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1.
Clin Endocrinol (Oxf) ; 99(6): 566-578, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37656656

RESUMO

OBJECTIVE: Polycystic ovary syndrome (PCOS) is a complex disorder with diverse metabolic implications. Diagnosis typically relies on oligo-amenorrhoea (OA), hyperandrogenism (HA), and polycystic ovarian morphology (PCOM). However, the role of polymenorrhoea in PCOS remains understudied. Additionally, limited information exists regarding metabolic disturbances in women with partial PCOS phenotypes that do not meet diagnostic criteria. This extensive database aims to provide substantial evidence on the metabolic implications of polymenorrhoea and partial PCOS phenotypes. DESIGN: Prospective observational study. PATIENTS AND MEASUREMENTS: In this single-centre study, 6463 women with PCOS-like characteristics and 3142 age-matched healthy women were included. The study compared clinical (anthropometry, modified Ferriman Gallwey [mFG] score), hormonal (serum testosterone), and metabolic (plasma glucose, serum lipids, insulin) characteristics between women diagnosed with PCOS, those with partial PCOS phenotypes, and the healthy control group RESULTS: In all, 5174 women met Rotterdam criteria for PCOS diagnosis, while 737 were classified as Pre-PCOS, including HA (n = 538), OA (n = 121), or PCOM (n = 78). Common clinical features included oligomenorrhoea (75.5%), hirsutism (82.9%), obesity (27.2%), hypertension (1.6%), metabolic syndrome (19.6%), and diabetes mellitus (5.6%). Women diagnosed with PCOS, HA only, and OA only exhibited higher average body mass index, plasma glucose levels (both fasting and 2 h after the oral glucose tolerance test), and lipid fractions in comparison to those with PCOM and the healthy controls. However, indices of insulin resistance were similar among women with PCOS, HA, PCOM, and OA, albeit higher than in the healthy controls. The polymenorrhoea subgroup (5.9%) had lower BMI and serum testosterone, but similar mFG score, plasma glucose, insulin, and lipid levels as the oligomenorrhoea subgroup. CONCLUSION: The metabolic disturbances observed in Pre-PCOS women highlight the need to reassess diagnostic criteria. Including the polymenorrhoea subcategory in PCOS criteria is recommended due to similar metabolic dysfunctions as the oligomenorrhoea group.


Assuntos
Hiperandrogenismo , Síndrome do Ovário Policístico , Feminino , Humanos , Oligomenorreia , Glicemia , Insulina , Testosterona , Lipídeos
2.
Br J Nutr ; 129(10): 1732-1739, 2023 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-35983775

RESUMO

Vitamin D (VD) deficiency (serum 25 hydroxy vitamin D (25(OH)D) concentration of < 20 ng/ml), in endemic proportions, demands a supplementation strategy with optimal dosing regimens. A randomised parallel-group, active-controlled trial was conducted among apparently healthy, VD-deficient subjects, aged 18-60 years who received 600 µg/d (Group A), 1000 µg/d (Group B), 2000 µg/d (Group C) and 60 000 µg/month (Group D) of oral cholecalciferol. The intervention was carried in two phases (I and II) of 12 weeks each, with same dose, separated by a washout phase of 12 weeks. Serum 25(OH)D, intact parathyroid hormones (iPTH), Ca, phosphorous (PO4), alkaline phosphatase (ALP) and spot urine Ca/Cr were measured at baseline, 12, 24 and 36 weeks following the intervention, and adverse events were recorded at each occurrence and at 12, 24 and 36 weeks. A statistically significant time-group interaction was found in serum 25(OH)D concentration (P < 0·05). Serum 25(OH)D concentration increased significantly from baseline to 12 weeks (P < 0·05) in all the groups with no change at 24 weeks but further increase at 36 weeks (P < 0·05). At the end of the study, Group C had maximum increment in serum 25(OH)D concentration, while as Groups C and D (95 %, and 90 %) had higher proportion of subjects VD sufficient than Groups A and B (65 % and 78 %) (P < 0·05). No significant time-dose interactions were observed in serum iPTH, Ca, PO4 and ALP or urine Ca/Cr ratio. Three subjects (two in Group C and one in Group D) developed transient hypercalciuria. Supplementation with daily 2000 µg or monthly 60 000 µg of oral cholecalciferol among adults seems optimal and safe.


