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1.
Future Oncol ; : 1-13, 2024 Apr 19.
Article in English | MEDLINE | ID: mdl-38639552

ABSTRACT

Aim: Evaluate the association of race/ethnicity and socioeconomic position (SEP) on emergency department (ED) visits for patients with hepatocellular carcinoma (HCC), which may reflect access to and quality of cancer care. Materials & methods: Patients with HCC identified from a commercial multi-payer claims database between 2015 and 2018 were matched to near-neighborhood social determinants of health (SDOH) and stratified by race/ethnicity and SEP (proxied by annual household income). Analyses evaluated the effect of race/ethnicity and SEP on ED utilization, adjusting for SDOH, demographic and clinical characteristics using multivariable regression methods. Results: A total of 22,247 patients were included. Black and Hispanic patients had 43 and 18% higher ED utilization than White patients at higher-income levels (p < 0.01); these differences were nonsignificant at lower-income. Regardless of income level, Asian patients had lower ED utilization. Conclusion: Further research on the intersectionality between race/ethnicity, SEP and other SDOH may guide structural-level interventions to address health inequities.


Health disparities among racial/ethnic minorities have been observed in patients with hepatocellular carcinoma (HCC). We conducted a real-world retrospective insurance claims study of more than 22,200 adult patients with HCC between 2015 and 2018. We evaluated the association of race/ethnicity and socioeconomic position (measured by income level) with emergency department (ED) utilization. Our study consisted of 69% White, 14% Black, 7% Hispanic, 6% Asian and 4% other patient populations. Black and Hispanic patients had the highest number of ED visits, followed by White and Asian patients. Compared with White patients, ED visits were 27% higher for Black, 17% higher for Hispanic and 36% lower for Asian patients. Compared with low income, middle income was associated with 4% more and high income with 6% less ED use, regardless of race/ethnicity. At higher income levels, Black and Hispanic but not Asian patients demonstrated higher ED use than White patients. These findings suggest that improved socioeconomic position of Black and Hispanic patients may not provide as protective an effect on health outcomes, potentially due to structural health inequities.

2.
Cancers (Basel) ; 15(5)2023 Feb 25.
Article in English | MEDLINE | ID: mdl-36900262

ABSTRACT

Treatments for unresectable hepatocellular carcinoma (HCC) have varying benefit-risk profiles. We elicited 200 US patients' preferences for attributes associated with various first-line systemic treatments for unresectable HCC in a discrete-choice experiment (DCE) survey. Respondents answered nine DCE questions, each offering a choice between two hypothetical treatment profiles defined by six attributes with varying levels: overall survival (OS), months of maintained daily function, severity of palmar-plantar syndrome, severity of hypertension, risk of digestive-tract bleeding, and mode and frequency of administration. A random-parameters logit model was used to analyze the preference data. Patients regarded an additional 10 months of maintaining daily function without decline to be as important or more important than 10 additional months of OS, on average. Respondents valued avoiding moderate-to-severe palmar-plantar syndrome and hypertension more than extended OS. A respondent would require >10 additional months of OS (the greatest increase presented in the study) on average to offset the increased burden of adverse events. Patients with unresectable HCC prioritize avoiding adverse events that would severely impact their quality of life over mode and frequency of administration or digestive-tract bleeding risk. For some patients with unresectable HCC, maintaining daily functioning is as important or more important than the survival benefit of a treatment.

