag/metabolismo , Infecções por HIV/virologia , HIV-1 , Humanos , Sistema Imunitário , Interferon gama/imunologia , Masculino , Pessoa de Meia-Idade , Linfócitos T/virologia , Viremia
16.
Immunity ; 51(5): 840-855.e5, 2019 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-31606264

RESUMO

TCF-1 is a key transcription factor in progenitor exhausted CD8 T cells (Tex). Moreover, this Tex cell subset mediates responses to PD-1 checkpoint pathway blockade. However, the role of the transcription factor TCF-1 in early fate decisions and initial generation of Tex cells is unclear. Single-cell RNA sequencing (scRNA-seq) and lineage tracing identified a TCF-1+Ly108+PD-1+ CD8 T cell population that seeds development of mature Tex cells early during chronic infection. TCF-1 mediated the bifurcation between divergent fates, repressing development of terminal KLRG1Hi effectors while fostering KLRG1Lo Tex precursor cells, and PD-1 stabilized this TCF-1+ Tex precursor cell pool. TCF-1 mediated a T-bet-to-Eomes transcription factor transition in Tex precursors by promoting Eomes expression and drove c-Myb expression that controlled Bcl-2 and survival. These data define a role for TCF-1 in early-fate-bifurcation-driving Tex precursor cells and also identify PD-1 as a protector of this early TCF-1 subset.


Assuntos
Linfócitos T CD8-Positivos/metabolismo , Redes Reguladoras de Genes , Fator 1 de Transcrição de Linfócitos T/metabolismo , Transcrição Genética , Animais , Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Doença Crônica , Perfilação da Expressão Gênica , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Camundongos , Receptor de Morte Celular Programada 1/metabolismo , Fator 1 de Transcrição de Linfócitos T/genética , Viroses/genética , Viroses/imunologia , Viroses/virologia
17.
Nat Immunol ; 20(8): 1059-1070, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31308541

RESUMO

Dysfunction of virus-specific CD4+ T cells in chronic human infections is poorly understood. We performed genome-wide transcriptional analyses and functional assays of CD4+ T cells specific for human immunodeficiency virus (HIV) from HIV-infected people before and after initiation of antiretroviral therapy (ART). A follicular helper T cell (TFH cell)-like profile characterized HIV-specific CD4+ T cells in viremic infection. HIV-specific CD4+ T cells from people spontaneously controlling the virus (elite controllers) robustly expressed genes associated with the TH1, TH17 and TH22 subsets of helper T cells. Viral suppression by ART resulted in a distinct transcriptional landscape, with a reduction in the expression of genes associated with TFH cells, but persistently low expression of genes associated with TH1, TH17 and TH22 cells compared to the elite controller profile. Thus, altered differentiation is central to the impairment of HIV-specific CD4+ T cells and involves both gain of function and loss of function.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Expressão Gênica/efeitos dos fármacos , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Células Th1/patologia , Células Th17/patologia , Perfilação da Expressão Gênica , Infecções por HIV/virologia , Humanos , Receptores CXCR5/metabolismo , Células Th1/citologia , Células Th1/imunologia , Células Th17/citologia , Células Th17/imunologia , Carga Viral/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos
18.
PLoS Pathog ; 15(2): e1007619, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30811499

RESUMO

The phenotypic characterization of the cells in which HIV persists during antiretroviral therapy (ART) remains technically challenging. We developed a simple flow cytometry-based assay to quantify and characterize infected cells producing HIV proteins during untreated and treated HIV infection. By combining two antibodies targeting the HIV capsid in a standard intracellular staining protocol, we demonstrate that p24-producing cells can be detected with high specificity and sensitivity in the blood from people living with HIV. In untreated individuals, the frequency of productively infected cells strongly correlated with plasma viral load. Infected cells preferentially displayed a transitional memory phenotype and were enriched in Th17, peripheral Tfh and regulatory T cells subsets. These cells also preferentially expressed activation markers (CD25, HLA-DR, Ki67), immune checkpoint molecules (PD-1, LAG-3, TIGIT, Tim-3) as well as the integrins α4ß7 and α4ß1. In virally suppressed individuals on ART, p24-producing cells were only detected upon stimulation (median frequency of 4.3 p24+ cells/106 cells). These measures correlated with other assays assessing the size of the persistent reservoir including total and integrated HIV DNA, Tat/rev Induced Limiting Dilution Assay (TILDA) and quantitative viral outgrowth assay (QVOA). In ART-suppressed individuals, p24-producing cells preferentially displayed a transitional and effector memory phenotype, and expressed immune checkpoint molecules (PD-1, TIGIT) as well as the integrin α4ß1. Remarkably, α4ß1 was expressed by more than 70% of infected cells both in untreated and ART-suppressed individuals. Altogether, these results highlight a broad diversity in the phenotypes of HIV-infected cells in treated and untreated infection and suggest that strategies targeting multiple and phenotypically distinct cellular reservoirs will be needed to exert a significant impact on the size of the reservoir.


