Tonsillar germinal center and immunoglobulin M+ (IgM+)IgD+ B cells as well as peripheral blood (PB) CD5+ and CD5- (conventional) B cells from a 4-yr-old child were isolated and nucleotide sequences of expressed Ig heavy chain variable regions encoded by VH4 gene family members were determined from amplified cDNA. Whereas both tonsillar IgM+IgD+ cells and the majority of IgM-expressing CD5+ and ...

The concentration of serum IgD was measured in 100 patients with Hodgkin disease; 65 had 3--50-fold increases in IgD levels. Several parameters were found to influence serum IgD concentration: IgD level in older patients (greater than 50 yr) was significantly lower than in the younger patients (P less than 18 yr). IgD concentration was significantly higher in splenectomized than in nonsplenecto...

We show that the IgD-induced augmentation of the immune response to trinitrophenylated keyhole limpet hemocyanin can be transferred to syngeneic mice with spleen cells from IgD-injected donors. The augmenting activity is present in the Lyt-1+2-, L3T4+ T cell population and is absent from B cells. The ability of transferred T cells to augment the immune response correlates with the presence of a...

During T cell-dependent antibody responses, B cells within germinal centers (GC) alter the affinity of their antigen receptor by introducing somatic mutations into variable region of immunoglobulin (IgV) genes. During this process, GC B cells are destined to die unless positively selected by antigens and CD40-ligand. To understand survival/death control of germinal center B cell, the expression...

During a germinal center reaction, random mutations are introduced into immunoglobulin V genes to increase the affinity of antibody molecules and to further diversify the B cell repertoire. Antigen-directed selection of B cell clones that generate high affinity surface Ig results in the affinity maturation of the antibody response. The mutations of Ig genes are typically basepair substitutions,...

There are a growing number of studies on structural and functional brain mechanisms underlying Internet gaming disorder (IGD). Recent functional magnetic resonance imaging studies showed that IGD adolescents and adults had reduced gray matter volume in regions associated with attention motor coordination executive function and perception. Adolescents with IGD showed lower white matter (WM) inte...

The expression of functional B cell antigen receptors (BCRs) is essential for development, survival and activation of B cells. During early developmental stages, immature B cells exclusively express IgM. Cells that pass the immature B cell stage and leave the bone marrow coexpress BCRs of IgM and IgD isotypes, which differ in the usage of the heavy chain (HC) µ versus δ that are generated by al...

OBJECTIVE Internet gaming disorder (IGD) is a type of behavioral addiction characterized by abnormal executive control, leading to loss of control over excessive gaming. Attention deficit and hyperactivity disorder (ADHD) is one of the most common comorbid disorders in IGD, involving delayed development of the executive control system, which could predispose individuals to gaming addiction. We ...

OBJECTIVE Internet gaming disorder (IGD) is a new disorder currently positioned in the appendix of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Few clinical studies report that psychological and pharmacological interventions can significantly reduce the severity of IGD symptomatology. The aim of this review was to assess current knowledge of the short- and long-term...

Secretion of outer membrane vesicles (OMV) is an intriguing phenomenon of Gram-negative bacteria and has been suggested to play a role as virulence factors. The respiratory pathogens Moraxella catarrhalis reside in tonsils adjacent to B cells, and we have previously shown that M. catarrhalis induce a T cell independent B cell response by the immunoglobulin (Ig) D-binding superantigen MID. Here ...