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1.
J Infect Dis ; 219(3): 420-428, 2019 01 09.
Article in English | MEDLINE | ID: mdl-30010905

ABSTRACT

Background: Initiation of antiretroviral therapy (ART) in human immunodeficiency virus (HIV)-infected individuals with cryptococcal meningitis places them at risk for Cryptococcus-associated immune reconstitution inflammatory syndrome (C-IRIS). The relationship between antibody immunity and C-IRIS risk has not been investigated. Methods: We compared plasma levels of immunoglobulins, C. neoformans glucuronoxylomannan (GXM) capsule-specific and laminarin (Lam)-binding IgM and IgG, and percentages of peripheral blood total and memory B cells between 27 HIV-infected patients with CM who developed C-IRIS and 63 who did not, and evaluated associations of these parameters with risk of C-IRIS. Results: Prior to initiation of ART, plasma IgM, Lam-binding IgM (Lam-IgM), Lam-IgG, and GXM-IgM levels were significantly lower in patients who developed C-IRIS than those who did not. Multivariate analysis revealed significant inverse associations between C-IRIS and IgM (P = .0003), Lam-IgM (P = .0005), Lam-IgG (P = .002), and GXM-IgM (P = .002) independent of age, sex, HIV viral load, CD4+ T-cell count, and cerebrospinal fluid fungal burden. There were no associations between C-IRIS and total or memory B cells. Discussion: Antibody profiles that include plasma IgM, Lam-IgM, Lam-IgG, and/or GXM-IgM may have value in furthering our understanding of C-IRIS pathogenesis and hold promise as candidate biomarkers of C-IRIS risk.


Subject(s)
Antibody Formation/immunology , Cryptococcosis/immunology , Immune Reconstitution Inflammatory Syndrome/immunology , Immunoglobulins/blood , Meningitis, Cryptococcal/immunology , Plasma/immunology , Anti-Retroviral Agents , B-Lymphocytes , Cryptococcus neoformans/immunology , HIV Infections/complications , HIV Infections/drug therapy , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Multivariate Analysis , Polysaccharides/immunology
3.
J Immunol ; 196(10): 4052-63, 2016 05 15.
Article in English | MEDLINE | ID: mdl-27076678

ABSTRACT

Tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) complicates combination antiretroviral therapy (cART) in up to 25% of patients with HIV/TB coinfection. Monocytes and IL-18, a signature cytokine of inflammasome activation, are implicated in TB-IRIS pathogenesis. In this study, we investigated inflammasome activation both pre- and post-cART in TB-IRIS patients. HIV/TB patients exhibited higher proportions of monocytes expressing activated caspase-1 (casp1) pre-cART, compared with HIV patients without TB, and patients who developed TB-IRIS exhibited the greatest increase in casp1 expression. CD64(+) monocytes were a marker of increased casp1 expression. Furthermore, IL-1ß, another marker of inflammasome activation, was also elevated during TB-IRIS. TB-IRIS patients also exhibited greater upregulation of NLRP3 and AIM2 inflammasome mRNA, compared with controls. Analysis of plasma mitochondrial DNA levels showed that TB-IRIS patients experienced greater cell death, especially pre-cART. Plasma NO levels were lower both pre- and post-cART in TB-IRIS patients, providing evidence of inadequate inflammasome regulation. Plasma IL-18 levels pre-cART correlated inversely with NO levels but positively with monocyte casp1 expression and mitochondrial DNA levels, and expression of IL-18Rα on CD4(+) T cells and NK cells was higher in TB-IRIS patients, providing evidence that IL-18 is a marker of inflammasome activation. We propose that inflammasome activation in monocytes/macrophages of HIV/TB patients increases with ineffective T cell-dependent activation of monocytes/macrophages, priming them for an excessive inflammatory response after cART is commenced, which is greatest in patients with TB-IRIS.


Subject(s)
Cell Self Renewal/immunology , HIV Infections/immunology , Inflammasomes/metabolism , Inflammation/immunology , Macrophages/physiology , Tuberculosis/immunology , Anti-Retroviral Agents/therapeutic use , Caspase 1/metabolism , Cell Death , Cells, Cultured , DNA, Mitochondrial/blood , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , HIV Infections/complications , HIV Infections/drug therapy , Humans , Inflammation/complications , Inflammation/drug therapy , Interleukin-18/metabolism , Interleukin-1beta/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Nitric Oxide/blood , Syndrome , Tuberculosis/complications , Tuberculosis/drug therapy
4.
Clin Infect Dis ; 65(9): 1551-1559, 2017 Oct 16.
Article in English | MEDLINE | ID: mdl-29048509

