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1.
Vaccines (Basel) ; 12(1)2024 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-38276676

RESUMO

Vaccination provides the best protection against the increasing infections of SARS-CoV-2. The magnitude and type of anti-SARS-CoV-2 vaccine side effects (SEs) depend on parameters that are not fully understood. In this cross-sectional study, the associations between different anti-SARS-CoV-2 vaccine SEs and age, sex, the presence of chronic diseases, medication intake, history of allergies, and infections with SARS-CoV-2 were investigated. Our survey used the Google platform and had 866 participants, contacted through e-mails, social media and chain referral sampling (margin of error ≈ 4.38%, 99% confidence). More than 99% of the participants received the BNT162b2 and ChAdOx1-S vaccines. Being female, having chronic diseases, taking medicines routinely and the presence of a SARS-CoV-2 infection (p < 0.05) were associated with strong SEs after the BNT162b2 vaccine second dose. Having a history of allergies and a female sex (p < 0.01) were associated with strong SEs after the ChAdOx1-S vaccine second dose. Furthermore, the results reveal, for the first time, the associations between having a history of allergies, chronic diseases, medication usage, and SEs of a strong magnitude for the BNT162b2 and ChAdOx1-S vaccines. Additionally, this study supports the association of the female sex and infection with SARS-CoV-2 with an increased potential of developing stronger SEs with certain anti-SARS-CoV-2 vaccines.

2.
J Immunol Res ; 2023: 7944102, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37850119

RESUMO

Midkine (MK) and pleiotrophin (PTN) belong to the same family of cytokines. They have similar sequences and functions. Both have important roles in cellular proliferation, tumors, and diseases. They regulate and are expressed by some immune cells. We have recently demonstrated MK production by some human innate antigen-presenting cells (iAPCs), i.e., monocyte-derived dendritic cells (MDDCs) and macrophages stimulated through Toll-like receptor (TLR)-4, and plasmacytoid dendritic cells (pDCs) stimulated through TLR 7. While PTN production was only documented in tissue macrophages. TLRs 3, 7, 8, and 9 are nucleic acid sensing (NAS) TLRs that detect nucleic acids from cell damage and infection and induce iAPC responses. We investigated whether NAS TLRs can induce MK and PTN production by human iAPCs, namely monocytes, macrophages, MDDCs, myeloid dendritic cells (mDCs), and pDCs. Our results demonstrated for the first time that PTN is produced by all iAPCs upon TLR triggering (p < 0.01). IAPCs produced more PTN than MK (p < 0.01). NAS TLRs and iAPCs had differential abilities to induce the production of MK, which was induced in monocytes and pDCs by all NAS TLRs (p < 0.05) and in MDDCs by TLRs 7/8 (p < 0.05). TLR4 induced a stronger MK production than NAS TLRs (p ≤ 0.05). Monocytes produced higher levels of PTN after differentiation to macrophages and MDDCs (p < 0.05). The production of MK and PTN differs among iAPCs, with a higher production of PTN and a selective induction of MK production by NAS TLR. This highlights the potentially important role of iAPCs in angiogenesis, tumors, infections, and autoimmunity through the differential production of MK and PTN upon TLR triggering.


Assuntos
Citocinas , Neoplasias , Humanos , Células Dendríticas , Midkina
3.
Sultan Qaboos Univ Med J ; 23(1): 68-75, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36865417

RESUMO

Objectives: Identification of the high risk alleles, genotypes and haplotypes of the human leukocyte antigens (HLA) in different populations is beneficial for understanding their roles in type 1 diabetes (T1D) pathogenesis and intervention practices. This study aimed to identify T1D-associated HLA gene alleles in the Omani population. Methods: The present case-control study included 73 diabetic seropositive children (mean age 9.08 ± 3.27 years) attending the paediatric clinic at Sultan Qaboos University Hospital in Muscat, Oman, and 110 healthy controls. HLA-A, -B, -C, -DRB1 and -DQB1 genes were genotyped using a sequence-specific primer polymerase chain reaction (SSP-PCR). Results: Two HLA class I alleles (B*08, B*58) and three class II alleles (DQB1*02, DRB1*03 and DRB1*04) were associated with T1D susceptibility, while one class I (B*51) and three class II (DQB1*05, DQB1*06 and DRB1*16) alleles were associated with T1D protection. HLA-DRB1*03 and DQB1*02 alleles showed the strongest risk association among all alleles. Six DRB1 residues (E9, S11, S13, Y30, V70 and K71) were significantly associated with T1D susceptibility. Heterozygous genotypes, HLA-DRB1*03/*04 and DQB1*02/*03 were significantly associated with T1D susceptibility (P <0.0001, odds ratio [OR] = 63.21 and P = 0.02, OR = 3.63, respectively). Furthermore, a significant combined action of DRB1*03-DQB1*02 haplotype in T1D risk (P = 0.000176, OR = 15) and DRB1*16-DQB1*05 haplotype in protection (P = 0.0312, OR = 0.48) was detected. Conclusion: Known HLA class II gene alleles are associated with T1D in Omani children.


