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1.
Nat Immunol ; 2024 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-38997431

RESUMEN

A subset of individuals exposed to Mycobacterium tuberculosis (Mtb) that we refer to as 'resisters' (RSTR) show evidence of IFN-γ- T cell responses to Mtb-specific antigens despite serially negative results on clinical testing. Here we found that Mtb-specific T cells in RSTR were clonally expanded, confirming the priming of adaptive immune responses following Mtb exposure. RSTR CD4+ T cells showed enrichment of TH17 and regulatory T cell-like functional programs compared to Mtb-specific T cells from individuals with latent Mtb infection. Using public datasets, we showed that these TH17 cell-like functional programs were associated with lack of progression to active tuberculosis among South African adolescents with latent Mtb infection and with bacterial control in nonhuman primates. Our findings suggested that RSTR may successfully control Mtb following exposure and immune priming and established a set of T cell biomarkers to facilitate further study of this clinical phenotype.

2.
J Immunol ; 210(9): 1236-1246, 2023 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-36961450

RESUMEN

mRNA vaccination of individuals with prior SARS-CoV-2 infection provides superior protection against breakthrough infections with variants of concern compared with vaccination in the absence of prior infection. However, the immune mechanisms by which this hybrid immunity is generated and maintained are unknown. Whereas genetic variation in spike glycoprotein effectively subverts neutralizing Abs, spike-specific T cells are generally maintained against SARS-CoV-2 variants. Thus, we comprehensively profiled human T cell responses against the S1 and S2 domains of spike glycoprotein in a cohort of SARS-CoV-2-naive (n = 13) or -convalescent (n = 17) individuals who received two-dose mRNA vaccine series and were matched by age, sex, and vaccine type. Using flow cytometry, we observed that the overall functional breadth of CD4 T cells and polyfunctional Th1 responses was similar between the two groups. However, polyfunctional cytotoxic CD4 T cell responses against both S1 and S2 domains trended higher among convalescent subjects. Multimodal single-cell RNA sequencing revealed diverse functional programs in spike-specific CD4 and CD8 T cells in both groups. However, convalescent individuals displayed enhanced cytotoxic and antiviral CD8 T cell responses to both S1 and S2 in the absence of cytokine production. Taken together, our data suggest that cytotoxic CD4 and CD8 T cells targeting spike glycoprotein may partially account for hybrid immunity and protection against breakthrough infections with SARS-CoV-2.


Asunto(s)
COVID-19 , Linfocitos T Citotóxicos , Humanos , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus/genética , Infección Irruptiva , ARN Mensajero , Vacunación , Inmunidad Adaptativa , Glicoproteínas , Anticuerpos Antivirales , Anticuerpos Neutralizantes
3.
J Infect Dis ; 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38838218

RESUMEN

BACKGROUND: The kinetics and durability of T-cell responses to SARS-CoV-2 in children are not well-characterized. We studied a cohort of children aged 6 months to 20 years with COVID-19 in whom peripheral blood mononuclear cells (PBMC) and sera were archived at approximately 1, 6, and 12 months post-symptom onset. METHODS: We compared antibody (N = 85) and T-cell responses (N = 26) to nucleocapsid (N) and spike (S) glycoprotein over time across four age strata: 6 months to 5 years, 5-9, 10-14, and 15-20 years. RESULTS: N-specific antibody responses declined over time, becoming undetectable in 26/32 (81%) children by approximately one year post-infection. Functional breadth of anti-N CD4+ T-cell responses also declined over time and were positively correlated with N-antibody responses (Pearson's r = 0.31, p = 0.008). CD4+ T-cell responses to S displayed greater functional breadth than N in unvaccinated children, and, along with neutralization titers, were stable over time and similar across age strata. Functional profiles of CD4+ T-cell responses against S were not significantly modulated by vaccination. CONCLUSIONS: Our data reveal durable, age-independent T-cell immunity to SARS-CoV-2 structural proteins in children over time following COVID-19 infection as well as S-Ab responses overall, in comparison to declining antibody responses to N.

