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1.
J Vector Borne Dis ; 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38238835

RESUMO

BACKGROUND OBJECTIVES: Aedes aegypti and Ae. albopictus mosquitoes breed in natural and artificial containers, and they transmit dengue and chikungunya. Therefore, a study was conducted to identify the contribution of bamboo stumps to these disease vectors that were used in the flower garden as pillars to hold the bamboo flex fence. METHODS: Two sizes of whole bamboo were used to hold fences around gardens at Dhaka University, Bangladesh, and they were painted red and green. Mosquito larvae and pupae were collected from bamboo stumps between July and August, and vectors were identified up to the species level. The data were analyzed using the STATA/MP 14.2 version. RESULTS: We found 83.5% and 0.2% were Ae. albopictus and Ae. aegypti, respectively, and the rest were Culex and Armigeres species. Ae. albopictus, Ae. aegypti, and both species-positive bamboo stumps were 46.9, 0.7, and 47.1 percent, respectively. 54.5% of bamboo stumps had at least one mosquito species. The average stump depth for Aedes positive stumps (mean =11.7 cm, SE = 0.5) was significantly (p <0.001) higher than the Aedes negative stumps (mean = 9.5 cm, SE = 0.4). 53.8% and 38.0% stumps were found Aedes positive on the ground and upper sides of fences, respectively, and found significant (p<0.01) differences between both sides. A zero-inflated negative binomial count model is significant at a 5% level of significance, χ2(4) = 11.8, p = 0.019 (<0.05) for Ae. albopictus. Stump depth is found to have a significant positive effect on the number of Aedes-positive stumps. INTERPRETATION CONCLUSION: Artificially used natural containers are adding pressure to current mosquito control activities as mosquitoes are breeding on them, which needs additional attention.

2.
Sci Total Environ ; 912: 168620, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-37977385

RESUMO

With the increasing complexity of influent composition in wastewater treatment plants, the potential stimulating effects of refractory organic matter in wastewater on growth characteristics and genera conversion of nitrifying bacteria (ammonium-oxidizing bacteria [AOB] and nitrite-oxidizing bacteria [NOB]) need to be further investigated. In this study, domestic wastewater was co-treated with landfill leachate in the lab-scale reactor, and the competition and co-existence of NOB genera Nitrotoga and Nitrospira were observed. The results demonstrated that the addition of landfill leachate could induce the growth of Nitrotoga, whereas Nitrotoga populations remain less competitive in domestic wastewater operation. In addition, the refractory organic matter in the landfill leachate also would have a potential stimulating effect on the maximum specific growth rate of AOB genus Nitrosomonas (µmax, aob). The µmax, aob of Nitrosomonas in the control group was estimated to be 0.49 d-1 by fitting the ASM model, and the µmax, aob reached 0.66-0.71 d-1 after injection of refractory organic matter in the landfill leachate, while the maximum specific growth rate of NOB (µmax, nob) was always in the range of 1.05-1.13 d-1. These findings have positive significance for the understanding of potential stimulation on nitrification processes and the stable operation of innovative wastewater treatment process.


Assuntos
Compostos de Amônio , Nitrosomonas europaea , Poluentes Químicos da Água , Águas Residuárias , Amônia , Oxirredução , Nitritos , Nitrificação , Nitrosomonas , Bactérias , Reatores Biológicos/microbiologia , Nitrogênio
3.
Heliyon ; 9(8): e18921, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37636466

RESUMO

Plastic waste is choking our planet, but the recycling rate is still universally low. Understanding factors affecting recycling behaviours can help address this pressing issue. Taking Dhaka as an example, this study explores the determinants of the intentions to recycle plastic waste. We employed the Theory of Planned Behaviour (TPB) and extended it with two additional variables: Moral Norms, and Perceived sufficiency of knowledge and policy support. Survey data of 577 were collected and analysed using PLS-SEM. The findings suggest attitude, perceived behavioural control, moral norms and subjective norms significantly impact recycling intention, among which moral norms (ß = 0.148, p < 0.05) acts even more strongly than subjective norms (ß = 0.12, p < 0.05). Moreover, low level perception of knowledge and policy support makes people perceive less control over recycling behaviour (ß = 0.188, p < 0.05), but actually reinforce their recycling intention (ß = -0.091, p < 0.1). This study enriches the theoretical discussion of TPB, and contributes to the efforts of encouraging plastic recycling in populated megacity of emerging economy.

