L3T4 but not LFA-1 participates in antigen presentation by Ak-positive L-cell transformants.
We report that mouse L cells expressing Ak class II molecules on their surface after DNA-mediated gene transfer are capable of presenting the synthetic copolymer (Glu60 Ala30 Tyr10) to Ak-restricted long-term T-cell clones. Antigen-induced T-cell stimulation could be inhibited by monoclonal antibodies (mAb) directed at spatially distinct determinants of the alpha and/or beta subunits of the Ak molecule, and by the rat L3T4-specific mAb H129.19. In contrast, several rat mAb reactive with the mouse LFA-1 molecule failed to inhibit T-cell activation when L cells were used as antigen-presenting cells (APC), although these mAb strongly inhibited the same T-cell responses in the presence of leukocytic APC. Similarly, the cytolytic activity of the Ak-specific T-cell clone A15.1.17 was blocked by L3T4-specific and by LFA-1-specific mAb when tested on Ak-positive B-cell hybridomas, but only by L3T4-specific mAb and not by LFA-1-specific mAb when Ak-positive L-cell transformants were used as targets. These data support the notion that the LFA-1 molecule is not necessary for T-cell activation, and suggest that its functional role as an accessory molecule depends on the leukocytic nature of the APC tested.
Naquet
P
P
Malissen
B
B
Bekkhoucha
F
F
Pont
S
S
Pierres
A
A
Hood
L
L
Pierres
M
M
D000818:Animals; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D000938:Antigen-Presenting Cells / Q000276:immunology*; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D007739:L Cells; D046911:Macromolecular Substances; D051379:Mice; D010455:Peptides / Q000276:immunology; D011108:Polymers; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D014170:Transformation, Genetic
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D000949:Histocompatibility Antigens Class II; D046911:Macromolecular Substances; D010455:Peptides; D011108:Polymers; C020749:GAT