Hirschsprung associated GDNF mutations do not prevent RET activation

Hirschsprung disease (HSCR) is a complex disorder characterised by aganglia of distal gastrointestinal tracts. The highest proportion of both familial and sporadic cases is due to mutations of the RET proto-oncogene. Five germline mutations in the glial cell-line-derived neurotrophic factor (GDNF) gene, one of the RET ligands, have been detected in HSCR patients. Pedigrees analysis and the observed association between these GDNF alterations and RET variants in the same patients raised the question of whether the GDNF gene plays any causative/predisposing role in HSCR pathogenesis. In the present work, we have studied the ability of GDNF proteins, each bearing one of the reported mutations, to activate RET by performing a functional test in cultured neuroblastoma cells. Consistently with the lack of genotype/phenotype correlation in human subjects, our results indicate absence of detectable alterations of mutant GDNF induced RET activation.     

Human respiratory coronavirus HKU1 versus other coronavirus infections in Italian hospitalised patients.

BACKGROUND: Human respiratory coronavirus (hCoV) HKU1 infections were reported for the first time in 2005 in Hong Kong. OBJECTIVE: To investigate epidemiological, clinical, and diagnostic features of HKU1 infections. STUDY DESIGN: Longitudinal, prospective study from November 2005 through May 2006 in a hospitalised patient population. RESULTS: Overall, 48/426 (11.3%) patients were found to be infected by hCoV acute respiratory tract infections (ARTI). Of these, 10 (19.2%) were caused by HKU1 (6 single infections and 4 coinfections) during the period January-May 2006. Diagnosis was made by using RT-PCR for all four hCoVs, and in parallel, in-house developed group-specific monoclonal antibodies (MAbs) for HKU1 and 229E. HKU1-specific MAb was able to retrospectively identify 8 of 10 HKU1 strains detected by RT-PCR. Phylogenetic analysis showed that four HKU1 strains were genotype A and six genotype B. In HKU1-infected patients, the predominant clinical symptom was rhinorrhea (nine patients). Within group II hCoV, HKU1-infected patients had a significantly lower rate of lower ARTI compared to OC43-infected patients. CONCLUSION: HKU1 hCoV strains circulated in northern Italy during the winter-spring season 2005-2006. Both HKU1 genotypes were detected. HKU1-specific MAb may contribute to the rapid diagnosis of HKU1 infections currently performed by RT-PCR.     

Results of unrelated cord blood transplant in fanconi anemia patients: risk factor analysis for engraftment and survival.

We retrospectively analyzed results of unrelated cord blood transplantation (UCBT) in 93 Fanconi anemia (FA) patients. Median age at transplantation was 8.6 years (1-45). The units transplanted were HLA-A, -B, or -DRB1 identical in 12 cases, 1 HLA mismatch in 35 cases, and 2 or 3 HLA differences in 45 cases. The median number of nucleated cells (NC) and CD34+ cells infused of recipient weight was 4.9x10(7)/kg and 1.9x10(5)/kg, respectively. Participating centers selected the preparative regimen of their choice, in 57 patients (61%), it included Fludarabine. Graft-versus-host disease (GVHD) prophylaxis consisted mostly of cyclosporine with prednisone. Cumulative incidence (CI) of neutrophil recovery was 60+/-5% at day +60. In multivariate analysis, Fludarabine containing regimen and NC infused>or=4.9x10(7)/kg were associated with higher probability of recovery. CI of grade II-IV acute and of chronic GVHD (aGVHD, cGVHD) was 32%+/-5% and 16%+/-4%, respectively. Overall survival (OS) was 40%+/-5%. In multivariate analysis, factors associated with favorable outcome were use of Fludarabine in the conditioning regimen, number of NC infused>or=4.9x10(7)/kg, and negative cytomegalovirus (CMV) serology in the recipient. In conclusion, factors easily modifiable such as donor selection and a Fludarabine-containing regimen can considerably improve survival in FA patients given a UCBT. These data are the basis for designing prospective protocols.     

