RESUMEN
Metal encapsulation delivers a straightforward strategy to improve miscellaneous nanoparticle properties and qualifies the resulting nanocomposite for exceptional application, including bioimaging, drug release, and theranostic development. Besides crucial applications, investigations associated with the nanocomposite impact on the biological media are highly relevant from a pharmacological viewpoint. Such studies can be conducted by exploring nanocomposite attributes and all aspects of their interaction with proteins existing in biofluids. Based on these aspects, the present work examines manganese-encapsulated carbonaceous nanocomposite (MnCQD) and their interaction with plasma proteins. On one side, the obtained nanocomposite has almost spherical shapes (≈12 nm in size), an appropriate composition and interesting optical properties for bioimaging applications. On another side, MnCQD quenches the fluorescence of two plasma proteins (BSA and HTF) following a static mechanism, confirming the formation of the MnCQD-BSA and MnCQD-HTF complexes. Although hydrophobic forces guide the stability of both formed complexes, MnCQD binds preferentially to BSA compared to HTF, with affinity constants differing by almost an order of magnitude. Furthermore, HTF and BSA underwent modifications in their secondary structure provoked due to contact with the nanocomposite, which also presented neglectable opsonization levels when exposed to appropriate biological media. These results highlight the MnCQD outstanding potential to be employed in diverse bioapplications.Communicated by Ramaswamy H. Sarma.
Asunto(s)
Manganeso , Nanocompuestos , Opsonización , Fluorescencia , Proteínas Sanguíneas , Nanocompuestos/química , Albúmina Sérica Bovina/química , Unión Proteica , Espectrometría de FluorescenciaRESUMEN
BACKGROUND: Opsonization, is the molecular mechanism by which target molecules promote interactions with phagocyte cell surface receptors to remove unwanted cells by induced phagocytosis. We designed an in vitro system to demonstrate that this procedure could be driven to eliminate adipocytes, using peptides mimicking regions of the complement protein C3b to promote opsonization and enhance phagocytosis. Two cell lines were used: (1) THP-1 monocytes differentiated to macrophages, expressing the C3b opsonin receptor CR1 in charge of the removal of unwanted coated complexes; (2) 3T3-L1 fibroblasts differentiated to adipocytes, expressing AQP7, to evaluate the potential of peptides to stimulate opsonization. (3) A co-culture of the two cell lines to demonstrate that phagocytosis could be driven to cell withdrawal with high efficiency and specificity. RESULTS: An array of peptides were designed and chemically synthesized p3691 and p3931 joined bound to the CR1 receptor activating phagocytosis (p < 0.033) while p3727 joined the AQP7 protein (p < 0.001) suggesting that opsonization of adipocytes could occur. In the co-culture system p3980 and p3981 increased lipid uptake to 91.2% and 89.0%, respectively, as an indicator of potential adipocyte phagocytosis. CONCLUSIONS: This in vitro model could help understand the receptorligand interaction in the withdrawal of unwanted macromolecules in vivo. The adipocyte-phagocytosis discussed may help to control obesity, since peptides of C3b stimulated the CR1 receptor, promoting opsonisation and phagocytosis of lipidcontaining structures, and recognition of AQP7 in the differentiated adipocytes, favored the phagocytic activity of macrophages, robustly supported by the co-culture strategy.
