Immature T cells produce a variety of multi-subunit T cell receptors (TCRs), which exhibit enormous sequence variability. Proper maturation depends on the extent to which a T cell's TCRs can interact with host-specific major histocompatibility complex (MHC) proteins. If this interaction is too strong or too weak, maturation will not take place. Immunologists have typically studied this important process in vivo via TCR engineering, generating transgenic animals that exclusively produce T cells expressing TCRs with specific subunit combinations.
Dario Vignali's laboratory previously described a system that enables single DNA molecules to act as 'assembly lines' for the simultaneous production of multiple, independent proteins. Here the team adapt this method to generate retroviral constructs expressing multiple TCR subunits, which were used to infect mouse marrow stem cells. These cells are transplanted into marrow-depleted recipients to make 'retrogenic' mice that produce only one type of TCR. This approach bypasses the time and trouble of generating and crossing multiple transgenic strains, and ensures equal production of all protein products-an essential consideration for TCR assembly.
In an associated 'News and Views' piece, Rémy Bosselut comments that although these retrogenics may not fully supplant transgenics for studying TCR-MHC interactions in vivo, they offer a rapid and elegant alternative for TCR mutant analysis or experimental scenarios where standard transgenics aren't an option.
Dario A. A. Vignali (St. Jude Children's Research Hospital, Memphis, TN, USA)
Rémy Bosselut (National Cancer Insitute, Bethesda, MD, USA)
Abstract available online.
(C) Nature Methods press release.
Message posted by: Trevor M. D'Souza