RESUMO
Natural killer (NK) cells are innate lymphocytes capable to recognize and kill virus-infected and cancer cells. In the past years, the use of allogeneic NK cells as anti-cancer therapy gained interest due to their ability to induce graft-versus-cancer responses without causing graft-versus-host disease and multiple protocols have been developed to produce high numbers of activated NK cells. While the ability of these cells to mediate tumor kill has been extensively studied, less is known about their capacity to influence the activity of other immune cells that may contribute to a concerted anti-tumor response in the tumor microenvironment (TME). In this study, we analyzed how an allogeneic off-the-shelf cord blood stem cell-derived NK-cell product influenced the activation of dendritic cells (DC). Crosstalk between NK cells and healthy donor monocyte-derived DC (MoDC) resulted in the release of IFNγ and TNF, MoDC activation, and the release of the T-cell-recruiting chemokines CXCL9 and CXCL10. Moreover, in the presence of prostaglandin-E2, NK cell/MoDC crosstalk antagonized the detrimental effect of IL-10 on MoDC maturation leading to higher expression of multiple (co-)stimulatory markers. The NK cells also induced activation of conventional DC2 (cDC2) and CD8+ T cells, and the release of TNF, GM-CSF, and CXCL9/10 in peripheral blood mononuclear cells of patients with metastatic colorectal cancer. The activated phenotype of MoDC/cDC2 and the increased release of pro-inflammatory cytokines and T-cell-recruiting chemokines resulting from NK cell/DC crosstalk should contribute to a more inflamed TME and may thus enhance the efficacy of T-cell-based therapies.
RESUMO
BACKGROUND: Duodenal adenocarcinoma (DA) is a rare tumor for which survival data on adjuvant chemotherapy in patients after surgical treatment are unclear. This case-matched study in a nationwide cohort aims to investigate the benefit of adjuvant chemotherapy for patients with resectable DA on overall survival. METHODS: All patients diagnosed with DA and intestinal type periampullary adenocarcinoma (PVA) in the Netherlands between 2000 and 2015 were included (n = 1316). Patients with disease stages II and III who underwent resection and adjuvant chemotherapy were matched (1:2), based on identified covariates associated with OS, with patients who underwent surgery alone. Overall survival was compared using Kaplan-Meier estimates. RESULTS: The median OS was 49.9 months in patients who underwent curative resection (n = 649). Univariate and multivariate analysis showed a significant influence of age, lymph node involvement, and T- stage on survival. The group of patients receiving adjuvant treatment consisted of 43 patients and the non-adjuvant group of 83 case-matched patients. The median OS of the complete matched cohort (n = 126) was 26.9 months. No statistically significant survival benefit was found for the adjuvant group as compared to the group treated with surgery alone (median OS = 34.4 months and 23.0 months, p = 0.20). CONCLUSION: This population-based, case-matched analysis demonstrates no statistically significant survival benefit for adjuvant chemotherapy after curative resection in stages II and III patients. Future studies with specified treatment regimens as well as thorough stratification for prognostic factors will be required in order to more definitively determine the role of adjuvant therapy.