3.
Clin Cancer Res ; 28(16): 3537-3545, 2022 08 15.
Article in English | MEDLINE | ID: mdl-35435967

ABSTRACT

PURPOSE: Atezolizumab + bevacizumab is the new standard of care for systemic treatment-naïve, unresectable hepatocellular carcinoma (HCC). This exploratory study investigated on-treatment alpha-fetoprotein (AFP) response as a potential surrogate biomarker of prognosis for the combination therapy. EXPERIMENTAL DESIGN: Data from Group A of the phase Ib GO30140 study were used to identify the optimal time for AFP measurement and AFP cutoffs to differentiate patients by their best confirmed response per independent review facility-assessed RECIST (IRF-RECIST) version 1.1: responders from nonresponders and patients with disease control from primary progressors. We applied these cutoffs to independent data from the atezolizumab + bevacizumab arm of the phase III IMbrave150 trial to distinguish patients based on (i) overall survival (OS) and progression-free survival (PFS) per IRF-RECIST 1.1 and (ii) best confirmed response per IRF-RECIST 1.1. RESULTS: We derived AFP cutoffs of ≥75% decrease and ≤10% increase from baseline at 6 weeks to identify responders and those who had disease control, respectively. These cutoffs had high sensitivity and specificity in GO30140. In IMbrave150 patients, sensitivity was 0.59 and specificity was 0.86 for the ≥75% decrease AFP cutoff; the sensitivity was 0.77 and specificity was 0.44 for the ≤10% increase AFP cutoff. Both AFP cutoffs were associated with longer OS and PFS, particularly in patients with hepatitis B virus etiology (HR < 0.5; P < 0.01). CONCLUSIONS: AFP response at 6 weeks after initiating treatment is a potential surrogate biomarker of prognosis for patients with HCC receiving atezolizumab + bevacizumab. See related commentary by Cappuyns and Llovet, p. 3405.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Antibodies, Monoclonal, Humanized , Bevacizumab , Biomarkers , Carcinoma, Hepatocellular/pathology , Humans , Liver Neoplasms/pathology , Retrospective Studies , alpha-Fetoproteins
4.
Liver Cancer ; 11(6): 558-571, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36589722

ABSTRACT

Introduction: The efficacy of systemic first-line treatments in older adults with unresectable hepatocellular carcinoma (HCC) has not been well-studied. We compared the safety and efficacy of atezolizumab plus bevacizumab versus sorafenib as a first-line treatment in younger versus older patients with unresectable HCC. Methods: This global, phase 3, open-label, randomized clinical trial (IMbrave150) recruited patients aged ≥18 years with locally advanced metastatic or unresectable HCC, an Eastern Cooperative Oncology Group performance status score of 0 or 1, and Child-Pugh class A liver function who had not previously received systemic therapy for liver cancer. Patients received either 1,200 mg atezolizumab plus 15 mg/kg bevacizumab intravenously every 3 weeks or 400 mg sorafenib orally twice daily until loss of clinical benefit or unacceptable toxicity. Primary endpoints were overall survival (OS) and progression-free survival (PFS). Secondary outcomes were the incidence of adverse events and time to deterioration of patient-reported outcomes (PROs). This subgroup analysis evaluated safety and efficacy endpoints in patients <65 years, ≥65 to <75 years, and ≥75 years. Results: Of 501 patients, 165 patients were randomized to sorafenib and 336 were randomized to atezolizumab plus bevacizumab (175 patients <65 years; 106 patients ≥65 to <75 years; 55 patients ≥75 years). Across all age groups, patients receiving atezolizumab plus bevacizumab had longer median OS (<65: 18.0 vs. 12.2 months [HR, 0.57; 95% CI: 0.40-0.82]; ≥65 to <75: 19.4 vs. 14.9 months [HR, 0.80; 95% CI: 0.52-1.23]; ≥75: 24.0 vs. 18.0 months [HR, 0.72, 95% CI: 0.37-1.41]) and PFS than those receiving sorafenib. Time to deterioration for multiple PROs was delayed for patients receiving atezolizumab plus bevacizumab, including older adults. There were no clinically meaningful differences in toxicity between age groups. Conclusion: Atezolizumab plus bevacizumab is safe and effective in adults <65, ≥65 to <75, and ≥75. Treatment was well-tolerated even in elderly patients.