Assuntos
Diabetes Mellitus Tipo 1 , Criança , Pré-Escolar , Humanos , Instituições de Assistência Ambulatorial , Estudos de Casos e Controles , Diabetes Mellitus Tipo 1/genética , Cadeias HLA-DRB1/genética , Hospitais Universitários
4.
Int J Infect Dis ; 121: 203-210, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35533833

RESUMO

BACKGROUND: A surge in COVID-19-associated mucormycosis cases has been observed during the second wave of COVID-19 in summer of 2021. Most cases were reported from India. The Delta variant (B.1.617.2) was the most common variant circulating at that time. Mucormycosis is an opportunistic angioinvasive fungal infection with high morbidity and mortality. METHODS: We present 10 cases of COVID-19-associated rhino-orbital and rhino-orbital-cerebral mucormycosis managed in a secondary hospital in Oman. RESULTS: The median time for developing mucormycosis was two weeks after COVID-19 diagnosis. All patients were newly diagnosed or already known to have poorly controlled diabetes mellitus. Five patients received corticosteroid therapy for COVID-19. Three patients had severe COVID-19 and died of severe acute respiratory distress syndrome and septic shock. Another three patients died of advanced mucormycosis and cerebral involvement. Despite aggressive medical and surgical intervention, the mortality rate was 60% (6/10). CONCLUSION: Mucormycosis is an aggressive opportunistic infection with high morbidity and mortality that requires prompt recognition and urgent intervention. Uncontrolled blood sugar, the use of corticosteroids, and immune dysfunction due to COVID-19 are all important risk factors for development of mucormycosis. Worse outcomes are associated with poor glycemic control despite aggressive medical and surgical interventions.


Assuntos
COVID-19 , Mucormicose , Infecções Oportunistas , COVID-19/complicações , Teste para COVID-19 , Humanos , Mucormicose/complicações , Mucormicose/diagnóstico , Mucormicose/tratamento farmacológico , Infecções Oportunistas/complicações , Infecções Oportunistas/diagnóstico , Infecções Oportunistas/tratamento farmacológico , SARS-CoV-2
5.
PLoS One ; 17(4): e0267662, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35476724

RESUMO

The cytokine midkine (MK) is a growth factor that is involved in different physiological processes including tissue repair, inflammation, the development of different types of cancer and the proliferation of endothelial cells. The production of MK by primary human macrophages and monocyte-derived dendritic cells (MDDCs) was never described. We investigated whether MK is produced by primary human monocytes, macrophages and MDDCs and the capacity of macrophages and MDDCs to modulate the proliferation of endothelial cells through MK production. The TLR stimulation of human monocytes, macrophages and MDDCs induced an average of ≈200-fold increase in MK mRNA and the production of an average of 78.2, 62, 179 pg/ml MK by monocytes, macrophages and MDDCs respectively (p < 0.05). MK production was supported by its detection in CD11c+ cells, CLEC4C+ cells and CD68+ cells in biopsies of human tonsils showing reactive lymphoid follicular hyperplasia. JSH-23, which selectively inhibits NF-κB activity, decreased the TLR-induced production of MK in PMBCs, macrophages and MDDCs compared to the control (p < 0.05). The inhibition of MK production by macrophages and MDDCs using anti-MK siRNA decreased the capacity of their supernatants to stimulate the proliferation of endothelial cells (p = 0.01 and 0.04 respectively). This is the first study demonstrating that the cytokine MK is produced by primary human macrophages and MDDCs upon TLR triggering, and that these cells can stimulate endothelial cell proliferation through MK production. Our results also suggest that NF-κB plays a potential role in the production of MK in macrophages and MDDCs upon TLR stimulation. The production of MK by macrophages and MDDCs and the fact that these cells can enhance the proliferation of endothelial cells by producing MK are novel immunological phenomena that have potentially important therapeutic implications.


