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1.
Sci Immunol ; 5(44)2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32034086

RESUMO

The accumulation of B cells and tertiary lymphoid organs in metastatic melanoma patients receiving checkpoint blockade therapy was associated with long-term survival.

2.
J Clin Invest ; 2020 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-31990684

RESUMO

Systemic sclerosis (SSc) is an autoimmune fibrotic disease whose pathogenesis is poorly understood and lacks effective therapies. We undertook quantitative analyses of T cell infiltrates in the skin of thirty-five untreated patients with early diffuse SSc and here show that CD4+ cytotoxic T cells and CD8+ T cells contribute prominently to these infiltrates. We also observed an accumulation of apoptotic cells in SSc tissues, suggesting that recurring cell death may contribute to tissue damage and remodeling in this fibrotic disease. HLA-DR expressing endothelial cells were frequent targets of apoptosis in SSc, consistent with the prominent vasculopathy seen in patients with this disease. A circulating effector population of cytotoxic CD4+ T cells, which exhibited signatures of enhanced metabolic activity, was clonally expanded in systemic sclerosis patients. These data suggest that cytotoxic T cells may induce the apoptotic death of endothelial and other cells in systemic sclerosis. Cell loss driven by immune cells may be followed by overly exuberant tissue repair processes that lead to fibrosis and tissue dysfunction..

3.
J Immunol ; 204(1): 49-57, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31740487

RESUMO

The control of cytoskeletal dynamics by dedicator of cytokinesis 2 (DOCK2), a hematopoietic cell-specific actin effector protein, has been implicated in TCR signaling and T cell migration. Biallelic mutations in Dock2 have been identified in patients with a recessive form of combined immunodeficiency with defects in T, B, and NK cell activation. Surprisingly, we show in this study that certain immune functions of CD8+ T cells are enhanced in the absence of DOCK2. Dock2-deficient mice have a pronounced expansion of their memory T cell compartment. Bone marrow chimera and adoptive transfer studies indicate that these memory T cells develop in a cell-intrinsic manner following thymic egress. Transcriptional profiling, TCR repertoire analyses, and cell surface marker expression indicate that Dock2-deficient naive CD8+ T cells directly convert into virtual memory cells without clonal effector T cell expansion. This direct conversion to memory is associated with a selective increase in TCR sensitivity to self-peptide MHC in vivo and an enhanced response to weak agonist peptides ex vivo. In contrast, the response to strong agonist peptides remains unaltered in Dock2-deficient T cells. Collectively, these findings suggest that the regulation of the actin dynamics by DOCK2 enhances the threshold for entry into the virtual memory compartment by negatively regulating tonic TCR triggering in response to weak agonists.

4.
Curr Opin Rheumatol ; 32(2): 146-151, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31842033

RESUMO

PURPOSE OF REVIEW: To summarize recent advances in the understanding of the pathogenesis of IgG4-related disease. RECENT FINDINGS: Limited data exist to explain genetic susceptibility to IgG4-related disease and the underlying triggers for this disease have not yet been identified. Cytotoxic CD4 T cells and activated B cells infiltrate affected organs and express proinflammatory and profibrotic molecules. Antigen presented by activated B cells likely reactivates cytotoxic CD4 T cells in disease tissues and these T cells in turn induce the targeted apoptotic death of host cells in certain organs - which presumably present the same antigenic peptide on human leukocyte antigen class II molecules of relevance that was also presented on B cells during reactivation. A subsequent exaggerated tissue remodeling process is orchestrated by cytokines, chemokines, and enzymes secreted by both activated B cells and CD4CTLs. These molecules induce an overexuberant repair process resulting in fibrosis and loss of target organ function. SUMMARY: In IgG4-related disease, presumably self-reactive cytotoxic CD4 T cells infiltrate tissues, are reactivated by T cells and induce apoptotic death. Molecules secreted by activated B cells and by CD4CTLs drive an exaggerated wound healing response resulting in fibrosis and compromised tissue function.

