Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.154
Filtrar
1.
Braz J Infect Dis ; 23(4): 246-253, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31421107

RESUMO

Accurate and rapid diagnostic tools are important aspects of managing tuberculosis (TB) cases appropriately. However, the sensitivity and specificity of diagnostic kits based on immune response such as the tuberculin skin test (TST) and interferon gamma release assay (IGRA) are still debated. Thus, the exploration and assessment of specific biomarker-targeted antibodies are needed for the development of an accurate and rapid diagnostic tool. The present study was conducted in patients with a respiratory problem suspected to be TB at Dr. Soetomo Hospital, Surabaya, Indonesia. Among 102 patients tested by GeneXpert and AFB, 59 serum samples were from cases retrospectively determined to have active TB. A total of 102 serum of healthy controls (HC) was also collected. The PPD antigen and the recombinant CFP-10 and ESAT-6 proteins were prepared. Antibody responses against these proteins were evaluated by ELISA. All samples were also screened for the possibility of Mycobacterium avium-intracellulare complex (MAC) infection using Capilla MaC kit. The results showed that TB patients had a significantly higher concentration of IgG antibody in response to PPD than the HC. In addition, the receiver operating characteristic (ROC) curve analysis showed that PPD was acceptable for diagnostic purposes with an AUC value of 0.835 (95% CI 0.770-0.900, p < 0.0001). However, ESAT-6 and CFP-10 had low AUCs, and 32 samples from both groups showed a low concentration of IgA antibody against all antigens. The MAC detection results also showed that the concentration of IgA in the HC group was the highest. The current results indicate that PPD is a better antigen for antibody-based detection of TB than ESAT-6 and CFP-10. Based on the MAC detection assay, 53 people in the HC group were probably infected with rapidly growing nontuberculous mycobacteria (NTM), although antibody response to PPD was low.


Assuntos
Formação de Anticorpos/imunologia , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Mycobacterium tuberculosis/imunologia , Tuberculina/imunologia , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/microbiologia , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Criança , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Indonésia , Masculino , Pessoa de Meia-Idade , Valores de Referência , Estudos Retrospectivos , Sensibilidade e Especificidade , Estatísticas não Paramétricas , Teste Tuberculínico , Tuberculose Pulmonar/sangue , Adulto Jovem
2.
Nature ; 571(7763): 122-126, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31189952

RESUMO

Antibodies secreted into mucosal barriers serve to protect the host from a variety of pathogens, and are the basis for successful vaccines1. In type I mucosa (such as the intestinal tract), dimeric IgA secreted by local plasma cells is transported through polymeric immunoglobulin receptors2 and mediates robust protection against viruses3,4. However, owing to the paucity of polymeric immunoglobulin receptors and plasma cells, how and whether antibodies are delivered to the type II mucosa represented by the lumen of the lower female reproductive tract remains unclear. Here, using genital herpes infection in mice, we show that primary infection does not establish plasma cells in the lamina propria of the female reproductive tract. Instead, upon secondary challenge with herpes simplex virus 2, circulating memory B cells that enter the female reproductive tract serve as the source of rapid and robust antibody secretion into the lumen of this tract. CD4 tissue-resident memory T cells secrete interferon-γ, which induces expression of chemokines, including CXCL9 and CXCL10. Circulating memory B cells are recruited to the vaginal mucosa in a CXCR3-dependent manner, and secrete virus-specific IgG2b, IgG2c and IgA into the lumen. These results reveal that circulating memory B cells act as a rapidly inducible source of mucosal antibodies in the female reproductive tract.


Assuntos
Anticorpos/imunologia , Linfócitos B/citologia , Linfócitos B/imunologia , Movimento Celular/imunologia , Memória Imunológica/imunologia , Vagina/citologia , Vagina/imunologia , Animais , Formação de Anticorpos/imunologia , Linfócitos T CD4-Positivos/imunologia , Feminino , Herpes Simples/imunologia , Herpes Simples/virologia , Herpesvirus Humano 2/imunologia , Imunização , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Interferon gama/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Receptores CXCR3/imunologia , Vagina/virologia
3.
Vet Immunol Immunopathol ; 211: 38-43, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31084892

