gB co-immunization with GP96 enhances pulmonary-resident CD8 T cells and exerts a long-term defence against MCMV pneumonitis
JOURNAL OF CELLULAR AND MOLECULAR MEDICINE
Authors: Guo, Bingnan; Xu, Peifeng; Chai, Dafei; Cao, Lei; Liu, Lin; Song, Tengfei; Hu, Shuqun; Chen, Yuling; Yan, Xianliang; Xu, Tie
Abstract
Human cytomegalovirus (HCMV) infection in the respiratory tract leads to pneumonitis in immunocompromised hosts without available vaccine. Considering cytomegalovirus (CMV) mainly invades through the respiratory tract, CMV-specific pulmonary mucosal vaccine development that provides a long-lasting protection against CMV challenge gains our attention. In this study, N-terminal domain of GP96 (GP96-NT) was used as a mucosal adjuvant to enhance the induction of pulmonary-resident CD8 T cells elicited by MCMV glycoprotein B (gB) vaccine. Mice were intranasally co-immunized with 50 mu g pgB and equal amount of pGP96-NT vaccine 4 times at 2-week intervals, and then i.n. challenged with MCMV at 16 weeks after the last immunization. Compared with pgB immunization alone, co-immunization with pgB/pGP96-NT enhanced a long-lasting protection against MCMV pneumonitis by significantly improved pneumonitis pathology, enhanced bodyweight, reduced viral burdens and increased survival rate. Moreover, the increased CD8 T cells were observed in lung but not spleen from pgB/pGP96-NT co-immunized mice. The increments of pulmonary CD8 T cells might be mainly due to non-circulating pulmonary-resident CD8 T-cell subset expansion but not circulating CD8 T-cell populations that home to inflammation site upon MCMV challenge. Finally, the deterioration of MCMV pneumonitis by depletion of pulmonary site-specific CD8 T cells in mice that were pgB/pGP96-NT co-immunization might be a clue to interpret the non-circulating pulmonary-resident CD8 T subset expansion. These data might uncover a promising long-lasting prophylactic vaccine strategy against MCMV-induced pneumonitis.
Immunosuppressive therapy alleviates murine cytomegalovirus recurrence by reducing TNF-alpha post cell transplantation with lethal GVHD
ANTIVIRAL RESEARCH
Authors: Deng, Jiang; Xiao, Jun; Lv, Liping; Ma, Ping; Song, Xin; Gao, Bo; Gong, Feng; Zhang, Yanyu; Xu, Jinbo
Abstract
Cytomegalovirus (CMV) reactivation leads to obvious morbidity and mortality in patients after allogeneic hematopoietic cell transplantation (allo-HCT). Current immunosuppressive therapy reduces the frequency of graft-versus-host disease (GVHD), and is generally accepted as a high risk factor for viral recurrence. In the present study, we investigated the influence of cyclosporin A (CsA) and rapamycin (RAPA), two commonly used immunosuppressive agents, on murine cytomegalovirus (MCMV) recurrence by two allo-HCT models: one with mild and one with severe GVHD. In models with mild GVHD and partial immune recovery, transplanted mice with CsA and RAPA showed a higher viral load and impaired CMV-specific immune recovery compared to those with placebo. In contrast, in HCT models with severe GVHD, groups treated with immunosuppressive therapy showed alleviation of viral recurrence as well as GVHD-related symptoms. In addition, no CMV-specific immune reconstitution was found in any group, implying immunosuppressive therapy was not relevant to antiviral response. Furthermore, a significant correlation between MCMV DNA copies and tumor necrosis factor alpha (TNF-alpha) was found, and recipients with immunosuppressive therapy showed a lower level of TNF-alpha. Finally, using lenalidomide (an inhibitor of TNF-alpha), a lower viral load was found in animals with lenalidomide. Having received lenalidomide, recipients showed no statistical difference in viral load between groups with and without immunosuppressive therapy. Taken together, we provide evidence of the dual effect of immunosuppressive therapy on viral reactivation. Importantly, we found that immunosuppressive therapy had the ability to alleviate viral load by reducing TNF-alpha, in a mouse model with severe GVHD. (C) 2016 Elsevier B.V. All rights reserved.