Immunology
InterMEM T Cell State Between Naïve and Effector
By Proceedings of the National Academy of Sciences
Apr 8, 2005, 04:35

After passing through an intermediary state, naïve T cells concurrently differentiate into memory and effector cells, according to Susan Holmes et al.

Previous research has shown that T cells require an encounter with antigen and other signals to undergo clonal expansion and differentiation, but the genetic events that underlie this process are not fully understood. Holmes et al. used FACSorting to isolate naïve, effector, and memory CD8+ T cells, based on the expression of CD27 and CD45RA, from the peripheral blood of 10 subjects.

The researchers identified 156 genes differentially expressed among the three T cell subsets. By multivariate analysis, they were able to discern an intermediary state between the three cell types, termed InterMEM, which was closer to the memory T cell state than to naïve or effector states. This expression pattern, the researchers argue, supports the parallel differentiation model, in which naïve T cells differentiate into effector and memory cells simultaneously. In addition to CD27 and CD45RA, the authors report other biomarkers able to further discriminate among the three T cell subsets: syntaphilin and IFN-&ggr; receptor 2 for naïve cells; vinculin and granzyme B for effector cells; and T cell receptor-interacting molecule and granzyme K for memory cells.

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