Asunto(s)
Fagocitosis , Proteínas del Sistema Complemento , Adipocitos , Técnicas In Vitro , Proteínas Opsoninas , Técnicas de Cocultivo , Células Espumosas , Macrófagos , Microscopía FluorescenteRESUMEN
Candida albicans is a commensal fungus that can cause disease ranging in severity from moderate to severe mucosal infections to more serious life-threating disseminated infections in severely immunocompromised hosts. Chronic mucocutaneous candidiasis (CMC) occurs in patients with mutations in genes affecting IL-17-mediated immunity, such as STAT3, AIRE, RORC, CARD9, IL12B, and IL12RB1, or gain of function (GOF) mutations in STAT1. New strategies for the treatment of candidiasis are needed because of the increased burden of infections and the emergence of drug-resistant strains. In this study, we investigated an aspect of the role of antibodies in the control of C. albicans infection. We tested in vitro the effects of C. albicans opsonization with commercial human polyvalent intravenous IgG (IV IgG) on NADPH oxidase activity and killing of the fungi by blood leukocytes from 11 healthy donors and found a significant enhancement in both phenomena that was improved by IV IgG opsonization. Then, we hypothesized that the opsonization of Candida in vivo could help its elimination by mucosal phagocytes in human patients with mucocutaneous candidiasis. We tested a novel adjunctive treatment for oral candidiasis in humans based on topical treatment with IV IgG. For this purpose, we choose two pediatric patients with well-characterized primary immunodeficiencies who are susceptible to CMC. Two 8-year-old female patients with an autosomal recessive mutation in the IL12RB1 gene (P1, with oral candidiasis) and a GOF mutation in STAT1 (P2, with severe CMC persistent since the age of 8 months and resistant to pharmacological treatments) were treated with IV IgG administered daily three times a day as a mouthwash over the course of 2 weeks. The treatment with the IV IgG mouthwash reduced C. albicans mouth infection by 98 and 70% in P1 and P2, respectively, after 13 days, and complete fungal clearance was observed after complementary nystatin and caspofungin treatments, respectively. Therefore, treatment of oral candidiasis with human polyvalent IgG administered as a mouthwash helps eliminate mucosal infection in humans, circumventing drug resistance, and opening its potential use in patients with primary or transient immunodeficiency.
Asunto(s)
Antifúngicos/administración & dosificación , Candidiasis Mucocutánea Crónica/tratamiento farmacológico , Candidiasis Bucal/tratamiento farmacológico , Inmunoglobulinas Intravenosas/administración & dosificación , Antisépticos Bucales/administración & dosificación , Administración Oral , Candida albicans/efectos de los fármacos , Candida albicans/inmunología , Candida albicans/aislamiento & purificación , Candidiasis Mucocutánea Crónica/genética , Candidiasis Mucocutánea Crónica/inmunología , Candidiasis Mucocutánea Crónica/microbiología , Candidiasis Bucal/genética , Candidiasis Bucal/inmunología , Candidiasis Bucal/microbiología , Caspofungina/administración & dosificación , Niño , Farmacorresistencia Fúngica/efectos de los fármacos , Farmacorresistencia Fúngica/inmunología , Quimioterapia Combinada , Femenino , Humanos , Mutación , Nistatina/administración & dosificación , Fagocitos/efectos de los fármacos , Fagocitos/inmunología , Resultado del TratamientoRESUMEN
The capsular switching process indicates the action of specific capsular antibodies on the meningococcal strains adaptation. Different antibodies were employed for assessing the effect of opsonization on the transformation of Neisseria meningitidis serogroups C and W135. These analyses showed the blocking action of the specific capsular antibodies on the meningococcal transformation capacity. Thus, the blocking effect of these antibodies on N. meningitidis transformation process was demonstrated. This effect could be involved in the capsular switching process and the found data might open new subjects for scientific exploratio.
Asunto(s)
ADN , Anticuerpos , Competencia de la Transformación por ADN , Neisseria meningitidisRESUMEN
O processo de comutação capsular indica a ação de anticorpos capsulares específicos na adaptação de linhagens de meningococo. Foram empregados diferentes anticorpos para verificar o efeito da opzonização sobre a transformação de Neisseria meningitidis dos sorogrupos C e W135. Essas análises mostraram o bloqueio da transformação pela ação de anticorpos capsulares específicos ao meningococo, demonstrando assim o efeito bloqueador da ação desses componentes sobre o processo de transformação de N. meningitidis. Tal efeito pode estar ligado com o processo de comutação capsular e abre novos campos para exploração científica.(AU)
The capsular switching process indicates the action of specific capsular antibodies on the meningococcal strains adaptation. Different antibodies were employed for assessing the effect of opsonization on the transformation of Neisseria meningitidis serogroups C and W135. These analyses showed the blocking action of the specific capsular antibodies on the meningococcal transformation capacity. Thus, the blocking effect of these antibodies on N. meningitidis transformation process was demonstrated. This effect could be involved in the capsular switching process and the found data might open new subjects for scientific exploration.(AU)