RESUMO
Cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) molecule is expressed on T-lymphocyte membrane and negatively influences the antigen-presenting process. Reduced expression of CTLA-4 due to gene polymorphisms is associated with increased risk of autoimmune disorders, whose physiopathology is similar to that of post-transfusion red blood cell (RBC) alloimmunization. Our goal was to evaluate if polymorphisms of CTLA-4 gene that affect protein expression are associated with RBC alloimmunization. This was a case-control study in which 134 sickle cell disease (SCD) patients and 253 non-SCD patients were included. All patients were genotyped for the polymorphisms 49A/G and -318C/T of CTLA-4 gene. The genotype frequency of -318C/T differed significantly between alloimmunized and nonalloimmunized SCD patients, irrespective of clinical confounders (p = .016). SCD patients heterozygous for -318T allele presented higher risk of alloantibody development (OR: 5.4, CI: 1.15-25.6). In conclusion, the polymorphism -318C/T of CTLA-4 gene is associated with RBC alloimmunization among SCD patients. This highlights the role played by CTLA-4 on post-transfusion alloantibody development.
Assuntos
Anemia Falciforme/genética , Doenças Autoimunes/genética , Antígeno CTLA-4/genética , Eritrócitos/imunologia , Adulto , Anemia Falciforme/sangue , Anemia Falciforme/imunologia , Anemia Falciforme/prevenção & controle , Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/patologia , Doenças Autoimunes/sangue , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Antígeno CTLA-4/imunologia , Eritrócitos/patologia , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Imunização/efeitos adversos , Isoanticorpos/imunologia , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genética , Fatores de Risco , Linfócitos T/imunologia , Linfócitos T/patologiaRESUMO
BACKGROUND: The valuable role of immunotherapy in treating autoimmune diseases is increasingly recognized by those involved in the research and clinical application of new biopharmaceuticals products. However, many aspects related to the mechanisms of immune-modulated therapies remain to be elucidated in order to explore fully the emerging opportunities. The non-obese diabetic NOD mouse develops insulin-dependent diabetes mellitus spontaneously as a consequence of an autoimmune process in the presence of pathogenic CD4(+) T cells that typically exhibit Th17 cell phenotypes. The change of a Th17 phenotype into a pattern of regulatory T cells (Treg) is extremely important in controlling autoimmune diseases. Heat shock proteins (HSPs) are stress-induced proteins with immunoregulatory properties. In the current study, the capacity of Hsp65 and Hsp70 mycobacterial HSPs and a constructed DNA encoded Hsp65 (DNAhsp65) to transform the pattern of the immune response from Th17 into Treg cells has been studied in vitro using co-cultures of antigen presenting cells (APCs) and T cells in NOD mice. RESULTS: Cells harvested from NOD mice and cultured for 48 h (without immunoregulatory compounds) presented with Th1/Th17 patterns and secretions of IL-6, IFN-γ, IL-10 and IL-17 cytokines. The cultured cells from the non-diabetic BALB/C mice exhibited a Th1 pattern and the production of IL 6 and IFN-γ secretions. An up-regulation was observed in the supernatants from the co-cultures of NOD cells that were stimulated with DNAhsp65, Hsp65 or Hsp70 through increased levels of IL-10 secretion and the suppression of IL-6, IFN-γ and IL-17 production. In addition, immunoregulation was demonstrated through IL-17 suppression in the co-culture stimulated by the specific insulin antigen. Moreover, an increase of immunoregulatory compounds were observed in the co-culture through the expression of CD11b(+)CD86(+) activation markers on APCs, as well as the frequency of Treg cells expressing CD4(+)CD3(+) and CD4(+)CD25(hi). CONCLUSIONS: The in vitro observation of Th17 cells differentiating into Tregs in NOD mice could raise the hypothesis that the immune regulatory activity of HSPs could be an efficient strategy for diabetes prevention and treatment.
