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1.
Immunol Cell Biol ; 99(8): 796-799, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34355822

RESUMO

The B-cell response to COVID-19 vaccines in convalescent individuals.


Assuntos
COVID-19 , SARS-CoV-2 , Anticorpos Antivirais , Linfócitos B/imunologia , Vacinas contra COVID-19 , Humanos , Memória Imunológica , Caminhada
2.
Int J Mol Sci ; 22(15)2021 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-34360781

RESUMO

To identify potential early biomarkers of treatment response and immune-related adverse events (irAE), a pilot immune monitoring study was performed in stage IV melanoma patients by flow cytometric analysis of peripheral blood mononuclear cells (PBMC). Overall, 17 patients were treated with either nivolumab or pembrolizumab alone, or with a combination of nivolumab and ipilimumab every three weeks. Of 15 patients for which complete response assessment was available, treatment responders (n = 10) as compared to non-responders (n = 5) were characterized by enhanced PD-1 expression on CD8+ T cells immediately before treatment (median ± median absolute deviation/MAD 26.7 ± 10.4% vs. 17.2 ± 5.3%). Responders showed a higher T cell responsiveness after T cell receptor ex vivo stimulation as determined by measurement of programmed cell death 1 (PD-1) expression on CD3+ T cells before the second cycle of treatment. The percentage of CD8+ effector memory (CD8+CD45RA-CD45RO+CCR7-) T cells was higher in responders compared to non-responders before and immediately after the first cycle of treatment (median ± MAD 39.2 ± 7.3% vs. 30.5 ± 4.1% and 37.7 ± 4.6 vs. 24.0 ± 6.4). Immune-related adverse events (irAE) were accompanied by a higher percentage of activated CD4+ (CD4+CD38+HLADR+) T cells before the second treatment cycle (median ± MAD 14.9 ± 3.9% vs. 5.3 ± 0.4%). In summary, PBMC immune monitoring of immune-checkpoint inhibition (ICI) treatment in melanoma appears to be a promising approach to identify early markers of treatment response and irAEs.


Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Inibidores de Checkpoint Imunológico/administração & dosagem , Melanoma , Nivolumabe/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados/efeitos adversos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Feminino , Citometria de Fluxo , Humanos , Inibidores de Checkpoint Imunológico/efeitos adversos , Memória Imunológica/efeitos dos fármacos , Ativação Linfocitária/efeitos dos fármacos , Masculino , Melanoma/tratamento farmacológico , Melanoma/imunologia , Melanoma/patologia , Pessoa de Meia-Idade , Proteínas de Neoplasias/imunologia , Nivolumabe/efeitos adversos , Receptor de Morte Celular Programada 1/imunologia
3.
Sci Immunol ; 6(62)2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376481

RESUMO

To understand how a protective immune response against SARS-CoV-2 develops over time, we integrated phenotypic, transcriptional and repertoire analyses on PBMCs from mild and severe COVID-19 patients during and after infection, and compared them to healthy donors (HD). A type I IFN-response signature marked all the immune populations from severe patients during the infection. Humoral immunity was dominated by IgG production primarily against the RBD and N proteins, with neutralizing antibody titers increasing post infection and with disease severity. Memory B cells, including an atypical FCRL5+ T-BET+ memory subset, increased during the infection, especially in patients with mild disease. A significant reduction of effector memory, CD8+ T cells frequency characterized patients with severe disease. Despite such impairment, we observed robust clonal expansion of CD8+ T lymphocytes, while CD4+ T cells were less expanded and skewed toward TCM and TH2-like phenotypes. MAIT cells were also expanded, but only in patients with mild disease. Terminally differentiated CD8+ GZMB+ effector cells were clonally expanded both during the infection and post-infection, while CD8+ GZMK+ lymphocytes were more expanded post-infection and represented bona fide memory precursor effector cells. TCR repertoire analysis revealed that only highly proliferating T cell clonotypes, which included SARS-CoV-2-specific cells, were maintained post-infection and shared between the CD8+ GZMB+ and GZMK+ subsets. Overall, this study describes the development of immunity against SARS-CoV-2 and identifies an effector CD8+ T cell population with memory precursor-like features.