ABSTRACT

BACKGROUND: Patients with human immunodeficiency virus/AIDS-associated cryptococcal meningitis (CM) frequently experience clinical deterioration, known as cryptococcosis-associated immune reconstitution inflammatory syndrome (C-IRIS), upon initiation of antiretroviral therapy (ART). The immunological mechanisms underlying C-IRIS are incompletely defined and no reliable predictive biomarkers exist. We investigated whether plasma or cerebrospinal fluid (CSF) levels of cytokines and chemokines predicted C-IRIS and are potential predictive biomarkers. METHODS: Patients with CM who experienced C-IRIS (N = 27) upon ART initiation were compared to CD4+ T-cell count-matched patients without C-IRIS (N = 27). Plasma and CSF collected pre-ART were assayed for cytokines and chemokines using a 17-plex Luminex kit or enzyme-linked immunosorbent assay. Cox proportional hazards regression and principal component analyses were also performed. RESULTS: Plasma interleukin (IL) 2, IL-4, IL-5, IL-7, IL-17, interferon-γ, and tumor necrosis factor-α levels were higher in C-IRIS patients compared to controls (all P < .05), with IL-5 and IL-7 significant after Bonferroni-Holm correction. In multivariate Cox proportional hazards regression, high IL-5 (hazard ratio [HR], 5.76 [95% confidence interval {CI}, .77-43.0]; P = .088) and IL-7 (HR, 9.30 [95% CI, 1.96-44.0]; P = .005) were predictive of C-IRIS. Plasma IL-5 (P = .0008) and IL-10 (P = .0089) were lower in those who achieved CSF cryptococcal culture negativity compared to those with positive cultures pre-ART. There were no significant differences in CSF cytokine or chemokine levels between cases and controls. CONCLUSIONS: High plasma IL-5 and IL-7 levels pre-ART were associated with increased risk of developing C-IRIS. High IL-5 levels may reflect a Th2 environment associated with impaired clearance of cryptococci while high IL-7 levels may reflect IL-7/IL-7R pathway dysfunction in T cells, both of which could be associated with C-IRIS immunopathogenesis.


Subject(s)
AIDS-Related Opportunistic Infections/blood , Cryptococcosis/blood , Immune Reconstitution Inflammatory Syndrome/blood , Interleukin-5/blood , Interleukin-7/blood , AIDS-Related Opportunistic Infections/cerebrospinal fluid , AIDS-Related Opportunistic Infections/epidemiology , Adult , Anti-Retroviral Agents/administration & dosage , Anti-Retroviral Agents/therapeutic use , Cryptococcosis/cerebrospinal fluid , Cryptococcosis/epidemiology , Female , HIV Infections/drug therapy , HIV Infections/epidemiology , Humans , Immune Reconstitution Inflammatory Syndrome/cerebrospinal fluid , Immune Reconstitution Inflammatory Syndrome/epidemiology , Interleukin-5/cerebrospinal fluid , Interleukin-7/cerebrospinal fluid , Male , Principal Component Analysis , Prospective Studies
5.
Clin Immunol ; 179: 54-63, 2017 06.
Article in English | MEDLINE | ID: mdl-28315414

ABSTRACT

Antibody responses have not been fully characterised in chronically HIV/HCV patients receiving antiretroviral therapy (ART). Seventeen HIV/HCV patients receiving ART were followed for a median (range) interval of 597 (186-766) weeks. Prior to ART, HIV/HCV patients had lower levels of antibodies reactive with HCV core and JFH-1, and lower genotype cross-reactive neutralising antibodies (nAb) titres, than HCV patients. Levels of JFH-1 reactive antibody increased on ART, irrespective of CD4+ T-cell counts or changes in serum ALT levels. The appearance of nAb coincided with control of HCV viral replication in five HIV/HCV patients. In other patients, HCV viral loads remained elevated despite nAb responses. Sustained virological responses following HCV therapy were associated with reduced antibody responses to JFH-1 and core but elevated responses to non-structural proteins. We conclude that nAb responses alone may fail to clear HCV, but contribute to control of viral replication in some HIV/HCV patients responding to ART.


Subject(s)
Antibodies, Neutralizing/blood , Antiviral Agents/therapeutic use , HIV Infections/immunology , Hepatitis C/immunology , Adult , Antibodies, Viral/blood , Antiviral Agents/pharmacology , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Cell Line, Tumor , Female , Genotype , HIV/genetics , HIV Infections/drug therapy , HIV Infections/virology , Hepacivirus/genetics , Hepacivirus/immunology , Hepatitis C/drug therapy , Hepatitis C/virology , Humans , Immunoglobulin G/blood , Lymphocyte Count , Male , RNA, Viral/blood , Viral Load
6.
J Immunol ; 194(11): 5320-8, 2015 Jun 01.
Article in English | MEDLINE | ID: mdl-25911748

