Regulatory function for murine intraepithelial lymphocytes. Two subsets of CD3+, T cell receptor-1+ intraepithelial lymphocyte T cells abrogate oral tolerance.
The murine intraepithelial lymphocyte (IEL) population is enriched in T cells that express the gamma delta-TCR, however, the biologic function served by these T cells remains obscure. IEL are considered to be major effector cells in mucosal immunity, and we have investigated whether IEL subsets could reverse orally induced systemic unresponsiveness (oral tolerance; OT) and support secondary type responses when adoptively transferred to mice orally tolerized with SRBC. When purified CD3+ IEL from mice orally primed with SRBC were transferred to adoptive hosts and challenged with SRBC, splenic IgM, IgG1, IgG2b, and IgA anti-SRBC plaque-forming cell responses were observed. However, CD3+ IEL from HRBC orally primed mice did not abrogate SRBC induced OT. Further, HRBC-primed CD3+, IEL converted HRBC-specific OT but not SRBC-specific OT. CD3+ IEL could be separated into four subsets based on expression of CD4 and CD8. CD3+, CD4-, 8+ T cells were the major subset (74.5%), with smaller numbers of CD4- and CD8- (double negatives, DN) (7.8%), CD4+, 8- (7.6%) and CD4+, CD8+ (double positives) (10.1%) T cells. Interestingly, both the CD3+, CD8+, and the CD3+, DN IEL subsets abrogated OT, resulting in significant IgM, IgG1, IgG2b, and IgA anti-SRBC plaque-forming cell responses when adoptively transferred to mice with OT. However, neither CD3+, CD4+, CD8-, nor double positive T cells affected OT when studied in this system. The CD3+, CD8+ IEL subset could be further separated into Thy-1+ (16.6%) and Thy-1- (83.4%) cells; adoptive transfer of Thy-1- cells abrogated oral tolerance whereas the Thy-1+ subset was without effect. When the expression of TCR on IEL with this biologic function was determined by use of monoclonal anti-alpha beta TCR (H57.597), TCR2-, CD3+ IEL possessed immunoregulatory function whereas the alpha beta-TCR+ (TCR2+) fraction did not abrogate OT. Immunoprecipitation of membrane fractions obtained from purified CD3+, CD4-, CD8+, Thy-1- IEL with polyclonal anti-delta peptide (Tyr-Ala-Asn-Ser-Phe-Asn-Asn-Glu-Lys-Leu) antibody revealed bands of 45 and 35 kDa, corresponding to the delta- and gamma-chains, respectively. These results suggest that gamma delta-TCR+ IEL possess a regulatory function, namely the restoration of immune responses in a state of oral tolerance. Further, both CD3+, CD4-, CD8+, Thy-1-, and CD3+, DN IEL T cells exhibit this effector contrasuppressor function.
Fujihashi
K
K
Department of Oral Biology, University of Alabama, Birmingham 35294.
Taguchi
T
T
McGhee
J R
JR
Eldridge
J H
JH
Bruce
M G
MG
Green
D R
DR
Singh
B
B
Kiyono
H
H
D000284:Administration, Oral; D000818:Animals; D000941:Antigens / Q000008:administration & dosage*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D000954:Antigens, Surface / Q000032:analysis; D017252:CD3 Complex; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D016827:CD8 Antigens; D004847:Epithelial Cells; D004848:Epithelium / Q000276:immunology; D005434:Flow Cytometry; D007108:Immune Tolerance; D007114:Immunization; D051379:Mice; D008809:Mice, Inbred C3H; D011948:Receptors, Antigen, T-Cell / Q000032:analysis / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D018800:Thy-1 Antigens
D000941:Antigens; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D017252:CD3 Complex; D016827:CD8 Antigens; D011948:Receptors, Antigen, T-Cell; D018800:Thy-1 Antigens