Assuntos
Adenocarcinoma , Neoplasias Duodenais , Humanos , Quimioterapia Adjuvante , Neoplasias Duodenais/tratamento farmacológico , Neoplasias Duodenais/cirurgia , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/cirurgia , Terapia Combinada , Linfonodos/patologia , Estudos Retrospectivos , Estadiamento de NeoplasiasRESUMO
BACKGROUND & AIMS: A low muscle mass before start of treatment and loss of muscle mass during chemotherapy is related to adverse outcomes in patients with cancer. In this randomized controlled trial, the effect of nutritional counseling on change in muscle mass and treatment outcome in patients with metastatic colorectal cancer during first-line chemotherapy was studied. METHODS: Patients scheduled for first-line chemotherapy (n = 107) were randomly assigned to individualized nutritional counseling by a dietitian (NC) or usual care (UC). NC was aimed at sufficient protein- and energy intake, supported by oral supplements or enteral feeding if indicated. Furthermore, physical activity was encouraged. Outcomes were assessed at baseline (T0) and the time of the first (T1) and second (T2) regular follow-up computed tomography scans. The proportion of patients with a clinically relevant decrease in skeletal muscle area of ≥6.0 cm2, measured by computed tomography, was the primary outcome. Secondary outcomes included body weight, quality of life, treatment toxicity and progression free and overall survival. RESULTS: A total of 107 patients were enrolled (mean age, 65 years (SD, 11 years), 63% male). Mean change in skeletal muscle area from T0 till T1 was -2.5 (SD, 9.5) cm2, with no difference between NC versus UC (p = 0.891). The proportion of patients with a clinically relevant decrease in skeletal muscle area of ≥6.0 cm2 did not differ (NC 30% versus UC 31%, p = 0.467). NC compared with UC had a significant positive effect on body weight (B coefficient 1.7, p = 0.045), progression free survival (p = 0.039) and overall survival (p = 0.046). CONCLUSIONS: NC of patients undergoing chemotherapy for metastatic colorectal cancer had no effect on muscle mass. However, we found that NC may increase body weight and improve progression free survival and overall survival compared to UC in this group of patients. These findings need further evaluation in future clinical trials. CLINICAL TRIAL INFORMATION: ClinicalTrials.gov NCT01998152; Netherlands Trial Register NTR4223.
Assuntos
Antineoplásicos/uso terapêutico , Composição Corporal , Neoplasias Colorretais/tratamento farmacológico , Aconselhamento , Músculo Esquelético/fisiopatologia , Apoio Nutricional , Sarcopenia/terapia , Idoso , Antineoplásicos/efeitos adversos , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/diagnóstico por imagem , Metástase Neoplásica , Países Baixos , Intervalo Livre de Progressão , Sarcopenia/diagnóstico , Sarcopenia/mortalidade , Sarcopenia/fisiopatologia , Método Simples-Cego , Fatores de Tempo , Tomografia Computadorizada por Raios X , Aumento de PesoRESUMO
Background: Objectives were to provide an overview and understand the strength of evidence and extent of potential biases and validity of claimed associations between body mass index (BMI) and risk of developing cancer. Methods: We carried out an umbrella review and comprehensively re-analyzed the data of dose-response meta-analyses on associations between BMI and risk of 20 specific cancers (bladder, brain, breast, colonic, rectal, endometrial, gallbladder, gastric, leukemia, liver, lung, melanoma, multiple myeloma, non-Hodgkins lymphoma, esophagus, ovarian, pancreatic, prostate, renal, thyroid) by adding big data or missed individual studies. Convincing evidence for an association was defined as a strong statistical significance in fixed-effects and random-effects meta-analyses at P < 0.001, 95% prediction interval (PI) excluded null, there was no large between-study heterogeneity and no small study effects. Suggestive evidence was defined as meeting the significance threshold for the random summary effects of P < 0.05, but 95% PI included the null. Weak evidence was defined as meeting the significance threshold for the random summary effects at a P < 0.05, but 95% PI included the null and there was large between-study heterogeneity or there were small study effects. Results: Convincing evidence for an association with BMI was detectable for six cancers (leukemia, multiple myeloma, pancreatic, endometrial, rectal, and renal cell carcinoma). Suggestive evidence was detectable for malignant melanoma, non-Hodgkins lymphoma, and esophageal adenocarcinoma. Weak evidence was detectable for brain and central nervous system tumors, breast, colon, gall bladder, lung, liver, ovarian, and thyroid cancer. No evidence was detectable for bladder, gastric, and prostate cancer. Conclusions: The association of increased BMI and cancer is heterogeneous across cancer types. Leukemia, multiple myeloma, pancreatic, endometrial, rectal, and renal cell carcinoma are convincingly associated with an increased BMI by dose-response meta-analyses.
