A Germinal Center Checkpoint of AIRE in B Cells Limits Antibody Diversification.

In response to antigens, B cells undergo affinity maturation and class switching mediated by activation-induced cytidine deaminase (AID) in germinal centers (GCs) of secondary lymphoid organs, but uncontrolled AID activity can precipitate autoimmunity and cancer. The regulation of GC antibody diversification is of fundamental importance but not well understood. We found that autoimmune regulator (AIRE), the molecule essential for T cell tolerance, is expressed in GC B cells in a CD40-dependent manner, interacts with AID and negatively regulates antibody affinity maturation and class switching by inhibiting AID function. AIRE deficiency in B cells caused altered antibody repertoire, increased somatic hypermutations, elevated autoantibodies to T helper 17 effector cytokines and defective control of skin Candida albicans. These results define a GC B cell checkpoint of humoral immunity and illuminate new approaches of generating high-affinity neutralizing antibodies for immunotherapy.

Generation and Characterization of iPS Cells Derived from APECED Patients for Gene Correction.

APECED (Autoimmune-Polyendocrinopathy-Candidiasis-Ectodermal-Dystrophy) is a severe and incurable multiorgan autoimmune disease caused by mutations in the AIRE (autoimmune regulator) gene. Without functional AIRE, the development of central and peripheral immune tolerance is severely impaired allowing the accumulation of autoreactive immune cells in the periphery. This leads to multiple endocrine and non-endocrine autoimmune disorders and mucocutaneous candidiasis in APECED patients. Recent studies have suggested that AIRE also has novel functions in stem cells and contributes to the regulatory network of pluripotency. In preparation of therapeutic gene correction, we generated and assessed patient blood cell-derived iPSCs, potentially suitable for cell therapy in APECED. Here, we describe APECED-patient derived iPSCs's properties, expression of AIRE as well as classical stem cell markers by qPCR and immunocytochemistry. We further generated self-aggregated EBs of the iPSCs. We show that APECED patient-derived iPSCs and EBs do not have any major proliferative or apoptotic defects and that they express all the classical pluripotency markers similarly to healthy person iPSCs. The results suggest that the common AIRE R257X truncation mutation does not affect stem cell properties and that APECED iPSCs can be propagated in vitro and used for subsequent gene-correction. This first study on APECED patient-derived iPSCs validates their pluripotency and confirms their ability for differentiation and potential therapeutic use.

Response to comment on 'AIRE-deficient patients harbor unique high-affinity disease-ameliorating autoantibodies'.

In 2016, we reported four substantial observations of APECED/APS1 patients, who are deficient in AIRE, a major regulator of central T cell tolerance (Meyer et al., 2016). Two of those observations have been challenged. Specifically, 'private' autoantibody reactivities shared by only a few patients but collectively targeting >1000 autoantigens have been attributed to false positives (Landegren, 2019). While acknowledging this risk, our study-design included follow-up validation, permitting us to adopt statistical approaches to also limit false negatives. Importantly, many such private specificities have now been validated by multiple, independent means including the autoantibodies' molecular cloning and expression. Second, a significant correlation of antibody-mediated IFNα neutralization with an absence of disease in patients highly disposed to Type I diabetes has been challenged because of a claimed failure to replicate our findings (Landegren, 2019). However, flaws in design and implementation invalidate this challenge. Thus, our results present robust, insightful, independently validated depictions of APECED/APS1, that have spawned productive follow-up studies.

Serotonin and tryptophan metabolites, autoantibodies and gut microbiome in APECED.

Objective Intestinal autoimmunity with gastrointestinal (GI) dysfunction has been shown in patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). Patients lack entero-endocrine (EE) cells and have circulating autoantibodies (Aabs) against critical enzymes in serotonin (5-HT) biosynthesis. Design We sought to determine the serum levels of 5-HT, tryptophan (Trp) metabolites and L-DOPA in 37 Finnish APECED patients and to correlate their abundance with the presence of TPH and AADC Aabs, GI dysfunction and depressive symptoms. We also performed an exploratory analysis of the gut microbiome. Methods Serum 5-HT, L-DOPA and Trp metabolite levels were determined by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). TPH and AADC Aabs were measured by ELISA. Depression was assessed with a structured RBDI questionnaire. The V3-V4 regions of the bacterial 16S rRNA gene were sequenced for gut microbiome exploration. Results Serum 5-HT levels were significantly decreased (130 ± 131 nmol/L vs 686 ± 233 nmol/L, P < 0.0001) in APECED patients with TPH-1 (±AADC) Aabs compared to controls and patients with only AADC Aabs. Reduced 5-HT levels correlated with constipation. The genus Escherichia/Shigella was overrepresented in the intestinal microbiome. No correlation between serum Trp, 5-HT or l-DOPA levels and the RBDI total score, fatigue or sleep disorders was found. Conclusions This exploratory study found low serum levels of 5-HT to be associated with constipation and the presence of TPH-1 and AADC Aabs, but not with symptoms of depression. Hence, serum 5-HT, TPH1 and AADC Aabs should be determined in APECED patients presenting with GI symptoms.

