Peripheral blood CD8αα + CD11c + MHC-II + CD3 - cells attenuate autoimmune glomerulonephritis in rats

Abstract

In an anti-GBM glomerulonephritis (GN) model, GN-resistant Lewis rats naturally recover from early glomerular inflammation. Here we investigated recovery mechanisms for development of a potential immunotherapy for autoimmune GN. Our previous studies suggested that glomeruli-infiltrating leukocytes with a phenotype of CD8αα+CD11c+MHC−II+CD3− (GIL CD8αα+ cells) were responsible for recovery through induction of T cell apoptosis. Now, we identified peripheral blood CD8αα+CD11c+MHC−II+CD3− cells (PBMC CD8αα+CD3− cells), which shared 9 markers with GIL CD8αα+ cells. Upon incubation, PBMC CD8αα+CD3− cells displayed a morphology resembling that of dendritic cells. Similar to GIL CD8αα+ cells, PBMC CD8αα+CD3− cells were capable of inducing T cell apoptosis in vitro. Hence, PBMC CD8αα+CD3− cells were likely the precursor of GIL CD8αα+ cells. We next tested their potential in vivo function. PBMC CD8αα+CD3− cells were able to infiltrate inflamed but not normal glomeruli. Isolated PBMC CD8αα+CD3− cells of Lewis rats were transferred into GN-prone Wistar Kyoto rats at early inflammatory stage (day 17–25). When examined at day 45, both histopathology and BUN/serum creatinine level showed significantly attenuated GN in 80% of cell recipient Wistar Kyoto rats. Separate experiments verified infiltration of transferred Lewis PBMC CD8αα+CD3− into the glomeruli, accompanied with apoptotic CD4+ T cells in the glomeruli of the recipient Wistar Kyoto rats. Thus, PBMC CD8αα+CD3− cells of Lewis rats were able to terminate ongoing autoimmune inflammation in the glomeruli.

CD8αα+MHC Class II+ Cell with the Capacity To Terminate Autoimmune Inflammation Is a Novel Antigen-Presenting NK-like Cell in Rats

“…1F). Thus, the CD8αα + RT1B/D + cells possessed Ag processing/presentation apparatus for a professional APC as we have previously reported (14, 15). In fact, both α and β chains of rt1b and rt1d have been cloned from the CD8αα + RT1B/D + cells ( GenBank AY701537-AY701540 ).…”

“…Glomeruli were purified from immunized rats and digested to release glomeruli-infiltrating leukocytes following a previously established method (14,15). The cells were subjected to isolation of various cell populations on a magnetic beads-based automatic cell sorter (Miltenyi Biotec, Germany).…”

“…For activation, T cells were incubated with irradiated thymic APC and pCol(28–40) at sub-optimal concentration (3μM) for 48 hours (14). In either cases T cells were then labelled by CFSE (15). Glomeruli-infiltrating CD8αα + RT1B/D + were isolated as described above and used as killing effectors.…”

“…We have linked migration deficiency to disease susceptibility in the disease-prone Wista Kyoto (WKY) rats. Significantly, transfer of this cell population of LEW rats attenuates pre-existing disease in WKY rats (15). This suggests that the CD8αα + RT1B/D + cell is a potential candidate for immunotherapy for a pre-existing autoimmune disease.…”

Differentiating Glomerular Inflammation from Fibrosis in a Bone Marrow Chimera for Rat Anti-Glomerular Basement Membrane Glomerulonephritis

“…We have shown that a BM-derived RT1B + CD8αα + DC-like population is associated with GN resistance in LEW rats [19–21]. We have further shown that transfer of LEW’s RT1B + CD8αα + cells attenuates severity of GN in WKY rats [26]. Thus, GN resistance in WKY LEW rats may be due to this DC-like population from LEW’s BM.…”