RESUMO

Natural antibodies (NAb) are antibodies that can bind to a particular antigen without any apparent antigenic stimulation. In this paper, a careful analysis has been carried out on NAb levels in goat kid serum; possible correlations with the total immunoglobulin (tot-Ig) levels and specific antibody (SpAb) response were considered. Twenty randomly chosen kids were submitted to a first blood sampling (day 0). After 60 and 100 days, new blood samplings were carried out in the same animals. On day 0, after blood collection, all animals were immunized with a commercial vaccine; the immunization was repeated 30 days apart. Some exogenous antigens were tested to verify their immunoreactivity to NAb. Among them, the synthetic hapten 2,4,6-trinitrophenyl (TNP) conjugated with bovine serum albumin, resulted as the antigen with the higher immunoreactivity to NAb. Tot-Ig levels increased over time (p < 0.001). On the contrary, NAb levels, both IgG- and IgM-isotypes, significantly decreased during the experimental period (p < 0.001 and <0.05, respectively). Linear regression analyses showed a high correlation between IgM-NAb and tot-IgM levels (p < 0.001) at all the evaluated sampling times. However, a significant correlation between IgG-NAb and IgM-NAb was found only at the 1st (p < 0.01) and at the 2nd sampling (p < 0.05). No significant correlations were found between SpAb response and the other assessed humoral immune parameters. The obtained results are discussed in the light of the possible use of NAb assessment for the evaluation of the immune system activity in goat.


Assuntos
Imunidade Adaptativa/imunologia , Anticorpos/imunologia , Cabras/imunologia , Imunoglobulinas/imunologia , Animais , Anticorpos/sangue , Formação de Anticorpos/imunologia , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Cabras/sangue , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Imunoglobulinas/sangue , Masculino
4.
Transplant Proc ; 51(4): 1115-1117, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31101183

RESUMO

INTRODUCTION: Seasonal influenza is an important cause of morbidity and mortality in the post-transplant period; therefore, the influenza vaccination has been recommended for all kidney transplant recipients before the influenza season. However, at least theoretically, the introduction of antigens via vaccines may trigger rejection attacks by causing an antibody response. In this study, we examined the development of de novo panel reactive antibody (PRA) development against the influenza vaccine in kidney transplant recipients. MATERIALS AND METHODS: Overall, 41 kidney transplant recipients who received the influenza vaccination and 50 kidney transplant recipients (study group) who refused to receive the influenza vaccination (control group) were enrolled in the study. Following basal biochemistry examination, the inactivated trivalent influenza vaccine was administered intramuscularly. Panel reactive antibodies were screened in all patients before and after vaccination on days 30 and 180. The primary outcome variable was development of de novo panel reactive antibodies. RESULTS: One patient in the study group developed de novo class I and II PRA at 6 months after vaccination (P > .05), while no antibody development was noted in the control group. Graft dysfunction or biopsy-confirmed rejection was not observed during the follow-up period in both groups. CONCLUSION: The influenza vaccination is generally effective and safe in solid organ transplant recipients. The vaccination procedure has the potential to trigger antibody development and occurrence of rejection. Therefore, vaccinated kidney transplant recipients should be monitored more carefully with regard to PRA; if the graft deteriorates, a rapid transplant biopsy should be performed.


Assuntos
Vacinas contra Influenza/imunologia , Transplante de Rim , Vacinação , Adulto , Formação de Anticorpos/imunologia , Feminino , Rejeição de Enxerto/imunologia , Humanos , Vacinas contra Influenza/administração & dosagem , Influenza Humana/imunologia , Masculino , Pessoa de Meia-Idade , Transplantados , Vacinação/efeitos adversos , Adulto Jovem
5.
Nat Immunol ; 20(5): 534-545, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30962593

RESUMO

Lymph-node (LN) stromal cell populations expand during the inflammation that accompanies T cell activation. Interleukin-17 (IL-17)-producing helper T cells (TH17 cells) promote inflammation through the induction of cytokines and chemokines in peripheral tissues. We demonstrate a critical requirement for IL-17 in the proliferation of LN and splenic stromal cells, particularly fibroblastic reticular cells (FRCs), during experimental autoimmune encephalomyelitis and colitis. Without signaling via the IL-17 receptor, activated FRCs underwent cell cycle arrest and apoptosis, accompanied by signs of nutrient stress in vivo. IL-17 signaling in FRCs was not required for the development of TH17 cells, but failed FRC proliferation impaired germinal center formation and antigen-specific antibody production. Induction of the transcriptional co-activator IκBζ via IL-17 signaling mediated increased glucose uptake and expression of the gene Cpt1a, encoding CPT1A, a rate-limiting enzyme of mitochondrial fatty acid oxidation. Hence, IL-17 produced by locally differentiating TH17 cells is an important driver of the activation of inflamed LN stromal cells, through metabolic reprogramming required to support proliferation and survival.


