RESUMO
Purpose: Recent evidence presented the important role of microRNAs in health and disease particularly in human cancers. Among those, miR-193 family contributes as a tumor suppressor in different benign and malignant cancers like breast cancer (BC) via interaction with specific targets. On the other hand, it was stated that miR-193 is able to modulate some targets in chemoresistant cancer cells. Therefore, the aim of this study was to evaluate the potential function of miR-193a-5p and paclitaxel in the apoptosis induction by targeting P53 in BC cells. Methods: At first, miR-193a-5p mimics were transfected to MDA-MB-231 BC cell line which indicated the lower expression level of miR-193a-5p. Subsequently, the transfected cells were treated with paclitaxel. Then, cell viability, apoptosis, and migration were evaluated by MTT, flow cytometry and DAPI staining, and scratch-wound motility assays, respectively. Moreover, the expression levels of P53 was evaluated by qRT-PCR. Results: The expression level of miR-193a-5p was restored in MDA-MB-231 cells which profoundly inhibited the proliferation (P<0.0001), induced apoptosis (P <0.0001) and harnessed migration (P <0.0001) in the BC cells and more effectiveness was observed in combination with paclitaxel. Interestingly, increased miR-193a-5p expression led to a reduction in P53 mRNA, offering that it can be a potential target of miR-193a. Conclusion: Taken together, it is concluded that the combination of miR-193a-5p restoration and paclitaxel could be potentially considered as an effective therapeutic strategy to get over chemoresistance during paclitaxel chemotherapy.
RESUMO
MicroRNAs (miRNAs) are proposed as a family of short noncoding molecules able to manage and control the expression of the gene targets at the posttranscriptional level. They contribute in several fundamental physiological mechanisms as well as a verity of human and animal diseases such as cancer progression. Among these tiny RNAs, miR-451 placed on chromosome 17 at 17q11.2 presents an essential role in many biological processes in health condition and also in pathogenesis of different diseases. Besides, it has been recently considered as a valuable biomarker for cancer detection, prognosis and treatment. Therefore, this review will provide the critical functions of miR-451 on biological mechanisms including cell cycle and proliferation, cell survival and apoptosis, differentiation and development as well as disease initiation and progression such as tumor formation, migration, invasion, and metastasis.
Assuntos
Biomarcadores Tumorais/genética , Regulação Neoplásica da Expressão Gênica/genética , MicroRNAs/genética , Neoplasias/patologia , Animais , Ciclo Celular/genética , Proliferação de Células/genética , Humanos , Neoplasias/genéticaRESUMO
miR-143 is a tumor suppressor miRNA which its downregulation is frequently reported in colorectal cancer (CRC). This miRNA is a negative regulator of K-RAS, c-MYC, BCL-2, and MMP-9 genes which are engaged in tumor growth and metastasis. In the present study, miR-143 restoration was performed by transfection of the pCMV-miR-143 vector into the SW-480 CRC cells. Subsequently, alterations in proliferative and migratory potential of the cells were investigated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and wound-healing assays, respectively. Moreover, to detect apoptosis incidence in the transfected cells, 4',6-diamidino-2-phenylindole (DAPI) staining was used. Furthermore, mRNA levels of c-MYC, K-RAS, MMP-9, and BCL-2, as potential targets of miR-143, were assessed by quantitative Real-Time PCR (qRT-PCR). Also the expression levels of c-MYC, K-RAS, and MMP-9 proteins were investigated by the western blot analysis. Finally, the ratio of BAX to BCL-2 expression, as a potential marker of the response to apoptosis stimuli, was compared between the control and test groups. Furthermore, the trypan blue test was performed to determine the cell viability in cell suspension. According to the results, a decreased viability and migratory potential was observed for the miR-143 receiving cells. The DAPI staining also confirmed the occurrence of apoptosis. Moreover, BCL-2, K-RAS, MMP-9, and c-MYC mRNAs were significantly downregulated in the miR-143 grafted cells. The BAX/BCL-2 ratio also indicated a notable increase in the cells with miR-143 overexpression. In brief, miR-143 replacement could be considered as an effective strategy for the management of CRC and attenuating its invasive features.