5.
Liver Cancer ; 10(4): 296-308, 2021 Jul.
Article in English | MEDLINE | ID: mdl-34414118

ABSTRACT

INTRODUCTION: Atezolizumab plus bevacizumab significantly improved overall survival (OS) and progression-free survival (PFS) versus sorafenib in patients with unresectable hepatocellular carcinoma (HCC) in IMbrave150. Efficacy and safety data from the Chinese subpopulation are reported. METHODS: IMbrave150, a global, randomized, open-label, phase 3 study in patients with systemic treatment-naive unresectable HCC, included an extension phase that enrolled additional patients from mainland China. Patients were randomized (2:1) to receive intravenous atezolizumab 1,200 mg plus bevacizumab 15 mg/kg once every 3 weeks or sorafenib 400 mg twice a day until unacceptable toxicity or loss of clinical benefit. Co-primary endpoints were OS and independent review facility-assessed PFS per Response Evaluation Criteria in Solid Tumors version 1.1 in the intention-to-treat population. RESULTS: Of 194 Chinese patients enrolled from April 16, 2018, to April 8, 2019 (137 in the global study and 57 in the China extension phase), 133 received atezolizumab plus bevacizumab and 61 received sorafenib. At the data cutoff (August 29, 2019), the stratified hazard ratio for OS was 0.44 (95% CI, 0.25-0.76) and for PFS was 0.60 (95% CI, 0.40-0.90). The respective median OS and PFS with atezolizumab plus bevacizumab were not reached (NR; 95% CI, 13.5 months to NR) and 5.7 months (95% CI, 4.2-8.3) versus 11.4 months (95% CI, 6.7 to NR) and 3.2 months (95% CI, 2.6-4.8) with sorafenib. Grade 3-4 adverse events (AEs) occurred in 78 of 132 (59.1%) atezolizumab plus bevacizumab-treated and 27 of 58 (46.6%) sorafenib-treated patients. The most common grade 3-4 AE with atezolizumab plus bevacizumab was hypertension, occurring in 15.2% of patients; however, other high-grade AEs were infrequent. CONCLUSION: Clinically meaningful improvements in OS and PFS observed with atezolizumab plus bevacizumab versus sorafenib suggest that atezolizumab plus bevacizumab may become a practice-changing treatment for Chinese patients with unresectable HCC.

6.
Cancer Med ; 10(16): 5437-5447, 2021 08.
Article in English | MEDLINE | ID: mdl-34189869

ABSTRACT

BACKGROUND: IMbrave150 is a phase III trial that assessed atezolizumab + bevacizumab (ATEZO/BEV) versus sorafenib (SOR) in patients with unresectable hepatocellular carcinoma (HCC) and demonstrated a significant improvement in clinical outcomes. Exploratory analyses characterized objective response rate (ORR), depth (DpR), and duration of response (DoR), and patients with a complete response (CR). METHODS: Patients were randomized 2:1 to intravenous ATEZO (1200 mg) + BEV (15 mg/kg) every 3 weeks or oral SOR (400 mg) twice daily. Tumors were evaluated using Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1) and HCC-modified RECIST (mRECIST). ORR by prior treatment and largest baseline liver lesion size, DoR, time to response (TTR), and complete response (TTCR) were analyzed. RESULTS: For both criteria, responses favored ATEZO/BEV versus SOR regardless of prior treatment and in patients with lesions ≥3 cm. Median TTR was 2.8 months per RECIST 1.1 (range: 1.2-12.3 months) and 2.8 months per mRECIST (range: 1.1-12.3 months) with ATEZO/BEV. Patients receiving ATEZO/BEV had a greater DpR, per both criteria, across baseline liver lesion sizes. Characteristics of complete responders were similar to those of the intent-to-treat population. In complete responders receiving ATEZO/BEV per mRECIST versus RECIST 1.1, respectively, median TTCR was shorter (5.5 vs. 7.0 months), mean baseline sum of lesion diameter was longer (5.0 [SD, 5.1] vs. 2.6 [SD, 1.4] cm), and mean largest liver lesion size was larger (4.8 [SD, 4.2] vs. 2.3 [SD, 1.0] cm). CONCLUSIONS: These data highlight the improved ORR, DpR, and CR rates with ATEZO/BEV in unresectable HCC.


Subject(s)
Antibodies, Monoclonal, Humanized/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Bevacizumab/administration & dosage , Carcinoma, Hepatocellular/drug therapy , Liver Neoplasms/drug therapy , Sorafenib/administration & dosage , Administration, Intravenous , Adult , Aged , Aged, 80 and over , Antibodies, Monoclonal, Humanized/adverse effects , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Bevacizumab/adverse effects , Carcinoma, Hepatocellular/diagnosis , Carcinoma, Hepatocellular/mortality , Female , Follow-Up Studies , Humans , Liver Neoplasms/diagnosis , Liver Neoplasms/mortality , Male , Middle Aged , Neoplasm Staging , Progression-Free Survival , Response Evaluation Criteria in Solid Tumors , Sorafenib/adverse effects , Tomography, X-Ray Computed
7.
Lancet Oncol ; 22(7): 991-1001, 2021 07.
Article in English | MEDLINE | ID: mdl-34051880