Assuntos
Proliferação de Células , Fibroblastos/imunologia , Interleucina-17/imunologia , Linfonodos/imunologia , Células Estromais/imunologia , Animais , Formação de Anticorpos/genética , Formação de Anticorpos/imunologia , Sobrevivência Celular/genética , Sobrevivência Celular/imunologia , Células Cultivadas , Colite/genética , Colite/imunologia , Colite/metabolismo , Encefalomielite Autoimune Experimental/genética , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/metabolismo , Fibroblastos/metabolismo , Interleucina-17/genética , Interleucina-17/metabolismo , Linfonodos/citologia , Linfonodos/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Receptores de Interleucina-17/genética , Receptores de Interleucina-17/imunologia , Receptores de Interleucina-17/metabolismo , Células Estromais/metabolismo , Células Th17/imunologia , Células Th17/metabolismo
6.
Microb Pathog ; 131: 9-14, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30930220

RESUMO

Acinetobacter baumannii is considered as a major cause of nosocomial infection worldwide. Various vaccine formulations have been mostly studied based on secreted or surface-exposed proteins of A. baumannii in murine models. Serum resistance proteins are critical virulence factors in bloodstream infections. AbOmpA and PKF are two major factors involved in serum resistance and could be considered as promising vaccine targets. In this study IgG1, IgG2c, Total-IgG concentrations, survival rates and spleen bacterial loads were studied in C57/BL mice model according to PKF, AbOmpA and AbOmpA + PKF vaccine formulations. The findings showed significant raises of IgG2c and Total-IgG in all three vaccinated groups in comparison with the control group. Whereas, there were low concentrations of IgG1 in all immunization plans. Colony counts of mice spleen showed the bacterial load of PKF plan had the most decrease of bacterial load (DBL = 5 log10 CFU/g). Taken together, this evaluation indicated that PKF vaccination plan induced a polarized Th1 response and rendered an effective protection against bloodstream infection caused by A. baumannii.


Assuntos
Infecções por Acinetobacter/imunologia , Infecções por Acinetobacter/prevenção & controle , Acinetobacter baumannii/patogenicidade , Formação de Anticorpos/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Fatores R/sangue , Sepse/microbiologia , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/genética , Animais , Carga Bacteriana , Proteínas da Membrana Bacteriana Externa/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Clonagem Molecular , Modelos Animais de Doenças , Genes Bacterianos/genética , Imunização , Imunoglobulina G/sangue , Camundongos , Camundongos Endogâmicos C57BL , Fatores R/imunologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Baço/imunologia , Taxa de Sobrevida , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Fatores de Virulência/genética , Fatores de Virulência/imunologia
7.
Int J Mol Sci ; 20(8)2019 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-31013925

RESUMO

The etiology of Kawasaki disease (KD), the leading cause of acquired heart disease in children, is currently unknown. Epidemiology supports a relationship of KD to an infectious disease. Several pathological mechanisms are being considered, including a superantigen response, direct invasion by an infectious etiology or an autoimmune phenomenon. Treating affected patients with intravenous immunoglobulin is effective at reducing the rates of coronary aneurysms. However, the role of B cells and antibodies in KD pathogenesis remains unclear. Murine models are not clear on the role for B cells and antibodies in pathogenesis. Studies on rare aneurysm specimens reveal plasma cell infiltrates. Antibodies generated from these aneurysmal plasma cell infiltrates showed cross-reaction to intracellular inclusions in the bronchial epithelium of a number of pathologic specimens from children with KD. These antibodies have not defined an etiology. Notably, a number of autoantibody responses have been reported in children with KD. Recent studies show acute B cell responses are similar in children with KD compared to children with infections, lending further support of an infectious disease cause of KD. Here, we will review and discuss the inconsistencies in the literature in relation to B cell responses, specific antibodies, and a potential role for humoral immunity in KD pathogenesis or diagnosis.


Assuntos
Anticorpos/imunologia , Linfócitos B/imunologia , Síndrome de Linfonodos Mucocutâneos/etiologia , Animais , Formação de Anticorpos/imunologia , Autoanticorpos/imunologia , Autoimunidade , Linfócitos B/metabolismo , Modelos Animais de Doenças , Suscetibilidade a Doenças , Humanos , Imunidade Humoral , Ativação Linfocitária/imunologia , Síndrome de Linfonodos Mucocutâneos/diagnóstico , Síndrome de Linfonodos Mucocutâneos/epidemiologia , Síndrome de Linfonodos Mucocutâneos/metabolismo
8.
Nat Immunol ; 20(5): 593-601, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30886417