Assuntos
Células Endoteliais , Monócitos , Proliferação de Células , Citocinas/metabolismo , Células Dendríticas , Humanos , Lectinas Tipo C/metabolismo , Macrófagos , Glicoproteínas de Membrana/metabolismo , Midkina/metabolismo , NF-kappa B/metabolismo , Receptores Imunológicos/metabolismo
6.
Artigo em Inglês | MEDLINE | ID: mdl-34802414

RESUMO

Metabolites produced by bacteria can influence the immune system. These metabolites are produced by pathogenic bacteria as well as the friendly microbiota. This review sheds light on the major bacterial metabolites and their structures. It also describes the capacity of these molecules to stimulate and inhibit the immune responses in a way that affects their capacity to control different diseases.


Assuntos
Amigos , Microbiota , Humanos , Bactérias , Microbiota/fisiologia , Sistema Imunitário
7.
J Med Virol ; 93(6): 3915-3924, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33155686

RESUMO

BACKGROUND: Interleukin-6 (IL-6) is produced by and impacts different cell types in human. IL-6 is associated with different diseases and viral infections, including COVID-19. To our knowledge, no normal values were reported for IL-6 in the blood of healthy individuals. We have reviewed and performed a meta-analysis on a total of 140 studies, including 12,421 values for IL-6 in the blood of healthy adult donors. Among these studies, 83 did not report a mean value and the standard deviation. Therefore, for the statistical analysis, we used the values reported in 57 studies, which included 3166 values for IL-6. RESULTS: The reported values for IL-6 in the blood of healthy donors varied between 0 and 43.5 pg/ml. The pooled estimate of IL-6 was 5.186 pg/ml (95% confidence interval [CI]: 4.631, 5.740). As the age increased by 1 year, IL-6 values increased by 0.05 pg/ml (95% CI: 0.02, 0.09; p < .01). Though the heterogenicity, as determined by I2 statistics, was high in our study, the differences in IL-6 values are still at the level of a few pg/ml, which might be related to the differences in the conditions that influence IL-6 production in the healthy population. CONCLUSIONS: This is the first meta-analysis reporting the levels of IL-6 in the blood of healthy donors based on a large number of studies and donors. Therefore the 95% CI values determined in our study could well serve as a reference range for quick decision-making in clinical interventions, particularly those aiming to inhibit IL-6, especially urgent interventions, for example, COVID-19.


Assuntos
Interleucina-6/sangue , COVID-19/sangue , Bases de Dados Factuais , Humanos , Valores de Referência , SARS-CoV-2
8.
Sleep Breath ; 23(4): 1331-1339, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31041780

RESUMO

PURPOSE: The state of knowledge about the effect of sleep deprivation on the immune system is scarce and conflicting. It would therefore be useful to investigate the consequences of sleep deprivation on the immune system. We have studied the effect of sleep deprivation on the changes in neutrophil functions, and the ex vivo proliferative pattern of CD4+ T lymphocytes in relationship with blood cytokine and chemokine levels due to the crucial role of these cells in mounting potent immune responses. METHODS: Healthy volunteers were followed for 3 weeks. They had normal sleep in weeks 1 and 3 and they were sleep-deprived on week 2, sleeping < 6 h per 24 h, a pattern similar to sleep behaviors of many chronically sleep-deprived individuals. We assessed the levels of Th1/Th2 and inflammatory cytokines and chemokines, CD4+ T cells, and the NADPH oxidase activation and phagocytic functions in neutrophils. RESULTS: Our results suggest that sleep deprivation leads to a decreased neutrophil capacity to phagocytose bacteria and activate NADPH oxidase (p < 0.05). Sleep deprivation was associated with a potential increase in CXCL9 levels and decrease in CXCL10/CXCL9 and CCL5/CXCL9 ratios (p < 0.05). Furthermore, our results suggest that the decrease in CD4+ T cell due to sleep deprivation was not associated with changes in their proliferation as observed by Ki67 levels, but rather, it correlated with changes in CXCL10/CXCL9 ratio (p < 0.05). CONCLUSIONS: Sleep deprivation may lead to a decreased phagocytosis and NADPH oxidase activity in neutrophils and a decrease in the levels of CD4+ T cells which is related to changes in the Th1-related chemokine balance.


