Lung-restricted antibodies mediate primary graft dysfunction and prevent allotolerance after murine lung transplantation

A Bharat, S Chiu, Z Zheng, H Sun… - American journal of …, 2016 - atsjournals.org
A Bharat, S Chiu, Z Zheng, H Sun, A Yeldandi, MM DeCamp, H Perlman, GRS Budinger
American journal of respiratory cell and molecular biology, 2016atsjournals.org
Over one-third of lung recipients have preexisting antibodies against lung-restricted
antigens: collagen (Col) type V and K-α1 tubulin (KAT). Although clinical studies have
shown association of these antibodies with primary graft dysfunction (PGD), their biological
significance remains unclear. We tested whether preexisting lung-restricted antibodies can
mediate PGD and prevent allotolerance. A murine syngeneic (C57BL/6) or allogeneic
(C57BL/6 to BALB/c) left lung transplantation model was used. Rabbit polyclonal antibodies …
Over one-third of lung recipients have preexisting antibodies against lung-restricted antigens: collagen (Col) type V and K-α1 tubulin (KAT). Although clinical studies have shown association of these antibodies with primary graft dysfunction (PGD), their biological significance remains unclear. We tested whether preexisting lung-restricted antibodies can mediate PGD and prevent allotolerance. A murine syngeneic (C57BL/6) or allogeneic (C57BL/6 to BALB/c) left lung transplantation model was used. Rabbit polyclonal antibodies were produced against KAT and Col-V and injected pretransplantation. T cell frequency was analyzed using enzyme-linked immunospot, whereas alloantibodies were determined using flow cytometry. Wet:dry ratio, arterial oxygenation, and histology were used to determine PGD. Preexisting Col-V or KAT, but not isotype control, antibodies lead to dose-dependent development of PGD after syngeneic lung transplantation, as evidenced by poor oxygenation and increased wet:dry ratio. Histology confirmed alveolar and capillary edema. The native right lung remained unaffected. Epitope spreading was observed where KAT antibody treatment led to the development of IL-17–producing CD4+ T cells and humoral response against Col-V, or vice versa. In contrast, isotype control antibody failed to induce Col-V– or KAT-specific cellular or humoral immunity. In addition, none of the mice developed immunity against a non–lung antigen, collagen type II. Preexisting lung-restricted antibodies, but not isotype control, prevented development of allotolerance using the MHC-related 1 and cytotoxic T-lymphocyte-associated protein 4-Ig regimen. Lung-restricted antibodies can induce both early and delayed lung graft dysfunction. These antibodies can also cause spreading of lung-restricted immunity and promote alloimmunity. Antibody-directed therapy to treat preexisting lung-restricted antibodies might reduce PGD after lung transplantation.
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