Cutting edge: normal regional lymph node enrichment of antigen-specific regulatory T cells with autoimmune disease-suppressive capacity

Abstract

Natural CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg) effectively prevent autoimmune disease development, but their role in maintaining physiological tolerance against self-Ag of internal organs is not yet defined. In this study, we quantified disease-specific Treg (DS-Treg) as Treg that preferentially suppress one autoimmune disease over another in day 3 thymectomized recipients. A striking difference was found among individual lymph nodes (LN) of normal mice; Treg from draining LN were 15-50 times more efficient than those of nondraining LN at suppressing autoimmune diseases of ovary, prostate, and lacrimal glands. The difference disappeared upon auto-Ag ablation and returned upon auto-Ag re-expression. In contrast, the CD4(+)CD25(-) effector T cells from different individual LN induced multiorgan inflammation with comparable organ distribution. We propose that peripheral tolerance for internal organs relies on the control of autoreactive effector T cells by strategic enrichment of Ag-specific Treg in the regional LN.

Figure 1

Treg from normal ovarian LN suppress AOD more efficiently than Treg from non-ovarian LN. (A and B): Severity of AOD in d3tx recipients of ovarian LN Treg (A) or non-ovarian LN Treg (B). Filled circles represent positive serum oocyte antibody. (C): AOD incidences between recipients of ovarian LN Treg (squares) and recipients of non-ovarian LN Treg (circles) (n = 6-8).

Figure 2

Selective enrichment of EAP-specific Treg and DA-specific Treg in prostate LN and lacrimal gland LN of normal mice. (A and B): EAP severity between d3tx recipients of Treg from prostate LN (A) and lacrimal gland LN (B). Incidences of EAP between these Treg recipients are shown in C (squares, prostate LN Treg recipients; circles, lacrimal gland LN Treg recipients). (D and E): DA severity between d3tx recipients of Treg from prostate LN (D) and lacrimal gland LN (E). (F): Incidence of DA between these Treg recipients (squares, prostate LN Treg recipients; circles: lacrimal gland LN Treg recipients). Filled circles denote positive prostate autoantibody.

Figure 3

Loss and gain in prostate Ag expression influences EAP-specific Treg activity in the normal prostate LN. (A): EAP severity and incidence in mice that received Treg (0.03 – 0.05×10⁶) from prostate LN (PDLN) or lacrimal gland LN (LGLN), obtained from: normal donors, NOX donors, or donors with NOX and DHT treatment (NOX+DHT). (B): Immunohistochemical detection of prostate antigens in normal mice, NOX mice, and NOX+DHT. P-values determined by Mann-Whitney test.

Figure 4

Organ distribution of tissue inflammation in B6 RAG-/- recipients of CD4+CD25- T cells from individual LN of wild type B6 donors. Data represent the incidence (%) and severity (mean ± SD) of tissue inflammation and destruction. Comparisons are made between pathology induced by lacrimal gland-draining cervical LN (CLN; gray bars), mesenteric LN (MLN; white bars) or prostate LN (PLN; black bars). Each recipient received 0.2×10⁶ CD4+CD25- T cells i.v., and was studied 3-4 weeks later. Data represents the summation of three independent experiments, with two mice per experiment. LB, large bowel; LG, lacrimal gland; SB, small bowel.