5.
Arthritis Rheumatol ; 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31612628

RESUMO

OBJECTIVE: Four autoantigens have been described recently in IgG4-related disease (IgG4-RD): prohibitin, annexin A11, laminin 511-E8, and galectin-3. However, no external validation has been performed and the possibility that some individuals break tolerance to more than one autoantigen has not been explored. METHODS: Autoantibody responses against prohibitin, annexin A11 and laminin 511-E8 were measured by ELISA among a clinically diverse cohort of IgG4-RD patients (n=100). Autoantibody responses were correlated with disease severity and organ distribution. RESULTS: The frequencies of IgG4 autoantibody responses against prohibitin (10%), annexin A11 (12%), and laminin 511-E8 (7%) were not significantly different from those of controls. A portion of the cohort (n = 86) had been analyzed previously at our center for anti-galectin-3 antibody responses with 25 (29%) having IgG4 anti-galectin-3 antibodies. Among these 86 subjects, 32 (37%) had IgG4 antibodies to at least one of the 4 auto-antigens and 12 (14%) showed reactivity to ≥2 of the tested antigens. The subset of patients with ≥2 autoantibodies had higher total IgG1, IgG2, IgG4, and C-reactive protein levels; were more commonly hypocomplementemic; and were more likely to have visceral organ involvement. CONCLUSION: Antibodies against prohibitin, annexin A11, and laminin 511-E8 were found in only a small portion of patients with IgG4-RD. A subset of IgG4-RD patients, however, had IgG4 antibodies against ≥2 autoantigens. Patients with antibodies against ≥2 autoantigens present with robust IgG subclass elevations, complement consumption, and visceral organ involvement. This broader break in immunological tolerance in IgG4-RD was associated with more severe disease.

6.
Sci Signal ; 12(604)2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31641080

RESUMO

Transitional B cells must actively undergo selection for self-tolerance before maturing into their resting follicular B cell successors. We found that metabolic quiescence was acquired at the follicular B cell stage in both humans and mice. In follicular B cells, the expression of genes involved in ribosome biogenesis, aerobic respiration, and mammalian target of rapamycin complex 1 (mTORC1) signaling was reduced when compared to that in transitional B cells. Functional metabolism studies, profiling of whole-cell metabolites, and analysis of cell surface proteins in human B cells suggested that this transition was also associated with increased extracellular adenosine salvage. Follicular B cells increased the abundance of the cell surface ectonucleotidase CD73, which coincided with adenosine 5'-monophosphate-activated protein kinase (AMPK) activation. Differentiation to the follicular B cell stage in vitro correlated with surface acquisition of CD73 on human transitional B cells and was augmented with the AMPK agonist, AICAR. Last, individuals with gain-of-function PIK3CD (PI3Kδ) mutations and increased pS6 activation exhibited a near absence of circulating follicular B cells. Together, our data suggest that mTORC1 attenuation may be necessary for human follicular B cell development. These data identify a distinct metabolic switch during human B cell development at the transitional to follicular stages, which is characterized by an induction of extracellular adenosine salvage, AMPK activation, and the acquisition of metabolic quiescence.

7.
Sci Immunol ; 4(39)2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31492712

RESUMO

During pregnancy, mothers generate di-galactosylated IgGs that cross the placenta more readily and provide the fetus and the newborn infant with antibodies optimized for NK cell-mediated antibody-dependent cellular cytotoxicity.

8.
Glycobiology ; 29(12): 861-875, 2019 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-31411667

RESUMO

The origins of plasmacytoid dendritic cells (pDCs) have long been controversial and progenitors exclusively committed to this lineage have not been described. We show here that the fate of hematopoietic progenitors is determined in part by their surface levels of 9-O-acetyl sialic acid. Pro-pDCs were identified as lineage negative 9-O-acetyl sialic acid low progenitors that lack myeloid and lymphoid potential but differentiate into pre-pDCs. The latter cells are also lineage negative, 9-O-acetyl sialic acid low cells but are exclusively committed to the pDC lineage. Levels of 9-O-acetyl sialic acid provide a distinct way to define progenitors and thus facilitate the study of hematopoietic differentiation.

9.
Curr Opin Rheumatol ; 31(6): 576-581, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31369432

RESUMO

PURPOSE OF REVIEW: To summarize recent advances in the understanding of the pathogenesis of autoimmune fibrotic diseases. These diseases include IgG4-related disease, systemic sclerosis and lupus nephritis. RECENT FINDINGS: Recent studies indicate that a poorly studied subset of helper T cells, cytotoxic CD4+ T cells and sub-populations of disease-specific activated B cells infiltrate inflamed tissues and collaborate to induce tissue fibrosis in autoimmune fibrotic diseases. Cycles of apoptosis induced by antigen-specific cytotoxic CD4+ T cells followed by macrophage-mediated clearing of apoptotic cells and finally tissue remodeling driven by cytokines released by these auto-antigen-specific activated T and B cells may contribute to the activation of fibroblasts and myofibroblasts and the laying down of collagen. In scleroderma, this process likely involves the apoptosis of endothelial cells and other neighboring cells and the subsequent remodeling of the tissue. SUMMARY: Self-reactive cytotoxic CD4+ T cells infiltrate tissues where they may be nurtured by activated auto-reactive B cells, induce apoptosis, secrete cytokines and thus drive autoimmune fibrosis.