Calcium-Sensing Receptor Autoantibodies in Patients with Autoimmune Polyendocrine Syndrome Type 1: Epitopes, Specificity, Functional Affinity, IgG Subclass, and Effects on Receptor Activity.

A major manifestation of autoimmune polyendocrine syndrome type 1 (APS1) is hypoparathyroidism, which is suggested to result from aberrant immune responses against the parathyroid glands. The calcium-sensing receptor (CaSR), which plays a pivotal role in maintaining calcium homeostasis by sensing blood calcium levels and regulating release of parathyroid hormone (PTH), is an autoantibody target in APS1. In this study, the aim was to characterize the binding sites, specificity, functional affinity, IgG subclass, and functional effects of CaSR autoantibodies using phage-display technology, ELISA, and bioassays. The results indicated that CaSR autoantibody binding sites were at aa 41-69, 114-126, 171-195, and 260-340 in the extracellular domain of the receptor. Autoantibodies against CaSR epitopes 41-69, 171-195, and 260-340 were exclusively of the IgG1 subclass. Autoantibody responses against CaSR epitope 114-126 were predominantly of the IgG1 with a minority of the IgG3 subclass. Only autoantibodies recognizing CaSR epitopes 114-126 and 171-195 affected receptor activity; inositol-phosphate accumulation was increased significantly in HEK293-CaSR cells, and PTH secretion from PTH-C1 cells was reduced significantly when either were incubated with purified Ab and Ca2+ compared with Ca2+ alone. In conclusion, although the majority of APS1 patients do not have CaSR-stimulating autoantibodies, the hypoparathyroid state in a small minority of patients is the result of functional suppression of the parathyroid glands.

Autoantibody Repertoire in APECED Patients Targets Two Distinct Subgroups of Proteins.

High titer autoantibodies produced by B lymphocytes are clinically important features of many common autoimmune diseases. APECED patients with deficient autoimmune regulator (AIRE) gene collectively display a broad repertoire of high titer autoantibodies, including some which are pathognomonic for major autoimmune diseases. AIRE deficiency severely reduces thymic expression of gene-products ordinarily restricted to discrete peripheral tissues, and developing T cells reactive to those gene-products are not inactivated during their development. However, the extent of the autoantibody repertoire in APECED and its relation to thymic expression of self-antigens are unclear. We here undertook a broad protein array approach to assess autoantibody repertoire in APECED patients. Our results show that in addition to shared autoantigen reactivities, APECED patients display high inter-individual variation in their autoantigen profiles, which collectively are enriched in evolutionarily conserved, cytosolic and nuclear phosphoproteins. The APECED autoantigens have two major origins; proteins expressed in thymic medullary epithelial cells and proteins expressed in lymphoid cells. These findings support the hypothesis that specific protein properties strongly contribute to the etiology of B cell autoimmunity.

IL-6-specific autoantibodies among APECED and thymoma patients.

INTRODUCTION: Both autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) and the rare thymoma patients with chronic mucocutaneous candidiasis (CMC) have neutralizing autoantibodies to Th17 cytokines and significant defects in production of IL-22 and IL-17F by their T cells. The cause of these defects is unknown. We hypothesized that they might result from autoimmunity against upstream cytokines normally responsible for generating and maintaining Th17 cells. METHODS: Luciferase immunoprecipitation (LIPS) was used to screen for autoantibodies to IL-6, IL-1ß, TGF-ß3, IL-21, and IL-23 in patients with APECED or thymoma. We used Western blotting to assess the conformation-dependence of the IL-6 autoantibodies and flow cytometric analysis of intracellular phospho-STAT3 induction to assess IL-6-neutralizing capacity in IgGs isolated from patient and control sera. We also used Luminex xMAP to measure serum cytokine levels. RESULTS: We found autoantibodies binding to conformational epitopes of IL-6 in 19.5% of 41 patients with APECED and 12.5% of 104 with thymoma-especially in those with long disease durations. The autoantibodies were predominantly of IgG1 subclass and failed to neutralize IL-6 activity. Notably, serum levels of the IL-6 and IL-17A cytokines were higher in anti-IL-6 seropositive than-negative APECED patients or healthy controls. We also detected autoantibody binding to IL-23 in 27.9% of thymoma patients, resulting from cross-recognition through the p40 subunit it shares with IL-12. CONCLUSIONS: IL-6 and IL-17A elevation in these seropositive patients suggests that antibody-binding may protect IL-6 from degradation and prolong its half-life in vivo.

