D. Piancatelli

Local expression of cytokines in human colorectal carcinoma: evidence of specific interleukin-6 gene expression.

The expression of cytokine mRNAs in tumor tissue, normal mucosa, and peripheral blood mononuclear cells (PBMCs) was studied in 12 patients with colorectal cancer undergoing surgical resection, to characterize local immune conditions. mRNA transcripts for interleukin (IL)-1 beta, IL-2, IL-2-R(p55), IL-4, IL-5, IL-6, and IL-10 were detected using the reverse transcriptase-polymerase chain reaction (RT-PCR) technique. IL-6 mRNA was expressed in tumor tissue in 83% of the cases but only in one case in normal mucosa (p < 0.001); serum levels of IL-6 did not show any correlation with IL-6 mRNA; IL-1 beta transcripts were present in all tumor tissue samples; no IL-4 expression was detected; IL-2 mRNA was only present in two tumors; IL-2R(p55) mRNA was found in 58% of tumors but not in normal mucosae (p = 0.005). The expression of IL-10 suggests that it does not play a central role in colorectal cancer immunosuppression, and cytokine expression in PBMCs indicates a different and independent activation. This study suggests a pattern of expression of inflammatory cytokines in the tumor microenvironment, probably produced by infiltrating immune cells. The absence of the specific immune-activating cytokines, IL-2 and IL-4, could indicate an impairment of the anticancer immune response; IL-2R results confirm the dysregulation of the IL-2/IL-2R activation pathway. These findings may lead to a better understanding of the role of cytokines and especially IL-6 at the tumor site and hence their importance in developing an effective immunotherapy.

Correlation between genetic HLA class I and II polymorphisms and anthropological aspects in the Chaouya population from Morocco (Arabic speaking)

The aim of this study was to provide genetic and anthropological information on the Chaouya (CH), an Arabic-speaking population living in West Morocco, Atlantic coast (Settat). In 98 unrelated healthy CH volunteers, we first investigated the human leukocyte antigen (HLA) class I and II allele polymorphisms using a sequence-based typing method and examined haplotypes and relatedness of this group to other African and Mediterranean populations. The study showed the close relatedness with Tunisian population and other North Africans, together with a strong influence of various immigrations, mainly Spaniards, French, and Portuguese, as expected. Nevertheless, analysis of class II allele frequencies (afs) showed that Oromo and Amhara Ethiopian groups cluster together with the Berbers and other North Africans, confirming the relationship between these populations (Afro-Asiatic linguistic group, Hamites). South and sub-Saharan Africans cluster separately at a great distance from CH, except the sub-Saharan Bantu population from Congo Kinshasa, which shows a relatively close genetic relationship ascribable to the effect of a diversifying selection. On the other hand, considering HLA class I afs analyses, it was noteworthy that CH grouped together with sub-Saharans, showing a close genetic distance mainly with Ugandas and Kenians Luo.

Sequence-Based analysis of the HLA-DRB1 polymorphism in Metalsa Berber and Chaouya Arabic-speaking groups from Morocco

To examine the genetic diversity in Morocco, the polymorphism at the HLA-DRB1 locus was investigated in two populations: the Metalsa group consisting of Berbers from north Morocco (who speak the Tarifit language and live in the Nador area), and the Chaouya group who are Arabic-speaking people from west Morocco (Atlantic coast) living in the Settat area. The DRB1 alleles of 197 healthy unrelated individuals were identified by direct DNA sequencing of exon 2 using fluorescently-labeled primers. A total of 28 and 29 alleles at DRB1 locus were identified in the Metalsa and Chaouya groups, respectively. The most frequent alleles in the Metalsa group are DRB1*03011 (20.2%), DRB1*0701 (12.12%), and DRB1*1302 (11.11%). In the Chaouya group, DRB1*0701 (16.33%), DRB1*15011 (12.76%), and DRB1*03011 (11.73%) are most common. Each population exhibits some specific variants and some uncommon alleles. The frequency of the DRB1*03011 allele differs significantly between the two populations (p = 0.0311). The DRB1 frequency distributions in the two groups suggest the effects of balancing selection. The interpopulation analysis highlighted a strong relatedness, based on genetic distances, between the two Moroccan groups and the other north Africans (the Moroccans from El Jadida area, Moroccan Souss Berbers, Algerians, and Tunisians), and to a lesser extent with the Iberians, French, and Ethiopians.

Melanocortin-4 Receptor Gene Mutations in a Dutch Cohort of Obese Children

The most common monogenic form of obesity is caused by mutations in the gene encoding the melanocortin‐4 receptor (MC4R). We have screened the MC4R coding sequence in 291 patients of a Dutch outpatient pediatric obesity clinic. We analyzed the minimal promoter region of the gene in a random subgroup of 217 children. Our aims were (i) to determine the frequency of MC4R mutations in a cohort of Dutch clinically obese children and (ii) to search for mutations in the promoter of the gene. Eleven MC4R coding variants were detected. Five children had mutations that have been shown to affect receptor function by other research groups (p.Y35X, p.I251fs, p.G231S). These children did not have earlier onset of obesity or higher BMI‐SDS than the remainder of the cohort. One child had a novel nonsynonymous coding mutation (p.L304F). This variant showed a markedly decreased cell surface expression in in vitro experiments and is thus expected to be pathogenic. We detected 12 variants in the MC4R flanking regions. Five of these were not previously described (c.‐1101C>T, c.‐705A>T, c.‐461A>G, c.‐312T>C, c.‐213A>G). We investigated these mutations by family studies and a bioinformatic approach. We conclude that rare heterozygous mutations in the coding sequence of MC4R account for some severe obesity cases in the Dutch population. These patients are difficult to recognize in a clinical setting. We generated a list of all MC4R variants that were described in the literature so far, which can aid the interpretation of mutations found in a diagnostic setting.

