The immune response involves the generation of Ab-secreting cells and memory B cells through a process called terminal B lymphocyte differentiation. This program requires the transcriptional repressor Blimp-1, which inhibits c-myc expression and terminates proliferation. Although the role of c-Myc in cell proliferation is well characterized, it is not known whether it has other functions in ter...

lps-responsive beige-like anchor (lrba) deficiency is a disease which has recently been described in a group of patients with common variable immunodeficiency (cvid) in association with autoimmunity and/or inflammatory bowel disease (ibd)-like phenotype. we here describe a 10-year-old boy who experienced recurrent infections, mainly in the respiratory system, associated with thrombocytopenia an...

Hyper-immunoglobulin M (IgM) syndrome (HIGM) is a rare heterogeneous primary immune deficiency. We describe a patient with HIGM characterized by skewed production of serum IgG subclasses and normal somatic hypermutation. This case may represent a subgroup of HIGM type 4 that is characterized by a biased switching to the V-region proximal constant regions.

The gut is the major site of antibody production in humans. The most abundant isotype produced is IgA, but the importance of IgA has been questioned. On the one hand, in IgA deficient patients, IgM can compensate functionally ; on the other hand, it might be argued that such flexibility is an absolute requirement because the system is indispensable. The relationship between IgM and IgA in human...

Background: Hyper-Immunoglobulin M (IgM) syndrome (HIGM) is a rare primary immunodeficiency in which defective B-cell isotype switching results in a phenotype characterized by elevated or normal serum IgM levels and low levels of other Ig classes, leading to an increased susceptibility to infection, neutropenia, autoimmune disorders, and malignancies. In this disease, a mutation occurs in the C...

The epitheliochorial placenta of swine is considered a barrier to Ag and selective transport of IgG, so this species should be an excellent model with which to determine whether switch recombination is Ag dependent. Analysis of Ig levels and Ig isotype profiles in >150 normal and virus-infected fetuses from 38-110 days of gestation (DG) suggested that IgG, IgA, and IgM were most likely the resu...