N19 polyepitope as a carrier for enhanced immunogenicity and protective efficacy of meningococcal conjugate vaccines

N19, a string of human universal CD4 T-cell epitopes from various pathogen-derived antigens, was shown to exert a stronger carrier effect than CRM197 for the induction of anti-group C Neisseria meningitidis capsular polysaccharide (MenC), after immunization of mice with various dosages of N19-MenC or CRM-MenC conjugate vaccines. After two immunizations, the N19-based construct induced anti-MenC antibody and protective bactericidal antibody titers higher than those induced by three doses of the CRM-MenC conjugate and required lower amounts of conjugate. N19-based conjugates are superior to CRM-based conjugates to induce protective immune responses to MenC conjugates.     

Inducible nitric oxide synthase expression in human colorectal cancer: correlation with tumor angiogenesis

To investigate the potential involvement of the nitric oxide (NO) pathway in colorectal carcinogenesis, we correlated the expression and the activity of inducible nitric oxide synthase (iNOS) with the degree of tumor angiogenesis in human colorectal cancer. Tumor samples and adjacent normal mucosa were obtained from 46 surgical specimens. Immunohistochemical expression of iNOS, vascular endothelial growth factor (VEGF), and CD31 was analyzed on paraffin-embedded tissue sections. iNOS activity and cyclic GMP levels were assessed by specific biochemical assays. iNOS protein expression was determined by Western blot analysis. iNOS and VEGF mRNA levels were evaluated using Northern blot analysis. Both iNOS and VEGF expressions correlated significantly with intratumor microvessel density (r(s) = 0.31, P = 0.02 and r(s) = 0.67, P < 0.0001, respectively). A significant correlation was also found between iNOS and VEGF expression (P = 0.001). iNOS activity and cyclic GMP production were significantly higher in the cancer specimens than in the normal mucosa (P < 0.0001 and P < 0.0001, respectively), as well as in metastatic tumors than in nonmetastatic ones (P = 0.002 and P = 0.04, respectively). Western and Northern blot analyses confirmed the up-regulation of the iNOS protein and gene in the tumor specimens as compared with normal mucosa. NO seems to play a role in colorectal cancer growth by promoting tumor angiogenesis.     

Induction of apoptosis of human primary osteoclasts treated with extracts from the medicinal plant <Emphasis Type="Italic">Emblica officinalis</Emphasis>

Background  

Osteoclasts (OCs) are involved in rheumatoid arthritis and in several pathologies associated with bone loss. Recent results support the concept that some medicinal plants and derived natural products are of great interest for developing therapeutic strategies against bone disorders, including rheumatoid arthritis and osteoporosis. In this study we determined whether extracts of Emblica officinalis fruits display activity of possible interest for the treatment of rheumatoid arthritis and osteoporosis by activating programmed cell death of human primary osteoclasts.     

Allergenicity of goat’s milk in children with cow’s milk allergy

BACKGROUND: Cow's milk allergy (CMA) is a common disease of infancy and childhood. An appropriate cow's milk (CM) substitute is necessary for feeding babies with CMA. CM substitutes are soy formulas and casein- or whey-based extensively hydrolyzed formulas. In several countries, including Italy, goat's milk (GM) formulas are available, and some physicians recommend them for feeding babies with CMA. OBJECTIVE: We sought to investigate, in vitro and in vivo, the allergenicity of GM in 26 children with proven IgE-mediated CMA. METHODS: All the children underwent skin tests with CM and GM; detection of specific serum IgE to CM and GM; and double-blind, placebo-controlled, oral food challenges (DBPCOFCs) with fresh CM, GM, and, as placebo, a soy formula (Isomil, Abbott, Italy). CAP inhibition and immunoblotting inhibition assays were also carried out in 1 of 26 and 4 of 26 children with positive RAST results to both CM and GM, respectively. RESULTS: All the children had positive skin test responses and CAP results to both CM and GM, all had positive DBPCOFC results to CM, and 24 of 26 had positive DBPCOFCs to GM. In CAP inhibition tests, preincubation of serum with CM or GM strongly inhibited IgE either to CM or to GM. In immunoblotting inhibition assays, preincubation with CM completely extinguished reactivity to GM, whereas GM partially inhibited reactivity to CM. CONCLUSIONS: These data strongly indicate that GM is not an appropriate CM substitute for children with IgE-mediated CMA. A warning on the lack of safety of GM for children with CMA should be on the label of GM formulas to prevent severe allergic reactions in babies with CMA.     