Assuntos
Colecalciferol , Deficiência de Vitamina D , Adulto , Humanos , Colecalciferol/efeitos adversos , Cálcio , Vitamina D , Deficiência de Vitamina D/tratamento farmacológico , Hormônio Paratireóideo , Fosfatase Alcalina , Suplementos Nutricionais
3.
Indian J Med Res ; 156(2): 348-356, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-36629195

RESUMO

Background & objectives: Vitamin D deficiency (VDD) is prevalent across all age groups in general population of India but studies among tribal populations are scanty. This study aimed to evaluate the prevalence of VDD in the indigenous tribal population of the Kashmir valley and examine associated risk factors. Methods: In this cross-sectional investigation, a total of 1732 apparently healthy tribal participants (n=786 males and n=946 females) were sampled from five districts of Kashmir valley by using probability proportional to size method. Serum 25-hydroxy vitamin D (25(OH)D) levels were classified as per the Endocrine Society (ES) recommendations: deficiency (<20 ng/ml), insufficiency (20-30 ng/ml) and sufficiency (>30 ng/ml). The serum 25(OH)D levels were assessed in relation to various demographic characteristics such as age, sex, education, smoking, sun exposure, body mass index and physical activity. Results: The mean age of the male participants was 43.79±18.47 yr with a mean body mass index (BMI) of 20.50±7.53 kg/m[2], while the mean age of female participants was 35.47±14.92 yr with mean BMI of 22.24±4.73 kg/m2. As per the ES guidelines 1143 of 1732 (66%) subjects had VDD, 254 (14.71%) had insufficient and 334 (19.3%) had sufficient serum 25(OH)D levels. VDD was equally prevalent in male and female participants. Serum 25(OH)D levels correlated positively with serum calcium, phosphorous and negatively with serum alkaline phosphatase. Gender, sun exposure, altitude, physical activity and BMI did not seem to contribute significantly to VDD risk. Interpretation & conclusions: VD deficiency is highly prevalent among Kashmiri tribals, although the magnitude seems to be lower as compared to the general population. These preliminary data are likely to pave way for further studies analyzing the impact of vitamin D supplementation with analysis of functional outcomes.


Assuntos
Deficiência de Vitamina D , Vitamina D , Humanos , Masculino , Feminino , Estudos Transversais , Deficiência de Vitamina D/epidemiologia , Deficiência de Vitamina D/etiologia , Vitaminas , Índice de Massa Corporal , Prevalência
4.
Indian J Med Res ; 154(3): 467-475, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35345072

RESUMO

Background & objectives: The prevalence of hypertension is increasing among all ethnic groups across the globe with only a handful of studies from India addressing the prevalence of hypertension among tribal population. In view of paucity of data, this study was aimed at estimating the prevalence of hypertension and associated risk factors among tribal population of Kashmir, India. Methods: This cross-sectional survey included 6808 tribals aged >20 yr (5695 Gujjars and 1113 Bakarwals) from five randomly selected districts of Kashmir. Modified WHO-STEPS surveillance questionnaire was used to collect relevant data. Hypertension was defined by Joint National Committee on Prevention, Detection, Evaluation and Treatment of Hypertension (JNC 8) criteria. Results: The mean age of our study participants was 43.12 ± 15.69 years. Overall prevalence of hypertension [95% confidence interval (CI)] was 41.4% (39.9-42.9%) [men=46.7% (44.1-49.1%); women=37.9% (35.9-39.9%)]. The prevalence of prehypertension (95% CI) in our study was 35 per cent (33.7-36.6%). Higher age [adjusted odds ratio (OR) (95% CI): >70 yr-2.2 (1.9-2.4)], passive smoking [OR-1.3 (1.1-1.5)], family history of hypertension [OR-1.6 (1.4-1.7)] and obesity [OR-1.3 (1.1-1.6)] were significantly associated with hypertension. A weak positive correlation was observed between BP (systolic/diastolic) with haemoglobin, red blood cell count and haematocrit (P<0.05). Interpretation & conclusions: Gujjar and Bakarwal tribes of Jammu and Kashmir showed high prevalence of hypertension. Hence, urgent policies and reforms are needed to tackle this silent epidemic and further studies focusing on community-based interventions are required.


