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IgG-mediated immunosuppression is not dependent on erythrocyte clearance or immunological evasion: implications for the mechanism of action of anti-D in the prevention of haemolytic disease of the newborn?

Authors :
Alan H. Lazarus
Andrew R. Crow
John Freedman
Hoang Le-Tien
Davor Brinc
Source :
British Journal of Haematology. 139:275-279
Publication Year :
2007
Publisher :
Wiley, 2007.

Abstract

Haemolytic disease of the newborn (HDN) can be prevented by the passive administration of anti-D to the mother. The most accepted theory to describe this activity of anti-D is based upon its ability to clear opsonized erythrocytes before their recognition by the maternal immune system. We examined this hypothesis using a murine model of immunity to foreign erythrocytes. Whereas transfusion of foreign erythrocytes into mice induced immunoglobulin (Ig)M and IgG antibodies specific for the erythrocytes, these humoral immune responses were inhibited when the erythrocytes were opsonized with IgG. To specifically determine if immunological evasion occurs with these opsonized erythrocytes, we examined T-cell responses from these mice. An erythrocyte-specific T-cell response was clearly detected. We then tested whether phagocytosis of opsonized erythrocytes is sufficient to prevent the antibody response. We exposed mononuclear phagocytic cells to sheep red blood cells (SRBC) in vitro and then adoptively transferred the phagocytic cells to recipient mice; opsonized SRBC unexpectedly increased, rather than decreased, the antibody response. These data indicate that removal of opsonized erythrocytes by phagocytic cells does not prevent their immunological recognition and suggest that antigen clearance may not be the predominant mechanism of anti-erythrocyte action in downregulating the humoral immune response.

Details

ISSN :
13652141 and 00071048
Volume :
139
Database :
OpenAIRE
Journal :
British Journal of Haematology
Accession number :
edsair.doi.dedup.....b8745c08f4693d31cfd58ad69c5dbb6c
Full Text :
https://doi.org/10.1111/j.1365-2141.2007.06764.x