Assuntos
Células Apresentadoras de Antígenos/efeitos dos fármacos , Células Apresentadoras de Antígenos/imunologia , Diabetes Mellitus/tratamento farmacológico , Avaliação Pré-Clínica de Medicamentos/métodos , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Animais , Células Apresentadoras de Antígenos/patologia , Bioensaio/métodos , Células Cultivadas , Técnicas de Cocultura/métodos , Diabetes Mellitus/patologia , Relação Dose-Resposta a Droga , Feminino , Hipoglicemiantes/administração & dosagem , Fatores Imunológicos/administração & dosagem , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Avaliação de Resultados em Cuidados de Saúde/métodos , Linfócitos T Reguladores/patologiaRESUMO
Probiotics are live micro-organisms that when administered in adequate amounts confer a health benefit on the host. Cell surface molecules of these micro-organisms are being studied in relation to their ability to interact with the host. The cell wall of lactobacilli possesses lipoteichoic acids (LTA) which are molecules with immunomodulatory properties. UV radiation (UVR) has been proposed as the main cause of skin cancer because of its mutagenic and immunosuppressive effects. Photoprotection with some nutrition interventions including probiotics has recently been shown. The aim of the present study was to investigate whether the oral administration of purified LTA from Lactobacillus rhamnosus GG can modulate the immune-suppressive effect of UVR and skin tumour development in female Crl:SKH-1-hrBR mice. For this purpose, two irradiation models were studied: (1) a chronic irradiation scheme consisting of daily irradiations during twenty consecutive days and (2) a long-term irradiation schedule, irradiating the animals three times per week, during 34 weeks for tumour development. The results showed that T-cells in the inguinal lymph node of LTA-treated mice produced higher levels of (1) interferon-γ and (2) a number of total, helper and cytotoxic T-cells compared with non-treated mice. Moreover, a significant delay in tumour appearance was found in LTA-treated mice. An increased IgA⺠cell number was found in the small intestine together with a higher number of activated dendritic cells in the mesenteric lymph nodes. The latter results might be indicative of a direct effect of LTA in the gut, affecting the cutaneous immune system and restoring homeostasis through the gut-skin axis.
Assuntos
Anticarcinógenos/uso terapêutico , Intestino Delgado/imunologia , Lipopolissacarídeos/uso terapêutico , Neoplasias Induzidas por Radiação/prevenção & controle , Neoplasias Cutâneas/prevenção & controle , Pele/imunologia , Ácidos Teicoicos/uso terapêutico , Raios Ultravioleta/efeitos adversos , Animais , Anticarcinógenos/efeitos adversos , Anticarcinógenos/isolamento & purificação , Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/metabolismo , Células Apresentadoras de Antígenos/patologia , Células Apresentadoras de Antígenos/efeitos da radiação , Apoptose/efeitos da radiação , Carcinogênese/imunologia , Carcinogênese/metabolismo , Carcinogênese/patologia , Carcinogênese/efeitos da radiação , Células Cultivadas , Suplementos Nutricionais/efeitos adversos , Feminino , Imunomodulação/efeitos da radiação , Intestino Delgado/patologia , Intestino Delgado/efeitos da radiação , Lacticaseibacillus rhamnosus/imunologia , Lacticaseibacillus rhamnosus/metabolismo , Lipopolissacarídeos/efeitos adversos , Lipopolissacarídeos/isolamento & purificação , Linfonodos/imunologia , Linfonodos/metabolismo , Linfonodos/patologia , Linfonodos/efeitos da radiação , Camundongos , Camundongos Pelados , Neoplasias Induzidas por Radiação/imunologia , Neoplasias Induzidas por Radiação/metabolismo , Neoplasias Induzidas por Radiação/patologia , Probióticos/efeitos adversos , Probióticos/metabolismo , Probióticos/uso terapêutico , Pele/metabolismo , Pele/patologia , Pele/efeitos da radiação , Neoplasias Cutâneas/etiologia , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/patologia , Baço/imunologia , Baço/metabolismo , Baço/patologia , Baço/efeitos da radiação , Ácidos Teicoicos/efeitos adversos , Ácidos Teicoicos/isolamento & purificação , Carga Tumoral/efeitos da radiaçãoRESUMO