Assuntos
Hipertensão , Pré-Hipertensão , Adulto , Estudos Transversais , Feminino , Humanos , Hipertensão/epidemiologia , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência
5.
Front Public Health ; 8: 555840, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33194956

RESUMO

Background: There are scarce data on the prevalence of thyroid disorders and urinary iodine status among tribal populations of India, with no reported data from Kashmir valley. Objectives: To estimate the prevalence of thyroid disorders and evaluate urinary iodine concentration (UIC) and thyroid autoantibody status among Gujjar and Bakerwal tribes of Kashmir valley. Methods: This cross-sectional study recruited tribal subjects using multistage cluster sampling from 5 out of 22 districts of Jammu and Kashmir (J&K). Using a predesigned questionnaire, the details of past or current medical history and drug intake, including thyroid hormone medication etc. were recorded after obtaining an informed consent. Examination included anthropometry (height, weight, waist circumference), blood pressure measurement, and relevant general physical examination focusing on goiter palpation, while as laboratory assessment included estimation of serum thyroid hormone levels, antithyroid peroxidase antibody (anti-TPO Ab), and urinary iodine concentration. Results: A total of 763 subjects (56.4% women and 43.6% men) with a mean(±SD) age of 39.46 (±17.51) ranging from 10 to 85 years and mean(±SD) body mass index (BMI) of 21.28 (±4.16) kg/m2 were studied. Goiter was detected in 6.8%, while 33.2% subjects had some form of thyroid dysfunction (including 24.1% subclinical and 6.8% overt hypothyroidism). Subclinical and overt hyperthyroidism were observed in 1.3 and 0.9% of cases, respectively. Anti-TPO Ab was elevated in 13.6%, while the median [interquartile range (IQR)] for UIC was 154.50 (135) µg/L [156.13 (134) µg/L in men and 147.26 (136) µg/L in women]. A negative correlation was observed between UIC and anti-TPO Ab (r = -0.087, P = <0.05). Conclusion: These novel data on iodine and thyroid status among a tribal population of India generally inhabiting in remote sub-Himalayan belts demonstrate high prevalence of subclinical hypothyroidism (SCH) with persistent iodine deficiency. These preliminary data may warrant large well-designed studies to carry out comprehensive assessment of the problem in this high-risk and marginalized population.


Assuntos
Hipotireoidismo , Iodo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Estudos Transversais , Feminino , Humanos , Hipotireoidismo/epidemiologia , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Adulto Jovem
6.
Diabetes Res Clin Pract ; 169: 108457, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32979420

RESUMO

AIMS: Considering a surge in the incidence of Diabetes mellitus (DM) across all ethnic groups and lack of any representative data from the tribal communities of Jammu and Kashmir, the present study aimed to assess the prevalence of DM and prediabetes in them. METHODS: Subjects were recruited from five districts of Kashmir valley using multistage cluster sampling by probability proportional to size (PPS) technique. Data collection included recording of socio-demographic, medical facts, assessment of anthropometric parameters and biochemical evaluation HbA1c and random blood glucose measurements as per the American Diabetes Association (ADA) criteria were used for diagnosis of DM. RESULTS: A total of 6808 subjects were recruited in this study including 2872 (42%) men and 3936 (58%) women with mean age of 39.60 ± 20.19 years and 35.17 ± 16.70 years, respectively. Around 8.60% subjects were obese, 38.9% were found to be hypertensive, 73% had dyslipidemia and 3.75% had metabolic syndrome. About 1.26% (0.5% males and 0.9% females) had DM and 11.64% had prediabetes based on HbA1c cut offs. Increasing age, body mass index and family history portend significant risk factors while smoking and sedentary lifestyle increased the risk marginally. CONCLUSIONS: Although the prevalence of DM among tribals of Kashmir valley is lower than general population, the higher prediabetes to DM ratio may indicate a future trend of increasing DM prevalence in this disadvantageous subpopulation.