RESUMO

Interferon-λ (IFN-λ) acts on mucosal epithelial cells and thereby confers direct antiviral protection. In contrast, the role of IFN-λ in adaptive immunity is far less clear. Here, we report that mice deficient in IFN-λ signaling exhibited impaired CD8+ T cell and antibody responses after infection with a live-attenuated influenza virus. Virus-induced release of IFN-λ triggered the synthesis of thymic stromal lymphopoietin (TSLP) by M cells in the upper airways that, in turn, stimulated migratory dendritic cells and boosted antigen-dependent germinal center reactions in draining lymph nodes. The IFN-λ-TSLP axis also boosted production of the immunoglobulins IgG1 and IgA after intranasal immunization with influenza virus subunit vaccines and improved survival of mice after challenge with virulent influenza viruses. IFN-λ did not influence the efficacy of vaccines applied by subcutaneous or intraperitoneal routes, indicating that IFN-λ plays a vital role in potentiating adaptive immune responses that initiate at mucosal surfaces.


Assuntos
Imunidade Adaptativa/imunologia , Citocinas/imunologia , Imunidade nas Mucosas/imunologia , Interleucinas/imunologia , Imunidade Adaptativa/efeitos dos fármacos , Imunidade Adaptativa/genética , Animais , Formação de Anticorpos/efeitos dos fármacos , Formação de Anticorpos/imunologia , Células Cultivadas , Citocinas/genética , Citocinas/metabolismo , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Células Dendríticas/virologia , Imunidade nas Mucosas/efeitos dos fármacos , Imunidade nas Mucosas/genética , Imunização/métodos , Vírus da Influenza A/efeitos dos fármacos , Vírus da Influenza A/imunologia , Vírus da Influenza A/fisiologia , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/imunologia , Interleucinas/administração & dosagem , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Infecções por Orthomyxoviridae/virologia , Receptores de Interferon/genética , Receptores de Interferon/imunologia , Receptores de Interferon/metabolismo
9.
Biosens Bioelectron ; 131: 46-52, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30822687

RESUMO

Detection of viral infection is commonly performed using serological techniques like the enzyme-linked immunosorbent assay (ELISA) to detect antibody responses. Such assays may also be used to determine the infection phase based on isotype prevalence. However, ELISAs demonstrate limited sensitivity and are difficult to perform at the point of care. Here, we present a novel technique for label-free, rapid detection of ultra-low concentrations of virus specific antibodies. We have developed a simple, robust capacitive biosensor using microwires coated with Zika or Chikungunya virus envelope antigen. With little discernable nonspecific binding, the sensor can detect as few as 10 antibody molecules in a small volume (10 molecules/30 µL) within minutes. It can also be used to rapidly, specifically, and accurately determine the isotype of antigen-specific antibodies. Finally, we demonstrate that anti-Zika virus antibody can be sensitively and specifically detected in dilute mouse serum and can be isotyped using the sensor. Overall, our findings suggest that our microwire sensor platform has the potential to be used as a reliable, sensitive, and inexpensive diagnostic tool to detect immune responses at the point of care.


Assuntos
Anticorpos Antivirais/isolamento & purificação , Técnicas Biossensoriais , Infecção por Zika virus/diagnóstico , Zika virus/isolamento & purificação , Anticorpos Antivirais/sangue , Formação de Anticorpos/imunologia , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Proteínas do Envelope Viral/sangue , Proteínas do Envelope Viral/isolamento & purificação , Zika virus/patogenicidade , Infecção por Zika virus/virologia
10.
Proc Natl Acad Sci U S A ; 116(8): 3112-3117, 2019 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-30718433

RESUMO

CD8+ T cells are essential effectors in antiviral immunity, recognizing short virus-derived peptides presented by MHC class I (pMHCI) on the surface of infected cells. However, the fraction of viral pMHCI on infected cells that are immunogenic has not been shown for any virus. To approach this fundamental question, we used peptide sequencing by high-resolution mass spectrometry to identify more than 170 vaccinia virus pMHCI presented on infected mouse cells. Next, we screened each peptide for immunogenicity in multiple virus-infected mice, revealing a wide range of immunogenicities. A surprisingly high fraction (>80%) of pMHCI were immunogenic in at least one infected mouse, and nearly 40% were immunogenic across more than half of the mice screened. The high number of peptides found to be immunogenic and the distribution of responses across mice give us insight into the specificity of antiviral CD8+ T cell responses.