Assuntos
Contagem de Linfócito CD4 , Quimiocinas/fisiologia , Neutrófilos/fisiologia , Privação do Sono/imunologia , Equilíbrio Th1-Th2/fisiologia , Adulto , Proliferação de Células , Citocinas/sangue , Feminino , Humanos , Masculino , NADPH Oxidases/sangue , Fagocitose/imunologia , Valores de Referência
9.
J Immunol Res ; 2018: 9480497, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29854853

RESUMO

The role of the innate immune response in detecting RNA viruses is crucial for the establishment of proper inflammatory and antiviral responses. Different receptors, known as pattern recognition receptors (PRRs), are present in the cytoplasm, endosomes, and on the cellular surface. These receptors have the capacity to sense the presence of viral nucleic acids as pathogen-associated molecular patterns (PAMPs). This recognition leads to the induction of type 1 interferons (IFNs) as well as inflammatory cytokines and chemokines. In this review, we provide an overview of the significant involvement of cellular RNA helicases and Toll-like receptors (TLRs) 3, 7, and 8 in antiviral immune defenses.


Assuntos
Moléculas com Motivos Associados a Patógenos/imunologia , RNA Viral/imunologia , Receptores Toll-Like/metabolismo , Viroses/imunologia , Vírus/imunologia , Animais , Citocinas/metabolismo , Humanos , Imunidade Inata , Mediadores da Inflamação/metabolismo , Interferon Tipo I/metabolismo , RNA Helicases/metabolismo , Vírus/genética
10.
Immunol Lett ; 190: 272-278, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28830779

RESUMO

BACKGROUND: There are contradictory reports on the effects of obstructive sleep apnea (OSA) on the immune system. In order to clarify the effect of OSA on the different components of the immune system, we studied the association of OSA with changes in cytokine and chemokine levels, proliferative patterns of CD4 and CD8 T lymphocytes as well as NK cells ex vivo and neutrophil functions. METHODS: We investigated the association of OSA with potential alterations in 14 Th1/Th2 and inflammatory cytokines and chemokines, CD4 and CD8 T cells, NK cells, and the NADPH oxidase activation and phagocytic functions in neutrophils. RESULTS: Our results suggest that the increase in CD4 T cell frequency in OSA is associated with an increased expression of the nuclear protein Ki67 (p<0.05; power>0.8), and is correlated with the levels of IL-1ß (p<0.05; power>0.8). The levels of IL-1ß as well as IL-6 showed a potential increase, while the levels of IFN-γ (p<0.05; power>0.8) and the ratio IFN-γ/IL-4 in the blood were possibly decreased in OSA. Additionally, we observed a potential increase in the expression of Ki67 in CD8hi and CD8lo NK cells (p<0.05; power>0.8). Our results also suggest that neutrophils have a decreased capacity to phagocytose bacteria and activate NADPH oxidase in OSA patients (p<0.05; power>0.8). CONCLUSION: OSA may be associated with inflammatory and pro-Th2 immune responses, an increased proliferative potential of NK and CD4 T cells and a decreased capacity of neutrophils to phagocytose bacteria and produce ROS.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Células Matadoras Naturais/imunologia , Neutrófilos/imunologia , Apneia Obstrutiva do Sono/imunologia , Adulto , Células Cultivadas , Citocinas/sangue , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , NADPH Oxidases/metabolismo , Equilíbrio Th1-Th2
11.
PLoS One ; 11(6): e0158265, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27348308

