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Updated: Jun 16, 2026

In Vitro Analysis of Myd88-mediated Cellular Immune Response to West Nile Virus Mutant Strain Infection
Published on: November 27, 2014
Defective B cell response to TLR9 ligand (CpG-ODN), Streptococcus pneumoniae and Haemophilus influenzae extracts in
Danilo Escobar1, Jaime Pons, Antonio Clemente
1Servei d'Immunologia, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Hospital Son Dureta, Palma de Mallorca, Spain.
Abstract:
Common variable immunodeficiency (CVID) is a primary immunodeficiency characterized by hypogammaglobulinaemia and antibody deficiency to both T dependent and independent antigens. Patients suffer from recurrent sinopulmonary infections mostly caused by Streptococcus pneumoniae and Haemophilus influenzae, but also gastrointestinal or autoimmune symptoms. Their response to vaccination is poor or absent. In this study we investigated B cell activation induced by the TLR9 specific ligand (CpG-ODN) and bacterial extracts from S. pneumoniae and H. influenzae known to stimulate several TLR. We found that B cells from CVID patients express lower levels of CD86 after stimulation with CpG-ODN, S. pneumoniae and H. influenzae extracts in combination with anti-IgM antibody and also display a lower proliferative index when stimulated with bacterial extracts. Our results point to a broad TLR signalling defect in B lymphocytes from CVID patients that may be related to the hypogammaglobulinaemia and poor response to vaccination characteristic of these patients.
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