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1.
J Allergy Clin Immunol Pract ; 7(6): 1970-1985.e4, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30877075

RESUMO

BACKGROUND: Although autoimmunity and hyperinflammation secondary to recombination activating gene (RAG) deficiency have been associated with delayed diagnosis and even death, our current understanding is limited primarily to small case series. OBJECTIVE: Understand the frequency, severity, and treatment responsiveness of autoimmunity and hyperinflammation in RAG deficiency. METHODS: In reviewing the literature and our own database, we identified 85 patients with RAG deficiency, reported between 2001 and 2016, and compiled the largest case series to date of 63 patients with prominent autoimmune and/or hyperinflammatory pathology. RESULTS: Diagnosis of RAG deficiency was delayed a median of 5 years from the first clinical signs of immune dysregulation. Most patients (55.6%) presented with more than 1 autoimmune or hyperinflammatory complication, with the most common etiologies being cytopenias (84.1%), granulomas (23.8%), and inflammatory skin disorders (19.0%). Infections, including live viral vaccinations, closely preceded the onset of autoimmunity in 28.6% of cases. Autoimmune cytopenias had early onset (median, 1.9, 2.1, and 2.6 years for autoimmune hemolytic anemia, immune thrombocytopenia, and autoimmune neutropenia, respectively) and were refractory to intravenous immunoglobulin, steroids, and rituximab in most cases (64.7%, 73.7%, and 71.4% for autoimmune hemolytic anemia, immune thrombocytopenia, and autoimmune neutropenia, respectively). Evans syndrome specifically was associated with lack of response to first-line therapy. Treatment-refractory autoimmunity/hyperinflammation prompted hematopoietic stem cell transplantation in 20 patients. CONCLUSIONS: Autoimmunity/hyperinflammation can be a presenting sign of RAG deficiency and should prompt further evaluation. Multilineage cytopenias are often refractory to immunosuppressive treatment and may require hematopoietic cell transplantation for definitive management.

3.
PLoS One ; 13(8): e0201880, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30080903

RESUMO

Herpes Simplex Virus type 2 (HSV-2) is a neurotropic human pathogen. Upon de novo infection, the viral infected cell protein 0 (ICP0) is immediately expressed and interacts with various cellular components during the viral replication cycle. ICP0 is a multifunctional regulatory protein that has been shown to be important for both efficient viral replication and virus reactivation from latency. In particular, as previously demonstrated in transfected tissue culture models, ICP0 interacts with the cellular E3 ubiquitin ligase SIAH-1, which targets ICP0 for proteasomal degradation. However, the consequence of this virus-host interaction during the establishment of HSV-2 infection in vivo has not yet been elucidated. Here we confirmed that ICP0 of HSV-2 interacts with SIAH-1 via two conserved PxAxVxP amino acid binding motifs. We also demonstrate in vitro that a SIAH-1 binding-deficient HSV-2 strain, constructed by homologous recombination technology, exhibits an attenuated growth curve and impaired DNA and protein synthesis. This attenuated phenotype was also confirmed in an in vivo ocular infection mouse model. Specifically, viral load of the SIAH-1 binding-deficient HSV-2 mutant was significantly reduced in the trigeminal ganglia and brain stem at day 5 and 7 post infection. Our findings indicate that the interplay between ICP0 and SIAH-1 is important for efficient HSV-2 replication in vivo, thereby affecting viral dissemination kinetics in newly infected organisms, and possibly revealing novel targets for antiviral therapy.


Assuntos
Herpesvirus Humano 2/fisiologia , Interações Hospedeiro-Patógeno/fisiologia , Proteínas Imediatamente Precoces/metabolismo , Proteínas Nucleares/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Virais/metabolismo , Replicação Viral/fisiologia , Animais , Sítios de Ligação/genética , Tronco Encefálico/metabolismo , Tronco Encefálico/virologia , Linhagem Celular , Cricetinae , Modelos Animais de Doenças , Olho/metabolismo , Olho/virologia , Infecções Oculares Virais/genética , Infecções Oculares Virais/metabolismo , Feminino , Herpes Simples/genética , Herpes Simples/metabolismo , Herpesvirus Humano 2/genética , Herpesvirus Humano 2/crescimento & desenvolvimento , Interações Hospedeiro-Patógeno/genética , Humanos , Proteínas Imediatamente Precoces/genética , Camundongos Endogâmicos C57BL , Proteínas Nucleares/genética , Gânglio Trigeminal/metabolismo , Gânglio Trigeminal/virologia , Ubiquitina-Proteína Ligases/genética , Proteínas Virais/genética , Replicação Viral/genética
5.
Front Immunol ; 9: 2984, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30619340