Assuntos
COVID-19/genética , COVID-19/imunologia , Interações Hospedeiro-Patógeno/imunologia , Imunofenotipagem , SARS-CoV-2/imunologia , Transcriptoma , Adulto , Idoso , Anticorpos Antivirais/imunologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Biomarcadores , COVID-19/virologia , Plasticidade Celular/genética , Plasticidade Celular/imunologia , Evolução Clonal/imunologia , Feminino , Perfilação da Expressão Gênica , Humanos , Isotipos de Imunoglobulinas/imunologia , Memória Imunológica , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo
4.
Clin Immunol ; 230: 108817, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34352391

RESUMO

Many studies have analyzed myelin-reactivity of T cells in multiple sclerosis (MS); however, with conflicting results. In this study we compare methods to determine myelin reactivity of T cells and aim to delineate the cause of inconsistency in the literature. Challenging T cells with myelin antigens we found a significant increase in antigen-reactivity of T cells from patients with MS using an ELISpot-assay, in contrast to a CFSE-dilution assay. Comparing the two assays showed that the myelin-reactive T cells detected in the ELISpot-assay originated primarily from effector memory T cells in contrast to the myelin-reactive T cells of the CFSE-assay representing a population of both naïve, central memory and effector memory T cells. This diversity in T cell populations activated in the two assays likely contribute to the discrepancy found in the literature and encourages thorough considerations when choosing an assay to determine antigen-specificity of T cells in future studies.


Assuntos
Imunoensaio/métodos , Esclerose Múltipla Recidivante-Remitente/imunologia , Proteínas da Mielina/imunologia , Linfócitos T/imunologia , Adulto , Autoantígenos/imunologia , Estudos de Casos e Controles , ELISPOT , Feminino , Fluoresceínas , Corantes Fluorescentes , Humanos , Memória Imunológica , Masculino , Pessoa de Meia-Idade , Proteína Básica da Mielina/imunologia , Glicoproteína Mielina-Oligodendrócito/imunologia , Succinimidas , Linfócitos T/classificação , Adulto Jovem
5.
Clin Immunol ; 230: 108820, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34365017

RESUMO

BACKGROUND: Peanut oral immunotherapy (POIT) has provided desensitization to peanut allergic individuals. Limited immunological evaluation exists during the first 24-weeks of POIT. OBJECTIVE: Regulatory T-cells (Tregs) are antigen induced immunosuppressive T-cells important in establishing tolerance. Delineation of early immunologic changes contributing to the development of peanut desensitization would help clarify the mechanism of action in POIT. We performed single-cell RNA sequencing (scRNAseq) on Tregs in pediatric subjects undergoing POIT during the first 24-weeks of therapy to evaluate early immunological changes induced by POIT. METHODS: PBMC samples from peanut allergic subjects between 5 and 12 years of age enrolled in a Phase 1/2a POIT study were collected and analyzed at 0, 6, and 24-weeks after POIT initiation and samples were compared to healthy non-peanut allergic controls. Tregs were enriched from PBMCs and scRNAseq analysis performed. Cell Ranger 3.1.0 (10× Genomics) was utilized to identify cell clusters and differentially expressed genes, and results were analyzed with Seurat suite version 3.0.0. RESULTS: Gene analysis revealed 10 major clusters corresponding to different cell types observed to change during POIT when compared to the healthy, non-peanut-allergic state. scRNAseq analysis of Tregs revealed strong CD3G expression correlating with gdTregs. scRNAseq analysis of gdTregs revealed dynamic changes occurring within the first 6-weeks of treatment and cell frequencies of naïve and memory gdTregs at 24-weeks of treatment reducing to levels similar to healthy controls. Analysis of transcriptomic cell identity analysis using SingleR showed gene expression in gdTregs similar to healthy control after 24-weeks of POIT treatment. scRNAseq analysis revealed alterations in gene expression for memory and naïve gdTregs during this timeframe. Specifically, expression of OX40R (TNFRSF4), GITR (TNFRSF18), TGFB1, CTLA4, ISG20, CD69 were upregulated in memory gdTregs compared to naive gdTregs by 24-weeks of POIT, while IL7R and SELL were downregulated in memory gdTregs compared to naïve gdTregs. CONCLUSIONS: There are specific expression profiles of peripheral naïve and mature gdTreg cells in peanut allergic patients undergoing POIT in the first 24-weeks of treatment implicating pathways involved in maintenance of immune homeostasis. gdTreg cells may contribute to the tolerogenic effect of POIT within the first 24-weeks of POIT treatment. These findings suggest that gdTregs cells may be an early marker of desensitization in subjects undergoing POIT.


