Stigma Variations: Observations on Suppressor T Cells and Leprosy

Abstract

Few areas of immunology have been so controversial as that of suppressor T cells. Studies of T cell clones derived from patients with infectious diseases, including leprosy, and allergies have allowed the delineation of functional human T cell subsets. Both CD4 and CD8 cells can be discriminated into subsets that are differentiated by their functions and patterns of lymphokines. Type 1 CD4 cells reactive with lepromin and PPD produce IFN-gamma and IL-2 predominantly, while Type 2 CD4 clones, specific for tetanus toxoid, produce IL-4 and IL-5. Type 1 CD8 cytotoxic T lymphocytes produce predominantly IFN-gamma and IL-2. T suppressor clones derived from immunologically unresponsive lepromatous leprosy patients are antigen-specific, CD8 cells, HLA-DQ restricted, and produce predominantly IL-4, and were designated Type 2 CD8 cells. Several models for peripheral tolerance based on distinct functional T cell subsets are discussed. Previous models of T cell suppression in the mouse and the reciprocal relationship between humoral and cell-mediated immunity in general are reinterpreted in light of such T cell subset interactions.

Cd8high+ (CD57+) T cells in patients with rheumatoid arthritis

“…Furthermore, unusual restriction of CD8+ T cells through MHC class I1 cannot be discounted. This has been reported with HLA-DQ and antigen-specific, suppressive CD8+ T cells from patients with lepromatous leprosy (39). Because of the preponderance of DR1/4 in RA patients, only a larger study with appropriately chosen, HLA-matched, and agematched controls would define this.…”

Suppressor role of rat CD8+CD45RClow T cells in experimental autoimmune uveitis (EAU)

“…Moreover, CD8 autoreactive T cells may act either as pathogenic T cells (Bloom et al, 1992, Jiang et al, 1992, Rifa'i et al, 2004, Sun et al, 1988b, Sun et al, 1999a or suppressive T cells, which inhibit disease development (Endharti et al, 2005, Rifa'i et al, 2004. In the present study, we studied the role of the CD8 + CD45RC low T cell subset in the pathogenesis of the autoimmune diseases, EAE and EAU.…”

“…Although many studies have shown that CD8 + T cells play important roles in the pathogenesis of autoimmune diseases (Bloom et al, 1992, Jiang et al, 1992, Rifa'i et al, 2004, Sun et al, 1988b, Sun et al, 1999a, Endharti et al, 2005, the cellular and molecular mechanisms involved remain largely unclear. Moreover, CD8 autoreactive T cells may act either as pathogenic T cells (Bloom et al, 1992, Jiang et al, 1992, Rifa'i et al, 2004, Sun et al, 1988b, Sun et al, 1999a or suppressive T cells, which inhibit disease development (Endharti et al, 2005, Rifa'i et al, 2004.…”

“…Recent studies have demonstrated that, among the CD4 T cells, a subset expressing CD25 has strong suppressor activity (Shevach, 2000, Suripayer et al, 1998. There is also evidence that some subsets of CD8 T cells are functionally suppressive (Sun et al, 1988b, Sun et al, 1999b, Jiang et al, 1992, Endharti et al, 2005, Najafian et al, 2003 (Bloom et al, 1992, Jiang et al, 1992, Rifa'i et al, 2004, Sun et al, 1999a. It is important to note that, during the late phases of chronic autoimmune diseases, CD8 autoreactive T cells accumulate in the damaged organ and in the periphery (Friese and Fugger, 2005, Bradl et al, 2005, Sun et al, 2001.…”

Identification of a human CD8+regulatory T cell subset that mediates suppression through the chemokine CC chemokine ligand 4

“…Bacillus Calmette-Guérin's inadequacy as TB vaccine may, similarly, at least in part (10), be accounted for by its ability to induce Tregs (11). Tregs have been isolated from leprosy patients (12,13), which suppressed CD4 ϩ Th1 cells (12)(13)(14). More recently, IL-10-producing T cells were reported in anergic TB patients (15), and increased frequencies of CD4 ϩ CD25 HI T cells have been found in the circulation of TB patients (16,17).…”