In vivo Proliferation of Rat Lamina Propria T Lymphocytes: General Hyporesponsiveness but Increased Importance of the CD2 and CD28 Pathways

• Published in: Immunological investigations Vol. 38; no. 6; pp. 466 - 482
• Main Authors: Hoffmann, J. C., Peters, K., Pawlowski, N. N., Grollich, K., Henschke, S., Herrmann, B., Zeitz, M., Westermann, J.
• Format: Journal Article
• Language: English
• Published: England Informa UK Ltd 2009; Taylor & Francis
• Subjects: Animals; Apoptosis; CD2 Antigens - metabolism; CD28 Antigens - metabolism; Cell Proliferation; Costimulation; Female; Lymphocyte Activation - immunology; Lymphoid organs; Mucous Membrane - immunology; Proliferation; Rats; Rats, Inbred Lew; Receptors, Antigen, T-Cell, alpha-beta - metabolism; T cell receptor; T-Lymphocytes - immunology
• ISSN: 0882-0139; 1532-4311
• DOI: 10.1080/08820130902888342

Lamina propria T lymphocytes (LPL-T) have a low proliferative potential in vitro. We asked whether LPL-T are also hyporesponsive in vivo and whether this is specific for the αβ T cell receptor (TCR). Mitogenic mAb directed at the αβ TCR, CD2, CD28, or control mAbs plus IL-2 were injected into rats. Proliferation and or apoptosis were detected by double staining using 5-bromo-2′-deoxyuridine TUNEL and the αβ TCR. LPL-T were hyporesponsive to various stimuli compared to other T cells. The strongest proliferation was found upon CD2 CD28 stimulation (LPL-T: 281 ± 6%; spleen: 642 ± 31%). LPL-T proliferation was only detectable at 24 h while proliferation in other compartments also occurred later. Hyporesponsiveness was not caused by enhanced T cell apoptosis upon αβ TCR stimulation. In conclusion, stimulation of LPL-T results in much shorter and weaker in vivo proliferation than in other lymphoid organs. Overall, CD2 CD28 costimulation is the strongest T cell stimulus in vivo.