Related Experiment Video
Updated: Sep 1, 2026

Mouse Naïve CD4+ T Cell Isolation and In vitro Differentiation into T Cell Subsets
Published on: April 16, 2015
T cell regulation of isotype expression. The requirement for a second Ig-specific helper T cell population for the
A characteristic of the in vivo responses to T-dependent antigens is the highly restricted expression of Ig heavy chain classes of both the antibody and nonspecific Ig produced. To investigate the cellular interactions which regulate expression of Ig class, sheep red blood cell- and keyhole limpet hemocyanin-primed BALB/c T cells were tested in vitro for their ability to induce normal BALB/c B cells to selective Ig secretion. The results, based initially on linear regression analysis, indicate that while the production of IgM required help from a single antigen-specific helper cell, additional signals from a second pool of helper cells were necessary for the expression of IgG isotypes. The greatly diminished ability of primed T cells from mice suppressed from birth for IgM production to induce IgG responses indicated that the generation of this second class-regulating T cell pool requires the presence of Ig, probably B cell-presented, during the period of priming. Bases on the present data, secretion of IgG by normal B cells can be explained by invoking the requirement for a second pool of helper T cells which recognize Ig determinant, in contrast to the I region recognition known to exist for effective help by the first helper cell. In addition, it is proposed that in the absence of such a second signal only IgM secretion will occur.
A characteristic of the in vivo responses to T-dependent antigens is the highly restricted expression of Ig heavy chain classes of both the antibody and nonspecific Ig produced. To investigate the cellular interactions which regulate expression of Ig class, sheep red blood cell- and keyhole limpet hemocyanin-primed BALB/c T cells were tested in vitro for their ability to induce normal BALB/c B cells to selective Ig secretion. The results, based initially on linear regression analysis, indicate that while the production of IgM required help from a single antigen-specific helper cell, additional signals from a second pool of helper cells were necessary for the expression of IgG isotypes. The greatly diminished ability of primed T cells from mice suppressed from birth for IgM production to induce IgG responses indicated that the generation of this second class-regulating T cell pool requires the presence of Ig, probably B cell-presented, during the period of priming. Bases on the present data, secretion of IgG by normal B cells can be explained by invoking the requirement for a second pool of helper T cells which recognize Ig determinant, in contrast to the I region recognition known to exist for effective help by the first helper cell. In addition, it is proposed that in the absence of such a second signal only IgM secretion will occur.
More Related Videos
06:15Characterization of Thymus-dependent and Thymus-independent Immunoglobulin Isotype Responses in Mice Using Enzyme-linked Immunosorbent Assay
Published on: September 7, 2018
07:07Evaluation of T Follicular Helper Cells and Germinal Center Response During Influenza A Virus Infection in Mice
Published on: June 27, 2020
Related Concept Videos
Special Features of Adaptive Immunity
The primary cell types involved in adaptive immunity are T cells and B cells. Each type has a unique role in defending the body against pathogens. T cells are responsible for cell-mediated immunity. They identify and eliminate infected cells directly,...
Cells of the Adaptive Immune Response
Diversity of Antigen Receptors
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
T Cell Activation and Clonal Selection
Naive T cells that have not yet encountered an antigen express two primary CD...
T Cell Types and Functions
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
B Cell Activation and Differentiation
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...