AIRE-Deficient Patients Harbor Unique High-Affinity Disease-Ameliorating Autoantibodies.

APS1/APECED patients are defined by defects in the autoimmune regulator (AIRE) that mediates central T cell tolerance to many self-antigens. AIRE deficiency also affects B cell tolerance, but this is incompletely understood. Here we show that most APS1/APECED patients displayed B cell autoreactivity toward unique sets of approximately 100 self-proteins. Thereby, autoantibodies from 81 patients collectively detected many thousands of human proteins. The loss of B cell tolerance seemingly occurred during antibody affinity maturation, an obligatorily T cell-dependent step. Consistent with this, many APS1/APECED patients harbored extremely high-affinity, neutralizing autoantibodies, particularly against specific cytokines. Such antibodies were biologically active in vitro and in vivo, and those neutralizing type I interferons (IFNs) showed a striking inverse correlation with type I diabetes, not shown by other anti-cytokine antibodies. Thus, naturally occurring human autoantibodies may actively limit disease and be of therapeutic utility.

Gastrointestinal Autoimmunity Associated With Loss of Central Tolerance to Enteric α-Defensins.

BACKGROUND & AIMS: Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED) is an autoimmune disorder characterized by chronic mucocutaneous candidiasis, hypoparathyroidism, and adrenal insufficiency, but patients also develop intestinal disorders. APECED is an autosomal recessive disorder caused by mutations in the autoimmune regulator (AIRE, which regulates immune tolerance) that allow self-reactive T cells to enter the periphery. Enteric α-defensins are antimicrobial peptides secreted by Paneth cells. Patients with APECED frequently have gastrointestinal symptoms and seroreactivity against secretory granules of Paneth cells. We investigated whether enteric α-defensins are autoantigens in humans and mice with AIRE deficiency. METHODS: We analyzed clinical data, along with serum and stool samples and available duodenal biopsies from 50 patients with APECED collected from multiple centers in Europe. Samples were assessed for expression of defensins and other molecules by quantitative reverse transcription polymerase chain reaction and flow cytometry; levels of antibodies and other proteins were measured by immunohistochemical and immunoblot analyses. Histologic analyses were performed on biopsy samples. We used Aire(-/-) mice as a model of APECED, and studied the effects of transferring immune cells from these mice to athymic mice. RESULTS: Enteric defensins were detected in extraintestinal tissues of patients with APECED, especially in medullary thymic epithelial cells. Some patients with APECED lacked Paneth cells and were seropositive for defensin-specific autoantibodies; the presence of autoantibodies correlated with frequent diarrhea. Aire(-/-) mice developed defensin-specific T cells. Adoptive transfer of these T cells to athymic mice resulted in T-cell infiltration of the gut, loss of Paneth cells, microbial dysbiosis, and the induction of T-helper 17 cell-mediated autoimmune responses resembling those observed in patients with APECED. CONCLUSIONS: In patients with APECED, loss of AIRE appears to cause an autoimmune response against enteric defensins and loss of Paneth cells. Aire(-/-) mice developed defensin-specific T cells that cause intestinal defects similar to those observed in patients with APECED. These findings provide a mechanism by which loss of AIRE-mediated immune tolerance leads to intestinal disorders in patients with APECED.

Gastrointestinal immunity against tryptophan hydroxylase-1, aromatic L-amino-acid decarboxylase, AIE-75, villin and Paneth cells in APECED.

Gastrointestinal dysfunction is a disabling manifestation of APECED possibly related to an autoimmune intestinal aggression. We evaluated its features in a cohort of 31 Finnish patients. The most frequent manifestations were constipation (48%), diarrhea, dysphagia and retrosternal pain (45%). AADC and TPH-1 autoantibodies were detected in 51% and 45% of the patients, respectively. Forty-three percent displayed a T-cell response to AADC. One third of the patients also had AIE-75 (33%) and villin (29%)-specific autoantibodies while antibodies against brush borders and Paneth cells were detected in 29% and 20%, respectively. Intestinal IL-17 expression was absent/decreased in 77% of the cases. Duodenal CgA and serotonin expression was absent/decreased in 50% and 66% of the patients, respectively. Constipation correlated with lacking serotonin expression and AADC antibodies (p < 0.05).