4.
Front Immunol ; 14: 1097090, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36865537

RESUMO

Immune checkpoint inhibitors (ICIs) by targeting PD-1/PD-L1 or CTLA-4 have markedly improved the outcome of cancer patients. However, most solid tumor patients can't benefit from such therapy. Identification of novel biomarkers to predict the responses of ICIs is crucial to enhance their therapeutic efficacy. TNFR2 is highly expressed by the maximally immunosuppressive subset of CD4+Foxp3+ regulatory T cells (Tregs), especially those present in tumor microenvironment (TME). Since Tregs represent a major cellular mechanism in tumor immune evasion, TNFR2 may be a useful biomarker to predict the responses to ICIs therapy. This notion is supported by our analysis of the computational tumor immune dysfunction and exclusion (TIDE) framework from published single-cell RNA-seq data of pan-cancer databases. The results show that, as expected, TNFR2 is highly expressed by tumor-infiltrating Tregs. Interestingly, TNFR2 is also expressed by the exhausted CD8 T cells in breast cancer (BRCA), hepatocellular carcinoma (HCC), lung squamous cell carcinoma (LUSC), and melanoma (MELA). Importantly, high expression of TNFR2 is associated with poor responses to the treatment with ICIs in BRCA, HCC, LUSC, and MELA. In conclusion, the expression of TNFR2 in TME may be a reliable biomarker for the precision of ICIs treatment of cancer patients, and this idea merits further research.


Assuntos
Inibidores de Checkpoint Imunológico , Neoplasias , Receptores Tipo II do Fator de Necrose Tumoral , Feminino , Humanos , Neoplasias da Mama , Carcinoma Hepatocelular , Carcinoma Pulmonar de Células não Pequenas , Carcinoma de Células Escamosas , Inibidores de Checkpoint Imunológico/uso terapêutico , Neoplasias Hepáticas , Neoplasias Pulmonares , Melanoma , Receptores Tipo II do Fator de Necrose Tumoral/genética , Microambiente Tumoral , Neoplasias/tratamento farmacológico
5.
Am J Trop Med Hyg ; 108(4): 783-790, 2023 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-36878211

RESUMO

We undertook a study to assess current knowledge, attitudes, and practices related to kala-azar to advise the national kala-azar elimination program in Bangladesh. A community-based cross-sectional study was conducted in two endemic subdistricts (upazilas): Fulbaria and Trishal. Based on upazila health complex surveillance data, one endemic village was selected randomly from each of these subdistricts. A total of 511 households (HHs) (261 in Fulbaria and 250 in Trishal) were included in the study. An adult from each HH was interviewed using a structured questionnaire. Specifically, data were collected on knowledge, attitudes, and practices related to kala-azar. Of the respondents, 52.64% were illiterate. All study participants had heard approximately kala-azar, and 30.14% of the HHs or neighboring HHs have had at least one kala-azar case. Of the respondents, 68.88% knew that kala-azar is transmitted through sick people, and more than 56.53% of the study participants said that mosquitoes transmitted kala-azar, even though 90.80% were aware of the presence of sand flies. Of the participants, 46.55% were aware that insect vectors laid their eggs in the water. The Upazila Health Complex was the preferable health-care facility for 88.14% of the villagers. In addition, 62.03% used bed nets for preventing sand fly bites and 96.48% of the families had mosquito nets. Based on these observations, the national program should strengthen its current community engagement activities to increase the knowledge of kala-azar in endemic communities.


Assuntos
Leishmaniose Visceral , Animais , Leishmaniose Visceral/epidemiologia , Estudos Transversais , Bangladesh/epidemiologia , Conhecimentos, Atitudes e Prática em Saúde , Características da Família , Índia/epidemiologia
6.
J Leukoc Biol ; 113(3): 236-254, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36807444