Assuntos
Formação de Anticorpos/imunologia , Linfócitos T CD8-Positivos/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Peptídeos/imunologia , Animais , Formação de Anticorpos/genética , Apresentação do Antígeno/genética , Apresentação do Antígeno/imunologia , Antígenos de Histocompatibilidade Classe I/genética , Humanos , Imunidade Celular/genética , Fenômenos Imunogenéticos/genética , Ativação Linfocitária/imunologia , Camundongos , Peptídeos/genética , Linfócitos T Citotóxicos/imunologia , Vírus Vaccinia/imunologia , Vírus Vaccinia/patogenicidade
11.
Fish Shellfish Immunol ; 87: 627-637, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30708057

RESUMO

Aeromonas veronii is an important type of gram-negative pathogen of human-livestock-aquatic animal and causes great economic losses in the aquaculture industry. Vaccination is an effective method of defence against A. veronii. There are many factors that restrict the use of vaccination, and the development of new oral vaccines is urgently needed. The selection of suitable antigens is of great significance for the development of aquaculture vaccines. Bacterial flagellin can specifically bind to TLR5 and induce the release of cytokines from the organism, which could be used in the development of vaccines. In this study, we constructed two recombinant Lactobacillus casei (L. casei) (surface-displayed or secretory) expressing the flaB of A. veronii and evaluated the effect of immune responses in common carp. The flaB gene (900 bp) of A. veronii was subcloned into the L. casei expression plasmids pPG-1 (surface-displayed) and pPG-2 (secretory). Western blot and immunofluorescence assays confirmed the expression of the recombinant flaB protein. Common carp immunized with Lc-pPG-1-flaB and Lc-pPG-2-flaB via oral administration route exhibited induction of antibody expression and innate immune responses. The results indicated that Lc-pPG-1-flaB and Lc-pPG-2-flaB can induce high levels of IgM, ACP, AKP, LZM and SOD activity in organisms, and Lc-pPG-1-flaB can induce even higher levels. The recombinant L. casei may effectively induce humoral immunity and increase the serum immunological index. Furthermore, leukocytes phagocytosis percentage and index of the recombinant L. casei were enhanced. The results of qRT-PCR showed that recombinant L. casei can significantly increase the expression of IL-10, IL-ß, IFN-γ and TNF-α in the tissues of immunized common carp, compared with control groups. Viable recombinant L. casei strains, which were delivered directly survived throughout the intestinal tract. Common carp that received Lc-pPG-1-flaB (66.7%) and Lc-pPG-2-flaB (53.3%) exhibited higher survival rates than the controls after challenge with the pathogen A. veronii. Our work indicated that Lc-pPG-1-flaB and Lc-pPG-2-flaB had beneficial effects on immune response and enhanced the disease resistance of common carp against A. veronii infection. The combination of flaB delivery and the Lactic acid bacteria (LAB) approach may be a promising method for the development of oral vaccines for treating A. veronii. In future research, we will focus on the colonization ability of LAB in the intestines and on the impact of these bacteria on intestinal flora.


Assuntos
Aeromonas veronii/efeitos dos fármacos , Vacinas Bacterianas/imunologia , Carpas/imunologia , Flagelina/farmacologia , Imunização/veterinária , Imunogenicidade da Vacina/imunologia , Lactobacillus casei/imunologia , Administração Oral , Animais , Anticorpos Antibacterianos/imunologia , Formação de Anticorpos/imunologia , Flagelina/administração & dosagem , Vacinas Sintéticas/imunologia
12.
ACS Appl Mater Interfaces ; 11(10): 9824-9831, 2019 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-30758939

RESUMO

We describe the preparation and characterization of synthetic antibodies based on molecularly imprinted polymer nanoparticles (MIP-NPs) for the recognition and binding of the highly conserved and specific peptide motif SWSNKS (3S), an epitope of the envelope glycoprotein 41 (gp41) of human immunodeficiency virus type 1 (HIV-1). This motif is implicated in the decline of CD4+ T cells and leads to the deterioration of the immune system during HIV infection. Therefore, the development of MIP-NPs that can target and block the 3S peptide to prevent subsequent cascade interactions directed toward the killing of CD4+ T cells is of prime importance. Because most antibodies recognize their protein antigen via a conformational or structured epitope (as opposed to a linear epitope commonly used for molecular imprinting), we employed protein molecular modeling to design our template epitope so that it mimics the three-dimensional structure fold of 3S in gp41. The resulting template peptide corresponds to a cyclic structure composed of CGSWSNKSC, with the 3S motif well orientated for imprinting. MIP-NPs with a size of 65 nm were obtained by solid-phase synthesis and were water-soluble. They were prepared by a judicious combination of multiple functional monomers affording hydrogen bonding, ionic, π-π, and hydrophobic interactions, conferring high affinity and selectivity toward both the cyclic peptide and the whole gp41 protein. These results suggest that our MIPs could potentially be used for blocking the function of the 3S motif on the virus.