Assuntos
Arachis/imunologia , Dessensibilização Imunológica/métodos , Genes Codificadores da Cadeia delta de Receptores de Linfócitos T , Genes Codificadores da Cadeia gama de Receptores de Linfócitos T , Hipersensibilidade a Amendoim/terapia , Linfócitos T Reguladores/imunologia , Administração Oral , Alérgenos/administração & dosagem , Criança , Pré-Escolar , Humanos , Memória Imunológica , Família Multigênica , Hipersensibilidade a Amendoim/genética , Hipersensibilidade a Amendoim/imunologia , RNA-Seq , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Análise de Célula Única , Fatores de Tempo , Transcriptoma
6.
Nat Immunol ; 22(9): 1152-1162, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34385712

RESUMO

The transcription factor TCF-1 is essential for the development and function of regulatory T (Treg) cells; however, its function is poorly understood. Here, we show that TCF-1 primarily suppresses transcription of genes that are co-bound by Foxp3. Single-cell RNA-sequencing analysis identified effector memory T cells and central memory Treg cells with differential expression of Klf2 and memory and activation markers. TCF-1 deficiency did not change the core Treg cell transcriptional signature, but promoted alternative signaling pathways whereby Treg cells became activated and gained gut-homing properties and characteristics of the TH17 subset of helper T cells. TCF-1-deficient Treg cells strongly suppressed T cell proliferation and cytotoxicity, but were compromised in controlling CD4+ T cell polarization and inflammation. In mice with polyposis, Treg cell-specific TCF-1 deficiency promoted tumor growth. Consistently, tumor-infiltrating Treg cells of patients with colorectal cancer showed lower TCF-1 expression and increased TH17 expression signatures compared to adjacent normal tissue and circulating T cells. Thus, Treg cell-specific TCF-1 expression differentially regulates TH17-mediated inflammation and T cell cytotoxicity, and can determine colorectal cancer outcome.


Assuntos
Neoplasias do Colo/patologia , Fator 1-alfa Nuclear de Hepatócito/metabolismo , Linfócitos T Citotóxicos/imunologia , Linfócitos T Reguladores/imunologia , Células Th17/imunologia , Polipose Adenomatosa do Colo/genética , Polipose Adenomatosa do Colo/imunologia , Animais , Proliferação de Células/fisiologia , Fatores de Transcrição Forkhead/imunologia , Regulação da Expressão Gênica/genética , Regulação da Expressão Gênica/imunologia , Fator 1-alfa Nuclear de Hepatócito/genética , Memória Imunológica/imunologia , Inflamação/imunologia , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Knockout , Transcrição Genética/genética , Proteínas Supressoras de Tumor/metabolismo
8.
Viruses ; 13(8)2021 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-34452355

RESUMO

BACKGROUND: New coronavirus SARS-CoV-2, a causative agent of the COVID-19 pandemic, has been circulating among humans since November 2019. Multiple studies have assessed the qualitative and quantitative characteristics of virus-specific immunity in COVID-19 convalescents, however, some aspects of the development of memory T-cell responses after natural SARS-CoV-2 infection remain uncovered. METHODS: In most of published studies T-cell immunity to the new coronavirus is assessed using peptides corresponding to SARS-CoV-1 or SARS-CoV-2 T-cell epitopes, or with peptide pools covering various parts of the viral proteins. Here, we determined the level of CD4+ and CD8+ memory T-cell responses in COVID-19 convalescents by stimulating PBMCs collected 1 to 6 months after recovery with sucrose gradient-purified live SARS-CoV-2. IFNγ production by the central and effector memory helper and cytotoxic T cells was assessed by intracellular cytokine staining assay and flow cytometry. RESULTS: Stimulation of PBMCs with live SARS-CoV-2 revealed IFNγ-producing T-helper effector memory cells with CD4+CD45RA-CCR7- phenotype, which persisted in circulation for up to 6 month after COVID-19. In contrast, SARS-CoV-2-specific IFNγ-secreting cytotoxic effector memory T cells were found at significant levels only shortly after the disease, but rapidly decreased over time. CONCLUSION: The stimulation of immune cells with live SARS-CoV-2 revealed a rapid decline in the pool of effector memory CD8+, but not CD4+, T cells after recovery from COVID-19. These data provide additional information on the development and persistence of cellular immune responses after natural infection, and can inform further development of T cell-based SARS-CoV-2 vaccines.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , COVID-19/imunologia , Memória Imunológica , Interferon gama/imunologia , Leucócitos Mononucleares/imunologia , SARS-CoV-2/imunologia , COVID-19/virologia , Epitopos de Linfócito T/imunologia , Humanos , Leucócitos Mononucleares/virologia , SARS-CoV-2/genética , SARS-CoV-2/fisiologia , Linfócitos T Citotóxicos/imunologia
9.
J Immunol ; 207(5): 1377-1387, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34380645