RESUMO

A significant number of persons with coronavirus disease 2019 (COVID-19) experience persistent, recurrent, or new symptoms several months after the acute stage of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This phenomenon, termed post-acute sequelae of SARS-CoV-2 (PASC) or long COVID, is associated with high viral titers during acute infection, a persistently hyperactivated immune system, tissue injury by NETosis-induced micro-thrombofibrosis (NETinjury), microbial translocation, complement deposition, fibrotic macrophages, the presence of autoantibodies, and lymphopenic immune environments. Here, we review the current literature on the immunological imbalances that occur during PASC. Specifically, we focus on data supporting common immunopathogenesis and tissue injury mechanisms shared across this highly heterogenous disorder, including NETosis, coagulopathy, and fibrosis. Mechanisms include changes in leukocyte subsets/functions, fibroblast activation, cytokine imbalances, lower cortisol, autoantibodies, co-pathogen reactivation, and residual immune activation driven by persistent viral antigens and/or microbial translocation. Taken together, we develop the premise that SARS-CoV-2 infection results in PASC as a consequence of acute and/or persistent single or multiple organ injury mediated by PASC determinants to include the degree of host responses (inflammation, NETinjury), residual viral antigen (persistent antigen), and exogenous factors (microbial translocation). Determinants of PASC may be amplified by comorbidities, age, and sex.


Assuntos
COVID-19 , Síndrome de COVID-19 Pós-Aguda , Humanos , SARS-CoV-2 , Leucócitos , Antígenos Virais , Autoanticorpos , Progressão da Doença
7.
PLoS One ; 18(1): e0280747, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36662825

RESUMO

Para Kala-azar Dermal Leishmaniasis (Para-KDL) manifests the concomitant presence of Post Kala-azar Dermal Leishmaniasis and Visceral Leishmaniasis and works as a reservoir of infection. The study discusses the cases and their management and aims to address the gaps within existing methods of diagnosis and treatment. This retrospective cross-sectional study discusses 16 Para-KDL cases with one-year follow-up data, treated between 2012-2021 at the Surya Kanta Kala-azar Research Center, Bangladesh. We collected data from hospital records and used STATA 16 to analyze and see the frequency distribution and variable means. We found five patients without any history of kala-azar infection. All the patients were treated with 20 mg/kg Liposomal Amphotericin B in 4 divided doses except one with a history of AmBisome hypersensitivity. One year after treatment, all patients were free from skin lesions, with no hepatosplenomegaly, and observed significant improvement in BMI and hemoglobin levels. The Para-KDL patients are challenging to diagnose, and the relapse and treatment failure leishmania patients might have belonged to this rare group, contributing to their poor prognosis. Therefore, developing an appropriate diagnostic workflow and a new drug regimen is essential to sustain the success of our elimination efforts.


Assuntos
Antiprotozoários , Leishmaniose Cutânea , Leishmaniose Visceral , Humanos , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/epidemiologia , Antiprotozoários/uso terapêutico , Estudos Retrospectivos , Bangladesh/epidemiologia , Estudos Transversais , Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Cutânea/epidemiologia
8.
Cell Oncol (Dordr) ; 46(1): 167-177, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36369606

RESUMO

BACKGROUND: TNFR2 expression is a characteristic of highly potent immunosuppressive tumor infiltrating CD4+Foxp3+ regulatory T cells (Tregs). There is compelling evidence that TNF through TNFR2 preferentially stimulates the activation and expansion of Tregs. We and others, therefore, proposed that targeting TNFR2 may provide a novel strategy in cancer immunotherapy. Several studies have shown the effect of TNFR2 antagonistic antibodies in different tumor models. However, the exact action of the TNFR2 antibody on Tregs remained understood. METHOD: TY101, an anti-murine TNFR2 antibody, was used to examine the effect of TNFR2 blockade on Treg proliferation and viability in vitro. The role of TNFR2 on Treg viability was further validated by TNFR2 knockout mice and in the TY101 antagonistic antibody-treated mouse tumor model. RESULTS: In this study, we found that an anti-mouse TNFR2 antibody TY101 could inhibit TNF-induced proliferative expansion of Tregs, indicative of an antagonistic property. To examine the effect of TY101 antagonistic antibody on Treg viability, we treated unfractionated lymph node (L.N.) cells with Dexamethasone (Dex) which was known to induce T cell death. The result showed that TY101 antagonistic antibody treatment further promoted Treg death in the presence of Dex. This led us to find that TNFR2 expression was crucial for the survival of Tregs. In the mouse EG7 lymphoma model, treatment with TY101 antagonistic antibody potently inhibited tumor growth, resulting in complete regression of the tumor in 60% of mice. The treatment with TY101 antagonistic antibody elicited potent antitumor immune responses in this model, accompanied by enhanced death of Tregs. CONCLUSION: This study, therefore, provides clear experimental evidence that TNFR2 antagonistic antibody, TY101, can promote the death of Tregs, and this effect may be attributable to the antitumor effect of TNFR2 antagonistic antibody.


