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1.
J Infect Dis ; 2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32052044

RESUMO

BACKGROUND: A higher proportion of circulating memory CD4+ T cells is associated with prevalent diabetes mellitus in the general population. Given the broad changes in adaptive immunity, including memory T cell expansion, and rising prevalence of diabetes in the HIV population, we assessed whether similar relationships were present in persons with HIV (PWH). METHODS: Multiple CD4+ and CD8+ T cell subsets were measured by flow cytometry and prevalent diabetes cases were adjudicated by two physicians for PWH and HIV-negative participants in the Veterans Aging Cohort Study. Multivariable logistic regression models evaluated the association of T cell subsets and diabetes stratified by HIV status, adjusted for cytomegalovirus serostatus and traditional risk factors. RESULTS: Among 2385 participants (65% PWH, 95% male, 68% African American), higher CD45RO+ memory CD4+ T cells and lower CD38+ CD4+ T cells were associated with prevalent diabetes, and had a similar effect size, in both the PWH and HIV-negative (p<0.05 for all). Lower CD38+ CD8+ T cells were also associated with diabetes in both groups. CONCLUSIONS: The CD4+ and CD8+ T cell subsets associated with diabetes are similar in PWH and HIV-negative individuals, suggesting that diabetes in PWH may be related to chronic immune activation.

2.
Cell ; 179(7): 1636-1646.e15, 2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31787378

RESUMO

B cell receptor (BCR) sequencing is a powerful tool for interrogating immune responses to infection and vaccination, but it provides limited information about the antigen specificity of the sequenced BCRs. Here, we present LIBRA-seq (linking B cell receptor to antigen specificity through sequencing), a technology for high-throughput mapping of paired heavy- and light-chain BCR sequences to their cognate antigen specificities. B cells are mixed with a panel of DNA-barcoded antigens so that both the antigen barcode(s) and BCR sequence are recovered via single-cell next-generation sequencing. Using LIBRA-seq, we mapped the antigen specificity of thousands of B cells from two HIV-infected subjects. The predicted specificities were confirmed for a number of HIV- and influenza-specific antibodies, including known and novel broadly neutralizing antibodies. LIBRA-seq will be an integral tool for antibody discovery and vaccine development efforts against a wide range of antigen targets.

3.
PLoS Pathog ; 15(12): e1008177, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31821379

RESUMO

Human immunodeficiency virus (HIV) can adapt to an individual's T cell immune response via genomic mutations that affect antigen recognition and impact disease outcome. These viral adaptations are specific to the host's human leucocyte antigen (HLA) alleles, as these molecules determine which peptides are presented to T cells. As HLA molecules are highly polymorphic at the population level, horizontal transmission events are most commonly between HLA-mismatched donor/recipient pairs, representing new immune selection environments for the transmitted virus. In this study, we utilised a deep sequencing approach to determine the HIV quasispecies in 26 mother-to-child transmission pairs where the potential for founder viruses to be pre-adapted is high due to the pairs being haplo-identical at HLA loci. This scenario allowed the assessment of specific HIV adaptations following transmission in either a non-selective immune environment, due to recipient HLA mismatched to original selecting HLA, or a selective immune environment, mediated by matched donor/recipient HLA. We show that the pattern of reversion or fixation of HIV adaptations following transmission provides insight into the replicative cost, and likely compensatory networks, associated with specific adaptations in vivo. Furthermore, although transmitted viruses were commonly heavily pre-adapted to the child's HLA genotype, we found evidence of de novo post-transmission adaptation, representing new epitopes targeted by the child's T cell response. High-resolution analysis of HIV adaptation is relevant when considering vaccine and cure strategies for individuals exposed to adapted viruses via transmission or reactivated from reservoirs.


Assuntos
Adaptação Biológica/genética , Infecções por HIV/genética , HIV-1/genética , Transmissão Vertical de Doença Infecciosa , Adaptação Biológica/imunologia , Adulto , Criança , Pré-Escolar , Evolução Molecular , Feminino , Infecções por HIV/imunologia , Infecções por HIV/transmissão , HIV-1/imunologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Lactente , Masculino , Pessoa de Meia-Idade
4.
Nat Med ; 25(8): 1243-1250, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31332390