ABSTRACT

Identifying the mechanisms of natural control of HIV-1 infection could lead to novel approaches to prevent or cure HIV infection. Several studies have associated natural control of HIV-1 infection with IgG Abs against HIV-1 Gag proteins (e.g., p24) and/or production of IgG2 Abs against HIV-1 proteins. These Abs likely exert their effect by activating antiviral effector cell responses rather than virus neutralization. We hypothesized that an opsonophagocytic IgG Ab response against HIV-1 p24 that activates plasmacytoid dendritic cells (pDCs) through FcγRIIa would be associated with control of HIV and that this would be enhanced by Ab isotype diversification. Using the Gen2.2 pDC cell line, we demonstrated that pDC-reactive opsonophagocytic IgG Ab responses against HIV-1 p24 were higher in HIV controllers (HIV RNA < 2000 copies/ml) than noncontrollers (HIV RNA > 10,000 copies/ml), particularly in controllers with low but detectable viremia (HIV RNA 75-2000 copies/ml). Opsonophagocytic Ab responses correlated with plasma levels of IgG1 and IgG2 anti-HIV-1 p24 and, notably, correlated inversely with plasma HIV RNA levels in viremic HIV patients. Phagocytosis of these Abs was mediated via FcγRIIa. Isotype diversification (toward IgG2) was greatest in HIV controllers, and depletion of IgG2 from Ig preparations indicated that IgG2 Abs to HIV-1 p24 do not enhance phagocytosis, suggesting that they enhance other aspects of Ab function, such as Ag opsonization. Our findings emulate those for pDC-reactive opsonophagocytic Ab responses against coxsackie, picorna, and influenza viruses and demonstrate a previously undefined immune correlate of HIV-1 control that may be relevant to HIV vaccine development.


Subject(s)
Dendritic Cells/immunology , HIV Antibodies/immunology , HIV Core Protein p24/immunology , HIV Infections/immunology , HIV-1/immunology , Immunoglobulin G/immunology , Viremia/immunology , AIDS Vaccines/immunology , CD4 Lymphocyte Count , CD4-Positive T-Lymphocytes/immunology , Cell Line , HIV Antibodies/blood , Humans , Immunoglobulin G/blood , Phagocytosis/immunology , RNA, Viral/blood , Receptors, IgG/immunology , Viremia/virology
7.
Immunol Rev ; 254(1): 114-42, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23772618

ABSTRACT

Despite significant reductions in morbidity and mortality secondary to availability of effective combination anti-retroviral therapy (cART), human immunodeficiency virus (HIV) infection still accounts for 1.5 million deaths annually. The majority of deaths occur in sub-Saharan Africa where rates of opportunistic co-infections are disproportionately high. In this review, we discuss the immunopathogenesis of five common infections that cause significant morbidity in HIV-infected patients globally. These include co-infection with Mycobacterium tuberculosis, Cryptococcus neoformans, hepatitis B virus, hepatitis C virus, and Plasmodium falciparum. Specifically, we review the natural history of each co-infection in the setting of HIV, the specific immune defects induced by HIV, the effects of cART on the immune response to the co-infection, the pathogenesis of immune restoration disease (IRD) associated with each infection, and advances in the areas of prevention of each co-infection via vaccination. Finally, we discuss the opportunities and gaps in knowledge for future research.


Subject(s)
AIDS-Related Opportunistic Infections/immunology , HIV Infections/immunology , AIDS-Related Opportunistic Infections/prevention & control , Africa South of the Sahara , Animals , Cryptococcosis/immunology , Cryptococcosis/prevention & control , HIV Infections/drug therapy , Hepatitis B/immunology , Hepatitis B/prevention & control , Hepatitis C/immunology , Hepatitis C/prevention & control , Humans , Malaria/immunology , Malaria/prevention & control , Tuberculosis/immunology , Tuberculosis/prevention & control
8.
Lancet ; 386(10011): 2395-403, 2015 Dec 12.
Article in English | MEDLINE | ID: mdl-26431823