10.
Artigo em Inglês | MEDLINE | ID: mdl-31319101

RESUMO

BACKGROUND: IgG4-related disease (IgG4-RD) is a fibroinflammatory condition marked by rapid clinical improvement after selective depletion of B lymphocytes with rituximab. This feature suggests that B cells might participate in fibrogenesis and wound healing. OBJECTIVE: In the present work we aimed to demonstrate that B lymphocytes contribute directly to tissue fibrosis in patients with IgG4-RD. METHODS: Total circulating CD19+ B lymphocytes, naive B cells, memory B cells, or plasmablasts from patients with IgG4-RD were cultivated with human fibroblasts. Profibrotic soluble factors and collagen production in cocultures were assessed by using ELISAs and Luminex assays. RNA sequencing and quantitative RT-PCR were used to assess fibroblast activation in the presence of B cells, as well as induction of profibrotic pathways in B-cell subsets. Relevant profibrotic and inflammatory molecules were confirmed in vitro by using functional experiments and on IgG4-RD tissue sections by using multicolor immunofluorescence studies. RESULTS: B cells from patients with IgG4-RD (1) produced the profibrotic molecule platelet-derived growth factor B and stimulated collagen production by fibroblasts; (2) expressed enzymes implicated in extracellular matrix remodeling, such as lysyl oxidase homolog 2; (3) produced the chemotactic factors CCL4, CCL5, and CCL11; and (4) induced production of these same chemokines by activated fibroblasts. Plasmablasts expressed sets of genes implicated in fibroblast activation and proliferation and therefore represent cells with intrinsic profibrotic properties. CONCLUSION: We have demonstrated that B cells contribute directly to tissue fibrosis in patients with IgG4-RD. These unanticipated profibrotic properties of B lymphocytes, particularly plasmablasts, might be relevant for fibrogenesis in patients with other fibroinflammatory disorders and for wound-healing processes in physiologic conditions.

11.
Mol Genet Genomic Med ; 7(6): e686, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30993913

RESUMO

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

12.
Sci Immunol ; 4(34)2019 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-30952807

RESUMO

T cells that target ß-synuclein induce damage to the gray matter of the brain in multiple sclerosis and contribute to neurodegeneration.

13.
Glycobiology ; 29(3): 222-228, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30597004

RESUMO

We used Casd1-deficient mice to confirm that this enzyme is responsible for 9-O-acetylation of sialic acids in vivo. We observed a complete loss of 9-O-acetylation of sialic acid on the surface of myeloid, erythroid and CD4+ T cells in Casd1-deficient mice. Although 9-O-acetylation of sialic acids on multiple hematopoietic lineages was lost, there were no obvious defects in hematopoiesis. Interestingly, erythrocytes from Casd1-deficient mice also lost reactivity to TER-119, a rat monoclonal antibody that is widely used to mark the murine erythroid lineage. The sialic acid glyco-epitope recognized by TER-119 on erythrocytes was sensitive to the sialic acid O-acetyl esterase activity of the hemagglutinin-esterase from bovine coronavirus but not to the corresponding enzyme from the influenza C virus. During erythrocyte development, TER-119+ Ery-A and Ery-B cells could be stained by catalytically inactive bovine coronavirus hemagglutinin-esterase but not by the inactive influenza C hemagglutinin-esterase, while TER-119+ Ery-C cells and mature erythrocytes were recognized by both virolectins. Although the structure of the sialoglycoconjugate recognized by TER-119 was not chemically demonstrated, its selective binding to virolectins suggests that it may be comprised of a 7,9-di-O-acetyl form of sialic acid. As erythrocytes mature, the surfaces of Ery-C cells and mature erythrocytes also acquire an additional distinct CASD1-dependent 9-O-acetyl sialic acid moiety that can be recognized by virolectins from both influenza C and bovine coronavirus.