4.
Immunol Cell Biol ; 102(6): 474-486, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38659280

RESUMEN

T cells express a T-cell receptor (TCR) heterodimer that is the product of germline rearrangement and junctional editing resulting in immense clonotypic diversity. The generation of diverse TCR repertoires enables the recognition of pathogen-derived peptide antigens presented by polymorphic major histocompatibility complex (MHC) molecules. However, T cells also recognize nonpeptide antigens through nearly monomorphic antigen-presenting systems, such as cluster of differentiation 1 (CD1), MHC-related protein 1 (MR1) and butyrophilins (BTNs). This potential for shared immune responses across genetically diverse populations led to their designation as donor-unrestricted T cells (DURTs). As might be expected, some CD1-, MR1- and BTN-restricted T cells express a TCR that is conserved across unrelated individuals. However, several recent studies have reported unexpected diversity among DURT TCRs, and increasing evidence suggests that this diversity has functional consequences. Recent reports also challenge the dogma that immune cells are either innate or adaptive and suggest that DURT TCRs may act in both capacities. Here, we review this evidence and propose an expanded view of the role for clonotypic diversity among DURTs in humans, including new perspectives on how DURT TCRs may integrate their adaptive and innate immune functions.


Asunto(s)
Receptores de Antígenos de Linfocitos T , Linfocitos T , Humanos , Linfocitos T/inmunología , Receptores de Antígenos de Linfocitos T/metabolismo , Receptores de Antígenos de Linfocitos T/inmunología , Células Clonales , Variación Genética , Animales , Donantes de Tejidos
5.
Genet Epidemiol ; 46(7): 463-474, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35702824

RESUMEN

Tuberculosis and sarcoidosis are inflammatory diseases characterized by granulomas that may occur in any organ but are often found in the lung. The panoply of classical human leukocyte antigen (HLA) alleles associated with occurrence and/or severity of both diseases varies considerably across studies. This heterogeneity of results, due to variation in factors like ancestry and disease subphenotype, as well as the use of simple modeling strategies to elucidate likely complex relationships, has made conclusions about underlying commonalities difficult. Here we perform HLA association analyses in individuals of African ancestry, using a greater resolution to include subphenotypes of disease and employing more comprehensive analytical techniques. Using a novel application of nearest-neighbor feature selection to score allelic importance, we investigated HLA allele association with Mycobacterium tuberculosis exposure outcomes in the first analysis of both latent Mycobacterium tuberculosis infection and active disease compared with those who, despite long-term exposure to active index cases, have neither positive diagnostic tests nor display clinical symptoms. We also compared persistent to resolved sarcoidosis. This led to the identification of novel HLA associations and evidence of main effects and interaction effects. We found strikingly similar main effects and interaction effects at HLA-DRB1, -DQB1, and -DPB1 in those resistant to tuberculosis (either latent or active) and persistent sarcoidosis.


Asunto(s)
Mycobacterium tuberculosis , Sarcoidosis , Tuberculosis , Alelos , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Cadenas HLA-DRB1/genética , Humanos , Mycobacterium tuberculosis/genética , Sarcoidosis/genética , Tuberculosis/genética
6.
Clin Infect Dis ; 77(8): 1133-1136, 2023 10 13.
Artículo en Inglés | MEDLINE | ID: mdl-37293702

RESUMEN

Infants who are human immunodeficiency virus (HIV)-exposed uninfected (iHEU) experience higher risk of infectious morbidity than infants HIV-unexposed uninfected (iHUU). We compared tuberculosis (TB) infection prevalence in 418 Bacillus Calmette-Guérin vaccinated sub-Saharan African iHEU and iHUU aged 9-18 months using T-SPOT.TB. Prevalence of TB infection was low and did not differ by HIV exposure status.


Asunto(s)
Infecciones por VIH , Tuberculosis Latente , Tuberculosis , Lactante , Humanos , Niño , VIH , Infecciones por VIH/epidemiología , Tuberculosis/prevención & control , Prevalencia
7.
J Immunol ; 206(6): 1240-1250, 2021 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-33536255