Assuntos
Índice de Massa Corporal , Neoplasias/epidemiologia , Adulto , Feminino , Humanos , Masculino , Metanálise como Assunto , Estudos Observacionais como AssuntoRESUMO
BACKGROUND: Various errors in the design, conduct, and analysis of medical and public health research studies can produce false results and waste valuable resources. While systematic reviews and meta-analyses are arguably considered the most dependable source of evidence-based medicine, increasing numbers of studies are indicating that, on the contrary to the public's belief, many of these investigations are redundant, erroneous, and even biased. METHODS: Ninety-four meta-analyses on microRNA polymorphism and risk of cancer were extracted from Pubmed database on August 2016. Two investigators independently extracted data (i.e. number of studies, ethnicity, number of cases/controls, bias, etc.) from each meta-analysis. PROSPERO registration status and reference status were also recorded. RESULTS: Among the 217 microRNA gene-variant cancer associations reported by 94 published meta-analyses, 37% had overlapping results and were extracted from the exact identical case-control studies. However, not one meta-analysis was registered into PROSPERO. Thirty-one percent of the overlapping associations referenced a previous meta-analysis investigating the same association; although only 36% of these overlapping associations referenced earlier meta-analysis that had the same overlapping results. Seventy-four percent of these references were limited to mere citations. Twenty-six percent of the overlapping associations from 16 meta-analyses showed discordant results, and of these, 87% of the genotype comparisons were found significant, contrary to the initial reports of being non-significant. However, no association was noteworthy in regards to false positive rate probability calculations at a given prior probability of 0.001 and 0.000001 and statistical power to detect an odds ratio (OR) of 1.1 and 1.5. CONCLUSIONS: Genetic association meta-analyses were by far more redundant, erroneous, and lacking references than initially expected. Careful search of similar studies, attention to small details, and inclination to reference previous works are needed. This paper proposes potential solutions for these problems in hopes of standardizing research efforts and in improving the quality of medical research.
Assuntos
Estudo de Associação Genômica Ampla , MicroRNAs/genética , Neoplasias/genética , Humanos , Polimorfismo GenéticoRESUMO
Hepatic CD1d-restricted and natural killer T-cell populations are heterogeneous. Classical 'type 1' α-galactosylceramide-reactive CD1d-restricted T cells express 'invariant' TCRα ('iNKT'). iNKT dominating rodent liver are implicated in inflammation, including in hepatitis models. Low levels of iNKT are detected in human liver, decreased in subjects with chronic hepatitis C (CHC). However, high levels of human hepatic CD161(±) CD56(±) noninvariant pro-inflammatory CD1d-restricted 'type 2' T cells have been identified in vitro. Unlike rodents, healthy human hepatocytes only express trace and intracellular CD1d. Total hepatic CD1d appears to be increased in CHC and primary biliary cirrhosis. Direct ex vivo analysis of human intrahepatic lymphocytes (IHL), including matched ex vivo versus in vitro expanded IHL, demonstrated detectable noninvariant CD1d reactivity in substantial proportions of HCV-positive livers and significant fractions of HCV-negative livers. However, α-galactosylceramide-reactive iNKT were detected only relatively rarely. Liver CD1d-restricted IHL produced IFNγ, variable levels of IL-10 and modest levels of Th2 cytokines IL-4 and IL-13 ex vivo. In a novel FACS assay, a major fraction (10-20%) of hepatic T cells rapidly produced IFNγ and up-regulated activation marker CD69 in response to CD1d. As previously only shown with murine iNKT, noninvariant human CD1d-specific responses were also augmented by IL-12. Interestingly, CD1d was found selectively expressed on the surface of hepatocytes in CHC, but not those CHC subjects with history of alcohol usage or resolved CHC. In contrast to hepatic iNKT, noninvariant IFNγ-producing type 2 CD1d-reactive NKT cells are commonly detected in CHC, together with cognate ligand CD1d, implicating them in CHC liver damage.