Assuntos
Diabetes Mellitus/epidemiologia , Etnicidade/estatística & dados numéricos , Estado Pré-Diabético/epidemiologia , Adolescente , Adulto , Glicemia/análise , Índice de Massa Corporal , Diabetes Mellitus/sangue , Dislipidemias/epidemiologia , Feminino , Hemoglobinas Glicadas/análise , Inquéritos Epidemiológicos , Humanos , Hipertensão/epidemiologia , Índia/epidemiologia , Masculino , Síndrome Metabólica/epidemiologia , Pessoa de Meia-Idade , Obesidade/epidemiologia , Estado Pré-Diabético/sangue , Prevalência , Fatores de Risco , Adulto Jovem
7.
Artigo em Inglês | MEDLINE | ID: mdl-31781027

RESUMO

Background: Sub-inflammation and insulin resistance characterize women with PCOS. Data on dietary modulation of inflammation among PCOS women is scant, particularly from Indian subcontinent. The present study aimed to assess the effect of plant based vs. animal origin diets on serum markers of inflammation (primary outcome measure). Methods: This observational case-control study compared age and BMI matched PCOS and apparently healthy women from two populations following different dietary practices. The vegetarian women from New-Delhi (n = 82 PCOS and n = 179 healthy) and non-vegetarian women from Srinagar (n = 62 PCOS and n = 141 healthy) formed the groups. Using a uniform methodology, detailed clinical, biochemical, hormonal, and inflammatory marker assessment was undertaken. Results: The mean age of the overall cohort was 26.23 ± 4.59 years with a mean BMI of 24.39 ± 3.72 kg/m2. Overall pro-inflammatory markers (TNF-α, IL-6, IL-1ß, hs-CRP and serum resistin) were significantly higher (p ≤ 0.05) and anti-inflammatory markers (IL-10 and adiponectin) were lower among women with PCOS than healthy subjects. On comparing vegetarian women with non-vegetarians, higher daily calorie intake (1895.46 ± 258.19 vs. 1860.13 ± 323.96 Kcal) with a higher protein and fat and lower carbohydrate intake was recorded in the latter, although the percent energy derived from carbohydrates was higher among vegetarians. Clinical and biochemical parameters were comparable among the groups except mFG score, total serum testosterone and serum lipid levels which were higher among non-vegetarian women as compared to their vegetarian counterparts from both categories (PCOS and healthy). Interestingly, vegetarian women with PCOS and healthy women had higher serum pro-inflammatory and lower anti-inflammatory markers compared to their non-vegetarian counterparts. Conclusion: Women with PCOS consuming Indian vegetarian diet have higher pro-inflammatory and lower anti-inflammatory marker levels than their age and BMI matched healthy non-vegetarian counterparts. This interesting observation can be attributed to the dietary composition, among other factors and needs confirmation from well-designed randomized studies on a larger cohort. Clinical Trial Registration: The study was registered with CTRI database under registration number CTRI/2013/09/003996.

8.
PLoS One ; 11(2): e0148446, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26828945

RESUMO

Eukaryotic Armadillo (ARM) repeat proteins are multifaceted with prominent roles in cell-cell adhesion, cytoskeletal regulation and intracellular signaling among many others. One such ARM repeat containing protein, ARM Repeats Only (ARO), has recently been demonstrated in both Toxoplasma (TgARO) and Plasmodium (PfARO) parasites to be targeted to the rhoptries during the late asexual stages. TgARO has been implicated to play an important role in rhoptry positioning i.e. directing the rhoptry towards the apical end of the parasite. Here, we report for the first time that PfARO exhibits a DNA binding property and a dynamic sub-cellular localization between the nucleus (early schizont) and rhoptry (late schizont) during the different stages of the asexual blood-stage life cycle. PfARO possesses a putative nuclear export signal (NES) and the nucleo-apical shuttling was sensitive to Leptomycin B (LMB) suggesting that the nuclear export was mediated by CRM1. Importantly, PfARO specifically bound an A-T rich DNA sequence of the P. falciparum Gyrase A (PfgyrA) gene, suggesting that the DNA binding specificity of PfARO is likely due to the AT-richness of the probe. This is a novel functional characteristic that has not been reported previously for any P. falciparum ARM containing protein and suggests a putative role for PfARO in gene regulation. This study describes for the first time a conserved P. falciparum ARM repeat protein with a high degree of functional versatility.