RESUMO

B cell activation via the B cell receptor (BCR) signalosome involves participation of signaling molecules such as BTK and BLNK. Genetic defects in these molecules are known to impair B cell differentiation and subsequently lead to agammaglobulinemia. Here we identified novel mutations in BTK and BLNK in two unrelated patients that perturb the intrinsic B-cell receptor signaling pathway and lead to selective IgM deficiency, whereas production of other immunoglobulin isotypes and IgG antibody response remain intact. Currently it is unknown how BCR signaling strength affects mature B cell development in humans. Both patients show reduced levels of BCR signalosome phosphorylation as well as impaired BCR-dependent Ca2+ influx, which was accompanied by a marked decrease in IgD+IgM+CD27+ MZ-like B-cells. We further describe reduced expression of essential B cell differentiation factors such as BAFF-R and T-Bet in the patients' B-cells, which might contribute to the observed deficiency of MZ-like B cells. MZ-like B cells are known to produce natural IgM antibodies that play an essential role in immune homeostasis. By using surface plasmon resonance (SPR) technology and a synthetic blood group A trisaccharide as antigen we were able to show that both patients lack the presence of anti-blood group A IgM considered to be prototypical natural antibodies whereas IgG levels were normal. Antibody binding dynamics and binding affinity of anti-blood group A IgG were comparable between patients and healthy controls. These results indicate that human IgM deficiency can be associated with signaling defects in the BCR signalosome, defective production of natural IgM antibodies in the blood group A/B/0 system and abnormalities in B cell development.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Tirosina Quinase da Agamaglobulinemia/genética , Agamaglobulinemia/genética , Linfócitos B/imunologia , Imunoglobulina M/deficiência , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adolescente , Adulto , Tirosina Quinase da Agamaglobulinemia/metabolismo , Agamaglobulinemia/imunologia , Linfócitos B/metabolismo , Humanos , Imunoglobulina M/imunologia , Masculino , Receptores de Antígenos de Linfócitos B/imunologia , Receptores de Antígenos de Linfócitos B/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/imunologia
6.
Eur J Immunol ; 47(11): 1959-1969, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28718914

RESUMO

Recent studies identified an emerging role of group 2 and 3 innate lymphoid cells (ILCs) as key players in the generation of T-dependent and T-independent antibody production. In this retrospective case-control study, CD117+ ILCs (including the majority of ILC2 and ILC3) were reduced in patients with common variable immunodeficiency (CVID). The reduction in CD117+ ILCs was distinctive to CVID and could not be observed in patients with X-linked agammaglobulinemia. Patients with a more pronounced reduction in CD117+ ILC numbers showed significantly lower numbers of peripheral MZ-like B cells and an increased prevalence of chronic, non-infectious enteropathy. Subsequent phenotyping of ILC subsets in CVID revealed that the reduction in CD117+ ILC numbers is due to a reduction in ILC2 numbers. In vitro expansion of CVID ILC2 in response to IL-2, IL-7, IL-25 and IL-33 was impaired. Furthermore, upregulation of MHCII and IL-2RA in response to IL-2, IL-7, IL-25 and IL-33 was impaired in CVID ILC2. Thus, our results indicate a dysregulation of ILC subsets with a reduction in ILC2 numbers in CVID, however, further studies are needed to explore whether ILC abnormalities are a primary finding or secondary to disease complications encountered in CVID.