Assuntos
Movimento Celular/genética , Proliferação de Células/genética , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica/genética , MicroRNAs/metabolismo , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , HumanosRESUMO
Phosphatidylinositol 3-kinases (PI3Ks) are crucial coordinators of intracellular signalling in response to the extracellular stimulators. Hyperactivation of PI3K signalling cascades is one among the most ordinary events in human cancers. Focusing on the PI3K pathway remains both a chance and a challenge for cancer therapy. The high recurrence of phosphoinositide 3-kinase (PI3K) pathway adjustments in cancer has led to a surge in the progression of PI3K inhibitors. Recent developments incorporate a re-assessment of the oncogenic mechanisms behind PI3K pathway modifications. Receptor tyrosine kinases upstream of PI3K, the p110a catalytic fractional unit of PI3K, the downstream kinase, AKT, and therefore the negative regulator, PTEN, are all often altered in cancer. In this review, we consider about the phosphoinositide 3-kinases family and mechanisms of PI3K-Akt stimulation in cancer.
Assuntos
Neoplasias/metabolismo , Fosfatidilinositol 3-Quinases/fisiologia , Proteínas Proto-Oncogênicas c-akt/fisiologia , Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Humanos , Recidiva Local de Neoplasia/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Inibidores de Proteínas Quinases/metabolismo , Receptores Proteína Tirosina Quinases/fisiologia , Transdução de Sinais/fisiologia , Serina-Treonina Quinases TOR/fisiologiaRESUMO
microRNAs (miRNAs) are known as a large group of short noncoding RNAs, which structurally consist of 19-22 nucleotides in length and functionally act as one of the main regulators of gene expression in important biological and physiological contexts like cell growth, apoptosis, proliferation, differentiation, movement (cell motility), and angiogenesis as well as disease formation and progression importantly in cancer cell invasion, migration, and metastasis. Among these notable tiny molecules, many studies recently presented the important role of the miR-193 family comprising miR-193a-3p, miR-193a-5p, miR-193b-3p, and miR-193b-5p in health and disease biological processes by interaction with special targeting and signaling, which mainly contribute as a tumor suppressor. Therefore, in the present paper, we review the functional role of this miRNA family in both health and disease conditions focusing on various tumor developments, diagnoses, prognoses, and treatment.
Assuntos
MicroRNAs/metabolismo , Neoplasias/metabolismo , Carcinogênese , Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença , Humanos , MicroRNAs/genética , Neoplasias/genéticaRESUMO
Among the main promising systems to triggering therapeutic antitumor immunity is the blockade of immune checkpoints. Immune checkpoint pathways regulate the control and eradication of infections, malignancies, and resistance against a host of autoantigens. Initiation point of the immune response is T cells, which have a critical role in this pathway. As several immune checkpoints are initiated by ligand-receptor interactions, they can be freely blocked by antibodies or modulated by recombinant forms of ligands or receptors. Antibodies against cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) were the first immunotherapeutics that achieved the US Food and Drug Administration approval. Preliminary clinical results with the blockers of additional immune checkpoint proteins, such as programmed cell death protein 1 (PD-1) indicate extensive and different chances to boost antitumor immunity with the objective of conferring permanent clinical effects. This study provides an overview of the immune checkpoint pathways, including CTLA-4, PD-1, lymphocyte activation gene 3, T-cell immunoglobulin and mucin domain 3, B7-H3, and diacylglycerol kinase α and implications of their inhibition in the cancer therapy.
Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Imunoterapia , Neoplasias/tratamento farmacológico , Receptores Imunológicos/efeitos dos fármacos , Animais , Antineoplásicos Imunológicos/efeitos adversos , Resistencia a Medicamentos Antineoplásicos , Humanos , Imunoterapia/efeitos adversos , Terapia de Alvo Molecular , Neoplasias/imunologia , Neoplasias/metabolismo , Neoplasias/patologia , Receptores Imunológicos/imunologia , Receptores Imunológicos/metabolismo , Transdução de Sinais , Microambiente TumoralRESUMO
microRNAs (miRNAs) are a family of small noncoding RNAs that play a pivotal role in the regulation of main biological and physiological processes, including cell cycle regulation, proliferation, differentiation, apoptosis, stem cell maintenance, and organ development. Dysregulation of these tiny molecules has been related to different human diseases, such as cancer. It has been estimated that more than 50% of these noncoding RNA sequences are placed on fragile sites or cancer-associated genomic regions. After the discovery of the first specific miRNA signatures in breast cancer, many studies focused on the involvement of these small RNAs in the pathophysiology of breast tumors and their possible clinical implications as reliable prognostic biomarkers or as a new therapeutic approach. Therefore, the present review will focus on the recent findings on the involvement of miRNAs in the biology of breast cancer associated with their clinical implications.
