What are possible consequences of class switching from IgM to another isotype?

After immunization or infection, activated naïve B cells can switch from expressing IgM and IgD on their surface to expressing IgG, IgE or IgA. This isotype/class switch changes the effector function of the antibody, and improves its ability to eliminate the pathogen that induced the response.

Is IgM produced after class switching?

Class switching is the process whereby an activated B cell changes its antibody production from IgM to either IgA, IgG, or IgE depending on the functional requirements. By the end of this CAL you should understand: the basic structure and function of an antibody.

How does B cell class switching occur?

Class switching occurs after activation of a mature B cell via its membrane-bound antibody molecule (or B cell receptor) to generate the different classes of antibody, all with the same variable domains as the original antibody generated in the immature B cell during the process of V(D)J recombination, but possessing …

What are class switched memory B cells?

Class switching allows memory B cells to secrete different types of antibodies in future immune responses. The B cells then either differentiate into plasma cells, germinal center B cells, or memory B cells depending on the expressed transcription factors.

What are non switched memory B cells?

Non-switched memory B cells can differentiate into antibody producing plasmablasts and secret IL-6 after activation (Torigoe et al. 2017. 2017. Metabolic reprogramming commits differentiation of human CD27+IgD+ B cells to plasmablasts or CD27-IgD- Cells.

Do memory B cells switch class?

Is class switching reversible?

Therefore, class switches are irreversible and must proceed from upstream classes to downstream classes, according to the order of the IGH constant region loci on the chromosome, which is shown in Figure 1—figure supplement 3.

What stimulates B cells to form antibodies?

helper T-cells
There are two main types of T-cells: helper T-cells and killer T-cells. Helper T-cells stimulate B-cells to make antibodies and help killer cells develop.

How does IgA class switching occur in B cells?

IgA class switching is the process whereby B cells acquire the expression of IgA, the most abundant antibody isotype in mucosal secretions. IgA class switching occurs via both T-cell-dependent and T-cell-independent pathways, and the antibody targets both pathogenic and commensal microorganisms.

How is class switching performed in IgD and IgM?

Class switching substitutes the IgH constant region μ (Cμ) and Cδgenes encoding primary IgM and IgD isotypes with Cγ, Cαor Cεgenes through a process known as class-switch recombination (CSR)9. This molecular event generates secondary IgG, IgA and IgE isotypes that have the same antigen specificity as IgM and IgD, but different effector functions10.

What happens to the immunoglobulin heavy chain during class switching?

If these activated B cells encounter specific signaling molecules via their CD40 and cytokine receptors (both modulated by T helper cells ), they undergo antibody class switching to produce IgG, IgA or IgE antibodies. During class switching, the constant region of the immunoglobulin heavy chain changes but the variable regions,…

How is IgD expressed in naive B cells?

Each antibody class has its own specific function within an immune response as we will discuss in a moment, other than IgD whose function is not yet understood. IgD is expressed by naïve B cells alongside IgM, and this expression is lost following activation.