Assuntos
Imunodeficiência de Variável Comum/imunologia , Subpopulações de Linfócitos/imunologia , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas c-kit/imunologia , Estudos Retrospectivos
7.
Clin Immunol ; 183: 41-45, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28705765

RESUMO

Over the past decades, a pleiotropic spectrum of B-cell intrinsic defects leading to early onset agammaglobulinemia and absent B cells has been described. Herein we report terminal 14q32.33 deletion as a novel cause of agammaglobulinemia. We describe a 20-year old man with a 1MB terminal 14q32.33 deletion resulting in a loss of the entire Immunoglobulin heavy chain gene region of chromosome 14. The patient presented with absent serum immunoglobulin levels and absent circulating B cells since age 2. The clinical picture was dominated by severe episodes of recurrent upper respiratory tract infections. In the literature, the most prevalent features of terminal 14q32.33 deletions include mental disability, facial malformation, hypotonia, seizures, and visual problems with retinal abnormalities. Neither increased susceptibility to infections nor agammaglobulinemia have been described as a manifestation of terminal 14q32.33 deletion. Thus, our findings expand the known clinical spectrum of terminal 14q32.33 deletion to include susceptibility to infections.


Assuntos
Agamaglobulinemia/genética , Deleção Cromossômica , Cromossomos Humanos Par 14/genética , Agamaglobulinemia/imunologia , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Masculino , Adulto Jovem
9.
Toxins (Basel) ; 8(11)2016 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-27801832

RESUMO

Among the toxin family of bacterial superantigens, the six members of the enterotoxin gene cluster (egc) seem to have unusual characteristics. They are present in the majority of Staphylococcus aureus strains, but their role in disease remains uncertain. We assessed secretion levels, immunogenicity, and toxicity of native and recombinant egc proteins. After having developed enzyme-linked immunosorbent assays, we found different quantities of egc proteins secreted by bacterial isolates. Supernatants induced proliferation of human peripheral blood mononuclear cells. However, purified recombinant egc proteins were shown to have differing superantigenicity potentials. Immunization with identical amounts of all members of egc, and the prominent toxic agent SEB, resulted in neutralizing antisera. Two egc proteins, SEI and SElN, were found to play a predominant role within the cluster. Both displayed the highest potential to activate blood cells, and were essential to be neutralized in supernatants. The application of a supernatant of a strain bearing only egc was sufficient for a lethal outcome in a rabbit model. Again, neutralization of SEI and SElN led to the survival of all tested animals. Finally, nanogram amounts of purified rSEI and rSElN led to lethality in vivo, pointing out the importance of both as virulence determinants among egc superantigens.


Assuntos
Proteínas de Bactérias , Toxinas Bacterianas , Enterotoxinas , Staphylococcus aureus , Superantígenos , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/farmacologia , Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Toxinas Bacterianas/farmacologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Enterotoxinas/genética , Enterotoxinas/metabolismo , Enterotoxinas/farmacologia , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Coelhos , Proteínas Recombinantes/farmacologia , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/metabolismo , Superantígenos/genética , Superantígenos/metabolismo , Superantígenos/farmacologia
10.
Lancet Infect Dis ; 16(9): 1036-1044, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27296693

