The Role of Cytomegalovirus-specific Immunoglobulins as Modulators of Antigen-specific T-cell Expansion In Vitro.

Background: Cytomegalovirus-specific immunoglobulins (CMV-IVIg) can contribute to viral control after transplantation. Apart from neutralizing antiviral activity, knowledge on their potential indirect effects on the restoration of virus-specific T-cell immunity is limited. Therefore, we tested whether CMV-IVIg may affect cytokine induction and proliferation of CMV-specific T cells in vitro. Methods: Blood samples of 38 individuals (23 kidney transplant recipients and 15 immunocompetent controls) were stimulated using CMV antigens in saturating and low antigen concentration, or with the polyclonal stimulus Results: Irrespective of antigen concentration, the presence or absence of CMV-IVIg had no effect on the percentage of CMV-specific CD4 and CD8 T cells producing interferon-gamma, tumor necrosis factor, or interleukin-2. However, proliferation of CMV-specific CD3 T cells, including CD4 and CD8 T-cell subpopulations, was significantly higher in the presence of CMV-IVIg at both saturating ( Conclusions: CMV-IVIg did not have any effect on immediate T-cell effector function. However, the marked effect of CMV-IVIg on increasing the proliferation of CMV-specific T cells while concomitantly reducing polyclonal T-cell function may have implications for the therapeutic use of immunoglobulins to restore CMV-specific T cells in patients with active CMV infection without increasing the alloreactive burden.