Ingestion of Bacillus anthracis spores causes gastrointestinal (GI) anthrax. Humoral immune responses, particularly immunoglobulin A (IgA)-secreting B-1 cells, play a critical role in the clearance of GI pathogens. Here, we investigated whether B. anthracis impacts the function of colonic B-1 cells to establish active infection. GI anthrax led to significant inhibition of immunoglobulins (eg, I...

The pathogenesis of the immunoglobulin deficiency of 20 patients with ataxia telangiectasia was studied using an in vitro immunoglobulin biosynthesis system. 10 patients had no detectable IgA in their serum as assessed by radial diffusion in agar and 3 had a reduced serum IgA concentration. The peripheral blood mononuclear cells of 17 of the patients and 17 normal controls were cultured with po...

Our previous studies indicated that cloned T cells obtained from Peyer's patches (PP) (Lyt-1+, 2-, Ia+, and H-2K/D+) evoked immunoglobulin (Ig) class switching of PP B cells from sIgM to sIgA cells in vitro; however, these switch T cells could not in themselves provide optimal help for the differentiation of postswitch sIgA-bearing PP B cells to IgA-secreting cells. Thus, in the present report ...

The isotype distribution of Dextran B 512 (Dex)-specific plaque-forming cells (PFC) and serum antibodies was studied after in vivo immunization in C57BL/6 mice. Although IgG2b and IgG3 could also be detected in most individuals, the majority of non-IgM PFC were of the IgA isotype. All classes other than IgM were T cell-dependent, as shown by their complete absence in athymic "nude" mice. This u...

Recently, we identified that diverse heavy chain (H-chain)-only IgG is spontaneously produced in light chain (L-chain)-deficient mice (L(-/-) with silenced kappa and lambda loci) despite a block in B cell development. In murine H-chain IgG, the first Cgamma exon, C(H)1, is removed after DNA rearrangement and secreted polypeptides are comparable with camelid-type H-chain IgG. Here we show that L...

In cattle, Mycobacterium avium subsp. paratuberculosis infection is primarily mediated through M cells overlying Peyer's patches (PP) in the ileum. The capacity of M. avium subsp. paratuberculosis to invade ileal PP (IPP) versus discrete PP in the jejunum (JPP) and subsequent differences in mucosal immune responses were investigated. Intestinal segments were surgically prepared in both mid-jeju...

Inbred mouse strains used for gene manipulation studies vary in many respects, including immune system function. These differences can interfere with data interpretation unless the mice are well backcrossed. Here, we show that antibody class switching to IgG3 in cultured splenic B cells from Swiss James Lambert (SJL) and 129/Sv mice is 2- to 6-fold less efficient compared with C57BL/6 (B6). Und...

B lymphocyte stimulator (BLyS; also known as TNFSF20, BAFF, TALL-1, zTNF4, and THANK), a tumor necrosis factor ligand family member, has recently been identified as a factor that promotes expansion and differentiation of the B cell population, leading to increases in serum immunoglobulin levels. Here, pharmacokinetic parameters for BLyS administered i.v. and s.c. to mice are described, and the ...

BACKGROUND B-cell depletion can improve a variety of chronic inflammatory diseases, but does not appear beneficial for patients with Crohn's disease. OBJECTIVE To elucidate the involvement of B cells in Crohn's disease, we here performed an 'in depth' analysis of intestinal and blood B-cells in this chronic inflammatory disease. METHODS Patients with Crohn's disease were recruited to study ...

BACKGROUND Post-transplant food allergy (LTFA) is increasingly observed after paediatric liver transplantation (LT). Although the immunopathology of LTFA remains unclear, immunoglobulin (Ig) E seems to be implicated. OBJECTIVE To study humoral and cellular immunity in paediatric LT patients in search for factors associated with LTFA, and compare with healthy controls (HC) and non-transplant f...