title: CD154 blockade modulates the ratio of Treg to Th1 cells and prolongs the survival of allogeneic corneal grafts in mice.
abstract: Administration of anti-CD154 monoclonal antibody (mAb) may prolong the survival of an allograft; however, the associated therapeutic mechanisms remain poorly understood. This study aimed to evaluate the effects of anti-CD154 mAb on T-cell responses in a mouse model of corneal allograft transplantation. BALB/c mice were transplanted with corneal grafts from C57BL/6 mice and treated intraperitoneally with 250 μg anti-CD154 mAb or isotype IgG on days 0, 3 and 6 post surgery. The transparency of the corneal grafts was evaluated for potential rejection signs by slit-lamp biomicroscopy and histopathology. The percentages of CD4+T, Tim-3+CD4+T helper (Th) 1 and CD4+CD25+Foxp3+regulatory T cells (Tregs) in the spleen, ipsilateral draining lymph nodes and corneal grafts, and the frequency of splenic IFN-γ+and IL-10+expression in CD4+T cells were determined by flow cytometry. Moreover, the ratio of Tregs to Th1 cells was calculated and the suppressive activity of splenic Tregs was measured. Anti-CD154 neutralization significantly prolonged the survival of the corneal allograft (P=0.0012) and reduced the numbers of inflammatory infiltrates in the corneal graft. In the spleen and lymph nodes, anti-CD154 treatment reduced the frequency of CD4+T cells, Tregs and particularly Th1 cells. In the corneal allografts, anti-CD154 treatment downregulated graft-infiltrated CD4+T cells and Th1 cells, but increased graft-infiltrated Tregs. Furthermore, anti-CD154 treatment increased the frequency of splenic IL-10+CD4+T cells and decreased the concentration of splenic IFN-γ+CD4+T cells. As a result, the ratio of Tregs to Th1 cells in the anti-CD154-treated recipients increased. Anti-CD154 treatment did not enhance the suppressive activity of Tregs in the recipients. The results indicate that the therapeutic effects of anti-CD154 mAb on prolonging the survival of the corneal allograft may be associated with an increased ratio of Tregs to Th1 cells in mice.
authors.affiliation: Beijing Ophthalmology and Visual Science Key Laboratory, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, P.R. China ; Department of Ophthalmology, the Affiliated Hospital of Chengde Medical College, Chengde, Hebei 067000, P.R. China.
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Tan
authors.affiliation: Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing 100730, P.R. China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zeng
authors.affiliation: Beijing Ophthalmology and Visual Science Key Laboratory, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, P.R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Jie
authors.affiliation: Beijing Ophthalmology and Visual Science Key Laboratory, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, P.R. China.
authors.forename: Yingnan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Beijing Ophthalmology and Visual Science Key Laboratory, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, P.R. China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Beijing Ophthalmology and Visual Science Key Laboratory, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, P.R. China.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Pan
keywords: CD154; T helper 1 cells; corneal transplantation; mouse; regulatory T cells