title: The activation, by antigen, of naïve TCR transgenic CD4 T cells cultured at physiological, rather than artificially high, frequencies more accurately reflects the in vivo activation of normal numbers of naïve CD4(+) T cells.
abstract: The majority of in vitro studies investigating the activation of naïve TCR transgenic T cells routinely employ an artificially high frequency of such cells. To assess whether employing high frequencies of TCR transgenic cells in vitro accurately reflects the in vivo activation of a normal number of T cells, we cultured between 300 and 3×10(6) Rag2(-/-) DO11.10 T cells per well under otherwise identical conditions. We find that those T cells cultured at low frequencies proliferate more and are more potently activated, as assessed by the expression of CD44 and CD62L, each giving rise to a much larger number of cytokine producing cells, comparable to the number generated in vivo when a normal number of CD4(+) T cells are activated. The effect of T cell frequency on the level of their activation was not due to differences in MHCII or CD80/86 expression by B cells, the major APC population present, nor to increased death of B cells in high frequency cultures. Taken together, our observations illustrate the necessity of culturing naïve TCR transgenic CD4(+) T cells at a physiological frequency if one is to more accurately recapitulate the in vivo activation of naïve CD4(+) T cells.
authors.affiliation: Department of Microbiology and Immunology, University of Saskatchewan, A305-107, Saskatoon, Saskatchewan, Canada S7N 5E5. chris.rudulier@usask.ca
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Rudulier
authors.forename: David R
authors.initials: DR
authors.lastname: Kroeger
authors.forename: Peter A
authors.initials: PA
authors.lastname: Bretscher
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D018122:B7-1 Antigen / Q000096:biosynthesis; D051940:B7-2 Antigen / Q000096:biosynthesis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis; D018960:Hyaluronan Receptors / Q000096:biosynthesis; D019041:L-Selectin / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000276:immunology
chemical_list: D018122:B7-1 Antigen; D051940:B7-2 Antigen; D016207:Cytokines; D018960:Hyaluronan Receptors; D011948:Receptors, Antigen, T-Cell; D019041:L-Selectin