Assuntos
Antígenos CD1d/análise , Hepatite C Crônica/imunologia , Hepatócitos/química , Fígado/imunologia , Linfócitos T/imunologia , Adulto , Idoso , Animais , Citocinas/metabolismo , Feminino , Hepatite C Crônica/patologia , Humanos , Fígado/patologia , Masculino , Camundongos , Pessoa de Meia-Idade , Linfócitos T/química , Adulto JovemRESUMO
A 47-year-old man, who presented with dyspnoea, gynaecomasty, and aphasia due to an extensively metastasized malignancy, was transferred to the hospital for chemotherapy as a matter of urgency. Because of his severe clinical symptoms, the widespread presence of metastases on radiological examination, and a striking increase in serum human chorionic gonadotrophin (HCG), the patient was treated with bleomycin, etoposide, and cisplatin (BEP) for a suspected metastasized germ-cell tumour. Definitive histology, however, revealed not a germ-cell tumour, but instead a large-cell undifferentiated HCG-producing carcinoma of uncertain primary origin. Using this patient's history, ectopic HCG production by malignancies is described in more detail.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma de Células Grandes/metabolismo , Gonadotropina Coriônica/sangue , Metástase Neoplásica/diagnóstico , Carcinoma de Células Grandes/diagnóstico , Carcinoma de Células Grandes/tratamento farmacológico , Carcinoma de Células Grandes/patologia , Diagnóstico Diferencial , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica/tratamento farmacológico , Metástase Neoplásica/patologiaAssuntos
Antimetabólitos Antineoplásicos/efeitos adversos , Desoxicitidina/análogos & derivados , Fluoruracila/análogos & derivados , Isquemia Miocárdica/induzido quimicamente , Capecitabina , Desoxicitidina/efeitos adversos , Fluoruracila/efeitos adversos , Humanos , Isquemia Miocárdica/prevenção & controle , Nitritos/uso terapêuticoRESUMO
Two female patients aged 88 and 82 who were being treated for constipation with lactulose, developed life-threatening dilatation of the bowel. Both underwent surgery. One of them was found to have cancer of the bowel; she had an uneventful postoperative recovery. No mechanical abnormalities were found in the second patient but she died due to respiratory insufficiency following aspiration. Lactulose is one of the most frequently prescribed laxatives. In the colon it is metabolized by bacteria into short-chain fatty acids, hydrogen and carbon dioxide. The resulting production of gas in the colon can contribute to a non-toxic megacolon, particularly in patients with delayed intestinal passage.
Assuntos
Colo/metabolismo , Fármacos Gastrointestinais/efeitos adversos , Lactulose/efeitos adversos , Megacolo/etiologia , Idoso , Idoso de 80 Anos ou mais , Dióxido de Carbono/metabolismo , Colo/microbiologia , Neoplasias do Colo/complicações , Constipação Intestinal/tratamento farmacológico , Evolução Fatal , Ácidos Graxos Voláteis/metabolismo , Feminino , Fármacos Gastrointestinais/metabolismo , Fármacos Gastrointestinais/uso terapêutico , Humanos , Hidrogênio/metabolismo , Lactulose/metabolismo , Lactulose/uso terapêutico , Megacolo/cirurgia , Pneumonia Aspirativa/complicações , Complicações Pós-Operatórias , Insuficiência Respiratória/etiologiaRESUMO
Certain strains of Escherichia coli have been shown to cause gas accumulation in--for example, emphysematous pyelonephritis. This paper describes a patient with intramyocardial air collections resulting from an intramyocardial infection with gas forming E coli.
Assuntos
Cardiomiopatias/microbiologia , Enfisema/microbiologia , Infecções por Escherichia coli/microbiologia , Escherichia coli/metabolismo , Cardiomiopatias/diagnóstico por imagem , Enfisema/diagnóstico por imagem , Infecções por Escherichia coli/diagnóstico por imagem , Evolução Fatal , Gangrena Gasosa/diagnóstico por imagem , Gangrena Gasosa/microbiologia , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios XRESUMO
Patients infected with HIV are at increased risk of developing lymphoma. The lymphomas often involve extranodal sites and +/-90% are of B-cell phenotype. We describe an HIV-infected patient with unilateral multiple cranial nerve dysfunction, most likely as a result of a nasopharyngeal B-cell non-Hodgkin's lymphoma in which early histologic confirmation of the diagnosis was delayed by the simultaneous presence of nasopharyngeal lymphatic tissue hypertrophy. It is of practical importance to recognize non-Hodgkin's lymphoma as a cause of cranial nerve dysfunction and to be aware of the possibility and the implications of the simultaneous presence of nasopharyngeal lymphatic tissue hypertrophy in HIV-infected patients.
