In vivo proliferation of rat lamina propria T lymphocytes: general hyporesponsiveness but increased importance of the CD2 and CD28 pathways.
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 alphabeta T cell receptor (TCR). Mitogenic mAb directed at the alphabeta 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 alphabeta 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 alphabeta 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.
Hoffmann
J C
JC
Medizinische Klinik I mit Schwerpunkt Gastroenterologie/Infektiologie/Rheumatologie, Universitätsklinikum Benjamin Franklin, Berlin, Germany. joerg.hoffmann@st-marienkrankenhaus.de
Peters
K
K
Pawlowski
N N
NN
Grollich
K
K
Henschke
S
S
Herrmann
B
B
Zeitz
M
M
Westermann
J
J
D000818:Animals; D017209:Apoptosis; D018801:CD2 Antigens / Q000378:metabolism*; D018106:CD28 Antigens / Q000378:metabolism*; D049109:Cell Proliferation; D005260:Female; D008213:Lymphocyte Activation / Q000276:immunology; D009092:Mucous Membrane / Q000276:immunology*; D051381:Rats; D011917:Rats, Inbred Lew; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology*
D018801:CD2 Antigens; D018106:CD28 Antigens; D016693:Receptors, Antigen, T-Cell, alpha-beta