Annalisa Brozzetti

Evidence of microevolution in a clinical case of recurrent Cryptococcus neoformans meningoencephalitis.

The aim of this study was to examine three serial isolates of Cryptococcus neoformans from a patient with AIDS for genotypical and phenotypical characteristics. The isolates were obtained during a first episode of cryptococcosis (simultaneous sampling of blood and cerebrospinal fluid) and after a relapse 3 years later (sampling of cerebrospinal fluid). Pulsed-field gel electrophoresis and random amplification of polymorphic DNA revealed that the blood isolate 1525 (first episode) was different from the two cerebrospinal fluid isolates (1526, first episode; 1782, relapse), yet the cerebrospinal fluid isolates were indistinguishable from each other regardless of the analysis performed. Phenotypical studies showed that isolate 1782 had significantly improved resistance to phagocytosis and killing by monocytes and polymorphonuclear cells and an altered efficacy in evoking cytokine response (augmentation of tumour necrosis factor-α, interleukin [IL]-1β, IL-10, and interferon-γ, decrease of IL-12). Interestingly, capsule size and antifungal drug resistance remained unchanged, while production of phospholipase and protease was consistently enhanced in the 1782 isolate with respect to the 1525 and 1526 isolates. In conclusion, in serial Cryptococcus neoformans isolates from a patient with AIDS, phenotypical changes but not molecular changes were documented, thus supporting the role of microevolution as a pathogenetic mechanism(s) for persistence/reactivation of fungal organisms.

Primary ovarian insufficiency: autoimmune causes.

Purpose of review To review the pathogenesis of premature ovarian insufficiency due to steroid cell autoimmunity (SCA-POI). Recent findings Autoimmune oophoritis is characterized by a selective mononuclear cell infiltration into the theca layer of large, antral follicles, with earlier stage follicles consistently free of lymphocytic infiltration. SCA-POI is caused by the selective autoimmune destruction of theca cells with preservation of granulosa cells that produce low amounts of estradiol because of lack of substrates. Typically, serum concentrations of inhibins are increased in women with SCA-POI, as compared to both healthy fertile women and women with other forms of ovarian insufficiency. Normal serum antimüllerian hormone (AMH) concentrations were detected in two-thirds of women with recently diagnosed SCA-POI, which demonstrates that this form of ovarian insufficiency is associated with a preserved pool of functioning follicles. Summary The combined measurement of autoantibodies and markers of ovarian reserve (as inhibin B and AMH) may permit to identify women with POI due to steroid cell autoimmunity with a preserved proportion of primordial and primary follicles. In the future the development of techniques of in-vitro folliculogenesis may permit new treatment strategies for women with SCA-POI-related infertility.

Primary Ovarian Insufficiency due to Steroidogenic Cell Autoimmunity Is Associated with a Preserved Pool of Functioning Follicles

CONTEXT Primary ovarian insufficiency (POI) is defined as hypergonadotropic amenorrhea before the age of 40 yr. In 4-5% of patients with POI, an ovarian autoimmune process is present. DESIGN Serum concentrations of antimüllerian hormone (AMH) have been determined in 26 women with POI due to steroidogenic cell autoimmunity (SCA-POI), 66 with nonautoimmune idiopathic POI (iPOI), 40 postmenopausal women (PMW), and 44 healthy fertile women (HW). SCA-POI was diagnosed according to presence of steroidogenic enzyme autoantibodies (17alpha-hydroxylase, side chain cleavage, and 21-hydroxylase autoantibodies). RESULTS AMH concentrations were significantly higher in women with SCA-POI than women with iPOI (P = 0.018) or PMW (P = 0.03) but significantly lower than HW (P < 0.0001). AMH was detected in 11 of 26 women with SCA-POI (42%) and seven of 66 with iPOI (11%) (P = 0.002). Serum concentrations above the fifth percentile of the normal range (0.6 ng/ml) were detected in nine of 26 women with SCA-POI (35%) and four of 66 with iPOI (6%) (P = 0.001). Eight of 12 women with SCA-POI with less than 5 yr (67%) and one of 14 with longer disease duration (7%) had AMH concentrations within the normal range (P = 0.003). AMH concentrations correlated inversely with disease duration in women with SCA-POI (rho = -0.563, P = 0.003) but not women with iPOI. AMH correlated inversely with FSH serum concentrations in HW (rho = -0.584, P < 0.001) but not PMW or women with POI. CONCLUSIONS Two thirds of women with recent-onset SCA-POI had normal AMH concentrations. Women with SCA-POI, differently from those with iPOI, present a preserved ovarian follicle pool for several years after diagnosis of ovarian insufficiency.