Assuntos
Doenças dos Nervos Cranianos/etiologia , Infecções por HIV/complicações , Linfoma não Hodgkin/complicações , Neoplasias Nasofaríngeas/complicações , Neoplasias da Base do Crânio/complicações , Evolução Fatal , Feminino , Humanos , Linfoma não Hodgkin/diagnóstico , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Neoplasias Nasofaríngeas/diagnóstico , Neoplasias da Base do Crânio/diagnósticoRESUMO
Natural killer T (NKT) cells have been implicated as playing an important role in regulating immune responses. Defects in the NKT cell population were reported in animal autoimmune disease models and in distinct human autoimmune diseases. Here, we report that circulating V(alpha24+) Vbeta11+ NKT cell numbers are decreased in a broad variety of disorders with (auto)immune-mediated pathology, affecting the skin, bowel, central nervous system, and joints, regardless of disease duration or activity. Remarkably, normal circulating V(alpha24+) Vbeta11+ NKT cell numbers were found in Graves disease and coeliac disease. Since earlier studies noted a rise in NKT cells in myasthenia gravis, the picture emerges in which a defective NKT cell population is associated with autoreactive tissue damage rather than with the propensity to develop autoimmune disease. The present data support the idea that therapies aiming at the in vivo expansion of regulatory NKT cells might help to control immune-mediated damage in autoimmune disease.
Assuntos
Antígenos CD1/imunologia , Células Matadoras Naturais/imunologia , Doença , Humanos , Imunidade , Região Variável de Imunoglobulina , Contagem de Linfócitos , Receptores de Antígenos de Linfócitos T alfa-beta/imunologiaRESUMO
Natural killer T (NKT) cells have recently been shown to play an important role in the rejection of malignant tumors and in the regulation of autoimmune diseases. Potent antitumor effects of the marine sponge-derived NKT cell ligand KRN7000 were observed in mice. Therefore, the elucidation of the natural ligand of NKT cells, which is currently still unknown, might have important clinical consequences for the treatment of cancer and autoimmune diseases. Analysis of cord blood mononuclear cells from healthy term infants demonstrated that in sharp contrast with the vast majority of cord blood lymphocytes, human NKT cells have already acquired a memory-activated phenotype before birth. This observation indicates that NKT cells encounter a natural ligand during fetal life and that this ligand is unlikely to be of microbial origin.
Assuntos
Sangue Fetal/citologia , Memória Imunológica , Células Matadoras Naturais/imunologia , Fenótipo , Adulto , Feminino , Humanos , Imunofenotipagem , Recém-Nascido , Selectina L/análise , Antígenos Comuns de Leucócito/análise , Masculino , Receptores de Interleucina-2/análiseRESUMO
KRN7000, (2S, 3S, 4R)-1-O-(alpha-D-galactopyranosyl)-2-(N-hexacosanoylamino)-1, 3, 4-octadecanetriol, has been shown to prevent tumor metastasis to the liver through the activation of natural killer (NK) T cells in mice. In this study, the proliferation of human NK T cells, which express an invariant T cell antigen receptor (TCR) consisting of a Valpha24 chain and a Vbeta11 chain, was investigated using KRN7000, interleukin (IL)-15, IL-7, and IL-2 in vitro. KRN7000 stimulated the expansion of Valpha24(+)Vbeta11(+) T cells derived from peripheral blood mononuclear cells in a dose-dependent fashion, with some fluctuation between donors. IL-15, IL-7, and IL-2 synergistically stimulated the expansion of Valpha24(+)Vbeta11(+) T cells when combined with KRN7000. Intracellular expression of interferon (IFN)-gamma and IL-4 in Valpha24(+)Vbeta11(+) T cells expanded in the presence of KRN7000 was identified using flow cytometry. Valpha24(+)Vbeta11(+) T cells, expanded in the presence of KRN7000, contained granzyme (Gr) B-positive granules and perforin-positive granules. The addition of IL-15 to the culture containing KRN7000 increased GrB expression in Valpha24(+)Vbeta11(+) T cells while IL-7 and IL-2 failed to do it. In conclusion, the antitumor effect of KRN7000 may depend, in part, on granule-mediated cell killing through the activation of NK T cells and IL-15 may potentiate this effect.