Kidney involvement in autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy in a Finnish cohort.

BACKGROUND: Autoimmune tubulo-interstitial nephritis (TIN) is a rare complication of autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). Previous data on TIN and other renal or urologic manifestations of APECED are sparse. METHODS: We performed a retrospective study on the urinary and renal tract diseases in a cohort of 30 Finnish patients with APECED (mean age 40 years), with special emphasis on the clinical presentation and the immunologic characteristics of TIN. Clinical and laboratory findings, specific anticytokine and kidney-specific antibodies were analysed. RESULTS: Five of the 30 (17%) patients had moderate-to-severe renal failure, including 3 (10%) with TIN, leading to either transplantation, haemodialysis or immunosuppressive treatment. No other cause other than APECED was found for the TIN. All three patients with TIN had circulating antibodies against the distal part of the nephron, as did 30% of all cohort cases. Two had nephrocalcinosis, and two had renal tubular acidosis type 1. Immunosuppressive therapy with mycophenolate mofetil or rituximab in one pediatric case did not revert the TIN, however. CONCLUSIONS: Renal failure should raise concern for TIN in APECED. It discloses some specific features: no uveitis, no glycosuria and inconstant urinalysis anomalies. Regular renal monitoring for any APECED patient should be performed. Circulating antibodies against the distal part of the nephron are frequent and present in all TIN patients, but their pathologic significance is not yet known. Future studies will be needed to understand the triggers leading to overt clinical disease in these patients.

Prevalence and clinical associations of calcium-sensing receptor and NALP5 autoantibodies in Finnish APECED patients.

CONTEXT: Previous studies have identified the calcium-sensing receptor (CaSR) and NALP5 as parathyroid autoantibody targets in patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). However, although NALP5 antibodies have been associated with the occurrence of hypoparathyroidism (HP) in APECED, it is unclear whether CaSR antibodies are a specific or sensitive marker for APECED-associated HP. OBJECTIVE: The objective of the study was to identify associations between the presence of CaSR and NALP5 antibodies and the disease manifestations and demographic characteristics of Finnish APECED patients. DESIGN, SUBJECTS, AND METHODS: This was a case-control study including 44 APECED patients and 38 age- and sex-matched healthy controls. Antibodies against the CaSR and NALP5 were detected using immunoprecipitation assays and radioligand binding assays, respectively. RESULTS: CaSR and NALP5 antibodies were detected in 16 of 44 (36%) and 13 of 44 (30%) patients, respectively. No statistically significant associations were found between the presence of CaSR or NALP5 antibodies and the disease manifestations of APECED including HP (P > .05). For the diagnosis of HP, CaSR and NALP5 antibodies had specificities of 83% and 50%, respectively, and sensitivities of 39% and 26%, respectively. A significant association between both a shorter APECED and HP duration (<10 y) and positivity for CaSR antibodies was noted (P = .019 and P = .0061, respectively). CONCLUSION: Neither CaSR nor NALP5 antibodies were found to be specific or sensitive markers for HP in APECED. Further investigations are required to determine the exact role of the autoimmune response against the CaSR and NALP5 in the pathogenesis of this autoimmune syndrome.

Absence of some common organ-specific and non-organ-specific autoimmunity in autoimmune polyendocrinopathy candidiasis ectodermal dystrophy.

BACKGROUND: Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED) is a rare autosomal recessive disorder caused by mutations of the autoimmune regulator (AIRE) gene, whose loss of function leads to the escape of self-reactive T cells from the thymus and autoimmunity. APECED patients typically develop tissue-specific autoantibodies and anti-cytokine antibodies. Consequently, various endocrine and non-endocrine autoimmune disorders appear. However, only a certain number of autoimmune diseases develop, while some common autoimmune conditions have not been reported or are seen only anecdotally. OBJECTIVE: We investigated the clinical manifestations and occurrence of antinuclear antibodies (AN-Abs) and antibodies against extractable nuclear antigens, citrullinated peptide, and transglutaminase in 24 patients and against bullous pemphigoid antigen 180 and desmogleins 1 (Dsg1) and Dsg3 in 30 patients of a Finnish cohort of APECED patients. RESULTS: Despite the loss of central tolerance, the autoantibodies investigated were not overrepresented among the APECED patients. None of the patients had a history of autoimmune connective tissue disease, rheumatoid arthritis, celiac disease, or autoimmune cutaneous bullous disorders. Altogether, 25% (6/24) had low-titer (1:80) AN-Abs. Two patients had anti-BP180 antibodies and two others had anti-Dsg3 antibodies without any cutaneous or mucosal symptoms. No anti-citrullinated peptide and anti-transglutaminase reactivity was found. CONCLUSIONS: The mechanisms that drives tolerance to tissue autoantigens is not fully understood as even APECED patients, who are genetically prone to develop autoantibodies, are tolerant against some common autoantigens. The hypothesis that some of the anti-cytokine antibodies commonly found in APECED patients may be protective should be investigated in larger series.

