Class switching in human immunoglobulin transgenic mice

Area of Science:

• Immunology
• Genetics
• Molecular Biology

Background:

• Mice are crucial models for studying the immune system.
• Understanding antibody class switching is vital for immunology research.
• Human immunoglobulin gene regulation mechanisms are complex.

Purpose of the Study:

• To investigate the functionality of human immunoglobulin heavy and kappa light chain transgenes in mice.
• To determine if human gene sequences can direct antibody class switching in a heterologous system.
• To generate a mouse model reliant on human transgenes for B-cell development.

Main Methods:

• Introduction of human germline-configuration heavy and kappa light chain minilocus transgenes into mice via pronuclear microinjection.
• Disruption of endogenous mouse heavy and kappa light chain loci using homologous recombination in embryonic stem cells.
• Analysis of B-cell development and antibody repertoire generation in genetically modified mice.

Main Results:

• Transgenic mice successfully developed B-cell lineages and generated antibody repertoires solely from human transgenes.
• Engineered mouse B cells exhibited regulated switching to human gamma 1 isotype, both in vivo and in vitro.
• The human gamma 1 switch region demonstrated functional homology to mouse regulatory elements for class switching.

Conclusions:

• Human immunoglobulin transgenes can support B-cell development and antibody production in mice.
• The human gamma 1 switch region contains core sequences sufficient for mediating class switching.
• This study provides insights into the conserved mechanisms of antibody class switching across species.