RESUMO

Checkpoint inhibitors produce durable responses in numerous metastatic cancers, but immune-related adverse events (irAEs) complicate and limit their benefit. IrAEs can affect organ systems idiosyncratically; presentations range from mild and self-limited to fulminant and fatal. The molecular mechanisms underlying irAEs are poorly understood. Here, we report a fatal case of encephalitis arising during anti-programmed cell death receptor 1 therapy in a patient with metastatic melanoma. Histologic analyses revealed robust T cell infiltration and prominent programmed death ligand 1 expression. We identified 209 reported cases in global pharmacovigilance databases (across multiple cancer types) of encephalitis associated with checkpoint inhibitor regimens, with a 19% fatality rate. We performed further analyses from the index case and two additional cases to shed light on this recurrent and fulminant irAE. Spatial and multi-omic analyses pinpointed activated memory CD4+ T cells as highly enriched in the inflamed, affected region. We identified a highly oligoclonal T cell receptor repertoire, which we localized to activated memory cytotoxic (CD45RO+GZMB+Ki67+) CD4 cells. We also identified Epstein-Barr virus-specific T cell receptors and EBV+ lymphocytes in the affected region, which we speculate contributed to neural inflammation in the index case. Collectively, the three cases studied here identify CD4+ and CD8+ T cells as culprits of checkpoint inhibitor-associated immune encephalitis.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Encefalite/induzido quimicamente , Herpesvirus Humano 4/imunologia , Memória Imunológica , Ativação Linfocitária , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Encefalite/imunologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
5.
Mol Genet Genomic Med ; 7(6): e686, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30993913

RESUMO

BACKGROUND: Family screening of a 48-year-old male with recently diagnosed IgG4-related disease (IgG4-RD) revealed unanticipated elevations in plasma IgG4 in his two healthy teenaged sons. METHODS: We performed gene sequencing, immune cell studies, HLA typing, and analyses of circulating cytotoxic CD4+ T lymphocytes and plasmablasts to seek clues to pathogenesis. DNA from a separate cohort of 99 patients with known IgG4-RD was also sequenced for the presence of genetic variants in a specific gene, FGFBP2. RESULTS: The three share a previously unreported heterozygous single base deletion in fibroblast growth factor binding protein type 2 (FGFBP2), which causes a frameshift in the coding sequence. The FGFBP2 protein is secreted by cytotoxic T-lymphocytes and binds fibroblast growth factor. The variant sequence in the FGFBP2 protein is predicted to form a disordered random coil rather than a helical-turn-helix structure, unable to adopt a stable conformation. The proband and the two sons had 5-10-fold higher numbers of circulating cytotoxic CD4 + T cells and plasmablasts compared to matched controls. The three members also share a homozygous missense common variant in FGFBP2 found in heterozygous form in ~40% of the population. This common variant was found in 73% of an independent, well characterized IgG4-RD cohort, showing enrichment in idiopathic IgG4-RD. CONCLUSIONS: The presence of a shared deleterious variant and homozygous common variant in FGFBP2 in the proband and sons strongly implicates this cytotoxic T cell product in the pathophysiology of IgG4-RD. The high prevalence of a common FGFBP2 variant in sporadic IgG4-RD supports the likelihood of participation in disease.

6.
Front Immunol ; 10: 408, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30941121

RESUMO

Chronic T cell activation and accelerated immune senescence are hallmarks of HIV infection, which may contribute to the increased risk of cardiometabolic diseases in people living with HIV (PLWH). T lymphocytes play a central role in modulating adipose tissue inflammation and, by extension, adipocyte energy storage and release. Here, we assessed the CD4+ and CD8+ T cell profiles in the subcutaneous adipose tissue (SAT) and blood of non-diabetic (n = 9; fasting blood glucose [FBG] < 100 mg/dL), pre-diabetic (n = 8; FBG = 100-125 mg/dL) and diabetic (n = 9; FBG ≥ 126 mg/dL) PLWH, in addition to non- and pre-diabetic, HIV-negative controls (n = 8). SAT was collected by liposuction and T cells were extracted by collagenase digestion. The proportion of naïve (TNai) CD45RO-CCR7+, effector memory (TEM) CD45RO+CCR7-, central memory (TCM) CD45RO+CCR7+, and effector memory revertant RA+(TEMRA) CD45RO-CCR7- CD4+ and CD8+ T cells were measured by flow cytometry. CD4+ and CD8+ TEM and TEMRA were significantly enriched in SAT of PLWH compared to blood. The proportions of SAT CD4+ and CD8+ memory subsets were similar across metabolic status categories in the PLWH, but CD4+ T cell expression of the CD69 early-activation and tissue residence marker, particularly on TEM cells, increased with progressive glucose intolerance. Use of t-distributed Stochastic Neighbor Embedding (t-SNE) identified a separate group of predominantly CD69lo TEM and TEMRA cells co-expressing CD57, CX3CR1, and GPR56, which were significantly greater in diabetics compared to non-diabetics. Expression of the CX3CR1 and GPR56 markers indicate these TEM and TEMRA cells may have anti-viral specificity. Compared to HIV-negative controls, SAT from PLWH had an increased CD8:CD4 ratio, but the distribution of CD4+ and CD8+ memory subsets was similar irrespective of HIV status. Finally, whole adipose tissue from PLWH had significantly higher expression of TLR2, TLR8, and multiple chemokines potentially relevant to immune cell homing compared to HIV-negative controls with similar glucose tolerance.