Assuntos
Proteínas do Domínio Armadillo/metabolismo , Núcleo Celular/metabolismo , Plasmodium falciparum/metabolismo , Proteínas de Protozoários/metabolismo , beta Catenina/metabolismo , Animais , Anticorpos Antiprotozoários/metabolismo , Especificidade de Anticorpos/efeitos dos fármacos , Proteínas do Domínio Armadillo/química , Biomarcadores/metabolismo , Núcleo Celular/efeitos dos fármacos , Sequência Conservada , DNA/metabolismo , Eritrócitos/efeitos dos fármacos , Eritrócitos/parasitologia , Ácidos Graxos Insaturados/farmacologia , Imunofluorescência , Humanos , Estágios do Ciclo de Vida/efeitos dos fármacos , Espectrometria de Massas , Parasitos/efeitos dos fármacos , Parasitos/metabolismo , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/imunologia , Ligação Proteica/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Proteínas de Protozoários/química , Proteínas Recombinantes/metabolismo , Solubilidade
9.
Infect Immun ; 82(1): 152-64, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24126527

RESUMO

Plasmodium falciparum reticulocyte binding-like homologous protein 5 (PfRH5) is an essential merozoite ligand that binds with its erythrocyte receptor, basigin. PfRH5 is an attractive malaria vaccine candidate, as it is expressed by a wide number of P. falciparum strains, cannot be genetically disrupted, and exhibits limited sequence polymorphisms. Viral vector-induced PfRH5 antibodies potently inhibited erythrocyte invasion. However, it has been a challenge to generate full-length recombinant PfRH5 in a bacterial-cell-based expression system. In this study, we have produced full-length recombinant PfRH5 in Escherichia coli that exhibits specific erythrocyte binding similar to that of the native PfRH5 parasite protein and also, importantly, elicits potent invasion-inhibitory antibodies against a number of P. falciparum strains. Antibasigin antibodies blocked the erythrocyte binding of both native and recombinant PfRH5, further confirming that they bind with basigin. We have thus successfully produced full-length PfRH5 as a functionally active erythrocyte binding recombinant protein with a conformational integrity that mimics that of the native parasite protein and elicits potent strain-transcending parasite-neutralizing antibodies. P. falciparum has the capability to develop immune escape mechanisms, and thus, blood-stage malaria vaccines that target multiple antigens or pathways may prove to be highly efficacious. In this regard, antibody combinations targeting PfRH5 and other key merozoite antigens produced potent additive inhibition against multiple worldwide P. falciparum strains. PfRH5 was immunogenic when immunized with other antigens, eliciting potent invasion-inhibitory antibody responses with no immune interference. Our results strongly support the development of PfRH5 as a component of a combination blood-stage malaria vaccine.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antiprotozoários/imunologia , Basigina/imunologia , Proteínas de Transporte/imunologia , Eritrócitos/imunologia , Interações Hospedeiro-Parasita/imunologia , Vacinas Antimaláricas/imunologia , Plasmodium falciparum/imunologia , Animais , Basigina/metabolismo , Proteínas de Transporte/metabolismo , Eritrócitos/parasitologia , Escherichia coli , Evasão da Resposta Imune/imunologia , Malária Falciparum/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Ligação Proteica/imunologia , Proteínas Recombinantes/imunologia
10.
Infect Immun ; 81(2): 441-51, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23184525

RESUMO

Blood-stage malaria vaccines that target single Plasmodium falciparum antigens involved in erythrocyte invasion have not induced optimal protection in field trials. Blood-stage malaria vaccine development has faced two major hurdles, antigenic polymorphisms and molecular redundancy, which have led to an inability to demonstrate potent, strain-transcending, invasion-inhibitory antibodies. Vaccines that target multiple invasion-related parasite proteins may inhibit erythrocyte invasion more efficiently. Our approach is to develop a receptor-blocking blood-stage vaccine against P. falciparum that targets the erythrocyte binding domains of multiple parasite adhesins, blocking their interaction with their receptors and thus inhibiting erythrocyte invasion. However, with numerous invasion ligands, the challenge is to identify combinations that elicit potent strain-transcending invasion inhibition. We evaluated the invasion-inhibitory activities of 20 different triple combinations of antibodies mixed in vitro against a diverse set of six key merozoite ligands, including the novel ligands P. falciparum apical asparagine-rich protein (PfAARP), EBA-175 (PfF2), P. falciparum reticulocyte binding-like homologous protein 1 (PfRH1), PfRH2, PfRH4, and Plasmodium thrombospondin apical merozoite protein (PTRAMP), which are localized in different apical organelles and are translocated to the merozoite surface at different time points during invasion. They bind erythrocytes with different specificities and are thus involved in distinct invasion pathways. The antibody combination of EBA-175 (PfF2), PfRH2, and PfAARP produced the most efficacious strain-transcending inhibition of erythrocyte invasion against diverse P. falciparum clones. This potent antigen combination was selected for coimmunization as a mixture that induced balanced antibody responses against each antigen and inhibited erythrocyte invasion efficiently. We have thus demonstrated a novel two-step screening approach to identify a potent antigen combination that elicits strong strain-transcending invasion inhibition, supporting its development as a receptor-blocking malaria vaccine.