Interleukin 1-beta modulates the effects of hypoxia in neuronal culture

In order to study the role of interleukin-1beta (IL-1beta) in homeostasis, hypoxia and recovery of neuronal cells, we studied the expression and release of tumor necrosis factor-alpha (TNF-alpha) and nerve growth factor (NGF), in relation to the presence or absence of this cytokine in culture medium. Moreover, we evaluated cell mortality in the same conditions. For this aim, we used untreated and IL-1beta pre-immunoneutralized hippocampal neuronal cultures exposed to mild hypoxic stress and left to reoxygenate. Semiquantitative reverse-transciptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) determined gene expression and protein levels. Mild hypoxic stress provokes a decrease in both the expression and release of TNF-alpha and NGF. IL-1beta neutralization results in an inversion of this pattern since treated hypoxic cultures exhibited an increase of both expression and release of NGF. In pretreated hypoxic cells the increased expression of TNF-alpha was not followed by a rise in release. Reoxygenation reversed the observed effects in both cultures and the levels of cytokine expression and release were approaching control values. Our data show that in physiological conditions IL-1beta may have a neuroprotective action through positive modulation of NGF. Contrary to that, in presence of insult, IL-1beta may have an opposite role, since neutralization provoked an increase of expression and release of NGF. In addition, we demonstrated that neuronal cells are biochemically capable, not only of maintaining and recovering the homeostasis, but also of activating the appropriate response to insult. IL-1beta may have a pivotal role in this mechanism through the modulation of NGF and to a lesser degree of TNF-alpha.

A new HLA-A allele identified in a leukemic patient attending hematopoietic cell transplantation: A*2318.

Sequence-based typing procedure (SBT) procedure permitted us to identify a new human leukocyte antigen-A allele in a patient attending hematopoietic stem cell transplantation.

MICA∗078: A novel allele identified in a Moroccan individual affected by celiac disease

A novel MICA allele, MICA(∗)078, has been identified during HLA/MICA high resolution typing of Moroccan patients with celiac disease. MICA(∗)078 shows an uncommon variation at a highly conserved nucleotide position (nt 493, G → A), resulting in one amino acid change at codon 142 (V → I) of MICA gene (compared to MICA(∗)002:01), located in the α2-domain, in which V142 is the common residue.

Chimerism in a child with severe combined immunodeficiency: A case report

Abstract:  Severe combined immunodeficiency (SCID) represents a group of rare, sometimes fatal, congenital disorders in which there is a combined absence of T‐lymphocyte and B‐lymphocyte function. Children with SCID die within two years of age, if untreated. The effective treatment for SCID is a hematopoietic stem cell transplantation (HSCT). It has been repeatedly described that in peripheral blood of infants with SCID maternal T cells can be found. Here we report a case of blood chimerism in a one‐year‐old boy with SCID.

CD1A, D and E gene polymorphisms in a North African population from Morocco

CD1 molecules are specialized in capturing and presenting lipids and glycolipids to distinct subsets of T and NKT cells. Glycolipid presentation could play a significant role in the immune response against microbial infections. There are five closely linked CD1 genes in humans, named CD1A, B, C, D, and E, which all show a limited polymorphism. In this study, exon 2 polymorphisms of CD1A, CD1D and CD1E were investigated and allele, genotype and haplotype frequencies of these loci were reported in a Moroccan population. A comparison with allele, genotype and haplotype frequencies observed in other geographic areas was also performed. Results confirmed the presence of ethnic differences in CD1 polymorphism, mainly in CD1D (in this population two additional CD1D variant alleles, CD1D(∗)03 and CD1D(∗)04, were described) and E genes. These data could be useful to evaluate a possible pathogenetic role of CD1 in diseases. Increasing the knowledge in this field may offer possibilities for the development of new immunotherapeutic approaches.

Increased CD1D polymorphism: identification of two novel alleles, CD1D*03 and *04, in individuals from Morocco.

Two novel CD1D alleles were identified in unrelated individuals from Morocco. They differ each from the common CD1D*01 allele by one nucleotide substitution in exon 2 resulting in one amino acid change in the G‐ALPHA1‐LIKE domain. According to the IMGT unique numbering for G domain, CD1D*03 has one nucleotide transition c136 > t in codon 46, with an arginine‐to‐cysteine amino acid change (R46 > C) in the D‐STRAND, whereas CD1D*04 has one transition c98 > t in codon 33, with a threonine‐to‐methionine amino acid change (T33 > M) in the C‐STRAND. This suggests that CD1D is more polymorphic than previously assumed.