RESUMO

BACKGROUND: The failure to establish potent anti-HBV T cell responses suggests the absence of an effective innate immune activation. Kupffer cells and liver-infiltrating monocytes/macrophages have an essential role in establishing anti-HBV responses. These cells express the costimulatory molecules CD80 and CD86. CD80 expression on antigen-presenting cells (APCs) induces Th1 cell differentiation, whereas CD86 expression drives the differentiation towards a Th2 profile. The relative expression of CD80, CD86 and PD-L1 on APCs, regulates T cell activation. Few studies investigated CD80 and CD86 expression on KCs and infiltrating monocytes/macrophages in HBV-infected liver and knowledge about the expression of PD-L1 on these cells is controversial. The expression of these molecules together in CD68+ cells has not been explored in HBV-infected livers. METHODS: Double staining immunohistochemistry was applied to liver biopsies of HBV-infected and control donors to explore CD80, CD86 and PD-L1 expression in the lobular and portal areas. RESULTS: Chronic HBV infection was associated with increased CD68+CD86+ cell count and percentage in the lobular areas, and no changes in the count and percentage of CD68+CD80+ and CD68+PD-L1+ cells, compared to the control group. While CD68+CD80+ cell count in portal areas correlated with the fibrosis score, CD68+CD80+ cell percentage in lobular areas correlated with the inflammation grade. CONCLUSION: The upregulation of CD86 but not CD80 and PD-L1 on CD68+ cells in HBV-infected livers, suggests that these cells do not support the induction of potent Th1. Moreover, the expression of CD80 on CD68+ cells correlates with liver inflammation and fibrosis.


Assuntos
Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Antígeno B7-1/metabolismo , Antígeno B7-2/metabolismo , Antígeno B7-H1/metabolismo , Hepatite B Crônica/metabolismo , Fígado/metabolismo , Adulto , Biomarcadores , Biópsia , Estudos de Casos e Controles , Contagem de Células , Feminino , Fibrose , Hepatite B Crônica/patologia , Hepatite B Crônica/virologia , Humanos , Imuno-Histoquímica , Fígado/patologia , Fígado/virologia , Masculino , Pessoa de Meia-Idade , Carga Viral , Adulto Jovem
12.
Iran J Immunol ; 13(2): 114-23, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27350632

RESUMO

BACKGROUND: Helicobacter pylori (H. pylori), is a common infection in pregnant women accompanied by variations in the levels of the IgM, IgA and IgG antibody isotypes. The variations of anti-H. pylori antibodies during and after pregnancy, and the extent of protection they provide to the mother and the fetus are not completely understood. OBJECTIVES: To investigate the changes of the anti-H. pylori IgM, IgA and IgG levels in healthy Omani pregnant women during pregnancy and 3 months after delivery. METHODS: Serum samples obtained from 70 Omani healthy pregnant women, with no history of autoimmune diseases, were tested for anti-H. pylori IgM, IgA and IgG in the first trimester of pregnancy and 3 months after delivery. In parallel and as a control group, sera obtained from a group of 70 healthy non-pregnant Omani women were tested. The levels of anti-H. pylori IgM, IgA and IgG were measured using standard Enzyme Linked Immunosorbent Assays (ELISAs). RESULTS: Anti-H. pylori IgA levels were found to be significantly higher during pregnancy (p=0.046) and after delivery (p=0.02) when compared to the control group. Moreover, a significant increase in the levels of anti-H. pylori IgM, IgA and IgG was detected after delivery (p=0.002) when compared to the levels during pregnancy. CONCLUSION: Pregnancy is associated with an increase in the levels of anti-H. pylori IgA antibodies. In addition, anti-H. pylori IgM, IgG and IgA antibody levels increase after delivery.


Assuntos
Anticorpos Antibacterianos/sangue , Infecções por Helicobacter/imunologia , Helicobacter pylori/imunologia , Imunoglobulina A/sangue , Complicações Infecciosas na Gravidez/imunologia , Gravidez/imunologia , Adulto , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunidade Humoral , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Omã , Adulto Jovem
13.
PLoS One ; 11(4): e0153191, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27065104