The molecular basis of Natural Killer (NK) cell recognition and function

Natural Killer cells are likely to play an important role in the host defenses because they kill virally infected or tumor cells but spare normal self-cells. The molecular mechanism that explains why NK cells do not kill indiscriminately has recently been elucidated. It is due to several specialized receptors that recognize major histocompatibility complex (MHC) class I molecules expressed on normal cells. The lack of expression of one or more HLA class I alleles leads to NK-mediated target cell lysis. Different types of receptors specific for groups of HLA-C, HLA-B, and, very recently, HLA-A alleles have been identified. While in most instances, they function as inhibitory receptors, an activatory form of the HLA-C-specific receptors has been identified in some donors. Molecular cloning of HLA-C-, HLA-B- or HLA-A-specific receptors has revealed new members of the immunoglobulin superfamily with two or three Ig-like domains, respectively, in their extracellular portion. While the inhibitory form is characterized by a long cytoplasmic tail associated with a non-polar transmembrane portion, the activatory one has a short tail asociated with a Lys-containing transmembrane portion. Thus, these human NK receptors are different from the murine Ly49, that is a type II transmembrane protein characterized by a C-type lectin domain. A subset of activated T lymphocytes expresses NK-type class I-specific receptors. These receptors exert an inhibiting activity on T cell receptor-mediated functions and may provide an important mechanism of downregulation of T cell responses.     

Preaxial acrofacial dysostosis (Nager syndrome) associated with an inherited and apparently balanced X;9 translocation: Prenatal and postnatal late replication studies

We report on an infant with preaxial acrofacial dysostosis (Nager syndrome) who was diagnosed prenatally as having an apparently balanced X/autosome translocation [46,X,t(X;9)(p22.1;q32)mat] inherited from a previously diagnosed mosaic translocation carrier mother [46,XX/46,X,t(X;9)(p22.1;q32)]. Replication studies on amniocytes showed the normal X chromosome to be late replicating while the same studies repeated on the infant's lymphocytes showed the translocated X chromosome to be late replicating in most cells. Late replication studies of the mother's lymphocytes demonstrated that the normal X chromosome was late replicating in most cells. The presence of Nager syndrome in this infant may be the result of critical break-points and/or position effects on chromosome 9, inducing expression of a gene responsible for the syndrome. © 1993 Wiley-Liss, Inc.     

In vivo expression of interleukin-8, and regulated on activation, normal, T-cell expressed, and secreted, by human germinal centre B lymphocytes

T-cell homing within germinal centres (GCs) is required for humoral B-cell responses. However, the mechanisms implicated in the recruitment of T cells into the GC are not completely understood. Here we show, by immunohistology, and Northern and Western blots, that in vivo human GC B lymphocytes can express CxC and CC chemokines. Moreover, B-cell subset-specific experiments reveal that interleukin (IL)-8 and regulated on activation, normal, T-cell expressed, and secreted (RANTES) are predominantly expressed by GC centroblast and centrocytes, suggesting that chemokine expression is essential at stages in which B-lymphocytes engage in active antigen-dependent interactions with T lymphocytes. In keeping with this hypothesis, we show that the T cells recruited into the GC correlatively express the receptors for IL-8 and RANTES. We propose that chemokine expression is a key B-cell function that facilitates T-lymphocyte recruitment into the GCs and supports cognate B-cell : T-cell encounters. Moreover, our data are consistent with the impaired homing of T cells to secondary lymphoid organs in mice that are either deficient in CC and CxC chemokines or their receptors.     

Immunoglobulin M (IgM)-glycoinositolphospholipid enzyme-linked immunosorbent assay: an immunoenzymatic assay for discrimination between patients with acute toxoplasmosis and those with persistent parasite-specific IgM antibodies

In the present study we developed an enzyme-linked immunosorbent assay (ELISA) to measure immunoglobulin M (IgM) specific for glycoinositolphospholipids (GIPL) derived from tachyzoite membrane (IgM-GIPL ELISA). The sensitivity and specificity of the assay were compared with those of commercially available Toxoplasma-specific IgM serological tests, namely, immunofluorescence assay (IFA) with fixed tachyzoites and capture ELISA employing tachyzoite extracts. Our results show that all patients with acute toxoplasmosis, as determined by clinical data and conventional serological tests, were also positive by the IgM-GIPL ELISA. Interestingly, many patients that were classified as indeterminate, who had IgG with high avidity but positive results in the IgM-specific IFA and capture ELISA, were negative by the IgM-GIPL ELISA. Finally, we tested the sera from patients with rheumatoid arthritis and various parasitic infections and found no evidence of false positives in the IgM-GIPL ELISA.