TRANSFER OF THYROIDITIS, WITH SYNGENEIC SPLEEN-CELLS SENSITIZED WITH THE HUMAN THYROTROPIN RECEPTOR, TO NAIVE BALB C AND NOD MICE/

In previous studies we have induced TSH binding-inhibiting Igs and thy roiditis in BALB/c mice and thyroiditis alone in NOD mice immunized wi th the extracellular domain of the human TSH receptor produced as a ma ltose-binding protein fusion in bacteria (MBP-ECD). In this study, our aim was to determine whether thyroiditis can be transferred to syngen eic naive recipients with in vivo and in vitro primed spleen cells. Gr oups of 6-week-old female BALB/c and NOD mice were immunized ip with M BP-ECD in an adjuvant of alum plus attenuated Bordetella pertussis tox in, on days 0 (100 mu g), 14, 28, and 35 (50 mu g). These mice (in viv o primed) and nontreated age- and sex-matched controls were killed on day 43, and their spleens and thyroids were removed, the latter to ver ify the induction of thyroiditis in the antigen-treated mice. Splenocy tes were disrupted mechanically and cultured at 3 X 10(6)/ml in RPMI s upplemented with 20 mu g/ml MBP-ECD for 48-64 h. After this in vitro p riming, some of the splenocytes received no further treatment, but a p ortion was fractionated into a CD4(+)-enriched population. Groups of 6 -week-old female BALB/c and NOD mice were immunized into the tail vein with 100-200 mu l PBS containing approximately 10(5)-10(7) unfraction ated T cells (both in vivo primed and not) and CD4(+)-enriched (in viv o primed) splenocyte populations. The animals were killed 16 days late r, and their thyroids were examined histologically and by immunohistoc hemistry. In addition, levels of antibody to the MBP-ECD priming antig en were assessed by enzyme-linked immunosorbent assay in the antigen- and spleen-treated mice. In the donor animals, in vivo priming resulte d in an extensive lymphocytic infiltration of the thyroids in both BAL B/c and NOD mice and follicular destruction in the latter. There was n o evidence of thyroiditis in all 9 BALB/c mice and all 4 NOD mice who received unfractionated T cells from mice that had not been primed in vivo. In contrast, transfer of MBP-ECD in vivo primed unfractionated T cells resulted in thyroiditis in 9 of 13 BALB/c mice and 5 of 6 NOD m ice; similarly, the equivalent CD4(+)-enriched population produced ext ensive thyroiditis in 2 of 3 BALB/c mice and all three NOD mice. The m ost striking difference between the antigen- and spleen-treated mice w as in the quantity of the infiltrate, which was much greater in the la tter and extended throughout the thyroid glands of these animals. In c ommon with mice treated directly with the MBP-ECD antigen, the infiltr ates of both BALB/c and NOD recipient mice contained large numbers of activated T cells expressing the receptor for interleukin-2, and macro phages and dendritic cells were plentiful, particularly in the BALB/c mice, in which B cells and interleukin-10-positive T cells were also p resent. The most abundant infiltrates, containing numerous CD8(+) T ce lls and follicular destruction, were observed in NOD mice receiving pr imed unfractionated T cells or CD4(+)-enriched T cells. In contrast to the donors, none of the recipient animals had circulating antibodies to the MBP-ECD antigen. In conclusion, we have shown that it is possib le to transfer thyroiditis with spleen cells from mice primed in vivo with a human TSH receptor preparation. Furthermore, the thyroiditogeni c activity appears to reside in the CD4(+) population.