Assuntos
Neoplasias da Mama/genética , MicroRNAs/genética , RNA não Traduzido/genética , Apoptose/genética , Neoplasias da Mama/patologia , Diferenciação Celular/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Genoma Humano/genética , Humanos , Células-Tronco Neoplásicas/patologiaRESUMO
Purpose: T-cell acute lymphoblastic leukemia (T-ALL) is one of the most common malignancies associated with T-lymphocytes, accounting for 10 to 15 percent of ALL cases in children and 25 percent in adults. Innovative therapeutic approaches that overcome ineffective treatments on tumor cells may be a potential source of improvement in therapeutic approaches. Suppression of gene expression at transfusion level is one of the important strategies in gene therapy. The expression of PTPN22 and miR-181 genes in all types of hematologic malignancies increases and is likely to contribute to the survival and death of cells by affecting a variety of signaling pathways. The purpose of this study was to determine the role of PTPN22 inhibition by siRNA, and alteration in miR-181a and miR-181b in Jurkat cell line. Methods: Jurkat cells were transfected with 80 pmol of siRNA to inhibit PTPN22. After that, expression of PTPN22 mRNA and transcript levels of miR-181a and miR-181b were measured with Real-time PCR after 48hrs. Results: Experiments demonstrated that siRNA transfection resulted in significant downregulation of PTPN22 mRNA after 48 hrs in 80 pmol dose of siRNA. Moreover, transcript levels of both miR-181a and miR-181b was decreased after transfection. Conclusion: PTPN22, miR-181a and miR-181b might be involved in progression of Jurkat cells and targeting these molecules by RNAi might confer promising tool in treatment of T-ALL.
RESUMO
BACKGROUND: Prostate cancer is known as the most common malignancy in men. Chitosan has generated great interest as a useful biopolymer for the encapsulation of small interfering RNA (siRNA). Due to cationic nature, chitosan is able to efficiently encapsulate siRNA molecules and form nanoparticles. Furthermore, the biocompatible and biodegradable attributes of chitosan have paved the way for its potential application in the in vivo delivery of therapeutic siRNAs. In this study, we aimed to design chitosan/CMD nanoparticles for the efficient encapsulation of the anti-cancer drugs SN38 and Snail-specific siRNA. METHODS: Physicochemical characteristics, growth inhibitory properties, and anti-migratory capacities of the dual delivery of SN38-Snail siRNA CMD-chitosan nanoparticles were investigated in prostate cancer cells. RESULTS: Our findings provided evidence for the suggestion that, ChNP-CMD-SN38-siRNA treated cells, the mRNA level of snail decreased from 1.00 to 0.30 (±0.14) and 0.09 (±0.04) after 24h and 48h, respectively. Additionally, the fold induction of E-cadherin and Claudin-1 increased from 1.00 to now 3.12 (±0.62), 3.02 (±0.28) after 24h and 5.6 (±0.91), 4.42 (±0.51) after 48h, respectively. Also, co-delivery of SN38 and Snail-specific siRNA by an appropriate nanocerrier (chitosan nanoparticles) could reduce the viability, proliferation, and migration of PC-3 cells. CONCLUSIONS: In conclusion, ChNPs encapsulating SN38 and Snail-specific siRNA may represent huge potential as an effective anti-cancer drug delivery system for the treatment of prostate cancer.