Assuntos
Anticorpos/administração & dosagem , Infecções por HIV/tratamento farmacológico , Impressão Molecular , Nanopartículas/administração & dosagem , Peptídeos/administração & dosagem , Motivos de Aminoácidos/imunologia , Anticorpos/imunologia , Formação de Anticorpos/imunologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Epitopos/efeitos dos fármacos , Epitopos/imunologia , Proteína gp41 do Envelope de HIV/imunologia , Infecções por HIV/patologia , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/patogenicidade , Humanos , Ligações de Hidrogênio , Nanopartículas/química , Peptídeos/síntese química , Peptídeos/química , Polímeros/administração & dosagem , Polímeros/síntese química , Polímeros/química , Conformação Proteica/efeitos dos fármacos , Linfócitos T/efeitos dos fármacos , Linfócitos T/virologia
13.
PLoS One ; 14(1): e0208455, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30601814

RESUMO

Dengue virus (DENV) is an arbovirus responsible for a significant number of deaths in Latin America. This virus is transmitted through the bite of Aedes aegypti, the main mosquito vector, and Ae. albopictus. During blood uptake, the mosquito injects its saliva into the host to facilitate the feeding process. Mosquito saliva contains potent immunogens capable of inducing antibody production directly related to mosquito bite exposure intensity and disease risk. In this study, we first determined the DENV infection status by two different DENV non-structural protein 1 (NS1) based rapid tests and qRT-PCR, then measured the levels of IgG1 and IgG4 antibodies against salivary proteins of Ae. aegypti female mosquitoes in volunteers living in a dengue endemic area. Our results show that people with a positive DENV diagnosis present higher levels of IgG4 antibodies than people with a negative diagnostic test, and that these antibody levels were higher in people with secondary DENV infections. With this study, we show that detection of IgG4 antibodies against mosquito saliva may be a reliable method to evaluate the risk of dengue infection.


Assuntos
Aedes/imunologia , Dengue/epidemiologia , Imunoglobulina G/imunologia , Proteínas e Peptídeos Salivares/imunologia , Adolescente , Adulto , Animais , Formação de Anticorpos/imunologia , Antígenos Virais/imunologia , Criança , Pré-Escolar , Colômbia/epidemiologia , Feminino , Humanos , Lactente , Pessoa de Meia-Idade , Fatores de Risco , Glândulas Salivares/metabolismo , Proteínas não Estruturais Virais/metabolismo , Adulto Jovem
14.
Nat Commun ; 10(1): 254, 2019 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-30651550

RESUMO

Although B cell response is frequently found in cancer, there is little evidence that it alters tumor development or progression. The process through which tumor-associated antigens trigger humoral response is not well delineated. We investigate the repertoire of antigens associated with humoral immune response in pancreatic ductal adenocarcinoma (PDAC) using in-depth proteomic profiling of immunoglobulin-bound proteins from PDAC patient plasmas and identify tumor antigens that induce antibody response together with exosome hallmark proteins. Additional profiling of PDAC cell-derived exosomes reveals significant overlap in their protein content with immunoglobulin-bound proteins in PDAC plasmas, and significant autoantibody reactivity is observed between PDAC cell-derived exosomes and patient plasmas compared to healthy controls. Importantly, PDAC-derived exosomes induce a dose-dependent inhibition of PDAC serum-mediated complement-dependent cytotoxicity towards cancer cells. In summary, we provide evidence that exosomes display a large repertoire of tumor antigens that induce autoantibodies and exert a decoy function against complement-mediated cytotoxicity.


Assuntos
Formação de Anticorpos/imunologia , Antígenos de Neoplasias/imunologia , Linfócitos B/imunologia , Carcinoma Ductal Pancreático/imunologia , Proteínas do Sistema Complemento/imunologia , Exossomos/imunologia , Neoplasias Pancreáticas/imunologia , Idoso , Idoso de 80 Anos ou mais , Antígenos de Neoplasias/metabolismo , Autoanticorpos/imunologia , Carcinoma Ductal Pancreático/sangue , Linhagem Celular Tumoral , Estudos de Coortes , Conjuntos de Dados como Assunto , Exossomos/metabolismo , Exossomos/ultraestrutura , Feminino , Perfilação da Expressão Gênica , Voluntários Saudáveis , Humanos , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade , Neoplasias Pancreáticas/sangue , Proteômica/métodos , Análise de Sequência de RNA
15.
Int J Biol Macromol ; 125: 469-477, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30528998

