TLR-Mediated B Cell Defects and IFN-α in Common Variable Immunodeficiency

• Published in: Journal of clinical immunology Vol. 32; no. 1; pp. 50 - 60
• Main Authors: Yu, Joyce E., Zhang, Li, Radigan, Lin, Sanchez-Ramon, Silvia, Cunningham-Rundles, Charlotte
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.02.2012
• Subjects: Adolescent; Adult; Aged; B-Lymphocytes - immunology; B-Lymphocytes - metabolism; Biomedical and Life Sciences; Biomedicine; Common Variable Immunodeficiency - genetics; Common Variable Immunodeficiency - immunology; Common Variable Immunodeficiency - metabolism; Cytidine Deaminase - genetics; Dendritic Cells - immunology; Dendritic Cells - metabolism; Humans; Immunoglobulin A - metabolism; Immunoglobulin Class Switching; Immunoglobulin G - metabolism; Immunoglobulin gamma-Chains - genetics; Immunology; Infectious Diseases; Interferon-alpha - biosynthesis; Internal Medicine; Lymphocyte Activation - immunology; Medical Microbiology; Middle Aged; RNA, Messenger - biosynthesis; Toll-Like Receptor 7 - genetics; Toll-Like Receptor 7 - metabolism; Toll-Like Receptor 9 - genetics; Toll-Like Receptor 9 - metabolism; Toll-Like Receptors - genetics; Toll-Like Receptors - metabolism; Young Adult; IFN-α; B cell; common variable immune deficiency; Toll-like receptor
• ISSN: 0271-9142; 1573-2592; 1573-2592
• DOI: 10.1007/s10875-011-9602-y

Common variable immune deficiency (CVID) B cells have impaired responses to TLR7 and TLR9 agonists including poor cell proliferation, loss of cytokine production, and failure to produce IgG or IgA. We show that TLR7- or 9-activated B cells from CVID subjects with >0.5% peripheral isotype-switched CD27 + B cells (group 2) have increased mature Cγ1 and Cγ2 heavy-chain mRNA transcripts compared to subjects who have <0.5% isotype-switched cells (group 1). While TLR-stimulated CVID plasmacytoid dendritic cells for all subjects had impaired IFN-α production, TLR7 or TLR9 stimulation in the presence IFN-α normalized isotype-switched CD27 + B cells, enhanced activation-induced cytidine deaminase mRNA, and significantly improved IgG production only for group 2 subjects. IFN-α also upregulated TLR7 and TLR9 mRNA expression comparable to normal levels in B cells of group 2 subjects, indicating that the loss of IFN-α could be a significant component of the B-cell defect for these subjects.