Assuntos
Neoplasias , Linfócitos T Reguladores , Animais , Camundongos , Linfócitos T Reguladores/metabolismo , Receptores Tipo II do Fator de Necrose Tumoral/metabolismo , Neoplasias/metabolismo , Fatores de Transcrição Forkhead/metabolismo
9.
BMJ Open ; 12(11): e066653, 2022 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-36410810

RESUMO

OBJECTIVES: The study aimed to determine the seroprevalence, the fraction of asymptomatic infections, and risk factors of SARS-CoV-2 infections among the Forcibly Displaced Myanmar Nationals (FDMNs). DESIGN: It was a population-based two-stage cross-sectional study at the level of households. SETTING: The study was conducted in December 2020 among household members of the FDMN population living in the 34 camps of Ukhia and Teknaf Upazila of Cox's Bazar district in Bangladesh. PARTICIPANTS: Among 860 697 FDMNs residing in 187 517 households, 3446 were recruited for the study. One individual aged 1 year or older was randomly selected from each targeted household. PRIMARY AND SECONDARY OUTCOME MEASURES: Blood samples from respondents were tested for total antibodies for SARS-CoV-2 using Wantai ELISA kits, and later positive samples were validated by Kantaro kits. RESULTS: More than half (55.3%) of the respondents were females, aged 23 median (IQR 14-35) years and more than half (58.4%) had no formal education. Overall, 2090 of 3446 study participants tested positive for SARS-CoV-2 antibody. The weighted and test adjusted seroprevalence (95% CI) was 48.3% (45.3% to 51.4%), which did not differ by the sexes. Children (aged 1-17 years) had a significantly lower seroprevalence 38.6% (95% CI 33.8% to 43.4%) compared with adults (58.1%, 95% CI 55.2% to 61.1%). Almost half (45.7%, 95% CI 41.9% to 49.5%) of seropositive individuals reported no relevant symptoms since March 2020. Antibody seroprevalence was higher in those with any comorbidity (57.8%, 95% CI 50.4% to 64.5%) than those without (47.2%, 95% CI 43.9% to 50.4%). Multivariate logistic regression analysis of all subjects identified increasing age and education as risk factors for seropositivity. In children (≤17 years), only age was significantly associated with the infection. CONCLUSIONS: In December 2020, about half of the FDMNs had antibodies against SARS-CoV-2, including those who reported no history of symptoms. Periodic serosurveys are necessary to recommend appropriate public health measures to limit transmission.


Assuntos
COVID-19 , SARS-CoV-2 , Criança , Adulto , Feminino , Humanos , Masculino , Estudos Soroepidemiológicos , Estudos Transversais , Bangladesh/epidemiologia , Mianmar/epidemiologia , COVID-19/epidemiologia , Anticorpos Antivirais
10.
Int J Biol Sci ; 18(12): 4629-4641, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35874952

RESUMO

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has undergone multiple mutations since its emergence, and its latest variant, Omicron (B.1.1.529), is the most contagious variant of concern (VOC) which poses a major and imminent threat to public health. Since firstly reported by World Health Organization (WHO) in November 2021, Omicron variant has been spreading rapidly and has become the dominant variant in many countries worldwide. Omicron is the most mutated variant so far, containing 60 mutations in its genome, including 37 mutations in the S-protein. Since all current COVID-19 vaccines in use were developed based on ancestral SARS-CoV-2 strains, whether they are protective against Omicron is a critical question which has been the center of study currently. In this article, we systemically reviewed the studies regarding the effectiveness of 2- or 3-dose vaccines delivered in either homologous or heterologous manner. The humoral and cellular immune responses elicited by various vaccine regimens to protect against Omicron variant are discussed. Current understanding of the molecular basis underlying immune escape of Omicron was also analyzed. These studies indicate that two doses of vaccination are insufficient to elicit neutralizing antibody responses against Omicron variant. Nevertheless, Omicron-specific humoral immune responses can be enhanced by booster dose of almost all type vaccines in certain degree, and heterologous vaccination strategy may represent a better choice than homogenous regimens. Intriguingly, results of studies indicate that all current vaccines are still able to elicit robust T cell response against Omicron. Future focus should be the development of Omicron variant vaccine, which may induce potent humoral as well as cellular immune responses simultaneously against all known variants of the SARS-CoV-2 virus.