7.
Front Immunol ; 9: 2730, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30559739

RESUMO

Adipose tissue comprises one of the largest organs in the body and performs diverse functions including energy storage and release, regulation of appetite and other neuroendocrine signaling, and modulation of immuity, among others. Adipocytes reside in a complex compartment where antigen, antigen presenting cells, innate immune cells, and adaptive immune cells interact locally and exert systemic effects on inflammation, circulating immune cell profiles, and metabolic homeostasis. T lymphocytes are a major component of the adipose tissue milieu which are altered in disease states such as obesity and human immunodeficiency virus (HIV) infection. While obesity, HIV infection, and simian immunodeficiency virus (SIV; a non-human primate virus similar to HIV) infection are accompanied by enrichment of CD8+ T cells in the adipose tissue, major phenotypic differences in CD4+ T cells and other immune cell populations distinguish HIV/SIV infection from obesity. Furthermore, DNA and RNA species of HIV and SIV can be detected in the stromal vascular fraction of visceral and subcutaneous adipose tissue, and replication-competent HIV resides in local CD4+ T cells. Here, we review studies of adipose tissue CD4+ and CD8+ T cell populations in HIV and SIV, and contrast the findings with those reported in obesity.


Assuntos
Tecido Adiposo/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Infecções por HIV/imunologia , HIV/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia/imunologia , Animais , Humanos , Replicação Viral/imunologia
8.
Diabetes ; 67(11): 2361-2376, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30181158

RESUMO

Adipose tissue (AT) CD4+ and CD8+ T cells contribute to obesity-associated insulin resistance. Prior studies identified conserved T-cell receptor (TCR) chain families in obese AT, but the presence and clonal expansion of specific TCR sequences in obesity has not been assessed. We characterized AT and liver CD8+ and CD4+ TCR repertoires of mice fed a low-fat diet (LFD) and high-fat diet (HFD) using deep sequencing of the TCRß chain to quantify clonal expansion, gene usage, and CDR3 sequence. In AT CD8+ T cells, HFD reduced TCR diversity, increased the prevalence of public TCR clonotypes, and selected for TCR CDR3 regions enriched in positively charged and less polarized amino acids. Although TCR repertoire alone could distinguish between LFD- and HFD-fed mice, these properties of the CDR3 region of AT CD8+ T cells from HFD-fed mice led us to examine the role of negatively charged and nonpolar isolevuglandin (isoLG) adduct-containing antigen-presenting cells within AT. IsoLG-adducted protein species were significantly higher in AT macrophages of HFD-fed mice; isoLGs were elevated in M2-polarized macrophages, promoting CD8+ T-cell activation. Our findings demonstrate that clonal TCR expansion that favors positively charged CDR3s accompanies HFD-induced obesity, which may be an antigen-driven response to isoLG accumulation in macrophages.


Assuntos
Tecido Adiposo/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Regiões Determinantes de Complementaridade/metabolismo , Fígado/metabolismo , Obesidade/metabolismo , Prostaglandinas/metabolismo , Tecido Adiposo/imunologia , Animais , Linfócitos T CD8-Positivos/imunologia , Dieta Hiperlipídica , Teste de Tolerância a Glucose , Resistência à Insulina , Fígado/imunologia , Masculino , Camundongos , Obesidade/imunologia
9.
Cell Host Microbe ; 23(6): 845-854.e6, 2018 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-29861170

RESUMO

Characterization of single antibody lineages within infected individuals has provided insights into the development of Env-specific antibodies. However, a systems-level understanding of the humoral response against HIV-1 is limited. Here, we interrogated the antibody repertoires of multiple HIV-infected donors from an infection-naive state through acute and chronic infection using next-generation sequencing. This analysis revealed the existence of "public" antibody clonotypes that were shared among multiple HIV-infected individuals. The HIV-1 reactivity for representative antibodies from an identified public clonotype shared by three donors was confirmed. Furthermore, a meta-analysis of publicly available antibody repertoire sequencing datasets revealed antibodies with high sequence identity to known HIV-reactive antibodies, even in repertoires that were reported to be HIV naive. The discovery of public antibody clonotypes in HIV-infected individuals represents an avenue of significant potential for better understanding antibody responses to HIV-1 infection, as well as for clonotype-specific vaccine development.