ABSTRACT

BACKGROUND: Neovascular, or wet, age-related macular degeneration causes central vision loss and represents a major health problem in elderly people, and is currently treated with frequent intraocular injections of anti-VEGF protein. Gene therapy might enable long-term anti-VEGF therapy from a single treatment. We tested the safety of rAAV.sFLT-1 in treatment of wet age-related macular degeneration with a single subretinal injection. METHODS: In this single-centre, phase 1, randomised controlled trial, we enrolled patients with wet age-related macular degeneration at the Lions Eye Institute and the Sir Charles Gairdner Hospital (Nedlands, WA, Australia). Eligible patients had to be aged 65 years or older, have age-related macular degeneration secondary to active subfoveal choroidal neovascularisation, with best corrected visual acuity (BCVA) of 3/60-6/24 and 6/60 or better in the other eye. Patients were randomly assigned (3:1) to receive either 1 × 10(10) vector genomes (vg; low-dose rAAV.sFLT-1 group) or 1 × 10(11) vg (high-dose rAAV.sFLT-1 group), or no gene-therapy treatment (control group). Randomisation was done by sequential group assignment. All patients and investigators were unmasked. Staff doing the assessments were masked to the study group at study visits. All patients received ranibizumab at baseline and week 4, and rescue treatment during follow-up based on prespecified criteria including BCVA measured on the Early Treatment Diabetic Retinopathy Study (EDTRS) scale, optical coherence tomography, and fluorescein angiography. The primary endpoint was ocular and systemic safety. This trial is registered with ClinicalTrials.gov, number NCT01494805. FINDINGS: From Dec 16, 2011, to April 5, 2012, we enrolled nine patients of whom eight were randomly assigned to receive either intervention (three patients in the low-dose rAAV.sFLT-1 group and three patients in the high-dose rAAV.sFLT-1 group) or no treatment (two patients in the control group). Subretinal injection of rAAV.sFLT-1 was highly reproducible. No drug-related adverse events were noted; procedure-related adverse events (subconjunctival or subretinal haemorrhage and mild cell debris in the anterior vitreous) were generally mild and self-resolving. There was no evidence of chorioretinal atrophy. Clinical laboratory assessments generally remained unchanged from baseline. Four (67%) of six patients in the treatment group required zero rescue injections, and the other two (33%) required only one rescue injection each. INTERPRETATION: rAAV.sFLT-1 was safe and well tolerated. These results support ocular gene therapy as a potential long-term treatment option for wet age-related macular degeneration. FUNDING: National Health and Medical Research Council of Australia, Richard Pearce Bequest, Lions Save Sight Foundation, Brian King Fellowship, and Avalanche Biotechnologies, Inc.


Subject(s)
Genetic Therapy/methods , Vascular Endothelial Growth Factor Receptor-1/administration & dosage , Wet Macular Degeneration/therapy , Adenoviridae , Aged , Aged, 80 and over , Angiogenesis Inhibitors/administration & dosage , Angiogenesis Inhibitors/adverse effects , Choroidal Neovascularization/complications , Choroidal Neovascularization/physiopathology , Choroidal Neovascularization/therapy , Female , Genetic Therapy/adverse effects , Genetic Vectors/administration & dosage , Genetic Vectors/adverse effects , Humans , Injections, Intraocular , Male , Ranibizumab/administration & dosage , Ranibizumab/adverse effects , Recombinant Proteins , Vascular Endothelial Growth Factor Receptor-1/adverse effects , Visual Acuity , Wet Macular Degeneration/etiology , Wet Macular Degeneration/physiopathology
9.
J Immunol ; 193(5): 2178-86, 2014 Sep 01.
Article in English | MEDLINE | ID: mdl-25063872

ABSTRACT

To determine whether IFN-α is a cause of the T cell hyperactivation and IL-7 signaling pathway defects that are observed in some HIV patients receiving antiretroviral therapy, we have investigated the effect of IFN-α on the proliferation of CD4(+) and CD8(+) T cells from healthy donors (n = 30) and treated HIV(+) donors (n = 20). PBMC were cultured for 7 d with staphylococcal enterotoxin B or IL-7 in the absence or presence of 100 U/ml IFN-α8. Total and naive CD4(+) and CD8(+) T cells were assessed for proliferation (via Ki67 expression), CD127 expression, and phosphorylated STAT5 levels using flow cytometry. IFN-α significantly enhanced activation-induced proliferation (via staphylococcal enterotoxin B stimulation) but inhibited homeostatic proliferation (IL-7 induced) of CD4(+) and CD8(+) T cells. Both of these effects may adversely affect CD4(+) T cell homeostasis in HIV patients. CD127 expression was increased in both healthy and HIV(+) donors following culture with IFN-α8, and levels of IL-7-induced phosphorylated STAT5 were increased by IFN-α8 in healthy donors only. Hence, the inhibitory effects of IFN-α on IL-7-induced proliferation of CD4(+) T cells are unlikely to be mediated by downregulation of CD127 expression or inhibition of STAT5 phosphorylation. These data suggest that increased IFN-α activity may promote the loss of T cells by accelerating cell turnover and activation-induced cell death while decreasing the renewal of T cells by inhibiting the proliferative effect of IL-7.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , Cell Proliferation/drug effects , HIV Infections/immunology , Interferon-alpha/pharmacology , Interleukin-7/immunology , Adult , Aged , CD4 Lymphocyte Count , CD4-Positive T-Lymphocytes/pathology , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/pathology , Down-Regulation/drug effects , Down-Regulation/immunology , Female , HIV Infections/pathology , Humans , Interferon-alpha/immunology , Interleukin-7 Receptor alpha Subunit/immunology , Ki-67 Antigen/immunology , Male , Middle Aged , STAT5 Transcription Factor/immunology
10.
J Allergy Clin Immunol ; 136(4): 993-1006.e1, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26162572