ABSTRACT

BACKGROUND: Understanding patients' experience of cancer treatment is important. We aimed to evaluate patient-reported outcomes (PROs) with atezolizumab plus bevacizumab versus sorafenib in patients with advanced hepatocellular carcinoma in the IMbrave150 trial, which has already shown significant overall survival and progression-free survival benefits with this combination therapy. METHODS: We did an open-label, randomised, phase 3 trial in 111 hospitals and cancer centres across 17 countries or regions. We included patients aged 18 years or older with systemic, treatment-naive, histologically, cytologically, or clinically confirmed unresectable hepatocellular carcinoma and an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, with disease that was not amenable to curative surgical or locoregional therapies, or progressive disease after surgical or locoregional therapies. Participants were randomly assigned (2:1; using permuted block randomisation [blocks of six], stratified by geographical region; macrovascular invasion, extrahepatic spread, or both; baseline alpha-fetoprotein concentration; and ECOG performance status) to receive 1200 mg atezolizumab plus 15 mg/kg bevacizumab intravenously once every 3 weeks or 400 mg sorafenib orally twice a day, until loss of clinical benefit or unacceptable toxicity. The independent review facility for tumour assessment was masked to the treatment allocation. Previously reported coprimary endpoints were overall survival and independently assessed progression-free survival per Response Evaluation Criteria in Solid Tumors 1.1. Prespecified secondary and exploratory analyses descriptively evaluated treatment effects on patient-reported quality of life, functioning, and disease symptoms per the European Organisation for Research and Treatment of Cancer (EORTC) quality-of-life questionnaire for cancer (QLQ-C30) and quality-of-life questionnaire for hepatocellular carcinoma (QLQ-HCC18). Time to confirmed deterioration of PROs was analysed in the intention-to-treat population; all other analyses were done in the PRO-evaluable population (patients who had a baseline PRO assessment and at least one assessment after baseline). The trial is ongoing; enrolment is closed. This trial is registered with ClinicalTrials.gov, NCT03434379. FINDINGS: Between March 15, 2018, and Jan 30, 2019, 725 patients were screened and 501 patients were enrolled and randomly assigned to atezolizumab plus bevacizumab (n=336) or sorafenib (n=165). 309 patients in the atezolizumab plus bevacizumab group and 145 patients in the sorafenib group were included in the PRO-evaluable population. At data cutoff (Aug 29, 2019) the median follow-up was 8·6 months (IQR 6·2-10·8). EORTC QLQ-C30 completion rates were 90% or greater for 23 of 24 treatment cycles in both groups (range 88-100% in the atezolizumab plus bevacizumab group and 80-100% in the sorafenib group). EORTC QLQ-HCC18 completion rates were 90% or greater for 20 of 24 cycles in the atezolizumab plus bevacizumab group (range 88-100%) and 21 of 24 cycles in the sorafenib group (range 89-100%). Compared with sorafenib, atezolizumab plus bevacizumab reduced the risk of deterioration on all EORTC QLQ-C30 generic cancer symptom scales that were prespecified for analysis (appetite loss [hazard ratio (HR) 0·57, 95% CI 0·40-0·81], diarrhoea [0·23, 0·16-0·34], fatigue [0·61, 0·46-0·81], pain [0·46, 0·34-0·62]), and two of three EORTC QLQ-HCC18 disease-specific symptom scales that were prespecified for analysis (fatigue [0·60, 0·45-0·80] and pain [0·65, 0·46-0·92], but not jaundice [0·76, 0·55-1·07]). At day 1 of treatment cycle five (after which attrition in the sorafenib group was more than 50%), the mean EORTC QLQ-C30 score changes from baseline in the atezolizumab plus bevacizumab versus sorafenib groups were: -3·29 (SD 17·56) versus -5·83 (20·63) for quality of life, -4·02 (19·42) versus -9·76 (21·33) for role functioning, and -3·77 (12·82) versus -7·60 (15·54) for physical functioning. INTERPRETATION: Prespecified analyses of PRO data showed clinically meaningful benefits in terms of patient-reported quality of life, functioning, and disease symptoms with atezolizumab plus bevacizumab compared with sorafenib, strengthening the combination therapy's positive benefit-risk profile versus that of sorafenib in patients with unresectable hepatocellular carcinoma. FUNDING: F Hoffmann-La Roche and Genentech.