RESUMEN

Intradermal vaccination with Mycobacterium bovis bacillus Calmette-Guérin (BCG) protects infants from disseminated tuberculosis, and i.v. BCG protects nonhuman primates (NHP) against pulmonary and extrapulmonary tuberculosis. In humans and NHP, protection is thought to be mediated by T cells, which typically recognize bacterial peptide Ags bound to MHC proteins. However, during vertebrate evolution, T cells acquired the capacity to recognize lipid Ags bound to CD1a, CD1b, and CD1c proteins expressed on APCs. It is unknown whether BCG induces T cell immunity to mycobacterial lipids and whether CD1-restricted T cells are resident in the lung. In this study, we developed and validated Macaca mulatta (Mamu) CD1b and CD1c tetramers to probe ex vivo phenotypes and functions of T cells specific for glucose monomycolate (GMM), an immunodominant mycobacterial lipid Ag. We discovered that CD1b and CD1c present GMM to T cells in both humans and NHP. We show that GMM-specific T cells are expanded in rhesus macaque blood 4 wk after i.v. BCG, which has been shown to protect NHP with near-sterilizing efficacy upon M. tuberculosis challenge. After vaccination, these T cells are detected at high frequency within bronchoalveolar fluid and express CD69 and CD103, markers associated with resident memory T cells. Thus, our data expand the repertoire of T cells known to be induced by whole cell mycobacterial vaccines, such as BCG, and show that lipid Ag-specific T cells are resident in the lungs, where they may contribute to protective immunity.


Asunto(s)
Antígenos Bacterianos/inmunología , Vacuna BCG/administración & dosificación , Glucolípidos/inmunología , Linfocitos T/inmunología , Tuberculosis/prevención & control , Adolescente , Animales , Antígenos Bacterianos/metabolismo , Antígenos CD1/metabolismo , Línea Celular , Niño , Estudios de Cohortes , Modelos Animales de Enfermedad , Femenino , Glicoproteínas/metabolismo , Voluntarios Sanos , Humanos , Inyecciones Intravenosas , Pulmón/citología , Pulmón/inmunología , Pulmón/microbiología , Macaca mulatta , Masculino , Mycobacterium bovis/inmunología , Mycobacterium tuberculosis/inmunología , Cultivo Primario de Células , Linfocitos T/metabolismo , Tuberculosis/sangre , Tuberculosis/inmunología , Tuberculosis/microbiología
8.
J Immunol ; 201(3): 888-896, 2018 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-29914888

RESUMEN

Human T cells that recognize lipid Ags presented by highly conserved CD1 proteins often express semi-invariant TCRs, but the true diversity of lipid Ag-specific TCRs remains unknown. We use CD1b tetramers and high-throughput immunosequencing to analyze thousands of TCRs from ex vivo-sorted or in vitro-expanded T cells specific for the mycobacterial lipid Ag, glucose monomycolate. Our results reveal a surprisingly diverse repertoire resulting from editing of germline-encoded gene rearrangements analogous to MHC-restricted TCRs. We used a distance-based metric (TCRDist) to show how this diverse TCR repertoire builds upon previously reported conserved motifs by including subject-specific TCRs. In a South African cohort, we show that TCRDist can identify clonal expansion of diverse glucose monomycolate-specific TCRs and accurately distinguish patients with active tuberculosis from control subjects. These data suggest that similar mechanisms govern the selection and expansion of peptide and lipid Ag-specific T cells despite the nonpolymorphic nature of CD1.


Asunto(s)
Antígenos CD1/inmunología , Lípidos/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Tuberculosis/inmunología , Adolescente , Línea Celular Tumoral , Células Cultivadas , Niño , Femenino , Humanos , Células K562 , Masculino , Mycobacterium/inmunología , Linfocitos T
9.
J Infect Dis ; 220(6): 990-1000, 2019 08 09.
Artículo en Inglés | MEDLINE | ID: mdl-31058977