The intestinal mucosa is exposed to a vast antigenic contact. Several antigen presenting cell (APCs) have been described within the gut associated lymphoid tissue (GALT) (Peyer's patches, lamina propria, mesenteric lymph nodes, muscular layer); however, this has been done almost exclusively in adult organisms. As there is no characterization of intestinal muscular layer's APCs during early neonate development we adapted the conventional technique used in adults, to the neonate intestine. We obtained the intestinal muscular layer from early neonates (days 0-3 upon birth) and from young mice (2 and 3 weeks after birth). A planar network of CD45(+), MHC-II(+), DEC-205(+) cells with irregular, some with prominent dendritic morphology was found at birth under basal physiological conditions, whereas Langerin(+) DCs appeared after two weeks. The variations seen in CD45(+), MHC-II(+) and DEC-205(+) cells along the early neonatal development, could be related to the new challenges by intestinal antigen exposure from the newborn diet (breast milk, solid food), and to important environmental changes (start walking, exploring the surroundings, etc). Our study reveals the presence of APCs in intestinal muscular layer at birth, and their subsequent changes in physiological, non-induced conditions, contributing basic information about these cells in the neonate intestinal immune system.
Assuntos
Células Apresentadoras de Antígenos/metabolismo , Biomarcadores/metabolismo , Mucosa Intestinal/imunologia , Intestino Delgado/patologia , Adulto , Animais , Animais Recém-Nascidos , Células Apresentadoras de Antígenos/patologia , Antígenos CD/metabolismo , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Imuno-Histoquímica , Mucosa Intestinal/patologia , Lectinas Tipo C/metabolismo , Antígenos Comuns de Leucócito/metabolismo , Lectinas de Ligação a Manose/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Antígenos de Histocompatibilidade Menor , Músculos/patologia , Receptores de Superfície Celular/metabolismoRESUMO
BACKGROUND: Melanin and melanophages are commonly seen under the basement membrane zone of the skin in patients affected by a new variant of endemic pemphigus foliaceus in El Bagre, Colombia (El Bagre-EPF). OBJECTIVE: Our study was conducted to determine the nature of these pigmentary alterations. METHODS: We utilized clinical, histopathologic and immunologic techniques including direct and indirect immunofluorescence, immunohistochemistry, Bielschowsky staining and immunoelectron microscopy studies. RESULTS: In the El Bagre-EPF patients, we detected dermal melanin in melanophages and antigen-presenting cells, in close proximity to neural and vascular markers. The melanophages consisted of a mixed population expressing CD68, myeloid/histoid antigen and S-100 protein. By immunoelectron microscopy, the presence of autoantibodies in proximity to melanin granules was confirmed within the melanocytes utilizing 10-nm gold particles. CONCLUSION: Dermal antigen-presenting cells, including melanophages, seem to contain a diverse combination of molecules, representative of an immunologic process where these cells are engulfing both autoantigens and/or cellular debris in El Bagre-EPF. Autoantibodies to discrete components of melanocytes were also identified; the clinical and immunologic significance of these findings remains unknown. Our work may provide a possible explanation of a darkened complexion in patients affected by endemic pemphigus foliaceus.
