Transient antibody targeting of CD45RC induces transplant tolerance and potent antigen-specific regulatory T cells
Elodie Picarda, Séverine Bézie, Laetitia Boucault, Elodie Autrusseau, Stéphanie Kilens, Dimitri Meistermann, Bernard Martinet, Véronique Daguin, Audrey Donnart, Eric Charpentier, Laurent David, Ignacio Anegon, Carole Guillonneau
Elodie Picarda, Séverine Bézie, Laetitia Boucault, Elodie Autrusseau, Stéphanie Kilens, Dimitri Meistermann, Bernard Martinet, Véronique Daguin, Audrey Donnart, Eric Charpentier, Laurent David, Ignacio Anegon, Carole Guillonneau
View: Text | PDF
Research Article Therapeutics Transplantation

Transient antibody targeting of CD45RC induces transplant tolerance and potent antigen-specific regulatory T cells

Abstract

Rat and human CD4+ and CD8+ Tregs expressing low levels of CD45RC have strong immunoregulatory properties. We describe here that human CD45 isoforms are nonredundant and identify distinct subsets of cells. We show that CD45RC is not expressed by CD4+ and CD8+ Foxp3+ Tregs, while CD45RA/RB/RO are. Transient administration of a monoclonal antibody (mAb) targeting CD45RC in a rat cardiac allotransplantation model induced transplant tolerance associated with inhibition of allogeneic humoral responses but maintained primary and memory responses against cognate antigens. Anti-CD45RC mAb induced rapid death of CD45RChigh T cells through intrinsic cell signaling but preserved and potentiated CD4+ and CD8+ CD45RClow/– Tregs, which are able to adoptively transfer donor-specific tolerance to grafted recipients. Anti-CD45RC treatment results in distinct transcriptional signature of CD4+ and CD8+ CD45RClow/– Tregs. Finally, we demonstrate that anti-human CD45RC treatment inhibited graft-versus-host disease (GVHD) in immune-humanized NSG mice. Thus, short-term anti-CD45RC is a potent therapeutic candidate to induce transplantation tolerance in human.

Authors

Elodie Picarda, Séverine Bézie, Laetitia Boucault, Elodie Autrusseau, Stéphanie Kilens, Dimitri Meistermann, Bernard Martinet, Véronique Daguin, Audrey Donnart, Eric Charpentier, Laurent David, Ignacio Anegon, Carole Guillonneau

×

Figure 3

Transient anti-CD45RC mAb treatment induces rapid cell death of CD45RC+ T cells while preserving and increasing CD45RClow/– Tregs.

Options: View larger image (or click on image) Download as PowerPoint
Transient anti-CD45RC mAb treatment induces rapid cell death of CD45RC+ ...
PBMCs were harvested at day 0, 4, and 10 (during treatment), at day 15 (5 days after end of treatment), and long-term at day 120 from anti-CD45RC–treated recipients compared with naive PBMCs and analyzed by flow cytometry for absolute number of CD45RChigh T cells (A), as well as B cells, NK cells, NKT cells, monocytes, and DCs (B) or CD45RClow/– T cells (C). n = 3 for all groups. Results are expressed as number of cells per ml of blood. Friedman and Dunn’s post-test. *P < 0.05. Dotted lines represent normal values for the cell populations corresponding to the color codes. (D) IgG antibody production against mouse mAb was measured at day 13 in the sera of animals treated 10 days with anti-CD45RC (n = 3) or isotype control (n = 2) compared with naive animal (n = 5). Results are expressed as optical density ± SEM for the indicated dilution of serum. Two-way repeated measures ANOVA, *P < 0.05, **P < 0.01. (E–G) Apoptosis was analyzed on total splenocytes incubated with anti-CD45RC mAb, dexamethasone, or isotype control mAb and stained with annexin V and DAPI. Results are expressed as relative proportion of annexin V+DAPI+ cells among CD45RC+ T cells for 10 min to 18 hours (E), monocytes for 18 hours (F), and B cells for 18 hours (G) ± SEM. Fold-expression of one represents spontaneous apoptosis in culture medium (respectively 20%, 12%, and 8%). (E) Two-way repeated measures ANOVA test, **P < 0.01, ***P < 0.001. (F and G) Friedman and Dunn’s post-test, *P < 0.05. (H) Mitochondrial DiOC6(3) accumulation was analyzed on total splenocytes incubated with anti-CD45RC mAb, dexamethasone, or isotype control mAb for 1h to 18h and stained for TCR and DAPI. Results are expressed as percentage of DiOC6(3)– cells among DAPI– T cells ± SEM. Two-way repeated measures ANOVA test, **P < 0.01, ***P < 0.001, ****P < 0.0001.