Assuntos
Adjuvantes Imunológicos/farmacologia , Galactosilceramidas/farmacologia , Interleucinas/fisiologia , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/biossíntese , Subpopulações de Linfócitos T/efeitos dos fármacos , Subpopulações de Linfócitos T/imunologia , Células Cultivadas , Sinergismo Farmacológico , Galactosilceramidas/imunologia , Granzimas , Humanos , Interferon gama/biossíntese , Interleucina-15/fisiologia , Interleucina-2/fisiologia , Interleucina-4/biossíntese , Interleucina-7/fisiologia , Células Matadoras Naturais/imunologia , Glicoproteínas de Membrana/biossíntese , Perforina , Proteínas Citotóxicas Formadoras de Poros , Serina Endopeptidases/biossíntese , Subpopulações de Linfócitos T/metabolismoRESUMO
All-trans-retinoic acid (ATRA) induces complete clinical remissions in a high proportion of patients with acute promyelocytic leukemia and has become the standard induction therapy. Its use as a single agent results in short-lived remissions; thus, cytotoxic drugs are used for "consolidation" therapy. Side effects reported during treatment with ATRA include retinoic acid syndrome and Sweet's syndrome. Sweet's syndrome has been associated with acute myelogenous leukemia at presentation, but only two cases of Sweet's syndrome involving the musculoskeletal system in patients treated with ATRA have been described. We describe two additional patients with acute promyelocytic leukemia who had unexplained fever and myalgias (cutaneous lesions in one patient) during induction therapy with ATRA. Radiologic findings were similar to those in previously reported ATRA-associated Sweet's syndrome of the musculoskeletal system. The clinical course was characterized by a rapid resolution of the symptoms during treatment with dexamethasone. Recognition of the syndrome is important, especially considering the rapid resolution of symptoms after early institution of therapy with corticosteroids.
Assuntos
Miosite/induzido quimicamente , Tretinoína/efeitos adversos , Adulto , Dexametasona/uso terapêutico , Feminino , Febre/etiologia , Humanos , Leucemia Promielocítica Aguda/tratamento farmacológico , Imageamento por Ressonância Magnética , Masculino , Músculo Esquelético/efeitos dos fármacos , Miosite/diagnóstico , Síndrome de Sweet/tratamento farmacológico , Síndrome de Sweet/etiologiaRESUMO
The alpha-galactosylceramide KRN7000 was reported to be presented by CD1d to natural killer (NK) T cells, cells that are thought to play an important role in the rejection of malignant tumours and in the regulation of several autoimmune diseases. Here we analysed human peripheral blood (PB) NK T cells (Valpha24+ Vbeta11+ T cells) before and after a short-term culture in the presence of KRN7000. KRN7000 strongly activated PB Valpha24+ Vbeta11+ T cells and, when stimulated, the vast majority of these cells expressed interferon-gamma (IFN-gamma). Exposure of these KRN7000-cultured Valpha24+ Vbeta11+ T cells to interleukin-12 (IL-12), but not to IL-7, resulted in a relative increase in IFN-gamma-expressing Valpha24+ Vbeta11+ T cells, compared with IL-4-expressing Valpha24+ Vbeta11+ T cells, indicating a shift towards a T-helper type 1 (Th1) phenotype. KRN7000 strongly up-regulated the expression of the cytotoxic molecule granzyme B (GrB) in Valpha24+ Vbeta11+ T cells. Although IL-7 resulted in a decrease in GrB levels in KRN7000-cultured Valpha24+ Vbeta11+ T cells, IL-12 increased GrB levels in both Valpha24+ Vbeta11+ T cells and in Valpha24+ Vbeta11+ T-cell clones and increased cytotoxicity against hCD1d-transfected HeLa cells. Our data provide further insight into the characteristics of human Valpha24+ Vbeta11+ T cells and indicate that KRN7000 is a potent activator of Valpha24+ Vbeta11+ T cells. Combined with the established anti-tumour effects of KRN7000 in mouse models, these results may support the use of KRN7000 as an anti-tumour agent in man.
