Question

Autoimmune attacks often target ‘immune privileged’ sites, such as the brain, the eye or the testis. Once effector T cells specific for autoantigens expressed in these tissues are generated, these effector cells can gain entry to the tissue and cause tissue damage. Nevertheless, under normal circumstances, the priming and differentiation of effector cells specific for antigens found in ‘immune privileged’ sites is generally prevented. This is because ‘immune privileged’ sites [complete the sentence and assess each subsequent statement (15-20) as either factually correct (true) or incorrect (false)]:

15. express antigens that never leave the tissue where they are produced.

16. are surrounded by tissue barriers that block all lymphocyte trafficking.

17. express the cell death receptor, Fas.

18. express the cytokine, TGF-b.

19. promote the differentiation of TH17 cells.

20. express the Fas ligand.

Answer 1

15. Correct

Immune privileged sites are able to tolerate introduction of antigen without any occurrence of inflammatory immune response.

16. Correct

Lack of lymphatic drainage limits the immune system's ability to enter the site.

17. Correct

It controls Fas expressing lymphoid cells.

18. Correct

TGF-B playa a vital role in induction and/ or effector function CD8+ during immune deviation.

19. Correct

Expresses Fas which promotes differentiation of TH17 cells.

20. Correct