Developmental regulation of type 1 and type 3 interferon production and risk for infant infections and asthma development

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Mycobacterium tuberculosis subverts the differentiation of human monocytes into dendritic cells

Intracellular pathogens have developed strategies for evading elimination by the defenses of the host immune system. Here we describe an escape mechanism utilized by Mycobacterium tuberculosis that involves the interference with the generation of fully competent DC from monocytes. We show that monocytes infected with live M. tuberculosis differentiated into mature, CD83+ and CCR7+ DC (Mt-MoDC), but were characterized by a selective failure in the expression of the family of CD1 molecules. These cells also showed levels of MHC class II and CD80 (B7.1) that were reduced in comparison with LPS-matured DC. In addition, Mt-MoDC produced TNF-alpha and IL-10, but were unable to secrete IL-12. The generation of Mt-MoDC required the infection of monocytes with live M. tuberculosis, since infection with heat-killed bacteria partially abrogated the effects on monocyte differentiation. Interestingly, Mt-MoDC revealed an impaired antigen-presentation function as assessed by the reduced capability to induce proliferation of cord blood T lymphocytes. Further, naive T lymphocytes expanded by Mt-MoDC were unable to secrete cytokines, in particular IL-4 and IFN-gamma, suggesting that they could be ineffective in helping the macrophage-mediated killing of intracellular mycobacteria. Our results suggest that the interference with monocyte differentiation into fully competent DC is an evasion mechanism of M. tuberculosis that could contribute to its intracellular persistence by avoiding immune recognition.     

Serological survey of human immunodeficiency virus (HIV) in Ethiopia

The presence of anti-human immunodeficiency virus 1 antibodies was tested in 5,565 serum samples from Ethiopia of which 5,265 were collected from military recruits in the framework of a hepatitis B (HBV) seroepidemiological study performed on a national scale in 1985-1986; the remaining were 300 sera from a population of outpatients belonging to the Arsi region. Of the 5,565 sera, 121 (2.1%) were found to be repeatedly reactive by enzyme-linked immunosorbent assay (ELISA) test for HIV-1 antibodies, but these reactivities were confirmed by Western Blot (WB) assay in only four cases (0.07%) and by ENVACOR (confirmatory competitive ELISA) in three samples. Twenty-three sera were positive by WB to one or two bands related to core proteins but were all negative by ENVACOR. However, according to accepted criteria for positivity, these sera must be regarded as indeterminant reactors. A sample of 409 sera, both reactive and nonreactive by HIV-1 ELISA, were further tested for antibodies to HIV-2 by ELISA. Reactive sera were analysed by WB and by radioimmunoprecipitation assay (RIPA) using 35S-cysteine metabolically labelled SIVmac (HTLV-IV) infected cell lysates. Only 11 sera were found to be slightly reactive in ELISA, but this was not confirmed by WB or RIPA. Data indicate that HIV infection was not widespread in the general population of Ethiopia up to 1986.     

Checkpoint Blockade Immunotherapy Induces Dynamic Changes in PD-1−CD8+ Tumor-Infiltrating T Cells

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Microbiome as Mediator of Diet on Colorectal Cancer Risk: The Role of Vitamin D,Markers of Inflammation and Adipokines

Obesity and diet are associated with colorectal cancer (CRC) risk, and microbiome could mediate this risk factor. To investigate this interaction, we performed a case–control study (34 CRC cases and 32 controls) and analyzed fecal microbiota composition using 16S rRNA metabarcoding and sub-sequential shotgun analyses of genomic bacterial DNA to evaluate the role of microbiome and diet in CRC etiology, taking into account vitamin D and other risk biomarkers. Dietary habits were evaluated using a short questionnaire. Multivariate methods for data integration and mediation analysis models were used to investigate causal relationships. CRC cases were significantly more often deficient in vitamin D than controls (p = 0.04); FokI and CYP24A1 polymorphism frequency were different between cases and controls (p = 0.03 and p = 0.02, respectively). A diet poor in fatty fish and rich in carbohydrates was found to be significantly associated with CRC risk (p = 0.011). The mediation analysis confirmed the significant role of the microbiome in mediating CRC risk—increasing levels of Bifidobacteria/Escherichia genera ratio, an indicator of “healthy” intestinal microbiome, can overcome the effect of diet on CRC risk (p = 0.03). This study suggests that microbiome mediates the diet effect on CRC risk, and that vitamin D, markers of inflammation, and adipokines are other factors to consider in order to achieve a better knowledge of the whole carcinogenic process.