This paper from Tatiana Akimova and colleagues involved several years of work and is both a technical tour-de-force and a stellar contribution. Basically, Dr. Akimova isolated Tregs from within tumors of patients with lung cancer and compared their properties with Tregs from the blood, lymph node and lungs of these patients. Compared to the other Treg populations, tumor Tregs were especially potent as suppressors of T cell proliferation. Faced by a lack of distinctive phenotypic markers, Dr. Akimova introduced the novel RNA-by-flow approach to the project. This technique highlighted the remarkable level of FOXP3 mRNA in tumor vs. other Tregs and identified high expression of 4 transcription factors that induce FOXP3 expression. The effects of the tumor microenvironment on the expression of these factors is now under investigation. This paper is a trove of data and a credit to the persistence and high level of innovation of the investigators.

Human lung tumor FOXP+ Tregs upregulate four “Treg-locking” transcription factors. Akimova T, Zhang T, Negorev D, Singhal S, Stadanlick J, Rao A, Annunziata M, Levine MH, Beier UH, Diamond JM, Christie JD, Albelda SM, Eruslanov EB, Hancock WW. JCI Insight.