Using Specific Reporter Mice to Assess CD4⁺ T Cell Transdifferentiation

The hallmark of the adaptive immune response is its ability to adjust to the offending agents via antigen specificity and the type of immune mechanisms involved in the host defense. The cytokine milieu present in the inflammatory environment and the strength of T cell receptor (TCR) signaling control the differentiation of CD4⁺ T cells into specific effector or regulatory lineages. Nevertheless, CD4⁺ T cell differentiation is a dynamic ongoing process allowing for the plasticity of lineages, with CD4⁺ T cells possessing phenotypes of more than one effector lineage and transdifferentiation between effector states or from an effector into a regulatory phenotype. In this protocol, we describe how the use of reporter mice can be employed for studying cell transdifferentiation of CD4⁺ T cells in vitro.