RESUMO

BACKGROUND: Staphylococcal toxic shock syndrome is a superantigen-driven potentially life-threatening disease affecting mainly young and otherwise healthy individuals. Currently, no specific treatment or preventive measure is available. We aimed to assess the safety, tolerability, and immunogenicity of a recombinant detoxified toxic shock syndrome toxin-1 variant (rTSST-1v) vaccine in adult volunteers. METHODS: In this randomised, double-blind, adjuvant-controlled, dose-escalation first-in-human trial, healthy adults aged 18-64 years were enrolled from the Medical University of Vienna, Austria. Participants were randomly assigned (2:1 and 3:1) by block randomisation (block sizes of three and 12) to receive increasing doses of rTSST-1v (100 ng to 30 µg) or the adjuvant comparator aluminium hydroxide (Al(OH)3) (200 µg, 600 µg, or 1 mg). Investigators and participants were masked to group allocation. The per-protocol population received a booster immunisation 42 days after the first vaccination. The primary endpoint was safety and tolerability of rTSST-1v. The per-protocol population included all participants who had adhered to the study protocol without any major protocol deviations. The per-protocol population was the primary analysis population for immunogenicity. The trial is registered with EudraCT, number 2013-003716-50, and ClinicalTrials.gov, number NCT02340338. FINDINGS: Between Aug 19, 2014, and April 14, 2015, 46 participants were enrolled (safety population), of whom three were assigned to cohort 1 (two to receive 100 ng rTSST-1v and one to receive 200 µg Al(OH)3), three to cohort 2 (two to receive 300 ng rTSST-1v and one to receive 600 µg Al(OH)3), four to cohort 3 (three to receive 1 µg rTSST-1v and one to receive 1 mg Al(OH)3), 12 to cohort 4 (nine to receive 3 µg rTSST-1v and three to receive 1 mg Al(OH)3), 12 to cohort 5 (nine to receive 10 µg rTSST-1v and three to receive 1 mg Al(OH)3), and 12 to cohort 6 (nine to receive 300 µg rTSST-1v and three to receive 1 mg Al(OH)3). 45 participants (98%) were included in the per-protocol population. rTSST-1v had a good safety profile, and no vaccination-related severe or serious adverse events occurred. Adverse event rates were similar between participants who received rTSST-1v and those who received placebo (26 [76%] vs 10 [83%]; p=0·62) independent of pre-existing TSST-1 immunity. INTERPRETATION: rTSST-1v was safe, well-tolerated, and immunogenic. This study represents an important step in vaccine development to prevent or treat a potentially lethal disease. FUNDING: Biomedizinische Forschungs GmbH.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Imunização Secundária/métodos , Choque Séptico/prevenção & controle , Vacinas Sintéticas/administração & dosagem , Adolescente , Adulto , Toxinas Bacterianas/isolamento & purificação , Método Duplo-Cego , Enterotoxinas/isolamento & purificação , Feminino , Voluntários Saudáveis , Humanos , Esquemas de Imunização , Masculino , Pessoa de Meia-Idade , Superantígenos/isolamento & purificação , Vacinação , Vacinas Sintéticas/efeitos adversos , Vacinas Sintéticas/imunologia , Adulto Jovem
11.
BMC Microbiol ; 16: 13, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26830934

RESUMO

BACKGROUND: Nosocomial infections caused by the bacterial pathogen Staphylococcus aureus can lead to serious complications due to the varying presence of secreted toxins. Comparative studies of genomic information and production rates are needed to assess the pathogenic potential of isolated strains. Genotypic and phenotypic profiling of clinical and colonising isolates of S. aureus was used to characterise the release of exotoxins. Blood isolates were compared with colonisation strains to determine similarities and differences of single strains and clusters. RESULTS: Fifty-one fresh isolates obtained from colonised individuals (n = 29) and S. aureus bacteremia (SAB) patients (n = 22) were investigated. The prevalence of genes encoding for three cytolysins (alpha/beta/gamma toxin) and twenty-four superantigens (SEA-SElX) was determined. Isolates exhibited eighteen distinct combinations of superantigens. Sequence analysis identified mutated open reading frames in hla in 13.7% of all strains, in selw (92.2%) and in selx (15.7%). All corrupted genes were associated with specific clonal complexes. Functional assessment of alpha toxin activity by a rabbit erythrocyte lysis assay revealed that supernatants lacking alpha toxin still displayed hemolysis. This was due to the presence of gamma toxin, as proven by inhibition experiments using antisera raised against the respective recombinant proteins. Alpha toxin, SEC, and TSST1 production was quantified by enzyme-linked immunosorbent assays on supernatants of all hla, sec, and tst positive isolates. Blood isolates and colonising strains showed comparable amounts of secreted proteins within a wide range. Agr types I to IV were identified, but did not allow a prediction of high or low production rates. In contrast, alpha toxin production rates between distinct clonal complexes clearly differed. Spa typing was performed and revealed thirty-two unique spa gene patterns and eight small clusters comprising nineteen isolates. Recognised spa-typing clusters displayed highly similar production rates. CONCLUSION: Production rates of the three most prevalent exotoxins varied within both groups of blood isolates and colonising strains. By comparing genotypes and secretion, we found that identical complex gene patterns did not allow predictions of toxin production and function. However, identification of spa typing clusters was suitable to predict similar quantities of released exotoxins.


Assuntos
Proteínas de Bactérias/genética , Toxinas Bacterianas/metabolismo , Hemolíticos/metabolismo , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Animais , Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/toxicidade , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Genótipo , Hemolíticos/toxicidade , Humanos , Fenótipo , Coelhos , Staphylococcus aureus/classificação , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/metabolismo
12.
Immunotherapy ; 7(12): 1273-92, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26289364

RESUMO

Vaccination has been an important healthcare measure in preventing infectious diseases. The response to vaccination is reduced in immunocompromised patients, primary immune deficiency (PID) and secondary immune deficiency (SID), but vaccination studies still demonstrated a protective effect resulting in reducing complications, hospitalization, treatment costs and even mortality. The primary physician and the specialist directing patient care are responsible for vaccination. Live vaccines are contraindicated in patients with severe immune impairment, killed vaccines are highly recommended in PID and SID. Criteria have been defined to distinguish high- or low-level immune impairment in the different disease entities among PID and SID patients. For patients who do not respond to diagnostic vaccination as characterized by antibody failure immunoglobulin replacement is the mainstay of therapy.


Assuntos
Controle de Doenças Transmissíveis/normas , Hospedeiro Imunocomprometido/imunologia , Síndromes de Imunodeficiência/complicações , Síndromes de Imunodeficiência/imunologia , Vacinação/normas , Doenças Autoimunes/imunologia , Contraindicações , Pessoal de Saúde , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Neoplasias/imunologia , Transplante de Órgãos/efeitos adversos , Guias de Prática Clínica como Assunto , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/imunologia , Vacinas Vivas não Atenuadas/administração & dosagem , Vacinas Vivas não Atenuadas/imunologia
13.
PLoS One ; 10(7): e0133220, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26186701

RESUMO

Loss of function mutations in the recombination activating genes RAG1 and RAG2 have been reported to cause a T-B-NK+ type of severe combined immunodeficiency. In addition identification of hypomorphic mutations in RAG1 and RAG2 has led to an expansion of the spectrum of disease to include Omenn syndrome, early onset autoimmunity, granuloma, chronic cytomegalovirus- or EBV-infection with expansion of gamma/delta T-cells, idiophatic CD4 lymphopenia and a phenotype resembling common variable immunodeficiency. Herein we describe a novel presentation of leaky RAG1 and RAG2 deficiency in two unrelated adult patients with impaired antibody production against bacterial polysaccharide antigens. Clinical manifestation included recurrent pneumonia, sinusitis, otitis media and in one patient recurrent cutaneous vasculitis. Both patients harbored a combination of a null mutation on one allele with a novel hypomorphic RAG1/2 mutation on the other allele. One of these novel mutations affected the start codon of RAG1 and resulted in an aberrant gene and protein expression. The second novel RAG2 mutation leads to a truncated RAG2 protein, lacking the C-terminus with intact core RAG2 and reduced VDJ recombination capacity as previously described in a mouse model. Both patients presented with severely decreased numbers of naïve CD4+ T cells and defective T independent IgG responses to bacterial polysaccharide antigens, while T cell-dependent IgG antibody formation e.g. after tetanus or TBEV vaccination was intact. In conclusion, hypomorphic mutations in genes responsible for SCID should be considered in adults with predominantly antibody deficiency.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Homeodomínio/genética , Síndromes de Imunodeficiência/genética , Mutação , Proteínas Nucleares/genética , Adulto , Linfócitos T CD4-Positivos/imunologia , Proteínas de Ligação a DNA/metabolismo , Feminino , Proteínas de Homeodomínio/metabolismo , Humanos , Síndromes de Imunodeficiência/diagnóstico , Lipopolissacarídeos/imunologia , Proteínas Nucleares/metabolismo
14.
Front Immunol ; 6: 211, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25999949

RESUMO

BACKGROUND: Common variable immunodeficiency (CVID) is the most common clinically severe primary immunodeficiency and comprises a heterogeneous group of patients with recurrent severe bacterial infections due to the failure to produce IgG antibodies after exposure to infectious agents and immunization. Diagnostic recommendations for antibody failure include assessment of isoagglutinins. We have readdressed this four decades old but still accepted recommendation with up to date methodology. METHODS: Anti-A/B IgM- and IgG-antibodies were measured by Diamed-ID Micro Typing, surface plasmon resonance (SPR) using the Biacore(®) device and flow cytometry. RESULTS: When Diamed-ID Micro Typing was used, CVID patients (n = 34) showed IgG- and IgM-isoagglutinins that were comparable to healthy volunteers (n = 28), while all XLA patients (n = 8) had none. Anti-A/B IgM-antibodies were present in more than 2/3 of the CVID patients and showed binding kinetics comparable to anti-A/B IgM-antibodies from healthy individuals. A correlation could be found in CVID patients between levels of anti-A/B IgM-antibodies and levels of serum IgM and PnP-IgM-antibodies. In contrast in CVID patients as a group ABO antibodies were significantly decreased when assessed by SPR, which correlated with levels of switched memory, non-switched memory and naïve B cells, but all CVID patients had low/undetectable anti-A/B IgG-antibodies. CONCLUSION: These results indicate that conventional isoagglutinin assessment and assessment of anti-A/B IgM antibodies are not suited for the diagnosis of impaired antibody production in CVID. Examination of anti-A/B IgG antibodies by SPR provides a useful method for the diagnosis of IgG antibody failure in all CVID patients studied, thus indicating an important additional rationale to start immunoglobulin replacement therapy early in these patients, before post-infectious sequelae develop.

15.
Front Immunol ; 6: 32, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25699049

RESUMO

Hypogammaglobulinemia (serum IgG lower than 2 SD below the age-matched mean) and clinical symptoms such as increased susceptibility to infection, autoimmune manifestations, granulomatous disease, and unexplained polyclonal lymphoproliferation are considered to be diagnostic hallmarks in patients with common variable immunodeficiency (CVID), the most frequent clinically severe primary immunodeficiency syndrome. In the present study, we investigated patients with hypogammaglobulinemia and no clinical or immunological signs of defective cell-mediated immunity and differentiated two groups on the basis of their IgG antibody formation capacity against a variety of different antigens (bacterial toxins, polysaccharide antigens, viral antigens). Patients with hypogammaglobulinemia and intact antibody production (HIAP) displayed no or only mild susceptibility to infections, while CVID patients showed marked susceptibility to bacterial infections that normalized following initiation of IVIG or subcutaneous immunoglobulin replacement therapy. There was a substantial overlap in IgG serum levels between the asymptomatic HIAP group and the CVID patients examined before immunoglobulin treatment. HIAP patients showed normal levels of switched B-memory cells (CD19(+)CD27(+)IgD(-)), while both decreased and normal levels of switched B-memory cells could be found in CVID patients. IgG antibody response to a primary antigen, tick-borne encephalitis virus (TBEV), was defective in CVID patients, thus confirming their substantial defect in IgG antibody production. Defective IgG antibody production against multiple antigens could also be demonstrated in an adult patient with recurrent infections but normal IgG levels. To facilitate early treatment before recurrent infections may lead to organ damage, the antibody formation capacity should be examined in hypogammaglobulinemic patients and the decision to treat should be based on the finding of impaired IgG antibody production.

16.
J Clin Immunol ; 34(8): 941-53, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25205547

RESUMO

PURPOSE: Idiopathic CD4 lymphopenia constitutes a heterogeneous group of immunodeficiencies with characteristically low CD4+ T-cell counts with largely unknown genetic etiology. We here sought to determine the underlying molecular cause in an index family with two patients suffering from combined immunodeficiency that evolved into predominant CD4+ lymphopenia. The more severely affected index patient also presented with selective antibody deficiency against bacterial polysaccharide antigens. METHODS: For the genetic analysis, we used combined homozygosity mapping and exome sequencing. Functional assays included immunoblot analysis, flow cytometry and TCR Vß spectratyping. RESULTS: A novel homozygous missense mutation was revealed in the kinase domain of JAK3 (c.T3196C, p.Cys1066Arg). Further analysis showed revertant chimerism in CD8+ T-cells in both patients. The additional presence of revertant CD4+ T-cells was associated with a milder clinical and immunological phenotype in the second patient, although the role somatic chimerism plays in amelioration of disease phenotype is uncertain, as presence of revertant cells had no effect on residual CD4 cell JAK3 signaling function. Residual activity of JAK3-dependent STAT3 and STAT5 signaling was also found in immortalized B-cell lines indicating a hypomorphic nature of the described mutation which likely contributes to the milder clinical phenotype. CONCLUSIONS: We here present the first case of revertant mosaicism in JAK3 deficiency, manifesting as combined immunodeficiency evolving into predominant CD4+ lymphopenia. Revertant chimerism or hypomorphic mutations in genes typically associated with more severe T-cell deficiency should be considered when assessing patients with milder forms of combined immunodeficiencies.