Assuntos
COVID-19 , Vacinas Virais , Humanos , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Imunidade Celular , SARS-CoV-2
11.
Front Immunol ; 13: 800283, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35464441

RESUMO

There is compelling evidence that CD4+Foxp3+ regulatory T cells (Tregs) are indispensable in the inhibition of autoimmune inflammatory responses, including psoriasis. Recently, we showed that systemically treatment with tetrandrine (TET), a two-pore channel inhibitor identified from the Chinese herb Stephania tetrandra S. Moor, could promote the proliferative expansion of Tregs in mice through stimulation of TNF-TNFR2 interaction. We thus hypothesized that topical administration of TET might also expand Tregs and consequently inhibit psoriasis. To this end, we developed a TET nanoemulsion and examined its effect on the expansion of Tregs after topical administration on mouse psoriasis induced by imiquimod. The result of our experiment showed that topical treatment with TET nanoemulsion markedly increased the proportion and number of Tregs in the spleen, as well as TNFR2 and Ki-67 expression by Tregs, in WT and TNFR1 KO mice, but not in TNFR2 KO mice. Consequently, TET nanoemulsion potently inhibited IL-17-expressing cells in the spleen and lymph nodes of imiquimod-treated WT mice, accompanied by decreased serum levels of IL-17A, INF-γ, and TNF and their mRNA levels in the flamed lesion. Importantly, TET nanoemulsion treatment markedly inhibited the development of psoriasis-like disease in WT and TNFR1 KO mice but not in TNFR2 KO mice. Therefore, our study indicates that the topical administration of TET could also stimulate the expansion of Tregs through the TNF-TNFR2 pathway. This effect of TET and its analogs may be useful in the treatment of inflammatory skin diseases such as psoriasis.


Assuntos
Psoríase , Linfócitos T Reguladores , Animais , Benzilisoquinolinas , Fatores de Transcrição Forkhead/genética , Imiquimode/farmacologia , Camundongos , Psoríase/induzido quimicamente , Psoríase/tratamento farmacológico , Psoríase/genética , Receptores Tipo I de Fatores de Necrose Tumoral , Receptores Tipo II do Fator de Necrose Tumoral
12.
Rheumatol Immunol Res ; 3(4): 190-197, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36879838

RESUMO

Objectives: Topical administration of Tacrolimus (TAC) is efective in the treatment of psoriasis in human patients and in mouse models. Previously, we showed that, though promoting the proliferative expansion of CD4+Foxp3+ regulatory T cells (Tregs), TNFR2 was protective in mouse psoriasis model. We thus examined the role of TNFR2 signal in the efect of TAC in the treatment of mouse psoriasis. Methods: To this end, psoriasis was induced in WT, or TNFR1 KO, or TNFR2 KO mice, and the psoriatic mice were treated with or without IMQ. Results: The results showed that TAC treatment potently inhibited the development of psoriasis in WT and TNFR1 KO mice, but not in TNFR2 KO mice. However, the treatment of TAC failed to induce the expansion of Tregs in psoriatic mice. In addition to playing a decisive role in the activation of Tregs, TNFR2 stimulates the generation and activation of myeloid-derived suppressor cells (MDSCs). This led us to found that the topical treatment with TAC markedly increased the number of MDSCs in the spleen of WT and TNFR1 KO mice, but not in TNFR2 KO mice. Consequently, TAC potently decreased serum levels of IL-17A, INF-γ, and TNF and their mRNA levels in the inflamed skin lesion. Conclusion: Therefore, our study for the first time found that the therapeutic efect of TAC in psoriasis is associated with the expansion of MDSCs in a TNFR2-dependent manner.