RESUMO

Bispecific antibodies (BsAbs), are potential theranostics. Chemical procedures of preparation of BsAbs, in which two monospecific antibodies are split into half molecules and heterodimerized, continue to attract attention in view of their simplicity. Poor dissociation of antibodies with reduced inter-heavy chain disulfides into half molecules under neutral conditions however restricts the BsAbs formation. In this study, we report that the heterodimerization of antibodies can be improved leading to over 6-fold increase in the yield of BsAbs, by carrying out the redox procedure at pH 4.0. In view of improvement in heterodimerization, BsAbs could be conveniently prepared starting from partially purified ion-exchange fraction of the antiserum and purified by twin affinity chromatography on antigen supports. The UV, CD, intrinsic and extrinsic fluorescence spectral analysis of BsAbs prepared by the modified redox procedure were comparable with the native IgG, which suggest the absence of significant acid-pH-induced damage. ThT binding studies and native size exclusion chromatography ruled out amyloid fibril formation.


Assuntos
Ácidos/imunologia , Anticorpos Biespecíficos/imunologia , Formação de Anticorpos/imunologia , Animais , Dimerização , Dissulfetos/imunologia , Concentração de Íons de Hidrogênio , Imunoglobulina G/imunologia , Oxirredução , Coelhos
16.
Methods Mol Biol ; 1904: 147-162, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30539469

RESUMO

Antigen-specific monoclonal antibodies are useful tools to detect very small amounts of antigenic materials and are applicable for antibody therapeutics. To produce mouse monoclonal antibodies, a hybridoma between B lymphocytes and myeloma cells is used to produce antigen-specific monoclonal antibodies. However, a good hybridoma system is not available to obtain human monoclonal antibodies. To produce antigen-specific human monoclonal antibodies, transformation of B lymphocytes with Epstein-Barr viruses or a phage-display system is used. Here, we describe the screening of antigen-specific, antibody-secreting cells using microwell array chips to obtain antigen-specific human monoclonal antibodies. The system can be applied to screen antigen-specific, antibody-secreting cells from any animal species.


Assuntos
Formação de Anticorpos/imunologia , Células Produtoras de Anticorpos/imunologia , Antígenos/imunologia , Epitopos/imunologia , Imunoensaio , Análise em Microsséries , Formação de Anticorpos/genética , Células Produtoras de Anticorpos/metabolismo , Biomarcadores , Expressão Gênica , Vetores Genéticos/genética , Hibridomas/imunologia , Imunoensaio/métodos , Imunofenotipagem , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Análise em Microsséries/métodos
17.
Methods Mol Biol ; 1904: 109-145, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30539468

RESUMO

In the age of personalized medicine, an efficient method to generate monoclonal antibodies (mAbs) is essential for biomedical and immunotherapeutic research. Numerous aspects of basic B-cell biology can be studied at the monoclonal level, including B-cell development, antibody responses to infection or vaccination, and autoimmune responses. Single-cell B-cell receptor cloning allows for the rapid generation of antigen-specific mAbs in a matter of several weeks. In this chapter, we provide an efficient method to generate mAbs from peripheral blood plasmablasts and memory B cells induced by infection and vaccination. Additionally, we provide a protocol on how to optimize single-cell B-cell sorting for both single-cell B-cell receptor cloning and single-cell RNA-sequencing, for the application of studying B-cell specificity and function (spec-seq). This protocol can be easily adapted for other B-cell populations, B cells in tissues, and B cells from other organisms.


Assuntos
Anticorpos Monoclonais/biossíntese , Anticorpos Monoclonais/imunologia , Formação de Anticorpos/imunologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Engenharia de Proteínas , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/isolamento & purificação , Formação de Anticorpos/genética , Biomarcadores , Humanos , Imunidade Humoral , Cadeias Pesadas de Imunoglobulinas/genética , Cadeias Pesadas de Imunoglobulinas/imunologia , Cadeias Leves de Imunoglobulina/genética , Cadeias Leves de Imunoglobulina/imunologia , Memória Imunológica , Imunofenotipagem , Plasmócitos/imunologia , Plasmócitos/metabolismo , Reação em Cadeia da Polimerase
18.
BMJ Case Rep ; 11(1)2018 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-30567127

RESUMO

We report a case of a progressive supranuclear palsy-like phenotype with rapidly progressive dementia and prominent language and executive dysfunction. Pathological examination revealed no midbrain or white matter tauopathy, but rather chronic meningoencephalitis and other mixed pathology. The cerebrospinal fluid (CSF) in this case showed a novel antibody against central nervous system and renal tissue.