ABSTRACT

BACKGROUND: Follicular helper T (TFH) cells underpin T cell-dependent humoral immunity and the success of most vaccines. TFH cells also contribute to human immune disorders, such as autoimmunity, immunodeficiency, and malignancy. Understanding the molecular requirements for the generation and function of TFH cells will provide strategies for targeting these cells to modulate their behavior in the setting of these immunologic abnormalities. OBJECTIVE: We sought to determine the signaling pathways and cellular interactions required for the development and function of TFH cells in human subjects. METHODS: Human primary immunodeficiencies (PIDs) resulting from monogenic mutations provide a unique opportunity to assess the requirement for particular molecules in regulating human lymphocyte function. Circulating follicular helper T (cTFH) cell subsets, memory B cells, and serum immunoglobulin levels were quantified and functionally assessed in healthy control subjects, as well as in patients with PIDs resulting from mutations in STAT3, STAT1, TYK2, IL21, IL21R, IL10R, IFNGR1/2, IL12RB1, CD40LG, NEMO, ICOS, or BTK. RESULTS: Loss-of-function (LOF) mutations in STAT3, IL10R, CD40LG, NEMO, ICOS, or BTK reduced cTFH cell frequencies. STAT3 and IL21/R LOF and STAT1 gain-of-function mutations skewed cTFH cell differentiation toward a phenotype characterized by overexpression of IFN-γ and programmed death 1. IFN-γ inhibited cTFH cell function in vitro and in vivo, as corroborated by hypergammaglobulinemia in patients with IFNGR1/2, STAT1, and IL12RB1 LOF mutations. CONCLUSION: Specific mutations affect the quantity and quality of cTFH cells, highlighting the need to assess TFH cells in patients by using multiple criteria, including phenotype and function. Furthermore, IFN-γ functions in vivo to restrain TFH cell-induced B-cell differentiation. These findings shed new light on TFH cell biology and the integrated signaling pathways required for their generation, maintenance, and effector function and explain the compromised humoral immunity seen in patients with some PIDs.


Subject(s)
Immunologic Deficiency Syndromes/immunology , T-Lymphocyte Subsets/immunology , T-Lymphocytes, Helper-Inducer/immunology , Agammaglobulinaemia Tyrosine Kinase , B-Lymphocytes/immunology , CD40 Ligand/genetics , Cell Differentiation/genetics , Cell Proliferation/genetics , Cells, Cultured , Humans , I-kappa B Kinase/genetics , Immunity, Humoral/genetics , Immunologic Deficiency Syndromes/genetics , Immunologic Memory , Inducible T-Cell Co-Stimulator Protein/genetics , Interferon-gamma/genetics , Interferon-gamma/metabolism , Lymphocyte Activation , Mutation/genetics , Protein-Tyrosine Kinases/genetics , Receptors, Cytokine/genetics , STAT1 Transcription Factor/genetics , STAT3 Transcription Factor/genetics , Signal Transduction/genetics , Signal Transduction/immunology
12.
J Infect Dis ; 212(4): 585-95, 2015 Aug 15.
Article in English | MEDLINE | ID: mdl-25722296

ABSTRACT

BACKGROUND: Elevated interleukin 6 (IL-6) levels have been linked to cardiovascular disease, cancer and death. Persons with human immunodeficiency virus (HIV) infection receiving treatment have higher IL-6 levels, but few data are available on factors associated with circulating IL-6. METHODS: Participants in 3 trials with IL-6 measured at baseline were included (N = 9864). Factors associated with IL-6 were identified by linear regression. Demographic and HIV variables (nadir/entry CD4(+) cell count, HIV RNA level, antiretroviral therapy regimen) were investigated in all 3 trials. In the SMART (Strategies for Management of Anti-Retroviral Therapy) trial, CD4/CD8 ratio, smoking, comorbid conditions, serum lipids, renal function (estimated glomerular filtration rate [eGFR]), and educational level were assessed. RESULTS: Demographics associated with higher IL-6 levels were older age and lower education, whereas black race was associated with lower IL-6. Higher HIV RNA levels were associated with higher IL-6 levels, and higher nadir CD4(+) cell counts with lower IL-6 levels. Compared with efavirenz, protease inhibitors were associated with higher and nevirapine with lower IL-6 levels. Smoking and all comorbid conditions were related to higher IL-6. IL-6 levels increased with decreasing eGFR and decreasing serum lipids. CONCLUSIONS: Higher levels of IL-6 were associated with older age, nonblack race, higher body mass index, lower serum lipid levels, HIV replication, low nadir CD4(+) cell count, protease inhibitor use, comorbid conditions, and decreased eGFR. Multiple factors affect inflammation in HIV and should be considered in studies of IL-6 as a biomarker of clinical outcomes.