RESUMO

AIM: The lack of potent innate immune responses during HCV infection might lead to a delay in initiating adaptive immune responses. Kupffer cells (KCs) and liver-infiltrating monocytes/macrophages (CD68+ cells) are essential to establish effective anti-HCV responses. They express co-stimulatory molecules, CD80 and CD86. CD86 upregulation induces activator responses that are then potentially regulated by CD80. The relative levels of expression of CD80, CD86 and the inhibitory molecule, PD-L1, on CD68+ cells modulate T cell activation. A few studies have explored CD80 and PD-L1 expression on KCs and infiltrating monocytes/macrophages in HCV-infected livers, and none investigated CD86 expression in these cells. These studies have identified these cells based on morphology only. We investigated the stimulatory/inhibitory profile of CD68+ cells in HCV-infected livers based on the balance of CD80, CD86 and PD-L1 expression. METHODS: CD80, CD86 and PD-L1 expression by CD68+ cells in the lobular and portal areas of the liver of chronic HCV-infected (n = 16) and control (n = 14) individuals was investigated using double staining immunohistochemistry. RESULTS: The count of CD68+ KCs in the lobular areas of the HCV-infected livers was lower than that in the control (p = 0.041). The frequencies of CD68+CD80+ cells and CD68+PD-L1+ cells in both lobular and total areas of the liver were higher in HCV-infected patients compared with those in the control group (p = 0.001, 0.031 and 0.007 respectively). Moreover, in the lobular areas of the HCV-infected livers, the frequency of CD68+CD80+ cells was higher than that of CD68+CD86+ and CD68+PD-L1+ cells. In addition, the frequencies of CD68+CD80+ and CD68+CD86+ cells were higher in the lobular areas than the portal areas. CONCLUSIONS: Our results show that CD68+ cells have an inhibitory profile in the HCV-infected livers. This might help explain the delayed T cell response and viral persistence during HCV infection.


Assuntos
Antígeno B7-1/metabolismo , Antígeno B7-2/metabolismo , Antígeno B7-H1/metabolismo , Regulação da Expressão Gênica , Hepatite C/imunologia , Hepatite C/metabolismo , Fígado/imunologia , Adulto , Contagem de Células , Feminino , Humanos , Células de Kupffer/citologia , Células de Kupffer/metabolismo , Masculino , Monócitos/citologia , Monócitos/metabolismo
14.
Hum Immunol ; 77(6): 490-7, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27067905

RESUMO

Around 15-30% of AIDS patients fail to recover their CD4(+) T cell levels following combined antiretroviral therapy despite successful inhibition of HIV-1 replication. The exact reasons for this immune recovery failure are not completely understood. HLA alleles are among the candidate that may explain this failure. A total of 65 adult AIDS patients, with viral load of <50 copies per ml were investigated. Viral load and CD4 T cells counts were performed following standard techniques. HLA genotyping was performed using PCR-SSP technique. The Statistical Package for Social Sciences (SPSS version 19) was used for data processing and analysis. A significantly higher proportion of poor immune responders were carrying HLA-A68 (4.8% compared to 25.0%, P=0.025) and HLA-B15 (2.4% compared to 20.8%, P=0.023). The etiological fraction (Efe%) among carriers of HLA-A68 was 57.89% (95% CI=26.79, 75.79) and was 61.35% (95% CI=35.33, 76.91) among carriers of HLA-B15.


Assuntos
Síndrome da Imunodeficiência Adquirida/tratamento farmacológico , Síndrome da Imunodeficiência Adquirida/imunologia , Terapia Antirretroviral de Alta Atividade , HIV-1 , Antígenos HLA-A/genética , Antígeno HLA-B15/genética , Imunidade Celular/genética , Adulto , Alelos , Feminino , Estudos de Associação Genética , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Carga Viral
15.
BMC Cell Biol ; 16: 30, 2015 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-26714929

RESUMO

BACKGROUND: In mammalian cells, the quality control (QC) of properly folded proteins is monitored in the early secretory pathway, particularly in the endoplasmic reticulum (ER). Several proteins, including our protein of interest, major histocompatibility complex class I (MHC class I), can bypass the first line of ER-QC and reside in post-ER compartments in an unfolded form. Such forms entail both monomeric and dimeric structures that are devoid of peptides and thus cannot fulfill the immunological function of antigen presentation at the cell surface. MHC class I structures become mature and properly folded once loaded with the appropriate peptides in the framework of the peptide loading complex (PLC). Despite the flood of information on the diverse trafficking behavior of different MHC class I alleles, there is still controversy on the actual trajectory followed by improperly folded murine MHC class I alleles, namely H-2Kb. In this study, we employ an in vitro rapamycin trapping assay, live cell imaging, and a biochemical COPII budding approach to further investigate the trafficking of H-2Kb beyond the level of the ER. RESULTS: We confirm the egress of H-2Kb in an unfolded form to a post-ER compartment from where they can cycle back to the ER. Deciphering the exact identity of the post-ER compartment by laser scanning microscopy did not only point to the existence of the ERGIC and cis-Golgi compartments as residency areas for unfolded proteins, but also to the involvement of an addional compartment, that lies in close proximity and possesses high resemblance to the aforementioned compartments. Interestingly, we were capable of showing using the same rapamycin trapping assay that H-2Kb can undergo a potential maturation event during their cycling; this is attained upon addition of peptides and trapping of accumulated post-ER molecules at the cell surface. CONCLUSIONS: Our findings deepen the understanding of H-2Kb trafficking outside the ER and pave the way to decipher the role and the trafficking of certain PLC chaperones, such as tapasin, throughout H-2K(b) post-ER QC. Finally, we demonstrate the plausible usage of the rapamycin assay to assess the trafficking of defected proteins especially in diseases and under therapeutic studies.