Assuntos
Eritrócitos/química , Influenza Humana/imunologia , Influenzavirus C/imunologia , Ácido N-Acetilneuramínico/química , Acetilação , Animais , Linfócitos T CD4-Positivos/química , Linfócitos T CD4-Positivos/imunologia , Bovinos , Epitopos/química , Epitopos/imunologia , Eritrócitos/imunologia , Células Eritroides/química , Células Eritroides/imunologia , Hemaglutininas Virais/genética , Humanos , Influenza Humana/virologia , Influenzavirus C/enzimologia , Influenzavirus C/isolamento & purificação , Camundongos , Células Mieloides/química , Células Mieloides/imunologia , Ácido N-Acetilneuramínico/imunologia , Ratos , Proteínas Virais de Fusão/genética
14.
J Allergy Clin Immunol ; 143(2): 736-745.e6, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-29852256

RESUMO

BACKGROUND: The antigenic trigger that drives expansion of circulating plasmablasts and CD4+ cytotoxic T cells in patients with IgG4-related disease (IgG4-RD) is presently unknown. OBJECTIVE: We sought to sequence immunoglobulin genes from single-cell clones of dominantly expanded plasmablasts and generate recombinant human mAbs to identify relevant antigens in patients with IgG4-RD by using mass spectrometry. METHODS: Paired heavy and light chain cDNAs from dominant plasmablast clones were expressed as mAbs and used to purify antigens by using immunoaffinity chromatography. Affinity-purified antigens were identified by using mass spectrometry and validated by means of ELISA. Plasma levels of the antigen of interest were also determined by using ELISA. RESULTS: mAbs expressed from the 2 dominant plasmablast clones of a patient with multiorgan IgG4-RD stained human pancreatic tissue sections. Galectin-3 was identified as the antigen specifically recognized by both mAbs. Anti-galectin-3 autoantibody responses were predominantly of the IgG4 isotype (28% of the IgG4-RD cohort, P = .0001) and IgE isotype (11% of the IgG4-RD cohort, P = .009). No significant responses were seen from the IgG1, IgG2, or IgG3 isotypes. IgG4 anti-galectin-3 autoantibodies correlated with increased plasma galectin-3 levels (P = .001), lymphadenopathy (P = .04), total IgG level increase (P = .05), and IgG4 level increase (P = .03). CONCLUSION: Affinity chromatography using patient-derived mAbs identifies relevant autoantigens in patients with IgG4-RD. IgG4 galectin-3 autoantibodies are present in a subset of patients with IgG4-RD and correlate with galectin-3 plasma levels. The marked increases in levels of circulating IgG4 and IgE observed clinically are, at least in part, caused by the development of IgG4- and IgE-specific autoantibody responses.

15.
Sci Immunol ; 3(30)2018 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-30530729

RESUMO

Genomic biomarkers will help to elucidate which cancer patients will benefit from PD-1 blockade immunotherapy.

16.
Front Immunol ; 9: 2393, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30386341

RESUMO

The Mst1 and 2 cytosolic serine/threonine protein kinases are the mammalian orthologs of the Drosophila Hippo protein. Mst1 has been shown previously to participate in T-cell and B-cell trafficking and the migration of lymphocytes into secondary lymphoid organs in a cell intrinsic manner. We show here that the absence of Mst1 alone only modestly impacts B cell homing to lymph nodes. The absence of both Mst1 and 2 in hematopoietic cells results in relatively normal B cell development in the bone marrow and does not impact migration of immature B cells to the spleen. However, follicular B cells lacking both Mst1 and Mst2 mature in the splenic white pulp but are unable to recirculate to lymph nodes or to the bone marrow. These cells also cannot traffic efficiently to the splenic red pulp. The inability of late transitional and follicular B cells lacking Mst 1 and 2 to migrate to the red pulp explains their failure to differentiate into marginal zone B cell precursors and marginal zone B cells. Mst1 and Mst2 are therefore required for follicular B cells to acquire the ability to recirculate and also to migrate to the splenic red pulp in order to generate marginal zone B cells. In addition B-1 a B cell development is defective in the absence of Mst1.