Subject(s)
HIV Infections/blood , Interleukin-6/blood , Adult , Biomarkers , Cross-Sectional Studies , Female , Fibrin Fibrinogen Degradation Products/metabolism , HIV Infections/complications , HIV Infections/metabolism , Humans , Inflammation/metabolism , Interleukin-6/metabolism , Male , Middle Aged , RNA, Viral/blood , Smoking , Viral Load
14.
Blood ; 119(17): 3997-4008, 2012 Apr 26.
Article in English | MEDLINE | ID: mdl-22403255

ABSTRACT

T follicular helper (Tfh) cells are critical for providing the necessary signals to induce differentiation of B cells into memory and Ab-secreting cells. Accordingly, it is important to identify the molecular requirements for Tfh cell development and function. We previously found that IL-12 mediates the differentiation of human CD4(+) T cells to the Tfh lineage, because IL-12 induces naive human CD4(+) T cells to acquire expression of IL-21, BCL6, ICOS, and CXCR5, which typify Tfh cells. We have now examined CD4(+) T cells from patients deficient in IL-12Rß1, TYK2, STAT1, and STAT3 to further explore the pathways involved in human Tfh cell differentiation. Although STAT1 was dispensable, mutations in IL12RB1, TYK2, or STAT3 compromised IL-12-induced expression of IL-21 by human CD4(+) T cells. Defective expression of IL-21 by STAT3-deficient CD4(+) T cells resulted in diminished B-cell helper activity in vitro. Importantly, mutations in STAT3, but not IL12RB1 or TYK2, also reduced Tfh cell generation in vivo, evidenced by decreased circulating CD4(+)CXCR5(+) T cells. These results highlight the nonredundant role of STAT3 in human Tfh cell differentiation and suggest that defective Tfh cell development and/or function contributes to the humoral defects observed in STAT3-deficient patients.


Subject(s)
Cell Differentiation , Interleukin-12/pharmacology , Mutation/genetics , Receptors, Interleukin-12/genetics , STAT1 Transcription Factor/genetics , STAT3 Transcription Factor/genetics , T-Lymphocytes, Helper-Inducer/cytology , TYK2 Kinase/genetics , Animals , B-Lymphocytes/cytology , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , CD4-Positive T-Lymphocytes/cytology , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , Cells, Cultured , Cytokines/metabolism , Humans , Immunocompromised Host , Lymphocyte Activation , Mice , Receptors, Interleukin-12/deficiency , STAT1 Transcription Factor/metabolism , STAT3 Transcription Factor/deficiency , Signal Transduction , T-Lymphocytes, Helper-Inducer/immunology , T-Lymphocytes, Helper-Inducer/metabolism , TYK2 Kinase/metabolism , Transcription Factors/metabolism
15.
J Allergy Clin Immunol ; 131(4): 1130-5, 1135.e1, 2013 Apr.
Article in English | MEDLINE | ID: mdl-22857794

ABSTRACT

BACKGROUND: The 1858T allele of protein tyrosine phosphatase nonreceptor type 22 (PTPN22; R620W) exhibits one of the strongest and most consistent associations with sporadic autoimmune disease. Although autoimmunity is common in patients with primary antibody deficiency (PAD), it remains unknown whether its pathogenesis is similar when it arises in this context compared with in immunocompetent patients. OBJECTIVE: We set out to determine whether the 1858T allele of PTPN22 was associated with PAD or with autoimmunity in the context of PAD. METHODS: We genotyped rs2476601 (g.1858C>T), a single nucleotide polymorphism encoding substitution of arginine for tryptophan in PTPN22 (R620W), in 193 patients with PAD and 148 control subjects from an Australian cohort. We also performed a subgroup analysis according to the presence of autoimmunity and B-cell phenotypes. RESULTS: C/T and T/T PTPN22 genotypes were more common in patients with PAD than in the matched control subjects (C/T, 18.1% vs 9.5%; T/T, 1.04% vs 0.6%). The T allele was associated with an increased risk of PAD relative to control subjects (odds ratio, 2.10; 95% CI, 1.11-4.00). The distribution of genotypes in control subjects was similar to those reported previously and did not deviate significantly from Hardy-Weinberg equilibrium. We found a strong association between the 1858T allele and PAD with coexistent autoimmune diseases. In patients with PAD and autoimmunity, 16 (43.2%) of 37 had at least one T allele of PTPN22 compared with 27 (17.3%) of 156 with the C/C genotype (P=.0014; odds ratio, 3.64; 95% CI, 1.68-7.88). We found no evidence that this effect was mediated by enrichment of CD21low B cells. CONCLUSION: The 1858T PTPN22 allele is strongly associated with autoimmunity in patients with PAD.


Subject(s)
Amino Acid Substitution , Autoimmunity/genetics , Immunologic Deficiency Syndromes/genetics , Polymorphism, Single Nucleotide , Protein Tyrosine Phosphatase, Non-Receptor Type 22/genetics , Adult , Alleles , Australia , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , B-Lymphocytes/pathology , Case-Control Studies , Female , Gene Frequency , Genetic Predisposition to Disease , Genotyping Techniques , Humans , Immunologic Deficiency Syndromes/immunology , Immunophenotyping , Male , Middle Aged , Protein Tyrosine Phosphatase, Non-Receptor Type 22/immunology , Risk Factors
16.
J Allergy Clin Immunol ; 132(2): 400-11.e9, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23830147