Assuntos
Autoanticorpos/imunologia , Membrana Basal/imunologia , Membrana Basal/ultraestrutura , Melaninas/imunologia , Melanócitos/imunologia , Melanócitos/ultraestrutura , Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/patologia , Antígenos CD/imunologia , Antígenos de Diferenciação Mielomonocítica/imunologia , Colômbia , Derme/imunologia , Derme/patologia , Doenças Endêmicas , Feminino , Humanos , Masculino , Pênfigo , Proteínas S100/imunologiaRESUMO
The gut associated lymphoid tissue (GALT) is anatomical and functionally divided in inductive and effectors sites. In previous works we demonstrated that non-pathogenic bacteria with probiotic characteristics can improve the gut mucosal immune system, with an increase in the number of IgA and cytokines producing cells in the effector site of the intestine. In the present work we studied the effect of non-pathogenic Gram(+), Gram(-) bacteria and a Gram(+) probiotic strain on the inductor site (PP) after the oral administration to BALB/c mice. We also studied some signals induced by the assayed strain in the effectors site, such as the enzyme calcineurin and TLR-9 as a way to understand the mechanisms induced in such bacterial stimulation. The implicance of the lipoteichoic acid (LTA) in the immunostimulation was analyzed. All strains increased the number of IFN-gamma and TNF-alpha(+) cells, but not of IL-10(+) cells in the total population of PP. The release of IFN-gamma and TNF-alpha was only induced by LPS stimulation. All assayed strains increased the number of calcineurin(+) cells, while only Gram(+) strains increased the number of TLR-9(+) cells. The immunostimulatory properties of the purified LTA from Gram(+) strains was evaluated on a monocyte-macrophage U937 cell line. These cells showed capacity to release TNF-alpha and IL-10 in response to all LTA assayed in a dose-dependent way. Gram(+) strains induced signals through the calcineurin enzyme able to activate the transcriptional factor NFAT and through TLR-9. The LTA molecule from Gram(+) strains would not be the only structure involved in the immunostimulatory properties observed, specially for the probiotic strain.
Assuntos
Células Apresentadoras de Antígenos/metabolismo , Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/imunologia , Bactérias Gram-Positivas/imunologia , Infecções por Bactérias Gram-Positivas/imunologia , Imunidade nas Mucosas , Transdução de Sinais , Animais , Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/microbiologia , Células Apresentadoras de Antígenos/patologia , Calcineurina/metabolismo , Bactérias Gram-Negativas/patogenicidade , Infecções por Bactérias Gram-Negativas/genética , Infecções por Bactérias Gram-Negativas/metabolismo , Infecções por Bactérias Gram-Negativas/patologia , Bactérias Gram-Positivas/patogenicidade , Infecções por Bactérias Gram-Positivas/genética , Infecções por Bactérias Gram-Positivas/metabolismo , Infecções por Bactérias Gram-Positivas/patologia , Humanos , Imunização , Imunoglobulina A/biossíntese , Imunoglobulina A/genética , Imunoglobulina A/imunologia , Interferon gama/genética , Interferon gama/imunologia , Interferon gama/metabolismo , Interleucina-10/genética , Interleucina-10/imunologia , Interleucina-10/metabolismo , Mucosa Intestinal/patologia , Lipopolissacarídeos/imunologia , Lipopolissacarídeos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Probióticos/administração & dosagem , Ácidos Teicoicos/imunologia , Ácidos Teicoicos/metabolismo , Receptor Toll-Like 9/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia , Fator de Necrose Tumoral alfa/metabolismo , Células U937RESUMO
An immunoperoxidase technique was used to compare the number of CD1a+ and factor XIIIa+ dendritic cells (DCs), and CD68+ Macrophages (M) in 30 gingival samples from subjects with clinically healthy periodontitium (HP) and 10 samples from subjects with drug-induced gingival enlargement (DIGE). Fewer CD1a+ and factor XIIIa+ DCs were found in areas with inflammatory infiltration (II) of the lamina propria (LP) in the group with immunosuppressed DIGE (IDIGE) compared to the group with HP. In the sulcular and junctional/pocket epithelia, the number of CD1a+ DCs was decreased in the group with IDIGE (p<0.05). There was a tendency toward a reduced number of CD1a+ DCs and CD68+ M in areas without inflammatory infiltrate of the LP in the group with IDIGE. The alterations in the number of antigen-presenting cells (APCs) may be the reason for the decreased periodontal inflammation and breakdown clinically observed in subjects who are immunosuppressed.