Assuntos
Linfócitos B/citologia , Linfócitos B/metabolismo , Diferenciação Celular/genética , Movimento Celular/genética , Fator de Crescimento de Hepatócito/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Animais , Linfócitos B/imunologia , Biomarcadores , Imunofluorescência , Fator de Crescimento de Hepatócito/metabolismo , Imunofenotipagem , Ativação Linfocitária , Camundongos , Camundongos Knockout , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Baço/citologia , Baço/imunologia , Baço/metabolismo
17.
Front Immunol ; 9: 1975, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30258437

RESUMO

Broadly neutralizing antibodies (bnAbs) against HIV-1 are an effective means of preventing transmission. To better understand the mechanisms by which HIV-specific bnAbs naturally develop, we investigated blood and lymphoid tissue in pediatric infection, since potent bnAbs develop with greater frequency in children than adults. As in adults, the frequency of circulating effector T-follicular helper cells (TFH) in HIV infected, treatment naïve children correlates with neutralization breadth. However, major differences between children and adults were also observed both in circulation, and in a small number of tonsil samples. In children, TFH cells are significantly more abundant, both in blood and in lymphoid tissue germinal centers, than in adults. Second, HIV-specific TFH cells are more frequent in pediatric than in adult lymphoid tissue and secrete the signature cytokine IL-21, which HIV-infected adults do not. Third, the enrichment of IL-21-secreting HIV-specific TFH in pediatric lymphoid tissue is accompanied by increased TFH regulation via more abundant regulatory follicular T-cells and HIV-specific CXCR5+ CD8 T-cells compared to adults. The relationship between regulation and neutralization breadth is also observed in the pediatric PBMC samples and correlates with neutralization breadth. Matching neutralization data from lymphoid tissue samples is not available. However, the distinction between infected children and adults in the magnitude, quality and regulation of HIV-specific TFH responses is consistent with the superior ability of children to develop high-frequency, potent bnAbs. These findings suggest the possibility that the optimal timing for next generation vaccine strategies designed to induce high-frequency, potent bnAbs to prevent HIV infection in adults would be in childhood.


Assuntos
Envelhecimento/imunologia , Centro Germinativo/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Linfócitos T Reguladores/imunologia , Adulto , Fatores Etários , Envelhecimento/patologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Criança , Feminino , Centro Germinativo/patologia , Infecções por HIV/patologia , Humanos , Masculino , Linfócitos T Reguladores/patologia
18.
Sci Immunol ; 3(26)2018 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-30076284

RESUMO

CD8+ T cells formed early in life respond more rapidly to infection, and this appears to be the result of a pre-programmed effector-like chromatin landscape.


Assuntos
Linfócitos T CD8-Positivos , Linfócitos T Citotóxicos , Animais , Cromatina , Genes Controladores do Desenvolvimento , Camundongos , Camundongos Endogâmicos C57BL
19.
Life Sci Alliance ; 1(1)2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29984361

RESUMO

Distinct T follicular helper (TFH) subsets that influence specific class-switching events are assumed to exist, but the accumulation of isotype-specific TFH subsets in secondary lymphoid organs (SLOs) and tertiary lymphoid organs has not been hitherto demonstrated. IL-4-expressing TFH cells are surprisingly sparse in human SLOs. In contrast, in IgG4-related disease (IgG4-RD), a disorder characterized by polarized Ig class switching, most TFH cells in tertiary and SLOs make IL-4. Human IL-4+ TFH cells do not express GATA-3 but express nuclear BATF, and the transcriptomes of IL-4-secreting TFH cells differ from both PD1hi TFH cells that do not secrete IL-4 and IL-4-secreting non-TFH cells. Unlike IgG4-RD, IL-4+ TFH cells are rarely found in tertiary lymphoid organs in Sjögren's syndrome, a disorder in which IgG4 is not elevated. The proportion of CD4+IL-4+BATF+ T cells and CD4+IL-4+CXCR5+ T cells in IgG4-RD tissues correlates tightly with tissue IgG4 plasma cell numbers and plasma IgG4 levels in patients but not with the total plasma levels of other isotypes. These data describe a disease-related TFH subpopulation in human tertiary lymphoid organs and SLOs that is linked to IgG4 class switching.

20.
Sci Immunol ; 3(22)2018 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-29626173

RESUMO

Engineered cytokines are able to improve immunotherapy in mouse tumor models.


Assuntos
Interleucina-2 , Linfócitos T , Animais , Membrana Celular , Citocinas , Imunoterapia , Camundongos
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