Assuntos
Antineoplásicos/farmacologia , Citocinas/farmacologia , Galactosilceramidas/farmacologia , Interferon gama/imunologia , Células Matadoras Naturais/imunologia , Ativação Linfocitária , Adulto , Calcimicina/farmacologia , Células Cultivadas , Células Clonais , Feminino , Citometria de Fluxo , Granzimas , Humanos , Interleucina-12/farmacologia , Interleucina-4/imunologia , Interleucina-7/farmacologia , Ionóforos/farmacologia , Células Matadoras Naturais/metabolismo , Masculino , Serina Endopeptidases/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Células Th1/imunologiaRESUMO
CD8+ T cells employ granzyme B (GrB) to induce apoptosis in target cells. Increased expression of GrB has been put forward as a diagnostic marker in transplant rejection and viral infection. Three-color flow cytometric analysis revealed that peripheral blood CD8+ T lymphocytosis during primary cytomegalovirus infection after renal transplantation resulted from expansion of a CD8+GrB+CD62L+ T cell subset that was almost absent during stable transplant function or acute rejection. This expansion coincided with a temporary increase in systemic soluble GrB (sGrB) levels. No such increase was observed during stable transplant function or acute rejection. Thus, the primary immune response to cytomegalovirus infection is accompanied by appearance of CD8+GrB+CD62L+ T cells and increased sGrB levels in the peripheral blood compartment. Determination of the latter may provide a novel approach for monitoring viral infections.
Assuntos
Linfócitos T CD8-Positivos/enzimologia , Infecções por Citomegalovirus/imunologia , Transplante de Rim , Complicações Pós-Operatórias , Serina Endopeptidases/sangue , Adolescente , Adulto , Linfócitos T CD8-Positivos/imunologia , Criança , Infecções por Citomegalovirus/sangue , Infecções por Citomegalovirus/enzimologia , Feminino , Citometria de Fluxo , Granzimas , Humanos , Selectina L/sangue , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Serina Endopeptidases/biossínteseRESUMO
Granzyme B (GrB) has been implicated in induction of apoptosis in target cells. The presence of GrB in peripheral blood CD8+ T cells from healthy individuals was analysed in immunocytochemical and flow cytometric studies. Furthermore, CD8+ GrB- T cells and CD8+ GrB+ T cells were compared regarding phenotypical characteristics and susceptibility to both spontaneous and Fasmediated apoptosis. GrB was expressed by approximately one-fifth of CD8+ T cells. Compared with the CD8+ GrB- T-cell subset, the CD8+ GrB+ T-cell subset contained cells that were relatively more activated and more prone to spontaneous apoptosis. Culturing of cells with immunoglobulin M (IgM) anti-Fas monoclonal antibody had no additional effect on the number of CD8+ GrB+ T cells undergoing apoptosis. We suggest that the presence of CD8+ GrB+ T cells in peripheral blood from healthy individuals results from immune surveillance or contact with infectious agents, and that spontaneous apoptosis of these cells might serve as a mechanism for their eventual clearance.
Assuntos
Apoptose/fisiologia , Linfócitos T CD8-Positivos/enzimologia , Ativação Linfocitária , Subpopulações de Linfócitos/imunologia , Serina Endopeptidases/análise , Anticorpos Monoclonais/farmacologia , Apoptose/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Células Cultivadas , Citometria de Fluxo , Granzimas , Humanos , Imuno-Histoquímica , Receptor fas/imunologiaRESUMO
Neutrophils have the shortest half-life among circulating leucocytes and rapidly undergo apoptosis in vitro. The homologous Bcl-2 and Bax proteins have opposing effects, with Bcl-2 extending cellular survival and Bax promoting cell death following an apoptotic stimulus. We determined Bcl-2 to Bax expression ratios in peripheral blood lymphocytes, monocytes and granulocytes and related them to the susceptibility of these cells to anti-Fas (anti-CD95)-induced apoptosis. Here, we show that Bax/Bcl-2 ratios are high in granulocytes and relatively low in monocytes and lymphocytes. Furthermore, we show a relation between this ratio in the different leucocyte subsets and their susceptibility to anti-Fas-induced apoptosis, with granulocytes showing the highest susceptibility, followed by monocytes and lymphocytes. It is concluded that the balance between Bcl-2 and Bax forms an apoptotic rheostat, which seems to determine sensitivity to apoptosis.