title: The superantigen Pseudomonas exotoxin A requires additional functions from accessory cells for T lymphocyte proliferation.
abstract: We have examined the functions required of accessory cells (AC) for murine thymocyte proliferation induced by Pseudomonas exotoxin A (PE) and have compared these functions to those required of a known superantigen, staphylococcal enterotoxin B (SEB). We demonstrate that PE, like SEB, preferentially stimulates PNA+ thymocytes expressing a specific V beta element within the T cell receptor. However, PE requires functions from AC that are distinct from those required by SEB. AC treated with paraformaldehyde (PCHO) prior to stimulation supported thymocyte proliferation induced by SEB but not PE. However, when AC were treated with PCHO subsequent to stimulation with PE, thymocyte proliferation was observed, which suggests that PE requires antigen processing in addition to presentation. Furthermore, treatment of AC with lysosomotropic agents abrogated thymocyte proliferation induced by PE but not SEB. Antibodies to MHC class II molecules inhibited thymocyte proliferation induced by both PE and SEB. In addition, we observed that interleukin 1 alpha (IL-1 alpha) participated in the proliferation of thymocytes induced by PE but not SEB. Thus, our data indicate that PE is a unique microbial superantigen that requires additional AC functions for T lymphocyte proliferation.
authors.affiliation: Department of Molecular Microbiology and Immunology, University of Missouri-Columbia, School of Medicine 65212.
authors.forename: P K
authors.initials: PK
authors.lastname: Legaard
authors.forename: R D
authors.initials: RD
authors.lastname: LeGrand
authors.forename: M L
authors.initials: ML
authors.lastname: Misfeldt
mesh_terms: D036002:ADP Ribose Transferases; D000643:Ammonium Chloride / Q000494:pharmacology; D000818:Animals; D000938:Antigen-Presenting Cells / Q000502:physiology*; D001427:Bacterial Toxins / Q000494:pharmacology*; D002478:Cells, Cultured; D002738:Chloroquine / Q000494:pharmacology; D004768:Enterotoxins / Q000494:pharmacology; D005098:Exotoxins / Q000494:pharmacology*; D005557:Formaldehyde / Q000494:pharmacology; D000949:Histocompatibility Antigens Class II / Q000502:physiology; D007375:Interleukin-1 / Q000502:physiology; D037102:Lectins / Q000032:analysis; D008213:Lymphocyte Activation / Q000187:drug effects*; D051379:Mice; D019887:Peanut Agglutinin; D011108:Polymers / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000032:analysis; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A
chemical_list: D036002:ADP Ribose Transferases; D000643:Ammonium Chloride; D001427:Bacterial Toxins; D002738:Chloroquine; D004768:Enterotoxins; D005098:Exotoxins; D005557:Formaldehyde; D000949:Histocompatibility Antigens Class II; D007375:Interleukin-1; D037102:Lectins; D019887:Peanut Agglutinin; D011108:Polymers; D011948:Receptors, Antigen, T-Cell; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A; C031818:enterotoxin B, staphylococcal; C003043:paraform