Subject(s)
Angiogenesis Inhibitors/therapeutic use , Antibodies, Monoclonal, Humanized/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Bevacizumab/therapeutic use , Carcinoma, Hepatocellular/drug therapy , Liver Neoplasms/drug therapy , Patient Reported Outcome Measures , Protein Kinase Inhibitors/therapeutic use , Sorafenib/therapeutic use , Angiogenesis Inhibitors/adverse effects , Antibodies, Monoclonal, Humanized/adverse effects , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Bevacizumab/adverse effects , Carcinoma, Hepatocellular/mortality , Carcinoma, Hepatocellular/pathology , Humans , Liver Neoplasms/mortality , Liver Neoplasms/pathology , Progression-Free Survival , Protein Kinase Inhibitors/adverse effects , Quality of Life , Sorafenib/adverse effects , Time Factors
8.
N Engl J Med ; 382(20): 1894-1905, 2020 05 14.
Article in English | MEDLINE | ID: mdl-32402160

ABSTRACT

BACKGROUND: The combination of atezolizumab and bevacizumab showed encouraging antitumor activity and safety in a phase 1b trial involving patients with unresectable hepatocellular carcinoma. METHODS: In a global, open-label, phase 3 trial, patients with unresectable hepatocellular carcinoma who had not previously received systemic treatment were randomly assigned in a 2:1 ratio to receive either atezolizumab plus bevacizumab or sorafenib until unacceptable toxic effects occurred or there was a loss of clinical benefit. The coprimary end points were overall survival and progression-free survival in the intention-to-treat population, as assessed at an independent review facility according to Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST 1.1). RESULTS: The intention-to-treat population included 336 patients in the atezolizumab-bevacizumab group and 165 patients in the sorafenib group. At the time of the primary analysis (August 29, 2019), the hazard ratio for death with atezolizumab-bevacizumab as compared with sorafenib was 0.58 (95% confidence interval [CI], 0.42 to 0.79; P<0.001). Overall survival at 12 months was 67.2% (95% CI, 61.3 to 73.1) with atezolizumab-bevacizumab and 54.6% (95% CI, 45.2 to 64.0) with sorafenib. Median progression-free survival was 6.8 months (95% CI, 5.7 to 8.3) and 4.3 months (95% CI, 4.0 to 5.6) in the respective groups (hazard ratio for disease progression or death, 0.59; 95% CI, 0.47 to 0.76; P<0.001). Grade 3 or 4 adverse events occurred in 56.5% of 329 patients who received at least one dose of atezolizumab-bevacizumab and in 55.1% of 156 patients who received at least one dose of sorafenib. Grade 3 or 4 hypertension occurred in 15.2% of patients in the atezolizumab-bevacizumab group; however, other high-grade toxic effects were infrequent. CONCLUSIONS: In patients with unresectable hepatocellular carcinoma, atezolizumab combined with bevacizumab resulted in better overall and progression-free survival outcomes than sorafenib. (Funded by F. Hoffmann-La Roche/Genentech; ClinicalTrials.gov number, NCT03434379.).


Subject(s)
Antibodies, Monoclonal, Humanized/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Bevacizumab/administration & dosage , Carcinoma, Hepatocellular/drug therapy , Liver Neoplasms/drug therapy , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Aged , Antibodies, Monoclonal, Humanized/adverse effects , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Bevacizumab/adverse effects , Female , Humans , Intention to Treat Analysis , Kaplan-Meier Estimate , Male , Middle Aged , Quality of Life , Survival Analysis
9.
Cell Rep ; 25(1): 80-94, 2018 10 02.
Article in English | MEDLINE | ID: mdl-30282040

ABSTRACT

We examined hematopoietic protein kinase 1 (HPK1), whose reliance on scaffold versus kinase functions for negative immune cell regulation is poorly understood and critical to its assessment as a viable drug target. We identify kinase-dependent roles for HPK1 in CD8 T cells that restrict their anti-viral and anti-tumor responses by using HPK1 kinase-dead (HPK1.kd) knockin mice. Loss of HPK1 kinase function enhanced T cell receptor signaling and cytokine secretion in a T-cell-intrinsic manner. In response to chronic lymphocytic choriomeningitis virus (LCMV) infection or tumor challenge, viral clearance and tumor growth inhibition were enhanced in HPK1.kd mice, accompanied by an increase in effector CD8 T cell function. Co-blockade of PD-L1 further enhanced T effector cell function, resulting in superior anti-viral and anti-tumor immunity over single target blockade. These results identify the importance of HPK1 kinase activity in the negative regulation of CD8 effector functions, implicating its potential as a cancer immunotherapy target.