RESUMEN

BACKGROUND: Herpes simplex virus 2 (HSV2) causes genital herpes in >400 million persons worldwide. METHODS: We conducted a randomized, double-blinded, placebo-controlled trial of a replication-defective HSV2 vaccine, HSV529. Twenty adults were enrolled in each of 3 serogroups of individuals: those negative for both HSV1 and HSV2 (HSV1-/HSV2-), those positive or negative for HSV1 and positive for HSV2 (HSV1±/HSV2+), and those positive for HSV1 and negative for HSV2 (HSV1+/HSV2-). Sixty participants received vaccine or placebo at 0, 1, and 6 months. The primary end point was the frequency of solicited local and systemic reactions to vaccination. RESULTS: Eighty-nine percent of vaccinees experienced mild-to-moderate solicited injection site reactions, compared with 47% of placebo recipients (95% confidence interval [CI], 12.9%-67.6%; P = .006). Sixty-four percent of vaccinees experienced systemic reactions, compared with 53% of placebo recipients (95% CI, -17.9% to 40.2%; P = .44). Seventy-eight percent of HSV1-/HSV2- vaccine recipients had a ≥4-fold increase in neutralizing antibody titer after 3 doses of vaccine, whereas none of the participants in the other serogroups had such responses. HSV2-specific CD4+ T-cell responses were detected in 36%, 46%, and 27% of HSV1-/HSV2-, HSV1±/HSV2+, and HSV1+/HSV2- participants, respectively, 1 month after the third dose of vaccine, and CD8+ T-cell responses were detected in 14%, 8%, and 18% of participants, respectively. CONCLUSIONS: HSV529 vaccine was safe and elicited neutralizing antibody and modest CD4+ T-cell responses in HSV-seronegative vaccinees. CLINICAL TRIALS REGISTRATION: NCT01915212.


Asunto(s)
Herpes Genital/prevención & control , Herpes Simple/prevención & control , Herpesvirus Humano 2/inmunología , Vacunación , Vacunas Virales/administración & dosificación , Vacunas Virales/inmunología , Adulto , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Linfocitos T CD4-Positivos , Linfocitos T CD8-positivos , Método Doble Ciego , Femenino , Herpes Genital/inmunología , Herpes Simple/inmunología , Herpesvirus Humano 1/inmunología , Humanos , Masculino , Pruebas de Neutralización , Vacunas Virales/uso terapéutico , Adulto Joven
10.
Immunogenetics ; 71(7): 465-478, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31123763

RESUMEN

Invariant NKT (iNKT) cells in both humans and non-human primates are activated by the glycolipid antigen, α-galactosylceramide (α-GalCer). However, the extent to which the molecular mechanisms of antigen recognition and in vivo phenotypes of iNKT cells are conserved among primate species has not been determined. Using an evolutionary genetic approach, we found a lack of diversifying selection in CD1 genes over 45 million years of evolution, which stands in stark contrast to the history of the MHC system for presenting peptide antigens to T cells. The invariant T cell receptor (TCR)-α chain was strictly conserved across all seven primate clades. Invariant NKT cells from rhesus macaques (Macaca mulatta) bind human CD1D-α-GalCer tetramer and are activated by α-GalCer-loaded human CD1D transfectants. The dominant TCR-ß chain cloned from a rhesus-derived iNKT cell line is nearly identical to that found in the human iNKT TCR, and transduction of the rhesus iNKT TCR into human Jurkat cells show that it is sufficient for binding human CD1D-α-GalCer tetramer. Finally, we used a 20-color flow cytometry panel to probe tissue phenotypes of iNKT cells in a cohort of rhesus macaques. We discovered several tissue-resident iNKT populations that have not been previously described in non-human primates but are known in humans, such as TCR-γδ iNKTs. These data reveal a diversity of iNKT cell phenotypes despite convergent evolution of the genes required for lipid antigen presentation and recognition in humans and non-human primates.


Asunto(s)
Antígenos CD1/genética , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , Primates/genética , Secuencia de Aminoácidos , Animales , Antígenos CD1/metabolismo , Secuencia Conservada , Evolución Molecular , Femenino , Humanos , Células Jurkat , Macaca mulatta/inmunología , Masculino , Fenotipo , Primates/inmunología , Receptores de Antígenos de Linfocitos T/genética , Receptores de Antígenos de Linfocitos T/metabolismo
11.
J Immunol ; 195(10): 4595-603, 2015 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-26466957