Non‐food/feed seeds as biofactories for the high‐yield production of recombinant pharmaceuticals

We describe an attractive cloning system for the seed-specific expression of recombinant proteins using three non-food/feed crops. A vector designed for direct subcloning by Gateway® recombination was developed and tested in Arabidopsis, tobacco and petunia plants for the production of a chimeric form (GAD67/65) of the 65 kDa isoform of glutamic acid decarboxylase (GAD65). GAD65 is one of the major human autoantigens involved in type 1 diabetes (T1D). The murine anti-inflammatory cytokine interleukin-10 (IL-10) was expressed with the described system in Arabidopsis and tobacco, whereas proinsulin, another T1D major autoantigen, was expressed in Arabidopsis. The cost-effective production of these proteins in plants could allow the development of T1D prevention strategies based on the induction of immunological tolerance. The best yields were achieved in Arabidopsis seeds, where GAD67/65 reached 7.7% of total soluble protein (TSP), the highest levels ever reported for this protein in plants. IL-10 and proinsulin reached 0.70% and 0.007% of TSP, respectively, consistent with levels previously reported in other plants or tissues. This versatile cloning vector could be suitable for the high-throughput evaluation of expression levels and stability of many valuable and difficult to produce proteins.

High Serum Inhibin Concentration Discriminates Autoimmune Oophoritis from Other Forms of Primary Ovarian Insufficiency

CONTEXT Primary ovarian insufficiency (POI) is defined by hypergonadotropic amenorrhea occurring before the age of 40 yr. In 4-5% of women with POI, an ovarian autoimmune process can be demonstrated. DESIGN We have determined the serum concentrations of total inhibin and inhibin B by sensitive ELISAs in 22 women with autoimmune POI (aPOI), 71 women with non-autoimmune idiopathic POI (iPOI), 77 postmenopausal women, and 90 healthy, fertile women (HW). Diagnosis of aPOI was made according to the presence of steroid cell autoantibodies and/or 17alpha-hydroxylase autoantibodies and/or cytochrome P450 side-chain cleavage autoantibodies. All aPOI patients were also positive for adrenal autoantibodies. RESULTS Total inhibin levels were significantly higher in women with aPOI (median, 281 pg/ml) than in women with iPOI (median, 74 pg/ml) or HW (median, 133.5 pg/ml) (P < 0.001). Levels of inhibin B were also significantly higher in women with aPOI (median, 109 pg/ml) than in women with iPOI (median, 18 pg/ml) (P < 0.001) or HW (median, 39 pg/ml) (P < 0.05). Serum concentrations of total inhibin and inhibin B were significantly higher in women with POI than in postmenopausal women (P < 0.001), irrespective of the presence/absence of autoantibodies. At receiver-operating characteristic analysis, cutoff values of 133 pg/ml for total inhibin and 60.5 pg/ml for inhibin B ensured 86.4% sensitivity and 81-84.5% specificity for aPOI vs. iPOI. CONCLUSIONS We conclude that a variable degree of ovarian function is preserved in women with POI and that aPOI is characterized by increased inhibin production resulting from a selective theca cell destruction, with initial preservation of granulosa cells.

Cytotoxic T lymphocyte antigen-4 Ala17 polymorphism is a genetic marker of autoimmune adrenal insufficiency: Italian association study and meta-analysis of European studies

OBJECTIVE Cytotoxic T lymphocyte antigen-4 (CTLA4) gene polymorphism has been associated with human autoimmune diseases, but discordant data are available on its association with autoimmune Addisons disease (AAD). We tested the human leukocyte antigen (HLA)-independent association of CTLA4+49 (A/G) (Ala 17) and/or CTLA4 CT60 (A/G) polymorphism with AAD. DESIGN DNA samples from 180 AAD patients and 394 healthy control subjects from continental Italy were analyzed, and association statistical analyses and meta-analysis of published studies were performed. Methods TaqMan minor groove binder chemistry assays and PCR fragment length polymorphism assays were used. RESULTS Frequency of allele G of CTLA4+49 was significantly increased among AAD patients (40% alleles) than among healthy controls (27% alleles; P<0.0001). CTLA4 CT60 polymorphism was associated with AAD only in the heterozygous A/G individuals. The frequency of +49 AG+GG genotypes was significantly higher among AAD patients than among healthy control subjects, in both a co-dominant (P<0.0001) and G dominant model (P<0.0001). CTLA4+49 allele G was significantly associated with disease risk in both patients with isolated AAD and in patients with autoimmune polyendocrine syndrome. Multivariate logistic regression analysis showed that CTLA4+49 allele G was positively associated with AAD (P<0.0001, odds ratio (OR)=2.43, 95% confidence interval=1.54-3.86) also after correction for DRB1*03-DQA1*0501-DQB1*0201, DRB1*04-DQA1*0301-DQB1*0302, and sex. Meta-analysis of five studies revealed a significant association of CTLA4+49 allele G with AAD (P<0.0001) with an overall OR of 1.48 (1.28-1.71). CONCLUSIONS The CTLA4+49 polymorphism is strongly associated with genetic risk for AAD, independently from the well-known association with HLA class II genes.