Subject(s)
Protein Serine-Threonine Kinases/metabolism , T-Lymphocytes/enzymology , T-Lymphocytes/immunology , Animals , B7-H1 Antigen/antagonists & inhibitors , B7-H1 Antigen/immunology , CD8-Positive T-Lymphocytes/enzymology , CD8-Positive T-Lymphocytes/immunology , Colonic Neoplasms/immunology , Colonic Neoplasms/therapy , Female , Glioma/immunology , Glioma/therapy , Immunotherapy , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Protein Serine-Threonine Kinases/antagonists & inhibitors , Protein Serine-Threonine Kinases/immunology , Random Allocation , Signal Transduction
10.
J Immunol ; 192(7): 3166-79, 2014 Apr 01.
Article in English | MEDLINE | ID: mdl-24610013

ABSTRACT

B cells are required for follicular Th (Tfh) cell development, as is the ICOS ligand (ICOS-L); however, the separable contributions of Ag and ICOS-L delivery by cognate B cells to Tfh cell development and function are unknown. We find that Tfh cell and germinal center differentiation are dependent on cognate B cell display of ICOS-L, but only when Ag presentation by the latter is limiting, with the requirement for B cell expression of ICOS-L overcome by robust Ag delivery. These findings demonstrate that Ag-specific B cells provide different, yet compensatory, signals for Tfh cell differentiation, while reconciling conflicting data indicating a requirement for ICOS-L expression on cognate B cells for Tfh cell development with those demonstrating that the latter requirement could be bypassed in lieu of that tendered by noncognate B cells. Our findings clarify the separable roles of delivery of Ag and ICOS-L by cognate B cells for Tfh cell maturation and function, and have implications for using therapeutic ICOS blockade in settings of abundantly available Ag, such as in systemic autoimmunity.


Subject(s)
Antigens/immunology , B-Lymphocytes/immunology , Inducible T-Cell Co-Stimulator Ligand/immunology , T-Lymphocytes, Helper-Inducer/immunology , Animals , Antigens, CD19/genetics , Antigens, CD19/immunology , Antigens, CD19/metabolism , B-Lymphocytes/metabolism , Cell Proliferation , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Flow Cytometry , Inducible T-Cell Co-Stimulator Ligand/genetics , Inducible T-Cell Co-Stimulator Ligand/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Microscopy, Confocal , Nitrophenols/immunology , Ovalbumin/immunology , Phenylacetates/immunology , Proto-Oncogene Proteins c-bcl-6 , Reverse Transcriptase Polymerase Chain Reaction , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , T-Lymphocytes, Helper-Inducer/metabolism
11.
Immunol Rev ; 247(1): 160-71, 2012 May.
Article in English | MEDLINE | ID: mdl-22500839

ABSTRACT

Follicular helper T (Tfh) cells play an essential role in helping B cells generate antibodies upon pathogen encounters. Such T-cell help classically occurs in germinal centers (GCs) located in B-cell follicles of secondary lymphoid organs, a site of immunoglobulin affinity maturation and isotype switching. B-cell maturation also occurs extrafollicularly, in the red pulp of the spleen and medullary cords in lymph nodes, with plasma cell formation and antibody production. Development of extrafollicular foci (EF) in T-cell-dependent (TD) immune responses is reliant upon CD4(+) T cells with characteristics of Tfh cells. Pathogenic autoantibodies, arising from self-reactive B cells having undergone somatic hypermutation with affinity selection and class switching within GCs and EF, are major contributors to the end-organ injury in systemic autoimmunity. B cells maturing to produce autoantibodies in systemic autoimmune diseases, like those in normal immune responses, largely require T-helper cells. This review highlights Tfh cell development as an introduction to a more in-depth discussion of human Tfh cells and blood borne cells with similar features and the role of these cells in promotion of systemic autoimmunity.


