Related Experiment Video
Updated: Jun 5, 2026

Induction and Assessment of Class Switch Recombination in Purified Murine B Cells
Published on: August 13, 2010
The emergent dynamics of isotype switch
Jeffrey J Stewart1, Cordelia Vahadji, Philip E Seiden
1Theoretical Immunology Group, Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
The supplanting of the 1° IgM response by the 2° isotype-switched response is one of the best known phenomena of immune system dynamics. Given that the conditions determining which B cells will switch isotype and which ones will not are intrinsic to the entities of the immune system, it should be possible to predict the effects that the small-scale (e.g. molecular) properties have on the large scale dynamics of isotype switch. However, in practice, it is notoriously difficult to predict large scale, emergent effects from small scale conditions. Thus, it is unclear what effects (if any), mutation, IgM avidity and chronic immunization exert on isotype switch. To explore these effects, we have constructed a model of isotype switch. With this model, a modified version of the IMMSIM cellular automaton, we are able to alter small scale parameters at will and thus determine the conditions that lead to the observed large scale dynamics of isotype switch. We show that isotype switch is stabilized by high-IgM avidity, affinity/isotype-dependent cell division, and, surprisingly, mutation. We also demonstrate that chronic immunization leads, in our model, to a severe depletion of the IgM response even while the IgG response remains normal.
The supplanting of the 1° IgM response by the 2° isotype-switched response is one of the best known phenomena of immune system dynamics. Given that the conditions determining which B cells will switch isotype and which ones will not are intrinsic to the entities of the immune system, it should be possible to predict the effects that the small-scale (e.g. molecular) properties have on the large scale dynamics of isotype switch. However, in practice, it is notoriously difficult to predict large scale, emergent effects from small scale conditions. Thus, it is unclear what effects (if any), mutation, IgM avidity and chronic immunization exert on isotype switch. To explore these effects, we have constructed a model of isotype switch. With this model, a modified version of the IMMSIM cellular automaton, we are able to alter small scale parameters at will and thus determine the conditions that lead to the observed large scale dynamics of isotype switch. We show that isotype switch is stabilized by high-IgM avidity, affinity/isotype-dependent cell division, and, surprisingly, mutation. We also demonstrate that chronic immunization leads, in our model, to a severe depletion of the IgM response even while the IgG response remains normal.
Related Concept Videos
Stereotype Content Model
SN2 Reaction: Stereochemistry
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not observed.
Switching of BJT
Cut-off Mode ("Off" State): In this state, both the emitter-base and collector-base junctions are reverse-biased. The...
Stereoisomerism
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
The Two-State Receptor Model
The binding affinity of a drug determines its interaction with one...
Isomerism