13.
Int J Biol Sci ; 17(6): 1507-1520, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33907514

RESUMO

The severe cases of Coronavirus Disease 2019 (COVID-19) frequently exhibit excessive inflammatory responses, acute respiratory distress syndrome (ARDS), coagulopathy, and organ damage. The most striking immunopathology of advanced COVID-19 is cytokine release syndrome or "cytokine storm" that is attributable to the deficiencies in immune regulatory mechanisms. CD4+FoxP3+ regulatory T cells (Tregs) are central regulators of immune responses and play an indispensable role in the maintenance of immune homeostasis. Tregs are likely involved in the attenuation of antiviral defense at the early stage of infection and ameliorating inflammation-induced organ injury at the late stage of COVID-19. In this article, we review and summarize the current understanding of the change of Tregs in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and discuss the potential role of Tregs in the immunopathology of COVID-19. The emerging concept of Treg-targeted therapies, including both adoptive Treg transfer and low dose of IL-2 treatment, is introduced. Furthermore, the potential Treg-boosting effect of therapeutic agents used in the treatment of COVID-19, including dexamethasone, vitamin D, tocilizumab and sarilumab, chloroquine, hydroxychloroquine, azithromycin, adalimumab and tetrandrine, is discussed. The problems in the current study of Treg cells in COVID-19 and future perspectives are also addressed.


Assuntos
Antígenos CD4/imunologia , COVID-19/imunologia , COVID-19/terapia , Fatores de Transcrição Forkhead/imunologia , Linfócitos T Reguladores/imunologia , COVID-19/virologia , Síndrome da Liberação de Citocina , Humanos , SARS-CoV-2/isolamento & purificação
14.
Int J Biol Sci ; 17(6): 1588-1599, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33907523

RESUMO

At present, the COVID-19 pandemic is running rampant, having caused 2.18 million deaths. Characterizing the global patent landscape of coronaviruses is essential not only for informing research and policy, given the current pandemic crisis, but also for anticipating important future developments. While patents are a promising indicator of technological knowledge production widely used in innovation research, they are often an underused resource in biological sciences. In this study, we present a patent landscape for the seven coronaviruses known to infect humans. The information included in this paper provides a strong intellectual groundwork for the ongoing development of therapeutic agents and vaccines along with a deeper discussion of intellectual property rights under epidemic conditions. The results show that there has been a rapid increase in human coronavirus patents, especially COVID-19 patents. China and the United States play an outstanding role in global cooperation and patent application. The leading role of academic institutions and government is increasingly apparent. Notable technological issues related to human coronaviruses include pharmacochemical treatment, diagnosis of viral infection, viral-vector vaccines, and traditional Chinese medicine. Furthermore, a critical challenge lies in balancing commercial competition, enterprise profit, knowledge sharing, and public interest.


Assuntos
COVID-19/virologia , Internacionalidade , Patentes como Assunto , SARS-CoV-2/genética , Genes Virais , Humanos
15.
Immunotargets Ther ; 10: 103-122, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33907692

RESUMO

Immune checkpoint inhibitors (ICIs), including anti-CTLA-4 (cytotoxic T lymphocyte antigen-4) and anti-PD-1/PD-L1 (programmed death-1/programmed death-ligand 1), represent a turning point in the cancer immunotherapy. However, only a minor fraction of patients could derive benefit from such therapy. Therefore, new strategies targeting additional immune regulatory mechanisms are urgently needed. CD4+Foxp3+ regulatory T cells (Tregs) represent a major cellular mechanism in cancer immune evasion. There is compelling evidence that tumor necrosis factor (TNF) receptor type II (TNFR2) plays a decisive role in the activation and expansion of Tregs and other types of immunosuppressive cells such as myeloid-derived suppressor cells (MDSCs). Furthermore, TNFR2 is also expressed by some tumor cells. Emerging experimental evidence indicates that TNFR2 may be a therapeutic target to enhance naturally occurring or immunotherapeutic-triggered anti-tumor immune responses. In this article, we discuss recent advances in the understanding of the mechanistic basis underlying the Treg-boosting effect of TNFR2. The role of TNFR2-expressing highly suppressive Tregs in tumor immune evasion and their possible contribution to the non-responsiveness to checkpoint treatment are analyzed. Moreover, the role of TNFR2 expression on tumor cells and the impact of TNFR2 signaling on other types of cells that shape the immunological landscape in the tumor microenvironment, such as MDSCs, MSCs, ECs, EPCs, CD8+ CTLs, and NK cells, are also discussed. The reports revealing the effect of TNFR2-targeting pharmacological agents in the experimental cancer immunotherapy are summarized. We also discuss the potential opportunities and challenges for TNFR2-targeting immunotherapy.