Assuntos
Citometria de Fluxo/métodos , Infecções por HIV/imunologia , HIV/fisiologia , Adulto , Antirretrovirais , Linfócitos T CD4-Positivos , Reservatórios de Doenças/virologia , Feminino , HIV/patogenicidade , Proteína do Núcleo p24 do HIV , Infecções por HIV/virologia , HIV-1/imunologia , HIV-1/patogenicidade , Humanos , Integrina alfa4beta1/metabolismo , Masculino , Pessoa de Meia-Idade , Fenótipo , RNA Viral , Análise de Célula Única/métodos , Subpopulações de Linfócitos T , Carga Viral , Latência Viral
19.
mBio ; 9(2)2018 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-29559570

RESUMO

The conformation of the HIV-1 envelope glycoprotein (Env) substantially impacts antibody recognition and antibody-dependent cellular cytotoxicity (ADCC) responses. In the absence of the CD4 receptor at the cell surface, primary Envs sample a "closed" conformation that occludes CD4-induced (CD4i) epitopes. The virus controls CD4 expression through the actions of Nef and Vpu accessory proteins, thus protecting infected cells from ADCC responses. However, gp120 shed from infected cells can bind to CD4 present on uninfected bystander cells, sensitizing them to ADCC mediated by CD4i antibodies (Abs). Therefore, we hypothesized that these bystander cells could impact the interpretation of ADCC measurements. To investigate this, we evaluated the ability of antibodies to CD4i epitopes and broadly neutralizing Abs (bNAbs) to mediate ADCC measured by five ADCC assays commonly used in the field. Our results indicate that the uninfected bystander cells coated with gp120 are efficiently recognized by the CD4i ligands but not the bNabs. Consequently, the uninfected bystander cells substantially affect in vitro measurements made with ADCC assays that fail to identify responses against infected versus uninfected cells. Moreover, using an mRNA flow technique that detects productively infected cells, we found that the vast majority of HIV-1-infected cells in in vitro cultures or ex vivo samples from HIV-1-infected individuals are CD4 negative and therefore do not expose significant levels of CD4i epitopes. Altogether, our results indicate that ADCC assays unable to differentiate responses against infected versus uninfected cells overestimate responses mediated by CD4i ligands.IMPORTANCE Emerging evidence supports a role for antibody-dependent cellular cytotoxicity (ADCC) in protection against HIV-1 transmission and disease progression. However, there are conflicting reports regarding the ability of nonneutralizing antibodies targeting CD4-inducible (CD4i) Env epitopes to mediate ADCC. Here, we performed a side-by-side comparison of different methods currently being used in the field to measure ADCC responses to HIV-1. We found that assays which are unable to differentiate virus-infected from uninfected cells greatly overestimate ADCC responses mediated by antibodies to CD4i epitopes and underestimate responses mediated by broadly neutralizing antibodies (bNAbs). Our results strongly argue for the use of assays that measure ADCC against HIV-1-infected cells expressing physiologically relevant conformations of Env to evaluate correlates of protection in vaccine trials.


Assuntos
Citotoxicidade Celular Dependente de Anticorpos/fisiologia , HIV-1/imunologia , Anticorpos Neutralizantes/imunologia , Citotoxicidade Celular Dependente de Anticorpos/genética , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Citometria de Fluxo , Granzimas/genética , Granzimas/metabolismo , Células HEK293 , Proteína gp120 do Envelope de HIV/imunologia , Humanos
20.
Retrovirology ; 15(1): 18, 2018 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-29394935

RESUMO

Recent years have seen a substantial increase in the number of tools available to monitor and study HIV reservoirs. Here, we discuss recent technological advances that enable an understanding of reservoir dynamics beyond classical assays to measure the frequency of cells containing provirus able to propagate a spreading infection (replication-competent reservoir). Specifically, we focus on the characterization of cellular reservoirs containing proviruses able to transcribe viral mRNAs (so called transcription-competent) and translate viral proteins (translation-competent). We suggest that the study of these alternative reservoirs provides complementary information to classical approaches, crucially at a single-cell level. This enables an in-depth characterization of the cellular reservoir, both following reactivation from latency and, importantly, directly ex vivo at baseline. Furthermore, we propose that the study of cellular reservoirs that may not contain fully replication-competent virus, but are able to produce HIV mRNAs and proteins, is of biological importance. Lastly, we detail some of the key contributions that the study of these transcription and translation-competent reservoirs has made thus far to investigations into HIV persistence, and outline where these approaches may take the field next.


Assuntos
Infecções por HIV/virologia , HIV-1/genética , Proteínas do Vírus da Imunodeficiência Humana/análise , RNA Mensageiro/análise , RNA Viral/análise , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/virologia , Citometria de Fluxo , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Humanos , Hibridização In Situ , Provírus/genética , Análise de Célula Única
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