Assuntos
Encéfalo/patologia , Demência/diagnóstico , Meningoencefalite/patologia , Paralisia Supranuclear Progressiva/patologia , Proteínas tau/metabolismo , Idoso , Anticorpos/imunologia , Formação de Anticorpos/imunologia , Autopsia/métodos , Encéfalo/diagnóstico por imagem , Evolução Fatal , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Meningoencefalite/diagnóstico por imagem , Meningoencefalite/imunologia , Fenótipo , Tomografia por Emissão de Pósitrons , Paralisia Supranuclear Progressiva/líquido cefalorraquidiano , Paralisia Supranuclear Progressiva/diagnóstico por imagem , Paralisia Supranuclear Progressiva/imunologia
19.
PLoS One ; 13(12): e0208345, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30566493

RESUMO

Preventive HIV-1 vaccine strategies rely on the elicitation of broadly neutralizing antibody (bNAb) responses, but their induction in vivo by vaccination remains challenging. Considering that the ability of an epitope to elicit effective humoral immunity depends on its exposure on the virion, we have used a reverse genetics approach to select variants from an HIV-1 AC10_29 randomly mutated envelope library that showed increased affinity for a selected bNAb (4E10 bNAb targeting the HIV-1 MPER region). Isolated envelope sequences were analyzed by deep-sequencing showing a small number of dominant changes, including the loss of four potential N-linked glycosylation sites and disruption of the V1/V2 loop. Accordingly, the dominant variant (LR1-C1), showed not only increased affinity for MPER bNAbs 4E10 and 2F5, but also higher affinity for an additional antibody targeting the V3 loop (447-52D) that could be a consequence of an open conformation tier 1-like Env. Furthermore, the amino acids specific for the selected variant are associated with an increased sensitivity for 4E10 and 2F5 antibodies. In vivo studies showed that sera from mice immunized with LR1-C1 viruses possessed an improved neutralizing activity compared to the wild-type AC10_29 env. While Virus Like Particles (VLPs) carrying this envelope were unable to induce detectable neutralizing activity in immunized rabbits, one animal showed antibody response to the 4E10-proximal region. Our data establish a novel approach that has the potential to yield HIV envelope immunogen sequences that direct antibody responses to specific envelope regions.


Assuntos
HIV-1/imunologia , Imunidade Humoral/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Formação de Anticorpos/imunologia , Western Blotting , Microscopia Crioeletrônica , Ensaio de Imunoadsorção Enzimática , Feminino , Células HEK293 , Anticorpos Anti-HIV/imunologia , Humanos , Imunização , Camundongos , Camundongos Endogâmicos BALB C , Testes de Neutralização , Coelhos , Vacinas de Partículas Semelhantes a Vírus/imunologia
20.
J Transl Med ; 16(1): 349, 2018 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-30537967

RESUMO

BACKGROUND: we have recently shown that Tel-eVax, a genetic vaccine targeting dog telomerase (dTERT) and based on Adenovirus (Ad)/DNA Electro-Gene-Transfer (DNA-EGT) technology can induce strong immune response and increase overall survival (OS) of dogs affected by multicentric Diffuse Large B cell Lymphoma (DLBCL) when combined to COP therapy in a double-arm study. Here, we have utilized a clinically validated device for veterinary electroporation called Vet-ePorator™, based on Cliniporator™ technology currently utilized and approved in Europe for electrochemotherapy applications and adapted to electrogenetransfer (EGT). METHODS: 17 dogs affected by DLBCL were vaccinated using two Ad vector injections (Prime phase) followed by DNA-EGT (Boost phase) by means of a Vet-ePorator™ device and treated in the same time with a 27-week Madison Wisconsin CHOP protocol. The immune response was measured by ELISA assays using pool of peptides. RESULTS: No significant adverse effects were observed. The OS of vaccine/CHOP animals was 64.5 weeks, in line with the previous study. Dogs developed antibodies against the immunizing antigen. CONCLUSIONS: Tel-eVax in combination with CHOP is safe and immunogenic in lymphoma canine patients. These data confirm the therapeutic efficacy of dTERT vaccine and hold promise for the treatment of dogs affected by other cancer types. More importantly, our findings may translate to human clinical trials and represent new strategies for cancer treatment.


Assuntos
Vacinas Anticâncer/genética , Vacinas Anticâncer/imunologia , Linfoma Difuso de Grandes Células B/terapia , Linfoma Difuso de Grandes Células B/veterinária , Telomerase/metabolismo , Animais , Formação de Anticorpos/imunologia , Protocolos de Quimioterapia Combinada Antineoplásica , Ciclofosfamida , Cães , Doxorrubicina , Feminino , Estimativa de Kaplan-Meier , Cinética , Linfoma Difuso de Grandes Células B/imunologia , Masculino , Prednisona , Análise de Sobrevida , Vacinação , Vincristina
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA