Fatal CTLA-4 Heterozygosity With Autoimmunity and Recurrent Infections: a De Novo Mutation

Primary immunodeficiency disorders are rarely diagnosed in adults but must be considered in the differential diagnosis of combined recurrent infections and autoimmune disease. We describe a patient with CTLA-4 haploinsufficiency and an abnormal regulatory T-cell phenotype. Unusually, infections were more severe than autoimmunity, illustrating therapeutic challenges in disease course.info:eu-repo/semantics/publishedVersio

Antimicrobial activity against oral pathogens and immunomodulatory effects and toxicity of geopropolis produced by the stingless bee Melipona fasciculata Smith

<p>Abstract</p> <p>Background</p> <p>Native bees of the tribe Meliponini produce a distinct kind of propolis called geopropolis. Although many pharmacological activities of propolis have already been demonstrated, little is known about geopropolis, particularly regarding its antimicrobial activity against oral pathogens. The present study aimed at investigating the antimicrobial activity of <it>M. fasciculata </it>geopropolis against oral pathogens, its effects on <it>S. mutans </it>biofilms, and the chemical contents of the extracts. A gel prepared with a geopropolis extract was also analyzed for its activity on <it>S. mutans </it>and its immunotoxicological potential.</p> <p>Methods</p> <p>Antimicrobial activities of three hydroalcoholic extracts (HAEs) of geopropolis, and hexane and chloroform fractions of one extract, were evaluated using the agar diffusion method and the broth dilution technique. Ethanol (70%, v/v) and chlorhexidine (0.12%, w/w) were used as negative and positive controls, respectively. Total phenol and flavonoid concentrations were assayed by spectrophotometry. Immunotoxicity was evaluated in mice by topical application in the oral cavity followed by quantification of biochemical and immunological parameters, and macro-microscopic analysis of animal organs.</p> <p>Results</p> <p>Two extracts, HAE-2 and HAE-3, showed inhibition zones ranging from 9 to 13 mm in diameter for <it>S. mutans </it>and <it>C. albicans</it>, but presented no activity against <it>L</it>. <it>acidophilus</it>. The MBCs for HAE-2 and HAE-3 against <it>S. mutans </it>were 6.25 mg/mL and 12.5 mg/mL, respectively. HAE-2 was fractionated, and its chloroform fraction had an MBC of 14.57 mg/mL. HAE-2 also exhibited bactericidal effects on <it>S. mutans </it>biofilms after 3 h of treatment. Significant differences (p < 0.05) in total phenol and flavonoid concentrations were observed among the samples. Signs toxic effects were not observed after application of the geopropolis-based gel, but an increase in the production of IL-4 and IL-10, anti-inflammatory cytokines, was detected.</p> <p>Conclusions</p> <p>In summary, geopropolis produced by <it>M. fasciculata </it>can exert antimicrobial action against <it>S. mutans </it>and <it>C. albicans</it>, with significant inhibitory activity against <it>S. mutans </it>biofilms. The extract with the highest flavonoid concentration, HAE-2, presented the highest antimicrobial activity. In addition, a geopropolis-based gel is not toxic in an animal model and displays anti-inflammatory effect.</p

Fatal CTLA-4 Heterozygosity With Autoimmunity and Recurrent Infections: a De Novo Mutation

Primary immunodeficiency disorders are rarely diagnosed in adults but must be considered in the differential diagnosis of combined recurrent infections and autoimmune disease. We describe a patient with CTLA-4 haploinsufficiency and an abnormal regulatory T-cell phenotype. Unusually, infections were more severe than autoimmunity, illustrating therapeutic challenges in disease course.info:eu-repo/semantics/publishedVersio

A Novel STAT1 Mutation Associated with Disseminated Mycobacterial Disease

STAT1 is a key component of Interferon (IFN)-gamma and IFN-alpha signaling and mediates protection against mycobacteria, fungal, viral infections, and cancer. Dominant negative inhibitory as well as gain of function heterozygous STAT1 mutations demonstrate that IFN-gamma driven cellular responses need to be tightly regulated to control infections. We describe an autosomal dominant mutation in the SH2 domain of STAT1 that disrupts protein phosphorylation, c.1961T > A (M654K). The mutant allele does not permit STAT1 phosphorylation, and impairs STAT1 phosphorylation of the wild type allele. Protein dimerization is preserved but DNA binding activity, IFN-gamma driven GAS-luciferase activity, and expression of IFN-gamma target genes are reduced. IFN-alpha driven ISRE response, but not IFN-alpha driven GAS response, are preserved when cells are co-transfected with wild type and the mutant STAT1 constructs. M654K exerts a dominant negative effect on IFN-gamma related immunity and is recessive for IFN-alpha induced immune function

IL2RG Reversion Event in a Common Lymphoid Progenitor Leads to Delayed Diagnosis and Milder Phenotype

Severe combined immunodeficiency (SCID) is most frequently caused by mutations in the cytokine receptor common gamma chain, CD132, encoded by the X-linked gene, IL2RG. Most patients present in the first year of life with failure to thrive, severe, opportunistic infections and absence of CD3+ T cells. We present a patient with pediatric illness and a diagnosis of combined variable immune deficiency (CVID) who was diagnosed at age 23 with an inherited IL2RG mutation causing loss of signal transduction through CD132. His peripheral blood included CD3/CD4 and CD3/CD8 positive cells as well as low levels of CD19+ B cells containing a reversion to the wildtype IL2RG allele. The reversion, which was not present at birth, may account for his mild phenotype and late diagnosis