RESUMEN

Human T cells are activated by both peptide and nonpeptide Ags produced by Mycobacterium tuberculosis. T cells recognize cell wall lipids bound to CD1 molecules, but effector functions of CD1-reactive T cells have not been systematically assessed in M. tuberculosis-infected humans. It is also not known how these features correlate with T cell responses to secreted protein Ags. We developed a flow cytometric assay to profile CD1-restricted T cells ex vivo and assessed T cell responses to five cell wall lipid Ags in a cross-sectional study of 19 M. tuberculosis-infected and 22 M. tuberculosis-uninfected South African adolescents. We analyzed six T cell functions using a recently developed computational approach for flow cytometry data in high dimensions. We compared these data with T cell responses to five protein Ags in the same cohort. We show that CD1b-restricted T cells producing antimycobacterial cytokines IFN-γ and TNF-α are detectable ex vivo in CD4(+), CD8(+), and CD4(-)CD8(-) T cell subsets. Glucose monomycolate was immunodominant among lipid Ags tested, and polyfunctional CD4 T cells specific for this lipid simultaneously expressed CD40L, IFN-γ, IL-2, and TNF-α. Lipid-reactive CD4(+) T cells were detectable at frequencies of 0.001-0.01%, and this did not differ by M. tuberculosis infection status. Finally, CD4 T cell responses to lipids were poorly correlated with CD4 T cell responses to proteins (Spearman rank correlation -0.01; p = 0.95). These results highlight the functional diversity of CD1-restricted T cells circulating in peripheral blood as well as the complementary nature of T cell responses to mycobacterial lipids and proteins. Our approach enables further population-based studies of lipid-specific T cell responses during natural infection and vaccination.


Asunto(s)
Antígenos CD1/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Lípidos de la Membrana/inmunología , Mycobacterium tuberculosis/inmunología , Tuberculosis Pulmonar/inmunología , Adolescente , Antígenos Bacterianos/inmunología , Ligando de CD40/biosíntesis , Pared Celular/inmunología , Estudios Transversales , Femenino , Citometría de Flujo , Glucolípidos/inmunología , Humanos , Interferón gamma/biosíntesis , Interleucina-2/biosíntesis , Células K562 , Activación de Linfocitos/inmunología , Masculino , Sudáfrica/epidemiología , Tuberculosis Pulmonar/epidemiología , Tuberculosis Pulmonar/microbiología , Factor de Necrosis Tumoral alfa/biosíntesis
13.
Cytometry A ; 87(7): 675-82, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25908275

RESUMEN

An important aspect of immune monitoring for vaccine development, clinical trials, and research is the detection, measurement, and comparison of antigen-specific T-cells from subject samples under different conditions. Antigen-specific T-cells compose a very small fraction of total T-cells. Developments in cytometry technology over the past five years have enabled the measurement of single-cells in a multivariate and high-throughput manner. This growth in both dimensionality and quantity of data continues to pose a challenge for effective identification and visualization of rare cell subsets, such as antigen-specific T-cells. Dimension reduction and feature extraction play pivotal role in both identifying and visualizing cell populations of interest in large, multi-dimensional cytometry datasets. However, the automated identification and visualization of rare, high-dimensional cell subsets remains challenging. Here we demonstrate how a systematic and integrated approach combining targeted feature extraction with dimension reduction can be used to identify and visualize biological differences in rare, antigen-specific cell populations. By using OpenCyto to perform semi-automated gating and features extraction of flow cytometry data, followed by dimensionality reduction with t-SNE we are able to identify polyfunctional subpopulations of antigen-specific T-cells and visualize treatment-specific differences between them.


Asunto(s)
Antígenos/inmunología , Citocinas/análisis , Epítopos/inmunología , Citometría de Flujo/métodos , Linfocitos T/inmunología , Adolescente , Algoritmos , Biología Computacional/métodos , Humanos , Leucocitos Mononucleares , Coloración y Etiquetado , Linfocitos T/clasificación
14.
J Immunol ; 190(1): 278-84, 2013 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-23197260

RESUMEN

Most vaccines and basic studies of T cell epitopes in Mycobacterium tuberculosis emphasize water-soluble proteins that are secreted into the extracellular space and presented in the context of MHC class II. Much less is known about the role of Ags retained within the cell wall. We used polyclonal T cells from infected humans to probe for responses to immunodominant Ags in the M. tuberculosis cell wall. We found that the magnitude of response to secreted or cell wall intrinsic compounds was similar among healthy controls, patients with latent tuberculosis, and patients with active tuberculosis. Individual responses to secreted Ags and cell wall extract were strongly correlated (r(2) = 0.495, p = 0.001), suggesting that T cells responding to cell wall and secreted Ags are present at similar frequency. Surprisingly, T cell stimulatory factors intrinsic to the cell wall partition into organic solvents; however, these responses are not explained by CD1-mediated presentation of lipids. Instead, we find that molecules soluble in organic solvents are dependent upon MHC class II and recognized by IFN-γ-secreting CD4(+) T cells. We reasoned that MHC class II-dependent Ags extracting into lipid mixtures might be found among triacylated lipoproteins present in mycobacteria. We used M. tuberculosis lacking prolipoprotein signal peptidase A (lspA), an enzyme required for lipoprotein synthesis, to demonstrate loss of polyclonal T cell responses. Our results demonstrate the use of bacterial genetics to identify lipoproteins as an unexpected and immunodominant class of cell wall-associated Ags targeted by the polyclonal human T cell response to M. tuberculosis.