Subject(s)
Autoimmunity , B-Lymphocytes/cytology , B-Lymphocytes/immunology , Cell Differentiation , Animals , Gene Expression Regulation , Germinal Center/cytology , Germinal Center/immunology , Humans , Models, Biological , T-Lymphocytes, Helper-Inducer/cytology , T-Lymphocytes, Helper-Inducer/immunology
12.
Arthritis Rheum ; 64(4): 1247-56, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22127758

ABSTRACT

OBJECTIVE: Caspase-activated DNase (CAD) is an endonuclease that is activated by active caspase 3 during apoptosis and is responsible for degradation of chromatin into nucleosomal units. These nucleosomal units are then included in apoptotic bodies. The presence of apoptotic bodies is considered important for the generation of autoantigen in autoimmune diseases, such as systemic lupus erythematosus (SLE), that are characterized by the presence of antinuclear antibodies. The present study was carried out to determine the role of CAD in SLE and to investigate the ability of lupus autoantibodies to bind to CAD-deficient or CAD-sufficient apoptotic cells. METHODS: The Sle1, Sle123, and 3H9 mouse models of SLE, in which autoimmunity is genetically predetermined, were used. To determine the role of chromatin fragmentation in SLE, CAD deficiency was introduced in these mouse models. RESULTS: Deficiency of CAD resulted in increased anti-double-stranded DNA antibody titers in lupus-prone mice. Surprisingly, the absence of CAD exacerbated only genetically predetermined autoimmune responses. To further determine whether nuclear modifications are needed in order to maintain tolerance to nuclear autoantigens, we used the 3H9 mouse, an anti-DNA heavy chain knockin; in this model, the autoreactive B cells are tolerized by anergy. In accordance with findings in the CAD-mutant Sle1 and Sle123 mice, CAD-deficient 3H9 mice spontaneously generated anti-DNA antibodies. Finally, we showed that autoantibodies with specificities toward histone-DNA complexes bind more to CAD-deficient apoptotic cells than to CAD-sufficient apoptotic cells. CONCLUSION: We propose that in mice that are genetically predisposed to lupus development, nuclear apoptotic modifications are needed to maintain tolerance. In the absence of these modifications, apoptotic chromatin is abnormally exposed, facilitating the autoimmune response.


Subject(s)
Antibodies, Antinuclear/immunology , Apoptosis/immunology , Autoantigens/immunology , Deoxyribonucleases/metabolism , Lupus Erythematosus, Systemic/immunology , Animals , Cell Nucleus/immunology , Disease Models, Animal , Immune Tolerance/immunology , Lupus Erythematosus, Systemic/metabolism , Mice
13.
J Immunol ; 185(1): 313-26, 2010 Jul 01.
Article in English | MEDLINE | ID: mdl-20519643

ABSTRACT

Follicular helper T (T(FH)) cells, defined by expression of the surface markers CXCR5 and programmed death receptor-1 (PD-1) and synthesis of IL-21, require upregulation of the transcriptional repressor Bcl6 for their development and function in B cell maturation in germinal centers. We have explored the role of B cells and the cytokines IL-6 and IL-21 in the in vivo regulation of Bcl6 expression and T(FH) cell development. We found that T(FH) cells are characterized by a Bcl6-dependent downregulation of P-selectin glycoprotein ligand 1 (PSGL1, a CCL19- and CCL21-binding protein), indicating that, like CXCR5 and PD-1 upregulation, modulation of PSGL1 expression is part of the T(FH) cell program of differentiation. B cells were neither required for initial upregulation of Bcl6 nor PSGL1 downregulation, suggesting these events preceded T-B cell interactions, although they were required for full development of the T(FH) cell phenotype, including CXCR5 and PD-1 upregulation, and IL-21 synthesis. Bcl6 upregulation and T(FH) cell differentiation were independent of IL-6 and IL-21, revealing that either cytokine is not absolutely required for development of Bcl6(+) T(FH) cells in vivo. These data increase our understanding of Bcl6 regulation in T(FH) cells and their differentiation in vivo and identifies a new surface marker that may be functionally relevant in this subset.


Subject(s)
Cell Differentiation/immunology , DNA-Binding Proteins/physiology , Spleen/immunology , Spleen/metabolism , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , T-Lymphocytes, Helper-Inducer/immunology , T-Lymphocytes, Helper-Inducer/metabolism , Animals , Cell Communication/immunology , Cricetinae , DNA-Binding Proteins/biosynthesis , DNA-Binding Proteins/metabolism , Down-Regulation/immunology , Female , Immunophenotyping , Lymphocyte Cooperation/immunology , Membrane Glycoproteins/antagonists & inhibitors , Membrane Glycoproteins/biosynthesis , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Proto-Oncogene Proteins c-bcl-6 , Spleen/cytology , T-Lymphocyte Subsets/cytology , T-Lymphocytes, Helper-Inducer/cytology , Up-Regulation/immunology
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