RESUMO

T cells are essential mediators of immune responses against infectious diseases and provide long-lived protection from reinfection. The differentiation of naive to effector T cells and the subsequent differentiation and persistence of memory T cell populations in response to infection is a highly regulated process. E protein transcription factors and their inhibitors, Id proteins, are important regulators of both CD4+ and CD8+ T cell responses; however, their regulation at the protein level has not been explored. Recently, the deubiquitinase USP1 was shown to stabilize Id2 and modulate cellular differentiation in osteosarcomas. In this study, we investigated a role for Usp1 in posttranslational control of Id2 and Id3 in murine T cells. We show that Usp1 was upregulated in T cells following activation in vitro or following infection in vivo, and the extent of Usp1 expression correlated with the degree of T cell expansion. Usp1 directly interacted with Id2 and Id3 following T cell activation. However, Usp1 deficiency did not impact Id protein abundance in effector T cells or alter effector T cell expansion or differentiation following a primary infection. Usp1 deficiency resulted in a gradual loss of memory CD8+ T cells over time and reduced Id2 protein levels and proliferation of effector CD8+ T cell following reinfection. Together, these results identify Usp1 as a player in modulating recall responses at the protein level and highlight differences in regulation of T cell responses between primary and subsequent infection encounters. Finally, our observations reveal differential regulation of Id2/3 proteins between immune versus nonimmune cell types.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Proteases Específicas de Ubiquitina/metabolismo , Animais , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Imunidade Celular , Imunização , Memória Imunológica , Proteína 2 Inibidora de Diferenciação/metabolismo , Proteínas Inibidoras de Diferenciação/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Processamento de Proteína Pós-Traducional , Proteases Específicas de Ubiquitina/genética
10.
J Immunol ; 207(5): 1388-1400, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34380649

RESUMO

Acute viral infection generates lineage-committed Th1 and T follicular helper (Tfh) memory cells that recall their lineage-specific functions following secondary challenge with virus. However, the lineage commitment of effector and memory Th cells in vivo following protein vaccination is poorly understood. In this study, we analyzed effector and memory CD4+ T cell differentiation in mice (Mus musculus) following adjuvanted glycoprotein immunization compared with acute lymphocytic choriomeningitis virus infection. Glycoprotein immunization induced CXCR5- non-Tfh effector and memory CD4+ T cells that surprisingly had not undergone polarization toward any particular Th cell lineage but had undergone memory differentiation. However, upon challenge with virus, these Th lineage-nonpolarized memory CD4+ T cells were able to generate Th1 secondary effector cells, demonstrating their lineage plasticity. In addition, Tfh and memory Tfh cells were generated in response to protein immunization, and these cells differed from infection-induced Tfh cells by their lack of the transcription factor Tbet. Rechallenge experiments demonstrated that viral infection, but not protein immunization, during either the primary or secondary immune response, restricts the recall of Bcl6 expression and the generation of germinal center Tfh cells. Together, these data demonstrate that protein immunization generates a combination of nonpolarized memory cells that are highly plastic and memory Tfh cells that can undergo further Th1-like modulation during a secondary response to viral infection.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Centro Germinativo/imunologia , Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/fisiologia , Subpopulações de Linfócitos T/imunologia , Animais , Diferenciação Celular , Linhagem da Célula , Plasticidade Celular , Células Cultivadas , Imunização , Memória Imunológica , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Proto-Oncogênicas c-bcl-6/genética , Proteínas Proto-Oncogênicas c-bcl-6/metabolismo , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismo , Vacinação
11.
J Immunol ; 207(5): 1478-1492, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34389622