Assuntos
Antineoplásicos/administração & dosagem , Camptotecina/análogos & derivados , Quitosana/química , Neoplasias da Próstata/tratamento farmacológico , RNA Interferente Pequeno/administração & dosagem , Fatores de Transcrição da Família Snail/genética , Antineoplásicos/química , Caderinas/metabolismo , Camptotecina/administração & dosagem , Camptotecina/química , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Claudina-1/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Humanos , Irinotecano , Masculino , Nanopartículas/química , Neoplasias da Próstata/metabolismo , RNA Interferente Pequeno/químicaRESUMO
Nanoparticles are widely used to deliver anticancer drugs and inhibit tumor growth without systemic toxicity. Recently, chitosan has received much attention as a functional biopolymer for encapsulation of small interfering RNA (siRNA). Because of cationic nature, chitosan efficiently encapsulate siRNA and forming nanoparticles. Moreover, biocompatible and biodegradable properties represent chitosan as potential candidate for in vivo siRNA delivery. In the present study we designed carboxymethyl dextran (CMD) chitosan nanoparticles (ChNPs) to encapsulate snail siRNA and anticancer drug doxorubicin (DOX). The effect of ChNPs-drug/siRNA on cell growth and Epithelial mesenchymal transition (EMT) gene expression of HCT-116 cell lines were investigated. Furthermore the efficacy of dual agent nanoparticle to induce apoptosis and inhibit migration of colorectal cancer cells were assessed using Annexin-V and wound healing assays, respectively. The results demonstrated that treatment with dual agent nanoparticles led to significant changes of EMT genes (i.e down regulation of MMP-9 and Vimentin and up regulation of E-cadherin), apoptosis cell death and migration inhibition in HCT-116 cells. In conclusion, ChNPs encapsulating DOX and snail siRNA can be considered as an effective anti-cancer drugs delivery system for the treatment of colorectal cancer.
Assuntos
Antineoplásicos/administração & dosagem , Quitosana , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Sistemas de Liberação de Medicamentos , Nanopartículas , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Animais , Biomarcadores , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias Colorretais/terapia , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica , Técnicas de Transferência de Genes , Humanos , Camundongos , Espectroscopia de Infravermelho com Transformada de Fourier , Cicatrização/efeitos dos fármacos , Cicatrização/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Several studies have been performed to develop effective neutralizing monoclonal antibodies. The Epstein-Barr virus (EBV) can efficiently immortalize B-cells to establish lymphoblastoid cell lines (LCL) and so it has been used extensively for transformation of B-cells to produce and secrete immunoglobulin. The present study addressed the effect of TLR7/8 agonist (R848), feeder cells layer and ï¬uorescence-activated cell sorting (FACS) and magnetic-activated cell sorting (MACS) cell separation methods on the transformation efficiency of antibody-producing memory B-cells. For these studies, the antigen used for analyses of antibody formation was the tetanus neurotoxin (TeNT) derived from Clostridium tetani. The results here showed that employing an HFFF.PI6 feeder cell layer, R848 agonist and FACS-mediated purification of memory B-cells led to increased transformation efficiency. Altogether, the effects of the R848 and the feeder cells provided an efficient method for EBV transformation of human B-cells. Moreover, there was an advantage in using FACS sorting of B-cells over the MACS method in the context of EBV transformation and immortalization of precursors of antigen-specific B-cells.
Assuntos
Formação de Anticorpos , Linfócitos B/imunologia , Clostridium tetani/imunologia , Citometria de Fluxo/métodos , Herpesvirus Humano 4/imunologia , Separação Imunomagnética/métodos , Células Precursoras de Linfócitos B/imunologia , Linfócitos B/virologia , Linhagem Celular Transformada , Transformação Celular Neoplásica , Humanos , Imidazóis/farmacologia , Memória Imunológica , Metaloendopeptidases/imunologia , Células Precursoras de Linfócitos B/virologia , Toxina Tetânica/imunologia , Receptor 7 Toll-Like/antagonistas & inibidores , Receptor 8 Toll-Like/antagonistas & inibidoresRESUMO
The use of chimeric antigen receptor (CAR)-modified T cells is a promising approach for cancer immunotherapy. These genetically modified receptors contain an antigen-binding moiety, a hinge region, a transmembrane domain, and an intracellular costimulatory domain resulting in T-cell activation subsequent to antigen binding. Optimal tumor removal through CAR-modified T cells requires suitable target antigen selection, co-stimulatory signaling domain, and the ability of CAR T cells to traffic, persist, and retain antitumor function after adoptive transfer. There are several elements which can improve antitumor function of CAR T cells, including signaling, conditioning chemotherapy and irradiation, tumor burden of the disease, T-cell phenotype, and supplementary cytokine usage. This review outlines four generations of CAR. The pre-clinical and clinical studies showed that this technique has a great potential for treatment of solid and hematological malignancies. The main purpose of the current review is to focus on the pre-clinical and clinical developments of CAR-based immunotherapy.