Asunto(s)
Proteínas Bacterianas/metabolismo , Lipoproteínas/metabolismo , Activación de Linfocitos/inmunología , Mycobacterium tuberculosis/inmunología , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/microbiología , Adyuvantes Inmunológicos/genética , Adyuvantes Inmunológicos/metabolismo , Adulto , Antígenos Bacterianos , Proteínas Bacterianas/genética , Pared Celular/inmunología , Pared Celular/metabolismo , Pared Celular/microbiología , Células Clonales , Femenino , Humanos , Epítopos Inmunodominantes/genética , Epítopos Inmunodominantes/metabolismo , Lipoproteínas/genética , Masculino , Persona de Mediana Edad , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/patogenicidad , Subgrupos de Linfocitos T/metabolismo
15.
J Immunol ; 191(4): 1586-93, 2013 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-23858036

RESUMEN

CD1 proteins evolved to present diverse lipid Ags to T cells. In comparison with MHC proteins, CD1 proteins exhibit minimal allelic diversity as a result of nonsynonymous single nucleotide polymorphisms (SNPs). However, it is unknown if common SNPs in gene regulatory regions affect CD1 expression and function. We report surprising diversity in patterns of inducible CD1a expression on human dendritic cells (DCs), spanning the full range from undetectable to high density, a finding not seen with other CD1 isoforms. CD1a-deficient DCs failed to present mycobacterial lipopeptide to T cells but had no defects in endocytosis, cytokine secretion, or expression of costimulatory molecules after LPS treatment. We identified an SNP in the 5' untranslated region (rs366316) that was common and strongly associated with low CD1a surface expression and mRNA levels (p = 0.03 and p = 0.001, respectively). Using a CD1a promoter-luciferase system in combination with mutagenesis studies, we found that the polymorphic allele reduced luciferase expression by 44% compared with the wild-type variant (p < 0.001). Genetic regulation of lipid Ag presentation by varying expression on human DCs provides a mechanism for achieving population level differences in immune responses despite limited structural variation in CD1a proteins.


Asunto(s)
Regiones no Traducidas 5'/genética , Antígenos CD1/genética , Células Dendríticas/inmunología , Lipopéptidos/inmunología , Polimorfismo de Nucleótido Simple , Antígenos CD1/biosíntesis , Antígenos CD1/inmunología , Células Cultivadas , Citocinas/metabolismo , Endocitosis , Escherichia coli/inmunología , Femenino , Genes Reporteros , Variación Genética , Humanos , Lipopolisacáridos/uso terapéutico , Masculino , Mutagénesis Sitio-Dirigida , Mycobacterium tuberculosis/inmunología , Oxazoles/inmunología , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Subgrupos de Linfocitos T/inmunología
16.
Diagn Microbiol Infect Dis ; 108(1): 116106, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37931386

RESUMEN

Efforts are underway globally to develop effective vaccines and drugs against M. tuberculosis (Mtb) to reduce the morbidity and mortality of tuberculosis. Improving detection of slow-growing mycobacteria could simplify and accelerate efficacy studies of vaccines and drugs in animal models and human clinical trials. Here, a real-time reverse transcription PCR (RT-PCR) assay was developed to detect pre-ribosomal RNA (pre-rRNA) of Mycobacterium bovis bacille Calmette-Guérin (BCG) and Mtb. This pre-rRNA biomarker is indicative of bacterial viability. In two different mouse models, the presence of pre-rRNA from BCG and Mtb in ex vivo tissues showed excellent agreement with slower culture-based colony-forming unit assays. The addition of a brief nutritional stimulation prior to molecular viability testing further differentiated viable but dormant mycobacteria from dead mycobacteria. This research has set the stage to evaluate pre-rRNA as a BCG and/or Mtb infection biomarker in future drug and vaccine clinical studies.