16.
Adv Exp Med Biol ; 1278: 257-272, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33523452

RESUMO

The puzzling biphasic or dual roles of tumor necrosis factor α (TNF) in the inflammatory and immune responses are likely to be mediated by distinct signaling pathways transduced by one of its two receptors, e.g., TNF receptor type I (TNFR1) and TNF receptor type II (TNFR2). Unlike TNFR1 that is ubiquitously expressed on almost all types of cells, the expression of TNFR2 is rather restricted to certain types of cells, such as T lymphocytes. There is now compelling evidence that TNFR2 is preferentially expressed by CD4+Foxp3+ regulatory T cells (Tregs), and TNFR2 plays a decisive role in the activation, expansion, in vivo function, and phenotypical stability of Tregs. In this chapter, the current understanding of the molecular basis and signaling pathway of TNF-TNFRs signal is introduced. Latest studies that have further supported and substantiated the pivotal role of TNF-TNFR2 interaction in Tregs biology and its molecular basis are discussed. The research progress regarding TNFR2-targeting treatment for autoimmune diseases and cancer is analyzed. Future study should focus on the further understanding of molecular mechanism underlying Treg-stimulatory effect of TNFR2 signal, as well as on the translation of research findings into therapeutic benefits of human patients with autoimmune diseases, allergy, allograft rejection, and cancer.


Assuntos
Doenças Autoimunes , Neoplasias , Doenças Autoimunes/terapia , Fatores de Transcrição Forkhead/genética , Humanos , Neoplasias/terapia , Receptores Tipo II do Fator de Necrose Tumoral/genética , Linfócitos T Reguladores , Fator de Necrose Tumoral alfa/genética
17.
Sci Adv ; 6(40)2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32998896

RESUMO

CD4+Foxp3+ regulatory T cells (Tregs) are pivotal for the inhibition of autoimmune inflammatory responses. One way to therapeutically harness the immunosuppressive actions of Tregs is to stimulate the proliferative expansion of TNFR2-expressing CD4+Foxp3+ Tregs via transmembrane TNF (tmTNF). Here, we report that two-pore channel (TPC) inhibitors markedly enhance tmTNF expression on antigen-presenting cells. Furthermore, injection of TPC inhibitors including tetrandrine, or TPC-specific siRNAs in mice, increases the number of Tregs in a tmTNF/TNFR2-dependent manner. In a mouse colitis model, inhibition of TPCs by tetrandrine markedly attenuates colon inflammation by expansion of Tregs Mechanistically, we show that TPC inhibitors enhance tmTNF levels by disrupting surface expression of TNF-α-converting enzyme by regulating vesicle trafficking. These results suggest that the therapeutic potential of TPC inhibitors is mediated by expansion of TNFR2-expressing Tregs and elucidate the basis of clinical use in the treatment of autoimmune and other inflammatory diseases.


Assuntos
Colite , Receptores Tipo II do Fator de Necrose Tumoral/imunologia , Animais , Células Apresentadoras de Antígenos/metabolismo , Colite/metabolismo , Fatores de Transcrição Forkhead/genética , Ativação Linfocitária , Camundongos , Receptores Tipo II do Fator de Necrose Tumoral/genética , Linfócitos T Reguladores , Fator de Necrose Tumoral alfa/metabolismo
18.
Int J Biol Sci ; 16(10): 1708-1717, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32226288

RESUMO

Currently, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2, formerly known as 2019-nCoV, the causative pathogen of Coronavirus Disease 2019 (COVID-19)) has rapidly spread across China and around the world, causing an outbreak of acute infectious pneumonia. No specific anti-virus drugs or vaccines are available for the treatment of this sudden and lethal disease. The supportive care and non-specific treatment to ameliorate the symptoms of the patient are the only options currently. At the top of these conventional therapies, greater than 85% of SARS-CoV-2 infected patients in China are receiving Traditional Chinese Medicine (TCM) treatment. In this article, relevant published literatures are thoroughly reviewed and current applications of TCM in the treatment of COVID-19 patients are analyzed. Due to the homology in epidemiology, genomics, and pathogenesis of the SARS-CoV-2 and SARS-CoV, and the widely use of TCM in the treatment of SARS-CoV, the clinical evidence showing the beneficial effect of TCM in the treatment of patients with SARS coronaviral infections are discussed. Current experiment studies that provide an insight into the mechanism underlying the therapeutic effect of TCM, and those studies identified novel naturally occurring compounds with anti-coronaviral activity are also introduced.


