Stimulation of the Same B‐Cell Population by Thymus‐Independent Dextran and by Thymus‐Dependent Oligosaccharide‐Carrier

Abstract

The immune response of adult BALB/c mice against the bacterial antigen dextran B1355S (Dex) is well characterized as thymus independent (TI type 2) and Igha linked. The antisera consist of mainly IgM/lambda antibodies directed against the alpha(1-->3) glucosidic linkage. This study describes the immune response against the alpha(1-->3) linkage in the thymus dependent form (TD), i.e. tetra- or heptasaccharides (N4 or N7) of glucose as hapten coupled to chicken serum albumin (CSA) as carrier. Whereas athymic BALB/c-nu/nu mice did not respond to the TD antigens N4-CSA and N7-CSA, euthymic BALB/c showed high anti-Dex antibody titres of IgM and, after 2 degrees immunization, a class switch to IgG (mainly IgG1) isotypes with lambda light chains. The hapten N4 inhibited Dex-binding of M104E or of antisera from Dex or N4-CSA or N7-CSA immunized mice at 1.7-10 x 10(-4)M. The idiotype composition of these antibodies resembled those after Dex immunization. We conclude that the same Dex-specific precursor B cells have been stimulated by either form of antigen. The ontogenic development of a Dex-specific response could not be accelerated by the aid of T cells, even of adult origin. It seems, therefore, that the maturation of antigen specific B cells is the limiting step in ontogeny.

Exopolysaccharide from Lactobacillus fermentum Lf2 and its functional characterization as a yogurt additive

“…In the gut, secretory IgA is the main immunoglobulin whose key role is to exert an immune exclusion by intimate cooperation with the innate non-specific protection mechanisms (Brandtzaeg et al 1987). Various authors described antibody production at the systemic level after the oral administration of exopolysaccharides or their producing strains (Willers et al 1995; Vinderola et al 2006; Fanning et al 2012; Salazar et al 2014). In general, these studies refer to administration in higher doses than those evaluated in the present work, which are more representative of a real concentration of any EPS in a food matrix.…”

Adjuvant Effect of Killed Propionibacterium acnes on Mouse Peritoneal B-1 Lymphocytes and Their Early Phagocyte Differentiation

“…S2 A). This effect could be due to the precursor nature of this subset, which would allow them to respond to a thymus-independent antigen [36] (such as PS) better than to the whole bacteria. P. acnes and PS have already been demonstrated to have effects on precursor cells that include increasing the absolute number of CD34 + bone marrow hematopoietic stem cells [28].…”

“…TLR9 is located in an intracellular compartment, but was recently shown to be expressed on the cell membrane of human peripheral blood B lymphocytes [36].…”

Effects of the oral administration of the exopolysaccharide produced by Lactobacillus kefiranofaciens on the gut mucosal immunity

“…This immunoglobulin exerts immune exclusion by intimate cooperation with the innate non-specific defense mechanisms [34]. There have been reports of antibody production at the systemic level after the oral administration of exopolysaccharides [35,36]. The role of the non-bacterial fraction of kefir in immune stimulation was also reported [28].…”