Abstract
Abstract: :
Purpose: We have shown previously that mice with MAIDS are susceptible to MCMV retinitis following subretinal MCMV inoculation. Since other laboratories (Lu & Atherton, 1994; Kercher and Mitchell, 2000) have shown that adoptive transfer of immune cells will protect against MCMV retinitis in euthymic or cyclophosphamide-immunosuppressed BALB/c mice, we hypothesized that adoptive transfer to replenish immune cells during MAIDS would also prevent MCMV retinitis in C57BL/6 mice under conditions of retrovirus-induced immunosuppression. Methods: Groups of BALB/c mice immunosuppressed with methylprednisolone (2 mg, day -2, +2, and +6) and groups of C57BL/6 mice with MAIDS were injected intravenously with 2 to 5 million freshly-isolated splenic cells from MCMV-immunized BALB/c or C57BL/6 mice, respectively. Control mice received intravenous injections with freshly-isolated splenic cells from nonimmunized BALB/c or C57BL/6 mice. All mice were then challenged with MCMV by subretinal injection. MCMV-inoculated eyes from adoptive transfer and control groups were collected 9-10 days following subretinal MCMV injection, analyzed histopathologically, and scored for frequency and severity of retinitis. Results: As expected, adoptive transfer of immune cells reduced the frequency of MCMV retinitis in corticosteroid-immunosuppressed BALB/c mice (2/8) when compared with control animals (7/8). Surprisingly, adoptive transfer of immune cells in three separate experiments failed to protect against MCMV retinitis in mice with MAIDS when compared with control animals. No difference was observed in the severity of retinitis in MAIDS mice receiving immune or nonimmune cells. Conclusion: Whereas adoptive transfer of immune cells provided protection against MCMV retinitis in BALB/c mice immunosuppressed by corticosteroid treatment, frequency and severity of retinitis in mice with MAIDS was unaffected by adoptively transferred immune cells. We conclude that adoptively transferred immune cells cannot function in the unique milieu of retrovirus-induced immunosuppression.
Keywords: 382 cytomegalovirus • 568 retinitis • 316 animal model