Assuntos
Betacoronavirus , Infecções por Coronavirus/tratamento farmacológico , Medicamentos de Ervas Chinesas/uso terapêutico , Medicina Tradicional Chinesa , Pneumonia Viral/tratamento farmacológico , COVID-19 , China , Ensaios Clínicos como Assunto , Humanos , Pandemias , Fitoterapia , SARS-CoV-2 , Tratamento Farmacológico da COVID-19
19.
PLoS Negl Trop Dis ; 12(10): e0006846, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30273402

RESUMO

BACKGROUND: Visceral leishmaniasis (VL) in the Indian subcontinent is a fatal disease if left untreated. Between 1994 to 2013, the Ministry of Health of Bangladesh reported 1,09,266 cases of VL and 329 VL related deaths in 37 endemic districts. Indoor residual spraying (IRS) using dichlorodiphenyltrichloroethane (DDT) was used by the national programme in the 1960s to control malaria. Despite findings of research trials demonstrating that the synthetic pyrethroid deltamethrin 5 WP was very effective at reducing vector densities, no national VL vector control operations took place in Bangladesh between 1999 to early 2012. In 2012, IRS using deltamethrin 5 WP was re-introduced by the national programme, which consisted of pre-monsoon spraying in eight highly endemic sub-districts (upazilas). The present study aims to evaluate the effectiveness of IRS on VL vectors, as well as the process and performance of the spraying activities by national programme staff. METHODS: Five highly endemic upazilas of Mymensingh district were purposively selected (Fulbaria, Trishal, Mukthagacha, Gaforgaon and Bhaluka) to conduct the present study using the WHO/TDR monitoring and evaluation tool kit. IRS operations, conducted by 136 squads/teams, and 544 spraymen, were observed using check lists and questionnaires included in the WHO/TDR monitoring and evaluation tool kit. A household (HH) acceptability survey of IRS was conducted in all study areas using a structured questionnaire in 600 HHs. To measure the efficacy of IRS, pre-IRS (two weeks prior) and post-IRS (at one and five months after), vector density was measured using CDC light traps for two consecutive nights. Bioassays, using the WHO cone-method, were carried out in 80 HHs (40 sprayed and 40 unsprayed) to measure the effectiveness of the insecticide on sprayed surfaces. RESULTS: Of the 544 spraymen interviewed pre-IRS, 60%, 3% and 37% had received training for one, two and three days respectively. During spraying activities, 64% of the spraying squads had a supervisor in 4 upazilas but only one upazila (Mukthagacha) achieved 100% supervision of squads. Overall, 72.8% of the spraying squads in the study upazilas had informed HHs members to prepare their houses prior to spraying. The required personal protective equipment was not provided by the national programme during our observations and the spraying techniques used by all sprayers were sub-standard compared to the standard procedure mentioned in the M&E toolkit. In the HH interviews, 94.8% of the 600 respondents said that all their living rooms and cattle sheds had been sprayed. Regarding the effectiveness measurements (i.e. reduction of vector densities), a total of 4132 sand flies were trapped in three intervals, of which 3310 (80.1%) were P. argentipes; 46.5% (1540) males and 53.5% (1770) females. At one month post-IRS, P. argentipes densities were reduced by 22.5% but the 5 months post-IRS reduction was only 6.4% for both male and female. The bioassay tests showed a mean corrected mortality of P. argentipes sand flies at one month post-IRS of 87.3% which dropped to 74.5% at 4 months post-IRS in three upazilas, which is below the WHO threshold level (80%). CONCLUSION: The national programme should conduct monitoring and evaluation activities to ensure high quality of IRS operations as a pre-condition for achieving a fast and sustained reduction in vector densities. This will continue to be important during the maintenance phase of VL elimination on the Indian subcontinent. Further research is needed to determine other suitable vector control option(s) when the case numbers are very low.


Assuntos
Aerossóis/administração & dosagem , Controle de Insetos/métodos , Inseticidas/administração & dosagem , Leishmaniose Visceral/prevenção & controle , Psychodidae/crescimento & desenvolvimento , Animais , Bangladesh , Bioensaio , Características da Família , Pesquisa sobre Serviços de Saúde , Humanos , Nitrilas/administração & dosagem , Aceitação pelo Paciente de Cuidados de Saúde , Densidade Demográfica , Psychodidae/efeitos dos fármacos , Piretrinas/administração & dosagem , Inquéritos e Questionários , Análise de Sobrevida
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