RESUMO

Stable, long-term culture of primary B lymphocytes has many potential scientific and medical applications, but remains an elusive feat. A major obstacle to long-term culture is that in vitro mitogens quickly drive B cells to differentiate into short-lived plasma cells (PCs). PC differentiation is governed by opposing teams of transcription factors: Pax5, Bach2, and Bcl6 suppress PC commitment, whereas IFN regulatory factor 4 and Blimp1 promote it. To determine whether transcriptional programming could prolong B cell culture by blocking PC commitment, we generated mouse primary B cells harboring gain- or loss-of-function in the key transcription factors, continuously stimulated these cells with CD154 and IL-21, and determined growth potential and phenotypes in vitro. We found that transgenic expression of Bach2 prohibits PC commitment and endows B cells with extraordinary growth potential in response to external proliferation and survival cues. Long-term Bach2-transgenic B cell lines have genetically stable BCRs [i.e., do not acquire V(D)J mutations], express high levels of MHC class II and molecules for costimulation of T cells, and transduce intracellular signals when incubated with BCR ligands. Silencing the Bach2 transgene in an established transgenic cell line causes the cells to secrete large quantities of Ig. This system has potential applications in mAb production, BCR signaling studies, Ag presentation to T cells, and ex vivo clonal expansion for adoptive cell transfer. Additionally, our results provide insight into molecular control over activated B cell fate and suggest that forced Bach2 expression in vivo may augment germinal center B cell or memory B cell differentiation at the expense of PC commitment.


Assuntos
Linfócitos B/imunologia , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Centro Germinativo/imunologia , Animais , Fatores de Transcrição de Zíper de Leucina Básica/genética , Diferenciação Celular , Linhagem da Célula , Células Cultivadas , Regulação da Expressão Gênica , Memória Imunológica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutação/genética , Fator de Transcrição PAX5/genética , Fator de Transcrição PAX5/metabolismo , Cultura Primária de Células , Proteínas Proto-Oncogênicas c-bcl-6/genética , Proteínas Proto-Oncogênicas c-bcl-6/metabolismo , Receptores de Antígenos de Linfócitos B/genética , Receptores de Antígenos de Linfócitos B/metabolismo
12.
J Immunol ; 207(5): 1468-1477, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34408009

RESUMO

Immuno-positron emission tomography (PET), a noninvasive imaging modality, can provide a dynamic approach for longitudinal assessment of cell populations of interest. Transformation of mAbs into single-chain variable fragment (scFv)-based PET imaging agents would allow noninvasive tracking in vivo of a wide range of possible targets. We used sortase-mediated enzymatic labeling in combination with PEGylation to develop an anti-mouse CD4 scFv-based PET imaging agent constructed from an anti-mouse CD4 mAb. This anti-CD4 scFv can monitor the in vivo distribution of CD4+ T cells by immuno-PET. We tracked CD4+ and CD8+ T cells in wild-type mice, in immunodeficient recipients reconstituted with monoclonal populations of OT-II and OT-I T cells, and in a B16 melanoma model. Anti-CD4 and -CD8 immuno-PET showed that the persistence of both CD4+ and CD8+ T cells transferred into immunodeficient mice improved when recipients were immunized with OVA in CFA. In tumor-bearing animals, infiltration of both CD4+ and CD8+ T cells increased as the tumor grew. The approach described in this study should be readily applicable to convert clinically useful Abs into the corresponding scFv PET imaging agents.


Assuntos
Antígenos CD4/imunologia , Linfócitos T CD4-Positivos/imunologia , Imunoterapia/métodos , Linfócitos do Interstício Tumoral/imunologia , Melanoma/terapia , Monitorização Imunológica/métodos , Neoplasias Cutâneas/terapia , Animais , Anticorpos Monoclonais/metabolismo , Diagnóstico por Imagem , Feminino , Memória Imunológica , Melanoma Experimental , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Tomografia por Emissão de Pósitrons , Anticorpos de Cadeia Única/metabolismo
14.
Nat Immunol ; 22(9): 1140-1151, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34426691