Assuntos
Linfócitos T CD4-Positivos , Janus Quinase 3/genética , Linfopenia , Imunodeficiência Combinada Severa , Adolescente , Adulto , Sequência de Aminoácidos , Linfócitos T CD4-Positivos/imunologia , Células Cultivadas , Criança , Pré-Escolar , Quimerismo , Feminino , Humanos , Imunoglobulinas/sangue , Lactente , Janus Quinase 3/metabolismo , Linfopenia/genética , Masculino , Dados de Sequência Molecular , Mutação , Fator de Transcrição STAT5/metabolismo , Alinhamento de Sequência , Transdução de Sinais/genética
17.
Toxins (Basel) ; 6(6): 1724-41, 2014 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-24887085

RESUMO

Toxic shock syndrome (TSS) results from the host's overwhelming inflammatory response and cytokine storm mainly due to superantigens (SAgs). There is no effective specific therapy. Application of immunoglobulins has been shown to improve the outcome of the disease and to neutralize SAgs both in vivo and in vitro. However, in most experiments that have been performed, antiserum was either pre-incubated with SAg, or both were applied simultaneously. To mirror more closely the clinical situation, we applied a multiple dose (over five days) lethal challenge in a rabbit model. Treatment with toxic shock syndrome toxin 1 (TSST-1) neutralizing antibody was fully protective, even when administered late in the course of the challenge. Kinetic studies on the effect of superantigen toxins are scarce. We performed in vitro kinetic studies by neutralizing the toxin with antibodies at well-defined time points. T-cell activation was determined by assessing T-cell proliferation (3H-thymidine incorporation), determination of IL-2 release in the cell supernatant (ELISA), and IL-2 gene activation (real-time PCR (RT-PCR)). Here we show that T-cell activation occurs continuously. The application of TSST-1 neutralizing antiserum reduced IL-2 and TNFα release into the cell supernatant, even if added at later time points. Interference with the prolonged stimulation of proinflammatory cytokines is likely to be in vivo relevant, as postexposure treatment protected rabbits against the multiple dose lethal SAg challenge. Our results shed new light on the treatment of TSS by specific antibodies even at late stages of exposure.


Assuntos
Anticorpos Neutralizantes/uso terapêutico , Antitoxinas/uso terapêutico , Toxinas Bacterianas/antagonistas & inibidores , Modelos Animais de Doenças , Enterotoxinas/antagonistas & inibidores , Choque Séptico/tratamento farmacológico , Animais , Anticorpos Neutralizantes/farmacologia , Antitoxinas/farmacologia , Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Toxinas Bacterianas/toxicidade , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Enterotoxinas/genética , Enterotoxinas/metabolismo , Enterotoxinas/toxicidade , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Interleucina-2/genética , Interleucina-2/metabolismo , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Ativação Linfocitária/efeitos dos fármacos , Masculino , Proteínas Mutantes/antagonistas & inibidores , Proteínas Mutantes/metabolismo , Proteínas Mutantes/toxicidade , Coelhos , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/toxicidade , Choque Séptico/etiologia , Choque Séptico/imunologia , Choque Séptico/metabolismo , Superantígenos/genética , Superantígenos/metabolismo , Superantígenos/toxicidade , Análise de Sobrevida , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/metabolismo , Toxicocinética , Fator de Necrose Tumoral alfa/metabolismo
18.
Immunotherapy ; 4(3): 269-72, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22401632

RESUMO

Cortes et al. thoroughly analyzed the effect of the introduction of mass rotavirus vaccination on healthcare utilization in a population of approximately 2 million US children under 5 years of age. According to the results of the study, hospitalization has been reduced from prevaccination periods by 89% for rotavirus diarrhea and by 44% for diarrheal disease. The estimated reduction of hospitalizations during the two (single-year) periods amounted to 64,855 and the respective savings in treatment costs were US$278 million. The significance of this paper is its approach to the estimation of vaccine efficacy by the assessment of vaccination coverage and hospitalization, as well as emergency department and outpatient visits in a large population of children without any 'selection' (e.g., hospitalization) bias.