ABSTRACT

BACKGROUND: The capacity of CD8(+) T cells to control infections and mediate antitumor immunity requires the development and survival of effector and memory cells. IL-21 has emerged as a potent inducer of CD8(+) T-cell effector function and memory development in mouse models of infectious disease. However, the role of IL-21 and associated signaling pathways in protective CD8(+) T-cell immunity in human subjects is unknown. OBJECTIVE: We sought to determine which signaling pathways mediate the effects of IL-21 on human CD8(+) T cells and whether defects in these pathways contribute to disease pathogenesis in patients with primary immunodeficiencies caused by mutations in components of the IL-21 signaling cascade. METHODS: Human primary immunodeficiencies resulting from monogenic mutations provide a unique opportunity to assess the requirement for particular molecules in regulating human lymphocyte function. Lymphocytes from patients with loss-of-function mutations in signal transducer and activator of transcription 1 (STAT1), STAT3, or IL-21 receptor (IL21R) were used to assess the respective roles of these genes in human CD8(+) T-cell differentiation in vivo and in vitro. RESULTS: Mutations in STAT3 and IL21R, but not STAT1, led to a decrease in multiple memory CD8(+) T-cell subsets in vivo, indicating that STAT3 signaling, possibly downstream of IL-21R, regulates the memory cell pool. Furthermore, STAT3 was important for inducing the lytic machinery in IL-21-stimulated naive CD8(+) T cells. However, this defect was overcome by T-cell receptor engagement. CONCLUSION: The IL-21R/STAT3 pathway is required for many aspects of human CD8(+) T-cell behavior but in some cases can be compensated by other signals. This helps explain the relatively mild susceptibility to viral disease observed in STAT3- and IL-21R-deficient subjects.


Subject(s)
CD8-Positive T-Lymphocytes/cytology , Cell Differentiation , Immunologic Memory , Job Syndrome/genetics , Mutation , STAT3 Transcription Factor/metabolism , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , Cell Differentiation/genetics , Cell Differentiation/immunology , Humans , Interleukins/genetics , Interleukins/immunology , Interleukins/metabolism , Job Syndrome/immunology , Job Syndrome/pathology , Receptors, Interleukin-21/genetics , Receptors, Interleukin-21/immunology , Receptors, Interleukin-21/metabolism , STAT3 Transcription Factor/genetics
17.
J Infect Dis ; 207(9): 1379-88, 2013 May 01.
Article in English | MEDLINE | ID: mdl-23335804

ABSTRACT

BACKGROUND: Hepatitis C virus (HCV) and/or hepatitis B virus (HBV) coinfection with human immunodeficiency virus (HIV) has a greater risk of mortality than either HCV or HBV infection alone and is frequently associated with hepatitis flares after antiretroviral therapy (ART) initiation. METHODS: We performed a retrospective cohort study of 287 HIV-positive persons coinfected with HBV and/or HCV (70 had HBV coinfection only, 207 had HCV coninfection only, and 10 had HBV and HCV coinfections) who had pre-ART plasma samples evaluated for biomarkers associated with death (within 4 years) and/or hepatitis flare (within 4 months) after ART initiation. A predictive biomarker risk score was calculated. RESULTS: Forty-eight deaths and 50 hepatitis flares occurred. Nonsurvivors were older, had more prior AIDS-defining events, and had higher pre-ART triglycerides and aspartate transaminase levels. Detectable hyaluronic acid and higher d-dimer, interleukin 6, interleukin 8, and soluble CD14 levels were associated with death in univariate models and with a composite biomarker risk score. The risk of hepatitis flares was higher with HBV coinfection only (24.3%) and with HBV and HCV coinfection (50%) than with HCV coinfection only (13.5%). Higher levels of alanine transaminase and interleukin 10 were also associated with hepatitis flares. CONCLUSIONS: Among HIV-positive patients coinfected with HBV and/or HCV who are initiating ART, biomarkers of inflammation and coagulation are associated with an increased risk of death, whereas HBV coinfection and higher pre-ART interleukin 10 levels are associated with hepatitis flares.


Subject(s)
Biomarkers/blood , Blood Coagulation Disorders , HIV Infections/complications , Hepatitis B/mortality , Hepatitis B/pathology , Hepatitis C/mortality , Hepatitis C/pathology , Adult , Anti-Retroviral Agents/administration & dosage , Cohort Studies , Female , HIV Infections/drug therapy , HIV Infections/mortality , Hepatitis B/diagnosis , Hepatitis C/diagnosis , Humans , Inflammation , Male , Middle Aged , Prognosis , Retrospective Studies , Survival Analysis
18.
J Infect Dis ; 208(6): 898-906, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23766525