RESUMO

Tissue-resident memory T (TRM) cells are non-recirculating cells that exist throughout the body. Although TRM cells in various organs rely on common transcriptional networks to establish tissue residency, location-specific factors adapt these cells to their tissue of lodgment. Here we analyze TRM cell heterogeneity between organs and find that the different environments in which these cells differentiate dictate TRM cell function, durability and malleability. We find that unequal responsiveness to TGFß is a major driver of this diversity. Notably, dampened TGFß signaling results in CD103- TRM cells with increased proliferative potential, enhanced function and reduced longevity compared with their TGFß-responsive CD103+ TRM counterparts. Furthermore, whereas CD103- TRM cells readily modified their phenotype upon relocation, CD103+ TRM cells were comparatively resistant to transdifferentiation. Thus, despite common requirements for TRM cell development, tissue adaptation of these cells confers discrete functional properties such that TRM cells exist along a spectrum of differentiation potential that is governed by their local tissue microenvironment.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/imunologia , Plasticidade Celular/imunologia , Microambiente Celular/imunologia , Memória Imunológica/imunologia , Animais , Antígenos CD/imunologia , Linfócitos T CD8-Positivos/citologia , Feminino , Cadeias alfa de Integrinas/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais/imunologia , Fator de Crescimento Transformador beta1/metabolismo
15.
Sci Adv ; 7(34)2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34407944

RESUMO

The COVID-19 pandemic has spread worldwide, yet the role of antiviral T cell immunity during infection and the contribution of immune checkpoints remain unclear. By prospectively following a cohort of 292 patients with melanoma, half of which treated with immune checkpoint inhibitors (ICIs), we identified 15 patients with acute or convalescent COVID-19 and investigated their transcriptomic, proteomic, and cellular profiles. We found that ICI treatment was not associated with severe COVID-19 and did not alter the induction of inflammatory and type I interferon responses. In-depth phenotyping demonstrated expansion of CD8 effector memory T cells, enhanced T cell activation, and impaired plasmablast induction in ICI-treated COVID-19 patients. The evaluation of specific adaptive immunity in convalescent patients showed higher spike (S), nucleoprotein (N), and membrane (M) antigen-specific T cell responses and similar induction of spike-specific antibody responses. Our findings provide evidence that ICI during COVID-19 enhanced T cell immunity without exacerbating inflammation.


Assuntos
COVID-19/imunologia , Inibidores de Checkpoint Imunológico/imunologia , Melanoma/imunologia , SARS-CoV-2/imunologia , Linfócitos T/imunologia , Imunidade Adaptativa/efeitos dos fármacos , Imunidade Adaptativa/imunologia , Idoso , Anticorpos Antivirais/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , COVID-19/complicações , COVID-19/virologia , Feminino , Humanos , Inibidores de Checkpoint Imunológico/uso terapêutico , Memória Imunológica/efeitos dos fármacos , Memória Imunológica/imunologia , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Masculino , Melanoma/complicações , Melanoma/tratamento farmacológico , Pessoa de Meia-Idade , Estudos Prospectivos , SARS-CoV-2/metabolismo , SARS-CoV-2/fisiologia , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Linfócitos T/efeitos dos fármacos , Linfócitos T/virologia
16.
Front Immunol ; 12: 690534, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34367150

RESUMO

High quality medical assistance and preventive strategies, including pursuing a healthy lifestyle, result in a progressively growing percentage of older people. The population and workforce is aging in all countries of the world. It is widely recognized that older individuals show an increased susceptibility to infections and a reduced response to vaccination suggesting that the aged immune system is less able to react and consequently protect the organism. The SARS-CoV-2 pandemic is dramatically showing us that the organism reacts to novel pathogens in an age-dependent manner. The decline of the immune system observed in aging remains unclear. We aimed to understand the role of B cells. We analyzed peripheral blood from children (4-18 years); young people (23-60 years) and elderly people (65-91 years) by flow cytometry. We also measured antibody secretion by ELISA following a T-independent stimulation. Here we show that the elderly have a significant reduction of CD27dull memory B cells, a population that bridges innate and adaptive immune functions. In older people, memory B cells are mostly high specialized antigen-selected CD27bright. Moreover, after in vitro stimulation with CpG, B cells from older individuals produced significantly fewer IgM and IgA antibodies compared to younger individuals. Aging is a complex process characterized by a functional decline in multiple physiological systems. The immune system of older people is well equipped to react to often encountered antigens but has a low ability to respond to new pathogens.