Gastrointestinal manifestations in APECED syndrome.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) (or autoimmune polyendocrine syndrome type 1) is a rare autosomal recessive disorder caused by mutations in the autoimmune regulator gene. It causes a loss in central immune tolerance, failure to eliminate autoreactive T cells in the thymus, and their escape to the periphery. APECED patients are susceptible to mucocutaneous candidiasis and multiple endocrine and nonendocrine autoimmune diseases. Although it depends on the series, approximately 25% of APECED patients are affected by gastrointestinal (GI) manifestations, mainly autoimmune-related disorders like autoimmune hepatitis, atrophic gastritis with or without pernicious anemia (Biermer disease), intestinal infections, and malabsorption. In contrast to the major organ-specific autoimmune symptoms of APECED, the GI symptoms and their underlying pathogenesis are poorly understood. Yet isolated case reports and small series depict severe intestinal involvement in children, leading to malabsorption, multiple deficiencies, growth impairment, and possible death. Moreover, very few systematic studies of GI function with intestinal biopsies have been performed. GI symptoms may be the first manifestation of APECED, yet they may have various causes; effective treatment will therefore vary. We provide here an updated review of GI manifestations in APECED, including principles of diagnosis and therapy.

Neuron navigator 3 alterations in nervous system tumors associate with tumor malignancy grade and prognosis.

Copy number changes or reduced expression of the Neuron navigator 3 (NAV3) gene occurs in neuroblastomas and malignancies of epithelial or lymphoid origin. To elucidate whether NAV3 has a role in the tumorigenesis of nervous system tumors in general, we studied central and peripheral nervous system tumors for NAV3 copy number changes. In search for common tumorigenic denominators, we analyzed 113 central and peripheral nervous system tumors, including glial tumors (grades I-IV gliomas), medulloblastomas, and neuroblastomas. NAV3 copy number changes were studied by fluorescence in situ hybridization and correlated to survival analyses. To identify target genes of NAV3 deletion, NAV3 was silenced by siRNA in glioblastoma cell lines and gene expression profiles were analyzed by Agilent 4×44k dual-color microarrays. Selected upregulations were confirmed by immunohistochemistry and quantitative polymerase chain reaction. We found NAV3 amplifications to dominate in neuronally differentiated tumors, whereas glial tumors showed almost equal proportions of NAV3 deletion and amplification. However, Grade IV gliomas had more frequent NAV3 deletions than grades I-III gliomas. Silencing of NAV3 in glioma cell lines led to the upregulation of receptor genes associated with gonadotropin-releasing hormone and Jak-Stat signaling pathways. Kaplan-Meier analysis of the entire clinical tumor material showed association between NAV3 amplifications and favorable prognosis, as well as NAV3 deletions and unfavorable prognosis. With Cox regression model, a hazard ratio of 0.51 was observed for NAV3 amplifications and 1.36 for NAV3 deletions. We conclude that NAV3 may be a potential new prognostic biomarker and a potential therapeutic target.

What is the burden of living with autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED) in 2012? A health-related quality-of-life assessment in Finnish patients.