Assuntos
Bioquímica/métodos , Antígenos H-2/metabolismo , Sirolimo/farmacologia , Animais , Linhagem Celular , Retículo Endoplasmático/metabolismo , Complexo de Golgi/metabolismo , Antígenos H-2/química , Antígenos H-2/genética , Camundongos , Dobramento de Proteína , Transporte Proteico/efeitos dos fármacos
16.
Eur J Immunol ; 45(4): 1248-57, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25615938

RESUMO

The human MHC class I protein HLA-B*27:05 is statistically associated with ankylosing spondylitis, unlike HLA-B*27:09, which differs in a single amino acid in the F pocket of the peptide-binding groove. To understand how this unique amino acid difference leads to a different behavior of the proteins in the cell, we have investigated the conformational stability of both proteins using a combination of in silico and experimental approaches. Here, we show that the binding site of B*27:05 is conformationally disordered in the absence of peptide due to a charge repulsion at the bottom of the F pocket. In agreement with this, B*27:05 requires the chaperone protein tapasin to a greater extent than the conformationally stable B*27:09 in order to remain structured and to bind peptide. Taken together, our data demonstrate a method to predict tapasin dependence and physiological behavior from the sequence and crystal structure of a particular class I allotype. Also watch the Video Abstract.


Assuntos
Antígeno HLA-B27/química , Proteínas de Membrana Transportadoras/metabolismo , Chaperonas Moleculares/metabolismo , Espondilite Anquilosante/imunologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Sítios de Ligação/genética , Linhagem Celular , Antígeno HLA-B27/genética , Humanos , Camundongos , Modelos Moleculares , Simulação de Dinâmica Molecular , Ligação Proteica , Conformação Proteica , Dobramento de Proteína , Análise de Sequência de DNA , Espondilite Anquilosante/genética
17.
Sultan Qaboos Univ Med J ; 14(4): e478-85, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25364550

RESUMO

OBJECTIVES: Antiphospholipid antibodies fluctuate during a healthy normal pregnancy. This study aimed to investigate the levels of both immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies for cardiolipin and ß2-glycoprotein (ß2GP) among healthy pregnant women. METHODS: This study was conducted between May 2010 and December 2012. A total of 75 healthy Omani pregnant women with no history of autoimmune disease were investigated during their pregnancy and 90 days after delivery at the Armed Forces Hospital in Muscat, Oman. A control group of 75 healthy Omani non-pregnant women were also investigated as a comparison. Levels of IgM and IgG antibodies for both anti-cardiolipin antibodies (ACAs) and ß2GP were measured using a standard enzyme-linked immunosorbent assay. RESULTS: The ACA IgM levels were significantly higher in the control group compared to the pregnant women (P <0.001). No significant differences were observed in the ACA IgM levels between the control group and the pregnant women after delivery. In contrast, ACA IgG levels were significantly higher during pregnancy and after delivery compared with those of the healthy control group (P = 0.007 and 0.002, respectively). The levels of ß2GP IgG were significantly higher during pregnancy than after delivery and in the control group (P = 0.001 and <0.001, respectively). CONCLUSION: In this study, ACA IgG levels increased during healthy pregnancies and after normal deliveries whereas ß2GP IgG levels increased transiently during the pregnancies. Both phenomena were found to be significantly associated with a transient decline in the levels of IgM specific for these antigens. Therefore, the levels of these antibodies may be regulated during a healthy pregnancy.