Assuntos
Envelhecimento/imunologia , Linfócitos B/imunologia , COVID-19 , Memória Imunológica , Pandemias , SARS-CoV-2/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/epidemiologia , COVID-19/imunologia , Criança , Pré-Escolar , Citocinas/imunologia , Feminino , Humanos , Imunoglobulina A/imunologia , Imunoglobulina M/imunologia , Masculino , Pessoa de Meia-Idade
19.
mBio ; 12(4): e0150321, 2021 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-34311582

RESUMO

Severe coronavirus disease 2019 (COVID-19) has been associated with T cell lymphopenia, but no causal effect of T cell deficiency on disease severity has been established. To investigate the specific role of T cells in recovery from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, we studied rhesus macaques that were depleted of either CD4+, CD8+, or both T cell subsets prior to infection. Peak virus loads were similar in all groups, but the resolution of virus in the T cell-depleted animals was slightly delayed compared to that in controls. The T cell-depleted groups developed virus-neutralizing antibody responses and class switched to IgG. When reinfected 6 weeks later, the T cell-depleted animals showed anamnestic immune responses characterized by rapid induction of high-titer virus-neutralizing antibodies, faster control of virus loads, and reduced clinical signs. These results indicate that while T cells play a role in the recovery of rhesus macaques from acute SARS-CoV-2 infections, their depletion does not induce severe disease, and T cells do not account for the natural resistance of rhesus macaques to severe COVID-19. Neither primed CD4+ nor CD8+ T cells appeared critical for immunoglobulin class switching, the development of immunological memory, or protection from a second infection. IMPORTANCE Patients with severe COVID-19 often have decreased numbers of T cells, a cell type important in fighting most viral infections. However, it is not known whether the loss of T cells contributes to severe COVID-19 or is a consequence of it. We studied rhesus macaques, which develop only mild COVID-19, similar to most humans. Experimental depletion of T cells slightly prolonged their clearance of virus, but there was no increase in disease severity. Furthermore, they were able to develop protection from a second infection and produced antibodies capable of neutralizing the virus. They also developed immunological memory, which allows a much stronger and more rapid response upon a second infection. These results suggest that T cells are not critical for recovery from acute SARS-CoV-2 infections in this model and point toward B cell responses and antibodies as the essential mediators of protection from re-exposure.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/patologia , Memória Imunológica/imunologia , Linfopenia/imunologia , SARS-CoV-2/imunologia , Animais , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , COVID-19/imunologia , Feminino , Depleção Linfocítica/métodos , Macaca mulatta/imunologia , Masculino
20.
Nature ; 597(7875): 268-273, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34320609

RESUMO

SARS-CoV-2 spike mRNA vaccines1-3 mediate protection from severe disease as early as ten days after prime vaccination3, when neutralizing antibodies are hardly detectable4-6. Vaccine-induced CD8+ T cells may therefore be the main mediators of protection at this early stage7,8. The details of their induction, comparison to natural infection, and association with other arms of vaccine-induced immunity remain, however, incompletely understood. Here we show on a single-epitope level that a stable and fully functional CD8+ T cell response is vigorously mobilized one week after prime vaccination with bnt162b2, when circulating CD4+ T cells and neutralizing antibodies are still weakly detectable. Boost vaccination induced a robust expansion that generated highly differentiated effector CD8+ T cells; however, neither the functional capacity nor the memory precursor T cell pool was affected. Compared with natural infection, vaccine-induced early memory T cells exhibited similar functional capacities but a different subset distribution. Our results indicate that CD8+ T cells are important effector cells, are expanded in the early protection window after prime vaccination, precede maturation of other effector arms of vaccine-induced immunity and are stably maintained after boost vaccination.


Assuntos
Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Vacinas contra COVID-19/imunologia , COVID-19/imunologia , SARS-CoV-2/imunologia , Vacinação , Vacinas Sintéticas/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , COVID-19/virologia , Células Cultivadas , Epitopos de Linfócito T/imunologia , Humanos , Imunização Secundária , Memória Imunológica/imunologia , SARS-CoV-2/química , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/imunologia , Fatores de Tempo
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