Asunto(s)
Mycobacterium bovis , Mycobacterium tuberculosis , Tuberculosis , Animales , Ratones , Humanos , Mycobacterium bovis/genética , Mycobacterium tuberculosis/genética , Vacuna BCG , Precursores del ARN , Tuberculosis/diagnóstico , Tuberculosis/prevención & control , Desarrollo de Vacunas , Biomarcadores
17.
JCI Insight ; 9(9)2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38716731

RESUMEN

T cells are required for protective immunity against Mycobacterium tuberculosis. We recently described a cohort of Ugandan household contacts of tuberculosis cases who appear to "resist" M. tuberculosis infection (resisters; RSTRs) and showed that these individuals harbor IFN-γ-independent T cell responses to M. tuberculosis-specific peptide antigens. However, T cells also recognize nonprotein antigens via antigen-presenting systems that are independent of genetic background, known as donor-unrestricted T cells (DURTs). We used tetramer staining and flow cytometry to characterize the association between DURTs and "resistance" to M. tuberculosis infection. Peripheral blood frequencies of most DURT subsets were comparable between RSTRs and latently infected controls (LTBIs). However, we observed a 1.65-fold increase in frequency of MR1-restricted T (MR1T) cells among RSTRs in comparison with LTBIs. Single-cell RNA sequencing of 18,251 MR1T cells sorted from 8 donors revealed 5,150 clonotypes that expressed a common transcriptional program, the majority of which were private. Sequencing of the T cell receptor α/T cell receptor δ (TCRα/δ) repertoire revealed several DURT clonotypes were expanded among RSTRs, including 2 MR1T clonotypes that recognized mycobacteria-infected cells in a TCR-dependent manner. Overall, our data reveal unexpected donor-specific diversity in the TCR repertoire of human MR1T cells as well as associations between mycobacteria-reactive MR1T clonotypes and resistance to M. tuberculosis infection.


Asunto(s)
Mycobacterium tuberculosis , Humanos , Mycobacterium tuberculosis/inmunología , Uganda , Adulto , Masculino , Antígenos de Histocompatibilidad Menor/inmunología , Antígenos de Histocompatibilidad Menor/genética , Femenino , Tuberculosis/inmunología , Tuberculosis/microbiología , Linfocitos T/inmunología , Tuberculosis Latente/inmunología , Tuberculosis Latente/microbiología , Células Clonales/inmunología , Resistencia a la Enfermedad/inmunología , Resistencia a la Enfermedad/genética , Adulto Joven , Antígenos de Histocompatibilidad Clase I
18.
bioRxiv ; 2023 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-36945395

RESUMEN

Mycobacterium tuberculosis (Mtb) infection elicits both protein and lipid antigen-specific T cell responses. However, the incorporation of lipid antigens into subunit vaccine strategies and formulations has been underexplored, and the characteristics of vaccine-induced Mtb lipid-specific memory T cells have remained elusive. Mycolic acid (MA), a major lipid component of the Mtb cell wall, is presented by human CD1b molecules to unconventional T cell subsets. These MA-specific CD1b-restricted T cells have been detected in the blood and disease sites of Mtb-infected individuals, suggesting that MA is a promising lipid antigen for incorporation into multicomponent subunit vaccines. In this study, we utilized the enhanced stability of bicontinuous nanospheres (BCN) to efficiently encapsulate MA for in vivo delivery to MA-specific T cells, both alone and in combination with an immunodominant Mtb protein antigen (Ag85B). Pulmonary administration of MA-loaded BCN (MA-BCN) elicited MA-specific T cell responses in humanized CD1 transgenic mice. Simultaneous delivery of MA and Ag85B within BCN activated both MA- and Ag85B-specific T cells. Notably, pulmonary vaccination with MA-Ag85B-BCN resulted in the persistence of MA, but not Ag85B, within alveolar macrophages in the lung. Vaccination of MA-BCN through intravenous or subcutaneous route, or with attenuated Mtb likewise reproduced MA persistence. Moreover, MA-specific T cells in MA-BCN-vaccinated mice differentiated into a T follicular helper-like phenotype. Overall, the BCN platform allows for the dual encapsulation and in vivo activation of lipid and protein antigen-specific T cells and leads to persistent lipid depots that could offer long-lasting immune responses.