19.
J Virol ; 85(15): 7644-57, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21632771

RESUMO

Herpes simplex virus (HSV) immediate-early protein ICP0 is a transcriptional activator with E3 ubiquitin ligase activity that induces the degradation of ND10 proteins, including the promyelocytic leukemia protein (PML) and Sp100. Moreover, ICP0 has a role in the derepression of viral genomes and in the modulation of the host interferon response to virus infection. Here, we report that ICP0 interacts with SIAH-1, a cellular E3 ubiquitin ligase that is involved in multiple cellular pathways and is itself capable of mediating PML degradation. This novel virus-host interaction profoundly stabilized SIAH-1 and recruited this cellular E3 ligase into ICP0-containing nuclear bodies. Moreover, SIAH-1 mediated the polyubiquitination of HSV ICP0 in vitro and in vivo. After infection of SIAH-1 knockdown cells with HSV, higher levels of ICP0 were produced, ICP0 was less ubiquitinated, and the half-life of this multifunctional viral regulatory protein was increased. These results indicate an inhibitory role of SIAH-1 during lytic infection by targeting ICP0 for proteasomal degradation.


Assuntos
Proteínas Imediatamente Precoces/metabolismo , Proteínas Nucleares/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Sequência de Bases , Linhagem Celular , Primers do DNA , Interações Hospedeiro-Patógeno , Humanos , Hidrólise , Reação em Cadeia da Polimerase , Ligação Proteica , Ubiquitinação
20.
Toxins (Basel) ; 2(9): 2272-88, 2010 09.
Artigo em Inglês | MEDLINE | ID: mdl-22069685

RESUMO

Staphylococcal superantigens (sAgs), such as toxic shock syndrome toxin 1 (TSST-1), induce massive cytokine production, which may result in toxic shock syndrome (TSS) and sepsis. Recently, we reported that in vitro studies in human peripheral blood mononuclear cells (PBMC) do not reflect the immunological situation of the host, because after exposure to superantigens (sAgs) in vivo, mononuclear cells (MNC) leave the circulation and migrate to organs, e.g., the spleen, liver and lung. Our experimental model of choice is the rabbit because it is comparable to humans in its sensitivity to sAg. T cell activation has been assessed by lymphocyte proliferation and IL-2 gene expression after in vivo challenge with TSST-1 and the mutant antigens; expression of the genes of proinflammatory cytokines were taken as indicators for the inflammatory reaction after the combined treatment with TSST-1 and LPS. The question as to whether the biological activities of TSST-1, e.g., lymphocyte extravasation, toxicity and increased sensitivity to LPS, are mediated by T cell activation or activation by MHC II-only, are unresolved and results are contradictory. We have addressed this question by studying these reactions in vivo, with two TSST-1 mutants: one mutated at the MHC binding site (G31R) with reduced MHC binding with residual activity still present, and the other at the T cell binding site (H135A) with no residual function detectable. Here, we report that the mutant G31R induced all the biological effects of the wild type sAg, while the mutant with non-functional TCR binding did not retain any of the toxic effects, proving the pivotal role of T cells in this system.


Assuntos
Toxinas Bacterianas/farmacologia , Citocinas/metabolismo , Enterotoxinas/farmacologia , Ativação Linfocitária/efeitos dos fármacos , Proteínas Mutantes/farmacologia , Mutação , Superantígenos/farmacologia , Linfócitos T/efeitos dos fármacos , Animais , Toxinas Bacterianas/genética , Toxinas Bacterianas/imunologia , Sítios de Ligação , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Enterotoxinas/genética , Enterotoxinas/imunologia , Feminino , Expressão Gênica/efeitos dos fármacos , Interações Hospedeiro-Patógeno , Ativação Linfocitária/imunologia , Proteínas Mutantes/genética , Proteínas Mutantes/imunologia , Ligação Proteica , Coelhos , Superantígenos/genética , Superantígenos/imunologia , Linfócitos T/imunologia , Linfócitos T/metabolismo
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