HYPOIMMUNOGENIC CELLS
The present invention provides a highly functional hypoimmunogenic cell, namely, a hypoimmunogenic human cell (1) lacking an endogenous gene encoding an α chain of human leukocyte antigen (HLA) class Ia, (2) lacking an endogenous gene encoding HLA class II or an expression regulator thereof, (3) containing an exogenous gene encoding an α chain of HLA class Ib, (4) containing an exogenous gene encoding human PD-L1, and (5) containing an exogenous gene encoding human PD-L2.
1 . A hypoimmunogenic human cell
(1) lacking an endogenous gene encoding an α chain of human leukocyte antigen (HLA) class Ia,
(2) lacking an endogenous gene encoding HLA class II or an expression regulator thereof,
(3) comprising an exogenous gene encoding an α chain of HLA class Ib,
(4) comprising an exogenous gene encoding human PD-L1, and
(5) comprising an exogenous gene encoding human PD-L2.
2 . The cell according to claim 1 , wherein the cell does not express endogenous HLA class Ib on a cell surface.
3 . The cell according to claim 1 , wherein the endogenous gene encoding the α chain of the HLA class Ia comprises an endogenous gene encoding an α chain of HLA-A, an endogenous gene encoding an α chain of HLA-B, and an endogenous gene encoding an α chain of HLA-C.
4 . The cell according to claim 1 , wherein the endogenous gene encoding the HLA class II or an expression regulator thereof comprises the following (a) or (b):
(a) an endogenous gene encoding an α chain and/or a β chain of HLA-DP, an endogenous gene encoding an α chain and/or a β chain of HLA-DQ, an endogenous gene encoding an α chain and/or a β chain of HLA-DR, an endogenous gene encoding an α chain and/or a β chain of HLA-DM, and an endogenous gene encoding an α chain and/or a β chain of HLA-DO,
(b) an endogenous gene encoding human RFXANK, an endogenous gene encoding human RFX5, an endogenous gene encoding human RFXAP, and an endogenous gene encoding human CIITA.
5 . The cell according to claim 1 , wherein the exogenous gene encoding the α chain of the HLA class Ib comprises an exogenous gene encoding an α chain of HLA-E and/or an exogenous gene encoding an α chain of HLA-G.
6 . The cell according to claim 1 , comprising (6) an exogenous gene encoding human β2 microglobulin.
7 . The cell according to claim 1 , comprising (7) a suicide gene.
8 . The cell according to claim 1 , wherein the site containing the exogenous gene or suicide gene is a safe harbor region of the genome.
9 . The cell according to claim 8 , wherein the safe harbor region is an AAVS1 region, a CCR5 region, or a ROSA26 region.
10 . The cell according to claim 1 , wherein the hypoimmunogenic human cell is a pluripotent stem cell or a differentiated cell thereof.
11 . A method for producing a hypoimmunogenic human cell, comprising the following steps:
(i) a step of deleting an endogenous gene encoding an α chain of HLA class Ia of a human parental cell,
(ii) a step of deleting an endogenous gene encoding HLA class II or an expression regulator thereof from the human parental cell,
(iii) a step of introducing an exogenous gene encoding an α chain of HLA class Ib into the human parental cell,
(iv) a step of introducing an exogenous gene encoding human PD-L1 into the human parental cell, and
(v) a step of introducing an exogenous gene encoding human PD-L2 into the human parental cell.
12 . The method according to claim 11 , wherein the hypoimmunogenic human cell does not express endogenous HLA class Ib on a cell surface.
13 . The method according to claim 11 , wherein the endogenous gene encoding the α chain of the HLA class la comprises an endogenous gene encoding an α chain of HLA-A, an endogenous gene encoding an α chain of HLA-B, and an endogenous gene encoding an α chain of HLA-C.
14 . The method according to claim 11 , wherein the endogenous gene encoding HLA class II or an expression regulator thereof comprises the following (a) or (b):
(a) an endogenous gene encoding an α chain and/or a β chain of HLA-DP, an endogenous gene encoding an α chain and/or a β chain of HLA-DQ, an endogenous gene encoding an α chain and/or a β chain of HLA-DR, an endogenous gene encoding an α chain and/or a β chain of HLA-DM, and an endogenous gene encoding an α chain and/or a β chain of HLA-DO,
(b) an endogenous gene encoding human RFXANK, an endogenous gene encoding human RFX5, an endogenous gene encoding human RFXAP, and an endogenous gene encoding human CITTA.
15 . The method according to claim 11 , wherein the exogenous gene encoding the α chain of the HLA class Ib comprises an exogenous gene encoding an α chain of HLA-E and/or an exogenous gene encoding an α chain of HLA-G.
16 . The method according to claim 11 , further comprising the following step:
(vi) a step of introducing an exogenous gene encoding human β2 microglobulin into the human parental cell.
17 . The method according to claim 11 , further comprising the following step:
(vii) a step of introducing a suicide gene into the human parental cell.
18 . The method according to claim 11 , wherein the site into which the exogenous gene or suicide gene is introduced is a safe harbor region of the genome.
19 . The method according to claim 18 , wherein the safe harbor region is an AAVS1 region, a CCR5 region, or a ROSA26 region.
20 . The method according to claim 11 , wherein the human parental cell is a pluripotent stem cell or a differentiated cell thereof.