OBJECTIVE: Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED) is a rare disorder responsible for chronic candidiasis, a wide variety of autoimmune disorders and a risk of squamous cell carcinoma of the oral cavity or oesophagus. We investigated the impairment of quality of life in our cohort of Finnish patients. SUBJECTS, DESIGN AND MEASUREMENT: In a postal survey, 26 patients with APECED responded to three self-reported health-related quality-of-life questionnaires: RAND-36 (general health), RBDI (depression) and DLQI (dermatology life quality index). RESULTS: General health and vitality were the most affected items in our cohort. Male subjects presented higher impairment in emotional role limitations, social functioning, bodily pain, general mental health/emotional well-being, energy/vitality and general health perceptions but without reaching statistical significance. The number of accumulated diseases in APECED was not associated with lower results. But, age and duration of APECED correlated with fatigue (P = 0·01), well-being (P = 0·02) and general health (P = 0·03) impairment. Depressive symptoms affected 29% of the patients. There was a statistical negative correlation between RBDI score and age and duration of APECED. Hair loss, alopecia areata universalis especially, affected more severely the quality of life of female patients. Vitiligo and candidiasis did not have any significant impact on both the genders. CONCLUSIONS: We report the first study on specific impairment of quality of life related to APECED in a cohort of adult Finnish patients. General health, emotional well-being and vitality were the most diminished aspects of quality of life in our cohort. However, our results will need to be confirmed by additional controlled studies.

APECED: is this a model for failure of T cell and B cell tolerance?

In APECED, the key abnormality is in the T cell defect that may lead to tissue destruction chiefly in endocrine organs. Besides, APECED is characterized by high-titer antibodies against a wide variety of cytokines that could partly be responsible for the clinical symptoms during APECED, mainly chronic mucocutaneous candidiasis, and linked to antibodies against Th17 cells effector molecules, IL-17 and IL-22. On the other hand, the same antibodies, together with antibodies against type I interferons may prevent the patients from other immunological diseases, such as psoriasis and systemic lupus erythematous. The same effector Th17 cells, present in the lymphocytic infiltrate of target organs of APECED, could be responsible for the tissue destruction. Here again, the antibodies against the corresponding effector molecules, anti-IL-17 and anti-IL-22 could be protective. The occurrence of several effector mechanisms (CD4(+) Th17 cell and CD8(+) CTL and the effector cytokines IL-17 and IL-22), and simultaneous existence of regulatory mechanisms (CD4(+) Treg and antibodies neutralizing the effect of the effector cytokines) may explain the polymorphism of APECED. Almost all the patients develop the characteristic manifestations of the complex, but temporal course and severity of the symptoms vary considerably, even among siblings. The autoantibody profile does not correlate with the clinical picture. One could speculate that a secondary homeostatic balance between the harmful effector mechanisms, and the favorable regulatory mechanisms, finally define both the extent and severity of the clinical condition in the AIRE defective individuals. The proposed hypothesis that in APECED, in addition to strong tissue destructive mechanisms, a controlling regulatory mechanism does exist, allow us to conclude that APECED could be treated, and even cured, with immunological manipulation.

Molecular markers associated with clinical response to bexarotene therapy in cutaneous T-cell lymphoma.

Bexarotene (Targretin(®)), was registered for the treatment of cutaneous T-cell lymphoma (CTCL) in 2002, and has been reported to induce a 45% overall response. Responses are mostly partial or generate a stable, skin-restricted disease. This study explored the usefulness of a novel cancer-associated gene, NAV3 and corresponding chromosome 12 copy numbers as possible biomarkers to monitor the therapeutic response to bexarotene in 21 Finnish patients with CTCL. Six patients (29%) reached complete remission (CR) and 3 of these remained in CR for more than 24 months, 12 (57%) reached a partial response (PR, with one stable disease) and 3 were non-responders. Low-level NAV3 deletions were detected using a fluorescence in-situ hybridization (FISH) assay in the lesions of 5 patients, 4 of whom were non-responders or progressed after short PR. This occurrence of NAV3 deletions was statistically significant compared with non-progressors (p = 0.011, Fisher's exact test). Chromosome 12 tetraploidy was found in the lesions of two of the 3 patients with CR who remained in remission. While such tetraploidy is a feature of proliferating normal T cells, this observation may reflect a favourable anti-tumour immune response among the skin-infiltrating lymphocytes.

Immunization with dendritic cells transfected in vivo with HIV-1 plasmid DNA induces HIV-1-specific immune responses.

We evaluated the importance of dendritic cells (DCs) in the induction of the immune response after immunization of mice with DNA plasmid Auxo-GTU(®)-MultiHIV. First, GTU(®)-encoded protein was shown to be expressed by DCs of the draining lymph nodes (LNs) following intradermal (i.d.) immunization. Next, donor mice were immunized with the MultiHIV DNA plasmid, and DCs were enriched and further used to immunize naïve recipient mice. For the first time, the results show that i.d. immunization with Auxo-GTU(®)-MultiHIV transfects DCs in vivo, enabling them to present antigens and induce HIV-specific immune responses in recipient mice.