Assuntos
Anticorpos Neutralizantes/genética , Formação de Anticorpos/imunologia , Anticorpos Anti-HIV/genética , Infecções por HIV/imunologia , HIV-1/imunologia , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/sangue , Anticorpos Anti-HIV/química , Anticorpos Anti-HIV/imunologia , Infecções por HIV/sangue , Humanos , Imunidade Humoral/imunologia , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/virologia , Estudos Longitudinais , RNA/sangue , RNA/imunologia , Análise de Sequência de Proteína , Análise de Sequência de RNA , Análise de Célula Única
10.
PeerJ ; 6: e4803, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29796347

RESUMO

Helicobacter pylori requires genetic agility to infect new hosts and establish long-term colonization of changing gastric environments. In this study, we analyzed H. pylori genetic adaptation in the Mongolian gerbil model. This model is of particular interest because H. pylori-infected gerbils develop a high level of gastric inflammation and often develop gastric adenocarcinoma or gastric ulceration. We analyzed the whole genome sequences of H. pylori strains cultured from experimentally infected gerbils, in comparison to the genome sequence of the input strain. The mean annualized single nucleotide polymorphism (SNP) rate per site was 1.5e-5, which is similar to the rates detected previously in H. pylori-infected humans. Many of the mutations occurred within or upstream of genes associated with iron-related functions (fur, tonB1, fecA2, fecA3, and frpB3) or encoding outer membrane proteins (alpA, oipA, fecA2, fecA3, frpB3 and cagY). Most of the SNPs within coding regions (86%) were non-synonymous mutations. Several deletion or insertion mutations led to disruption of open reading frames, suggesting that the corresponding gene products are not required or are deleterious during chronic H. pylori colonization of the gerbil stomach. Five variants (three SNPs and two deletions) were detected in isolates from multiple animals, which suggests that these mutations conferred a selective advantage. One of the mutations (FurR88H) detected in isolates from multiple animals was previously shown to confer increased resistance to oxidative stress, and we now show that this SNP also confers a survival advantage when H. pylori is co-cultured with neutrophils. Collectively, these analyses allow the identification of mutations that are positively selected during H. pylori colonization of the gerbil model.

11.
J Immunol ; 199(9): 3187-3201, 2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-28972094

RESUMO

Select CMV epitopes drive life-long CD8+ T cell memory inflation, but the extent of CD4 memory inflation is poorly studied. CD4+ T cells specific for human CMV (HCMV) are elevated in HIV+ HCMV+ subjects. To determine whether HCMV epitope-specific CD4+ T cell memory inflation occurs during HIV infection, we used HLA-DR7 (DRB1*07:01) tetramers loaded with the glycoprotein B DYSNTHSTRYV (DYS) epitope to characterize circulating CD4+ T cells in coinfected HLA-DR7+ long-term nonprogressor HIV subjects with undetectable HCMV plasma viremia. DYS-specific CD4+ T cells were inflated among these HIV+ subjects compared with those from an HIV- HCMV+ HLA-DR7+ cohort or with HLA-DR7-restricted CD4+ T cells from the HIV-coinfected cohort that were specific for epitopes of HCMV phosphoprotein-65, tetanus toxoid precursor, EBV nuclear Ag 2, or HIV gag protein. Inflated DYS-specific CD4+ T cells consisted of effector memory or effector memory-RA+ subsets with restricted TCRß usage and nearly monoclonal CDR3 containing novel conserved amino acids. Expression of this near-monoclonal TCR in a Jurkat cell-transfection system validated fine DYS specificity. Inflated cells were polyfunctional, not senescent, and displayed high ex vivo levels of granzyme B, CX3CR1, CD38, or HLA-DR but less often coexpressed CD38+ and HLA-DR+ The inflation mechanism did not involve apoptosis suppression, increased proliferation, or HIV gag cross-reactivity. Instead, the findings suggest that intermittent or chronic expression of epitopes, such as DYS, drive inflation of activated CD4+ T cells that home to endothelial cells and have the potential to mediate cytotoxicity and vascular disease.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Epitopos de Linfócito T/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Proteínas Virais/imunologia , ADP-Ribosil Ciclase 1/imunologia , Linfócitos T CD4-Positivos/patologia , Infecções por Citomegalovirus/patologia , Feminino , Infecções por HIV/patologia , Antígeno HLA-DR7/imunologia , Humanos , Memória Imunológica , Masculino , Glicoproteínas de Membrana/imunologia
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