Assuntos
Transferência Adotiva/métodos , Antígenos de Neoplasias/imunologia , Ativação Linfocitária , Neoplasias , Receptores de Antígenos de Linfócitos T , Proteínas Recombinantes de Fusão , Animais , Humanos , Neoplasias/genética , Neoplasias/imunologia , Neoplasias/terapia , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologiaRESUMO
Tumor cells use several mechanisms such as soluble immune modulators or suppressive immune cells to evade from anti-tumor responses. Immunomodulatory cytokines, such as transforming growth factor-ß, interleukin (IL)-10, and IL-35, soluble factors, such as adenosine, immunosuppressive cells, such as regulatory T cells, NKT cells and myeloid-derived suppressor cells (MDSCs), are the main orchestra leaders involved in immune suppression in cancer by which tumor cells can freely expand without immune cell-mediated interference. Among them, MDSCs have attracted much attention as they represent a heterogenous population derived from myeloid progenitors that are expanded in tumor condition and can also shift toward other myeloid cells, such as macrophages and dendritic cells, after tumor clearing. MDSCs exert their immunosuppressive effects through various immune and non-immune mechanisms which make them as potent tumor-promoting cells. Although, there are several studies regarding the immunobiology of MDSCs in different solid tumors, little is known about the precise characteristics of these cells in hematological malignancies, particularly B cell malignancies. In this review, we tried to clarify the precise role of MDSCs in B cell-derived malignancies.
Assuntos
Linfócitos B/imunologia , Linfócitos B/patologia , Imunidade Celular/imunologia , Células Mieloides/imunologia , Neoplasias/imunologia , Neoplasias/patologia , Animais , HumanosRESUMO
The selective and efficient drug delivery to tumor cells can remarkably improve different cancer therapeutic approaches. There are several nanoparticles (NPs) which can act as a potent drug carrier for cancer therapy. However, the specific drug delivery to cancer cells is an important issue which should be considered before designing new NPs for in vivo application. It has been shown that cancer cells over-express folate receptor (FR) in order to improve their growth. As normal cells express a significantly lower levels of FR compared to tumor cells, it seems that folate molecules can be used as potent targeting moieties in different nanocarrier-based therapeutic approaches. Moreover, there is evidence which implies folate-conjugated NPs can selectively deliver anti-tumor drugs into cancer cells both in vitro and in vivo. In this review, we will discuss about the efficiency of different folate-conjugated NPs in cancer therapy.
Assuntos
Receptores de Folato com Âncoras de GPI/biossíntese , Terapia de Alvo Molecular , Nanopartículas/uso terapêutico , Neoplasias/tratamento farmacológico , Portadores de Fármacos , Receptores de Folato com Âncoras de GPI/genética , Ácido Fólico/química , Ácido Fólico/uso terapêutico , Regulação Neoplásica da Expressão Gênica , Humanos , Micelas , Nanopartículas/química , Neoplasias/patologiaRESUMO
While Tregs maintain self-tolerance and inhibit antitumor responses, T helper (Th)17 cells may enhance inflammatory and antitumor responses. The balance between these two important T-cell subsets has been skewed in many immunopathologic conditions such as autoimmune and cancer diseases. B-cell chronic lymphocytic leukemia (CLL) is the most common form of leukemia in the western world and is characterized with monoclonal expansion of B lymphocytes. There is evidence which implies that the progression of CLL is associated with expansion of Treg and downregulation of Th17 cells. In this review, we will discuss about immunobiology of Treg and Th17 cells and their role in immunopathogenesis of CLL as well as their reciprocal changes during disease progression.
