Phenotypes of Th lineages generated by the commonly used activation with anti-CD3/CD28 antibodies differ from those generated by the physiological activation with the specific antigen.

T-helper (Th) lineages have been generated in vitro by activating CD4 cells with anti-CD3/CD28 antibodies during polarization. Physiologically, however, the generation of Th lineages is by activation with the specific antigen presented by antigen-presenting cells (APC). Here, we used T-cell receptor (TCR)-transgenic mice to compare the phenotypes of Th1, Th9 and Th17 lineages when generated by either one of the two activation modes. Lineage Th cells specific against hen egg lysozyme (HEL), were adoptively transferred into recipient mice transgenically expressing HEL in their lens. Remarkable differences were found between lineages of Th1, Th9 or Th17, generated by either one of the two modes in their capacities to migrate to and proliferate in the recipient spleen and, importantly, to induce inflammation in the recipient mouse eyes. Substantial differences were also observed between the lineage pairs in their transcript expression profiles of certain chemokines and chemokine receptors. Surprisingly, however, close similarities were observed between the transcript expression profiles of lineages of the three phenotypes, activated by the same mode. Furthermore, Th cell lineages generated by the two activation modes differed considerably in their pattern of gene expression, as monitored by microarray analysis, but exhibited commonality with lineages of other phenotypes generated by the same activation mode. This study thus shows that (i) Th lineages generated by activation with anti-CD3/CD28 antibodies differ from lineages generated by antigen/APC; and (ii) the mode of activation determines to a large extent the expression profile of major transcripts.