Innate immune interferon responses to human immunodeficiency virus-1 infection.

Type I interferon (IFN) responses represent the canonical host innate immune response to viruses, which serves to upregulate expression of antiviral restriction factors and augment adaptive immune defences. There is clear evidence for type I IFN activity in both acute and chronic HIV-1 infection in vivo, and plasmacytoid dendritic cells have been identified as one important source for these responses, through innate immune detection of viral RNA by Toll-like receptor 7. In addition, new insights into the molecular mechanisms that trigger induction of type I IFNs suggest innate immune receptors for viral DNA may also mediate these responses. It is widely recognised that HIV-1 restriction factors share the characteristic of IFN-inducible expression, and that the virus has evolved to counteract these antiviral mechanisms. However, in some target cells, such as macrophages, IFN can still effectively restrict virus. In this context, HIV-1 shows the ability to evade innate immune recognition and thereby avoid induction of type I IFN in order to successfully establish productive infection. The relative importance of evasion of innate immune detection and evasion of IFN-inducible restriction in the natural history of HIV-1 infection is not known, and the data suggest that type I IFN responses may play a role in both viral control and in the immunopathogenesis of progressive disease. Further study of the relationship between HIV-1 infection and type I IFN responses is required to unravel these issues and inform the development of novel therapeutics or vaccine strategies.

Ex vivo expansion, maturation, and activation of umbilical cord blood-derived T lymphocytes with IL-2, IL-12, anti-CD3, and IL-7. Potential for adoptive cellular immunotherapy post-umbilical cord blood transplantation.

OBJECTIVES: We investigated whether umbilical cord blood (UCB) T cells could be ex vivo expanded and activated in short-term culture for potential utilization as adoptive cellular immunotherapy post-umbilical cord blood transplantation (UCBT). METHODS: Fresh UCB mononuclear cells (MNCs) were isolated by Ficoll density centrifugation. Cryopreserved UCB mononuclear cells were thawed and washed with 2.5% human serum albumin and 5% dextrose in isotonic saline. The nonadherent MNC fraction were then plated in a serum-free cocktail of IL-2, IL-12, and anti-CD3 with and without IL-7 for 48 hours. Proliferation, cytotoxicity, TH1 (IFN-gamma), CD25, and CD45RO assays were performed. RESULTS: Proliferation studies demonstrated a significant increase in the proliferative ability of the UCB MNCs incubated in anti-CD3, IL-2, IL-12, and IL-7 (fresh--p < 0.005, and thawed--p < 0.001). The combination of all four agonists significantly induced expression of CD45 RO (fresh--p < 0.05, and thawed--p < 0.001) in both the CD4(+) and CD8(+) T cells expressing CD25 (fresh UCB--p < 0.01 [CD4] and p < 0.005 [CD8], respectively; thawed UCB--p < 0.001 [CD4] and p < 0.001 [CD8]). Intracellular cytokine profiles also revealed a significant increase in the production of IFN-gamma (TH1 cells) (fresh UCB--p < 0.005, and thawed UCB--p < 0.001). The combination also significantly increased the killing of K562-labeled target cells (fresh--p < 0.0001, and thawed--0.731 +/- 0.03 vs 0.16 +/- 0.01) (p < 0.001). CONCLUSIONS: These data suggest that the ex vivo combination of IL-2, IL-12, anti-CD3, and IL-7 significantly enhances the proliferation, activation, maturation, and cytotoxic potential of UCB T cells of both fresh and thawed UCB MNC. Further studies, however, are required to determine whether these ex vivo--expanded MNC could also potentially exacerbate acute or chronic graft-vs-host disease and/or other toxicities if utilized post-UCBT.