ABSTRACT

BACKGROUND: Cryptococcosis-associated immune reconstitution inflammatory syndrome (C-IRIS) may be driven by aberrant T-cell responses against cryptococci. We investigated this in human immunodeficiency virus (HIV)-infected patients with treated cryptococcal meningitis (CM) commencing combination antiretroviral therapy (cART). METHODS: Mitogen- and cryptococcal mannoprotein (CMP)-activated (CD25+CD134+) CD4+ T cells and -induced production of interferon-gamma (IFN-γ), IL-10, and CXCL10 were assessed in whole blood cultures in a prospective study of 106 HIV-CM coinfected patients. RESULTS: Patients with paradoxical C-IRIS (n = 27), compared with patients with no neurological deterioration (no ND; n = 63), had lower CMP-induced IFN-γ production in 24-hour cultures pre-cART and 4 weeks post-cART (P = .0437 and .0257, respectively) and lower CMP-activated CD4+ T-cell counts pre-cART (P = .0178). Patients surviving to 24 weeks had higher proportions of mitogen-activated CD4+ T cells and higher CMP-induced CXCL10 and IL-10 production in 24-hour cultures pre-cART than patients not surviving (P = .0053, .0436 and .0319, respectively). C-IRIS was not associated with higher CMP-specific T-cell responses before or during cART. CONCLUSION: Greater preservation of T-cell function and higher CMP-induced IL-10 and CXCL10 production before cART are associated with improved survival while on cART. Lower CMP-induced IFN-γ production pre-cART, but not higher CMP-specific T-cell responses after cART, were risk factors for C-IRIS.


Subject(s)
AIDS-Related Opportunistic Infections/drug therapy , CD4-Positive T-Lymphocytes/immunology , Fungal Proteins/immunology , Immune Reconstitution Inflammatory Syndrome/immunology , Interferon-gamma/immunology , Meningitis, Cryptococcal/immunology , AIDS-Related Opportunistic Infections/immunology , Adult , Anti-Retroviral Agents/therapeutic use , Antifungal Agents/therapeutic use , Antiretroviral Therapy, Highly Active , Chemokine CXCL10/blood , Chemokine CXCL10/immunology , Cryptococcus , Humans , Immune Reconstitution Inflammatory Syndrome/complications , Immune Reconstitution Inflammatory Syndrome/drug therapy , Interferon-gamma/blood , Interleukin-10/blood , Interleukin-10/immunology , Membrane Glycoproteins/immunology , Meningitis, Cryptococcal/complications , Meningitis, Cryptococcal/drug therapy , Multivariate Analysis , Proportional Hazards Models , Prospective Studies , Recombinant Proteins , Risk Factors , South Africa
19.
J Infect Dis ; 208(10): 1604-12, 2013 Nov 15.
Article in English | MEDLINE | ID: mdl-23908492

ABSTRACT

BACKGROUND: Human immunodeficiency virus-infected patients with treated cryptococcal meningitis who start combination antiretroviral therapy (cART) are at risk of further neurological deterioration, in part caused by paradoxical cryptococcosis-associated immune reconstitution inflammatory syndrome (C-IRIS). We hypothesized that C-IRIS is associated with alterations of chemokine receptor expression on T cells and chemokine concentrations in cerebrospinal fluid (CSF) that enhance recruitment of T-helper 1 cells and/or myeloid cells to the central nervous system. METHODS: In a prospective study of 128 human immunodeficiency virus-infected patients with cryptococcal meningitis who received antifungal therapy followed by cART, we examined the proportions of CD4(+) and CD8(+) T cells expressing CCR5 and/or CXCR3, in CSF and whole blood and the concentrations of CXCL10, CCL2, and CCL3 in stored CSF and plasma. RESULTS: The proportion of CD4(+) and CD8(+) T cells expressing CXCR3(+)CCR5(+) and the concentrations of CXCL10, CCL2 and CCL3 were increased in CSF compared with blood at cART initiation (P < .0001). Patients with C-IRIS (n = 26), compared with those with no neurological deterioration (n = 63), had higher CSF ratios of CCL2/CXCL10 and CCL3/CXCL10 and higher proportions of CXCR3(+)CCR5(+)CD8(+)T cells in CSF compared with blood at cART initiation (P = .03, .0053, and .02, respectively). CONCLUSION: CD8(+) T-cell and myeloid cell trafficking to the central nervous system may predispose patients to C-IRIS.


Subject(s)
Chemokines/metabolism , HIV Infections/complications , HIV Infections/metabolism , Immune Reconstitution Inflammatory Syndrome/etiology , Meningitis, Cryptococcal/etiology , Receptors, Chemokine/metabolism , Adult , Antifungal Agents/therapeutic use , Antiretroviral Therapy, Highly Active , CD4 Lymphocyte Count , CD4-CD8 Ratio , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , Chemokines/blood , Chemokines/cerebrospinal fluid , Female , HIV Infections/drug therapy , HIV Infections/mortality , Humans , Immune Reconstitution Inflammatory Syndrome/drug therapy , Immune Reconstitution Inflammatory Syndrome/immunology , Male , Meningitis, Cryptococcal/drug therapy , Meningitis, Cryptococcal/immunology , Prospective Studies , Receptors, Chemokine/blood
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