Assuntos
Leucemia Linfocítica Crônica de Células B/imunologia , Subpopulações de Linfócitos T/imunologia , Linfócitos T Reguladores/imunologia , Células Th17/imunologia , Animais , Humanos , Leucemia Linfocítica Crônica de Células B/metabolismo , Contagem de Linfócitos , Transdução de Sinais , Subpopulações de Linfócitos T/metabolismo , Linfócitos T Reguladores/metabolismo , Células Th17/metabolismo , Microambiente Tumoral/imunologiaRESUMO
BACKGROUND: Tetanus neurotoxin (TeNT) is composed of a light (LC) and heavy chain (HC) polypeptides, released by anaerobic bacterium Clostridium tetani and can cause fatal life-threatening infectious disease. Toxin HC and LC modules represents receptor binding and zinc metalloprotease activity, respectively. The passive administration of animal-derived antibodies against tetanus toxin has been considered as the mainstay therapy for years. However, this treatment is associated with several adverse effects due to the presence of anti-isotype antibodies. OBJECTIVE: In the present study, we have produced the fully human single chain antibody fragments (HuScFv) from two human antibody phage display libraries. MATERIAL AND METHODS: Twenty-four different HuscFvs were isolated from two anti TeNT immune libraries. Our produced human ScFv (HuScFv) were converted to IgG platform and analyzed regarding their specific reactivity to TeNT. RESULTS: All of the selected scFvs have the same VL but different VH. Three HuscFvs from the first library (TTX15, 51, 75) and two HuscFvs from the second library (TTX16, 20) were chosen to convert to IgG1 using pOptiVEC and pcDNA3.3 systems. Production of IgG1 from transfected DG44 and binding capacity of them to tetanus toxin and toxoid were measured by ELISA. ELISA results showed no detectable production of TTX16 and TTX20 IgG1. Although, TTX51 and TTX75 were converted and produced as IgG1, no reactivity to tetanus toxin and toxoid was observed. However, TTX15 was successfully produced as whole IgG1 platform with reactivity to both tetanus toxin and toxoid. The latter would be an appropriate replacement for conventional polyclonal antibodies if would meet the further characterization including specificity determination, affinity measurement and toxin neutralizing assays. CONCLUSION: Our results demonstrated production of functional IgG1 derived from TTX15 scFv and might be an appropriate replacement for polyclonal Tetabulin but it needs further characterization.
Assuntos
Anticorpos Antibacterianos/biossíntese , Anticorpos Monoclonais/biossíntese , Imunoglobulina G/biossíntese , Biblioteca de Peptídeos , Anticorpos de Cadeia Única/biossíntese , Tétano/prevenção & controle , Anticorpos Antibacterianos/isolamento & purificação , Anticorpos Antibacterianos/farmacologia , Anticorpos Monoclonais/isolamento & purificação , Anticorpos Monoclonais/farmacologia , Linfócitos B/imunologia , Linfócitos B/microbiologia , Clostridium tetani/imunologia , Clostridium tetani/patogenicidade , Desenho de Fármacos , Ensaio de Imunoadsorção Enzimática , Humanos , Imunoglobulina G/isolamento & purificação , Imunoglobulina G/farmacologia , Metaloendopeptidases/antagonistas & inibidores , Metaloendopeptidases/química , Metaloendopeptidases/imunologia , Ligação Proteica , Engenharia de Proteínas , Anticorpos de Cadeia Única/isolamento & purificação , Anticorpos de Cadeia Única/farmacologia , Tétano/imunologia , Tétano/microbiologia , Toxina Tetânica/antagonistas & inibidores , Toxina Tetânica/química , Toxina Tetânica/imunologia , Toxoide Tetânico/antagonistas & inibidores , Toxoide Tetânico/química , Toxoide Tetânico/imunologiaRESUMO
Tetanus is caused by the tetanus neurotoxin (TeNT), a 150 kDa single polypeptide molecule which is cleaved into active two-chain molecules composed of a 50 kDa N-terminal light (L) and a 100 kDa C-terminal heavy (H) chains. Fragment C is further subdivided into two subdomains: the proximal HCN subdomain and the extreme carboxy subdomain, HCC. HCC is considered as an immunodominant part of TeNT and is responsible for TeNT binding activity to neurons.In the present study, we investigated the ability of recombinant HCC(r HCC) to induce T cell activation. Our results showed that recombinant HCC has a stimulatory effect on IFN-γ secretion by T cells after 48h co-incubation in the presence of anti-TLR-2 Ab. Also, Hcc can induce the expression of CD69 on T cells.Our finding indicated that stimulatory effects of HCC on T cells are TLR-2 independent and anti-TLR-2 inhibitory antibody fails to neutralize HCC stimulatory effects on T cells.Furthermore, HCC is critical for immunogenic activity of TeNT and is able to induce T cells through TLR-2 independent pathway.