Induction of eye-derived tolerance does not depend on naturally occurring CD4+CD25+ T regulatory cells.
OBJECTIVE
Regulatory CD4+ T cells (T regs) arise in the spleens of mice with anterior chamber-associated immune deviation (ACAID), an eye-derived tolerance evoked by injection of antigen into the ocular anterior chamber (AC). The current study was conducted to investigate the possibility that these T regs express CD25 and are derived from natural CD4+CD25+ T cells.


METHODS
Naïve T cells from DO11.10 mice were activated in vitro by ovalbumin (OVA)-pulsed, TGFbeta-treated antigen-presenting cells (APCs), and the expression of CD25 assayed by flow cytometry. OVA-specific ACAID T regs were obtained from the spleens of DO11.10 mice with ACAID to OVA. Immunomagnetic enrichment was used to sort out CD4+CD25+, and CD4+CD25- ACAID T cells before they were injected into OVA-immunized mice or examined for mRNA expression of the regulatory T-cell transcription factor Foxp3. In addition, before AC injection of OVA, systemic depletion of CD25+ T cells was performed with injections of anti-IL-2 receptor antibody into the mice.


RESULTS
OVA-specific T cells from DO11.10 mice expressed CD25 when exposed to OVA-pulsed, TGFbeta-treated APCs, even when the DO11.10 T cells were depleted of CD25+ cells before their in vitro stimulation. In addition, DH was suppressed in naïve mice that were injected with CD4+CD25+ or CD4+CD25- ACAID T cells. The CD4+CD25+, but not the CD4+CD25-, ACAID T regs expressed Foxp3. Finally, OVA induced ACAID in mice depleted of CD25+ cells.


CONCLUSIONS
Some of the CD4+ T regs of ACAID arise from CD25- precursors, and the induction of ACAID is not dependent on the presence of natural CD4+CD25+ T regs.
Keino
Hiroshi
H
Schepens Eye Research Institute, Harvard Medical School, Boston, Massachusetts 02114, USA.
Takeuchi
Masaru
M
Kezuka
Takeshi
T
Hattori
Takaaki
T
Usui
Masahiko
M
Taguchi
Osamu
O
Streilein
J Wayne
JW
Stein-Streilein
Joan
J
D019264:Adoptive Transfer; D000818:Animals; D000867:Anterior Chamber / Q000276:immunology; D000938:Antigen-Presenting Cells / Q000276:immunology; D015704:CD4 Antigens / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000235:genetics; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007108:Immune Tolerance / Q000502:physiology*; D008213:Lymphocyte Activation / Q000276:immunology; D008212:Lymphocyte Depletion; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D010047:Ovalbumin; D012333:RNA, Messenger / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000276:immunology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D016212:Transforming Growth Factor beta / Q000494:pharmacology
D015704:CD4 Antigens; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D012333:RNA, Messenger; D015375:Receptors, Interleukin-2; D016212:Transforming Growth Factor beta; D010047:Ovalbumin