19.
Elife ; 122023 10 25.
Artículo en Inglés | MEDLINE | ID: mdl-37877801

RESUMEN

Mycobacterium tuberculosis (Mtb) infection elicits both protein and lipid antigen-specific T cell responses. However, the incorporation of lipid antigens into subunit vaccine strategies and formulations has been underexplored, and the characteristics of vaccine-induced Mtb lipid-specific memory T cells have remained elusive. Mycolic acid (MA), a major lipid component of the Mtb cell wall, is presented by human CD1b molecules to unconventional T cell subsets. These MA-specific CD1b-restricted T cells have been detected in the blood and disease sites of Mtb-infected individuals, suggesting that MA is a promising lipid antigen for incorporation into multicomponent subunit vaccines. In this study, we utilized the enhanced stability of bicontinuous nanospheres (BCN) to efficiently encapsulate MA for in vivo delivery to MA-specific T cells, both alone and in combination with an immunodominant Mtb protein antigen (Ag85B). Pulmonary administration of MA-loaded BCN (MA-BCN) elicited MA-specific T cell responses in humanized CD1 transgenic mice. Simultaneous delivery of MA and Ag85B within BCN activated both MA- and Ag85B-specific T cells. Notably, pulmonary vaccination with MA-Ag85B-BCN resulted in the persistence of MA, but not Ag85B, within alveolar macrophages in the lung. Vaccination of MA-BCN through intravenous or subcutaneous route, or with attenuated Mtb likewise reproduced MA persistence. Moreover, MA-specific T cells in MA-BCN-vaccinated mice differentiated into a T follicular helper-like phenotype. Overall, the BCN platform allows for the dual encapsulation and in vivo activation of lipid and protein antigen-specific T cells and leads to persistent lipid depots that could offer long-lasting immune responses.


Asunto(s)
Mycobacterium tuberculosis , Nanopartículas , Humanos , Animales , Ratones , Diferenciación Celular , Vacunación , Ácidos Micólicos
20.
EBioMedicine ; 93: 104678, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37379655

RESUMEN

BACKGROUND: The prevalence of tuberculosis among men who work in the gold mines of South Africa is among the highest in the world, but a fraction of miners demonstrate consistently negative results upon tuberculin skin test (TST) and IFN-γ release assay (IGRA). We hypothesized that these "resisters" (RSTRs) may display unconventional immune signatures of exposure to M. tuberculosis (M.tb). METHODS: In a cohort of RSTRs and matched controls with latent TB infection (LTBI), we profiled the functional breadth of M.tb antigen-specific T cell and antibody responses using multi-parameter flow cytometry and systems serology, respectively. FINDINGS: RSTRs and LTBI controls both exhibited IFN-γ independent T-cell and IgG antibody responses to M.tb-specific antigens ESAT-6 and CFP-10. Antigen-specific antibody Fc galactosylation and sialylation were higher among RSTRs. In a combined T-cell and antibody analysis, M.tb lysate-stimulated TNF secretion by T cells correlated positively with levels of purified protein derivative-specific IgG. A multivariate model of the combined data was able to differentiate RSTR and LTBI subjects. INTERPRETATION: IFN-γ independent immune signatures of exposure to M.tb, which are not detected by approved clinical diagnostics, are readily detectable in an occupational cohort uniquely characterized by intense and long-term infection pressure. Further, TNF may mediate a coordinated response between M.tb-specific T-cells and B-cells. FUNDING: This work was supported by the US National Institutes of Health (R01-AI124348 to Boom, Stein, and Hawn; R01-AI125189 and R01-AI146072 to Seshadri; and 75N93019C00071 to Fortune, Alter, Seshadri, and Boom), the Doris Duke Charitable Foundation (Davies), the Bill & Melinda Gates Foundation (OPP1151836 and OPP1109001 to Hawn; and OPP1151840 to Alter), Mass Life Science Foundation (Fortune), and Good Ventures Fund (Fortune).


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis , Masculino , Humanos , Sudáfrica/epidemiología , Tuberculosis/diagnóstico , Tuberculosis/epidemiología , Antígenos Bacterianos , Interferón gamma , Prueba de Tuberculina
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