Search results for " lectin"
showing 10 items of 112 documents
Differential expression of the murine mannose-binding lectins A and C in lymphoid and nonlymphoid organs and tissues.
2003
Abstract Mannose-binding lectin (MBL), a member of the collectin family, binds to carbohydrate structures on the surfaces of micro-organisms and may serve as a recognition molecule of the lectin pathway of complement activation. In rodents two forms, MBL-A and MBL-C, were described and shown to be products of two related, but uncoupled, genes. The liver is the main source of MBL biosynthesis. For rat MBL-A, expression has also been described in the kidney. Here we report that the two forms of murine MBL are differentially expressed in a number of nonhepatic tissues. Real-time RT-PCR revealed that the liver is the major site of expression for both MBL genes. Lower copy numbers were found in …
Age-Dependent Association of Human Mannose-Binding Lectin Mutations With Susceptibility to Invasive Meningococcal Disease in Childhood
2007
Mannose-binding lectin (MBL) is an important factor of the innate immune system, and MBL-initiated complement activation is an important early defense mechanism against various bacterial infections, including invasive meningococcal disease.In a pediatric cohort (ages 2-215 months) with invasive meningococcal disease, we investigated the overall and age-stratified frequency of 3 MBL exon 1 variations (C154T, G161A, G170A), previously shown to result in markedly decreased MBL plasma concentrations, by allele specific fluorescent hybridization probe real-time PCR assays and direct sequencing. Healthy age-matched volunteers with the same ethnic background and no history of meningococcal disease…
The Major Conformational IgE-binding Epitopes of Hevein (Hev b6.02) Are Identified by a Novel Chimera-based Allergen Epitope Mapping Strategy
2002
A novel approach to localize and reconstruct conformational IgE-binding epitope regions of hevein (Hev b6.02), a major natural rubber latex allergen, is described. An antimicrobial protein (AMP) from the amaranth Amaranthus caudatus was used as an immunologically non-IgE-binding adaptor molecule to which terminal or central parts of hevein were fused. Hevein and AMP share a structurally identical core region but have different N-terminal and C-terminal regions. Only 1 of 16 hevein-allergic patients showed weak IgE binding to purified native or recombinant AMP. Chimeric AMP with the hevein N terminus was recognized by IgE from 14 (88%) patients, and chimeric AMP with the hevein C terminus wa…
Construction of hevein (Hev b 6.02) with reduced allergenicity for immunotherapy of latex allergy by comutation of six amino acid residues on the con…
2004
Abstract Recently we have established that IgE Abs bind to conformational epitopes in the N- and C-terminal regions of the major natural rubber latex allergen, hevein (Hev b 6.02). To identify the critical amino acid residues that interact with IgE, the hevein sequence was scanned by using site-specific mutations. Twenty-nine hevein mutants were designed and produced by a baculovirus expression system in insect cells and tested by IgE inhibition-ELISA using sera from 26 latex allergic patients. Six potential IgE-interacting residues of hevein (Arg5, Lys10, Glu29, Tyr30, His35, and Gln38) were identified and characterized further in detail. Based on these six residues, two triple mutants (HΔ…
Th1 and Th17 lymphocytes expressing CD161 are implicated in giant cell arteritis and polymyalgia rheumatica pathogenesis.
2012
International audience; OBJECTIVE: Giant cell arteritis (GCA) is the most frequently occurring vasculitis in elderly individuals, and its pathogenesis is not fully understood. The objective of this study was to decipher the role of the major CD4+ T cell subsets in GCA and its rheumatologic form, polymyalgia rheumatica (PMR). METHODS: A prospective study of the phenotype and the function of major CD4+ T cell subsets (Th1, Th17, and Treg cells) was performed in 34 untreated patients with GCA or PMR, in comparison with 31 healthy control subjects and with the 27 treated patients who remained after the 7 others withdrew. RESULTS: Compared with control subjects, patients with GCA and patients wi…
BRAF-V600E expression in precursor versus differentiated dendritic cells defines clinically distinct LCH risk groups.
2014
BRAF-V600E expression is identified in hematopoietic progenitor and precursor myeloid dendritic cells in patients with high-risk LCH, and enforced expression of BRAF-V600E in CD11c+ cells recapitulates a high-risk LCH-like phenotype in mice.
Human CD8 T lymphocytes recognize Mycobacterium tuberculosis antigens presented by HLA-E during active tuberculosis and express type 2 cytokines
2015
CD8 T cells contribute to protective immunity against Mycobacterium tuberculosis. In humans, M. tuberculosis reactive CD8 T cells typically recognize peptides associated to classical MHC class Ia molecules, but little information is available on CD8 T cells recognizing M. tuberculosis Ags presented by nonclassical MHC class Ib molecules. We show here that CD8 T cells from tuberculosis (TB) patients recognize HLA-E-binding M. tuberculosis peptides in a CD3/TCR αβ mediated and CD8-dependent manner, and represent an additional type of effector cells playing a role in immune response to M. tuberculosis during active infection. HLA-E-restricted recognition of M. tuberculosis peptides is detectab…
Study of nuclear and acrosomal sperm morphometry in ram using a computer-assisted sperm morphometry analysis fluorescence (CASMA-F) method.
2014
The aim of this study was to develop a new method that allows morphometric assessment of the sperm nucleus and acrosome in the ram using fluorescence microscopy and free software. The study was divided into three experiments. In the first experiment, semen smears from 20 ejaculates were fixed and labeled with a propidium iodide-pisum sativum agglutinin (PI/PSA) combination. Digital images of the sperm nucleus, acrosome, and whole sperm head were captured and analyzed using the ImageJ program. The computer-assisted sperm morphometry analysis fluorescence (CASMA-F) method used allowed the differentiation, capture, and morphometric analysis of most sperm nuclei, acrosomes, and whole heads with…
Langerin+ DCs regulate innate IL-17 production in the oral mucosa during Candida albicans-mediated infection
2018
The opportunistic fungal pathogen Candida albicans frequently causes diseases such as oropharyngeal candidiasis (OPC) in immunocompromised individuals. Although it is well appreciated that the cytokine IL-17 is crucial for protective immunity against OPC, the cellular source and the regulation of this cytokine during infection are still a matter of debate. Here, we directly visualized IL-17 production in the tongue of experimentally infected mice, thereby demonstrating that this key cytokine is expressed by three complementary subsets of CD90+ leukocytes: RAG-dependent αβ and γδ T cells, as well as RAG-independent ILCs. To determine the regulation of IL-17 production at the onset of OPC, we…
Effetti dell'esposizione in vitro al cloruro di metilmercurio Sulle risposte immunitarie di Dicentrarchus labrax.
2008
This study shows that high methylmercury concentrations are cytotoxic for Dicentrarchus labrax leucocytes, whereas subletal concentrations affect leucocyte phagocytosis and cells morphology in a dose dependent fashion. Although the serum hemoagglutinating activity was not inhibited by the metal, the activity of purified serum F-lectin fraction and mucus was significantly decreased by relevant methylmercury concentrations.