Establishment of protective immunity against cerebral cryptococcosis by means of an avirulent, non melanogenic Cryptococcus neoformans strain.

The opportunistic fungal pathogen, Cryptococcus neoformans, shows a marked predilection for the central nervous system (CNS). This can be partially explained by its ability to synthesize melanin starting from the catecholamines, highly concentrated at the CNS level. Two cryptococcal strains, the avirulent non-melanogenic strain Sb26 and the virulent melanogenic revertant strain Sb26Rev, were used in a murine model of intracerebral (i.c.) infection, in order to evaluate their virulence and immunomodulating properties at the cerebral level. We found that, unlike Sb26Rev, Sb26 i.c. infection was never lethal regardless of the challenging dose. Sb26Rev infection resulted in massive CNS tissue damage, associated with little or no cytokine response, as established by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). Differently, Sb26 infection failed to alter CNS structure, while inducing IL-12 p40, TNF-alpha, IL-1beta, IFN-gamma and iNOS specific-gene expression as well as IL-12, TNF-alpha and IL-1beta cytokine production. Interestingly, all Sb26 infected mice survived a subsequent lethal challenge with Sb26Rev. The phenomenon was associated with enhanced IL-12, TNF-alpha and IL-1beta production and was strictly specific, as shown by heterologous challenges and delayed type of hypersensitivity assay. Overall, we provide evidence that protective immunity against cerebral cryptococcosis is established by means of an avirulent strain of C. neoformans.

MICA Gene Polymorphism in the Pathogenesis of Type 1 Diabetes

Abstract:  Type 1 diabetes mellitus (T1DM) is a typical autoimmune disease and results from the destruction of insulin‐producing β cells of the pancreas. It develops in the presence of genetic susceptibility, even though more than 85% of patients with T1DM do not have a close relative with the disorder. The etiology of T1DM is complex, and both genetic and environmental factors play important roles. A permissive genetic background is required for the development of the islet autoimmune process. The strongest genetic association idengified is that with HLA class II genes located on the short arm of chromosome 6. It is well known that both HLA DRB1*04‐DQA1*0301‐DQB1*0302 (DR4‐DQ8) and DRB1*03‐DQA1*0501‐DQB1*0201 (DR3‐DQ2) are positively, and DRB1*15‐DQA1*0102‐DQB1*0602 is negatively, associated with T1DM. However, only a minority of the subjects carrying the high‐risk haplotypes/genotypes develops the disease, which suggests that additional genes play a crucial role in conferring either protection or susceptibility to T1DM. Major histocompatibility complex (MHC) class I chain–related A (MICA) is located in a candidate susceptibility region and activates natural killer (NK) cells, T cells and γδ CD8 T cells by its receptor NKG2D. The polymorphism of the MICA gene is associated with T1DM in different populations as demonstrated in several papers published in the last 7 years.

BClI polymorphism of the glucocorticoid receptor gene is associated with increased obesity, impaired glucose metabolism and dyslipidaemia in patients with Addison's disease.

Although glucocorticoids are essential for health, several studies have shown that glucocorticoids replacement in Addisons disease might be involved in anthropometric and metabolic impairment, with increased cardiovascular risk, namely if conventional doses are used. As the effects of glucocorticoids are mediated by the glucocorticoid receptor, encoded by NR3C1 gene, different polymorphisms in the NR3C1 gene have been linked to altered glucocorticoid sensitivity in general population as well as in patients with obesity or metabolic syndrome.

Role of the capsule in microglial cell– Cryptococcus neoformans interaction: impairment of antifungal activity but not of secretory functions

Using two isogenic strains of Cryptococcus neoformans, we studied the influence of the capsule in C. neoformans microglial-cell interaction. We demonstrate that the acapsular mutant yeasts (CAP67) are more susceptible to phagocytosis and killing than encapsulated yeasts (B3501) by the murine microglial cells, BV-2. RT-PCR analysis showed that the pattern of gene transcripts for tumour necrosis factor alpha (TNF-a), interleukin (IL)-1beta, IL-6, IL-12p40 and granulocyte macrophage colony stimulating factor remains unchanged following BV-2 cell infection with CAP67 or B3501 yeasts. Moreover, no induction of TNF-alpha secretion occurs in BV-2 cells infected with either B3501 or CAP67 yeasts or exposed to glucuronoxylomannan (GXM) or galactoxylomannan (GalXM). Nevertheless, lipopolysaccharide-induced TNF-alpha secretion is downregulated by cell infection with B3501 or CAP67 yeasts or exposure to GXM or GalXM. Overall, by means of a continuous cell line, it appears that the C. neoformans capsule is detrimental to microglial cell antifungal activity, while no effect can be attributed to the capsule as trend of cytokine gene expression and TNF-alpha secretion.