Assuntos
Anticorpos Neutralizantes/imunologia , Antígenos de Protozoários/imunologia , Interações Hospedeiro-Parasita/imunologia , Vacinas Antimaláricas/imunologia , Merozoítos/imunologia , Plasmodium falciparum/imunologia , Animais , Anticorpos Antiprotozoários/imunologia , Eritrócitos/imunologia , Eritrócitos/parasitologia , Ligantes , Malária Falciparum/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Ligação Proteica/imunologia , Domínios e Motivos de Interação entre Proteínas/imunologia , Proteínas de Protozoários/imunologia , Proteínas Recombinantes/imunologia
11.
PLoS One ; 6(2): e17102, 2011 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-21386888

RESUMO

Erythrocyte invasion by Plasmodium merozoites is a complex, multistep process that is mediated by a number of parasite ligand-erythrocyte receptor interactions. One such family of parasite ligands includes the P. falciparum reticulocyte binding homologue (PfRH) proteins that are homologous with the P. vivax reticulocyte binding proteins and have been shown to play a role in erythrocyte invasion. There are five functional PfRH proteins of which only PfRH2a/2b have not yet been demonstrated to bind erythrocytes. In this study, we demonstrated that native PfRH2a/2b is processed near the N-terminus yielding fragments of 220 kDa and 80 kDa that exhibit differential erythrocyte binding specificities. The erythrocyte binding specificity of the 220 kDa processed fragment of native PfRH2a/2b was sialic acid-independent, trypsin resistant and chymotrypsin sensitive. This specific binding phenotype is consistent with previous studies that disrupted the PfRH2a/2b genes and demonstrated that PfRH2b is involved in a sialic acid independent, trypsin resistant, chymotrypsin sensitive invasion pathway. Interestingly, we found that the smaller 80 kDa PfRH2a/2b fragment is processed from the larger 220 kDa fragment and binds erythrocytes in a sialic acid dependent, trypsin resistant and chymotrypsin sensitive manner. Thus, the two processed fragments of PfRH2a/2b differed with respect to their dependence on sialic acids for erythrocyte binding. Further, we mapped the erythrocyte binding domain of PfRH2a/2b to a conserved 40 kDa N-terminal region (rPfRH2(40)) in the ectodomain that is common to both PfRH2a and PfRH2b. We demonstrated that recombinant rPfRH2(40) bound human erythrocytes with the same specificity as the native 220 kDa processed protein. Moreover, antibodies generated against rPfRH2(40) blocked erythrocyte invasion by P. falciparum through a sialic acid independent pathway. PfRH2a/2b thus plays a key role in erythrocyte invasion and its conserved receptor-binding domain deserves attention as a promising candidate for inclusion in a blood-stage malaria vaccine.


Assuntos
Eritrócitos/parasitologia , Plasmodium falciparum/genética , Plasmodium falciparum/fisiologia , Proteínas de Protozoários/fisiologia , Reticulócitos/metabolismo , Adesão Celular/genética , Moléculas de Adesão Celular/química , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Moléculas de Adesão Celular/fisiologia , Células Cultivadas , Clonagem Molecular , Eritrócitos/metabolismo , Eritrócitos/fisiologia , Humanos , Proteínas de Membrana/química , Proteínas de Membrana/genética , Modelos Biológicos , Plasmodium falciparum/metabolismo , Plasmodium falciparum/patogenicidade , Domínios e Motivos de Interação entre Proteínas/genética , Domínios e Motivos de Interação entre Proteínas/fisiologia , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Reticulócitos/parasitologia , Homologia de Sequência
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