Undernutrition and Hypoleptinemia Modulate Alloimmunity and CMV-specific Viral Immunity in Transplantation.
Immunological mechanisms linking undernutrition to infection and the alloimmune response are poorly understood in transplantation. We aimed to determine how undernutrition and hypoleptinemia impact T-cell allospecific and cytomegalovirus (CMV) viral-specific immunity in a murine model.
Fed, fasted for 48 h (model of undernutrition), and fasted with leptin injections (leptin rescue), C57BL/6 mice received skin grafts from either C57BL/6 (syngeneic) or BALB/c (allogeneic) mice donors. Allograft rejection and survival were monitored. Fed, fasted, and leptin rescue C57BL/6 mice were inoculated with murine cytomegalovirus (mCMV). Mouse spleens were retrieved for T-cell flow cytometry analysis, mCMV DNA extraction, and quantitative polymerase chain reaction. Serum leptin levels were measured with ELISA.
Fasted mice had prolonged rejection-free and graft survival compared with fed mice (P = 0.0002 and P = 0.043). Leptin administration did not alter rejection-free survival or allograft failure. CD8+ central memory T cell and CD8+ effector T cell proportions were significantly lower in fasted mice receiving allogeneic skin transplants compared with fed mice (P = 0.0009 and P = 0.0015). Fasted mice had higher viral loads (P = 0.0028) and impaired mCMV-specific interferon-gamma-producing CD8+ T cells (P = 0.0007), which improved with leptin rescue (P = 0.032).
Undernutrition and its associated hypoleptinemia correlated with impaired allospecific and viral-specific immunities. Leptin administration decreased mCMV viral burden and increased mCMV-specific T-cell immunity, however, it did not increase rejection or worsen graft survival in complete major histocompatibility complex-mismatched skin allografts. Leptin may be a potential adjunctive therapy for CMV viremia in undernourished transplant recipients.
David, Emeraghi, Minghua Zhu, Braden C. Bennett, Daniel Cheng, Paul Schroder, Amanda Nichols, William Parker, Allan D. Kirk, Nancie MacIver, and Eileen T. Chambers. “Undernutrition and Hypoleptinemia Modulate Alloimmunity and CMV-specific Viral Immunity in Transplantation.” Transplantation 105, no. 12 (December 2021): 2554–63. https://doi.org/10.1097/tp.0000000000003743.