18.
Asian Pac J Trop Biomed ; 4(8): 610-3, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25183329

RESUMO

OBJECTIVE: To investigate the levels of zinc-α-2-glycoprotein (ZAG) among Omani AIDS patients receiving combined antiretroviral therapy (cART). METHODS: A total of 80 Omani AIDS patients (45 males and 35 females), average age of 36 years, who were receiving cART at the Sultan Qaboos University Hospital (SQUH), Muscat, Oman, were tested for the levels of ZAG. In addition, 80 healthy blood donors (46 males and 34 females), average age of 26 years, attending the SQUH Blood Bank, were tested in parallel as a control group. Measurement of the ZAG levels was performed using a competitive enzyme-linked immunosorbent assay and in accordance with the manufacturer's instructions. RESULTS: The ZAG levels were found to be significantly higher among AIDS patients compared to the healthy individuals (P=0.033). A total of 56 (70%) of the AIDS patients were found to have higher levels of ZAG and 16 (20%) AIDS patients were found to have high ZAG levels, which are significantly (P>0.031) associated with weight loss. CONCLUSIONS: ZAG levels are high among Omani AIDS patients on cART and this necessitates the measurement of ZAG on routine basis, as it is associated with weight loss.

19.
Asian Pac J Trop Biomed ; 3(7): 557-62, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23836413

RESUMO

OBJECTIVE: The antimicrobial activity of the ethanol extract of the Auklandia (Saussurea lappa)root plant was investigated to verify its medicinal use in the treatment of microbial infections. METHODS: The antimicrobial activity of the ethanol extract was tested against clinical isolates of some multidrug-resistant bacteria using the agar well diffusion method. Commercial antibiotics were used as positive reference standards to determine the sensitivity of the clinical isolates. RESULTS: The extracts showed significant inhibitory activity against clinical isolates of methicillin resistant Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia, Extended Spectrum Beta-Lactemase, Acinetobacter baumannii. The minimum inhibitory concentration values obtained using the agar dilution test ranged from 2.0 µg/µL-12.0 µg/µL. In the contrary the water extract showed no activity at all against the tested isolates. Furthermore, the results obtained by examining anti-resistant activity of the plant ethanolic extract showed that at higher concentration of the plant extract (12 µg) all tested bacteria isolates were inhibited with variable inhibition zones similar to those obtained when we applied lower extract concentration using the well diffusion assay. CONCLUSION: The results demonstrated that the crude ethanolic extract of the Auklandia (Saussurea lappa) root plant has a wide spectrum of activity suggesting that it may be useful in the treatment of infections caused by the above clinical isolates (human pathogens).


Assuntos
Bactérias/efeitos dos fármacos , Extratos Vegetais/farmacologia , Saussurea , Acinetobacter baumannii/efeitos dos fármacos , Infecções Bacterianas/tratamento farmacológico , Escherichia coli/efeitos dos fármacos , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Extratos Vegetais/isolamento & purificação , Raízes de Plantas , Pseudomonas aeruginosa/efeitos dos fármacos
20.
J Cell Sci ; 123(Pt 24): 4271-9, 2010 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-21098634

RESUMO

The translocation of cytosolic peptides into the lumen of the endoplasmic reticulum (ER) is a crucial step in the presentation of intracellular antigen to T cells by major histocompatibility complex (MHC) class I molecules. It is mediated by the transporter associated with antigen processing (TAP) protein, which binds to peptide-receptive MHC class I molecules to form the MHC class I peptide-loading complex (PLC). We investigated whether TAP is present and active in compartments downstream of the ER. By fluorescence microscopy, we found that TAP is localized to the ERGIC (ER-Golgi intermediate compartment) and the Golgi of both fibroblasts and lymphocytes. Using an in vitro vesicle formation assay, we show that COPII vesicles, which carry secretory cargo out of the ER, contain functional TAP that is associated with MHC class I molecules. Together with our previous work on post-ER localization of peptide-receptive class I molecules, our results suggest that loading of peptides onto class I molecules in the context of the peptide-loading complex can occur outside the ER.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Compartimento Celular , Retículo Endoplasmático/metabolismo , Animais , Vesículas Revestidas pelo Complexo de Proteína do Envoltório/metabolismo , Linhagem Celular , Complexo de Golgi/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Linfócitos/citologia , Linfócitos/metabolismo , Transporte Proteico
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