ISSN:
1432-1211
Keywords:
Key words Gene imprinting
;
HLA class I
;
Interferon-γ
;
Reverse-transcriptase-PCR
;
Trophoblast
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract Human trophoblast cells have developed various efficient regulatory mechanisms to prevent cell surface expression of the classical HLA-A, -B, and (but not always) -C class I molecules. This allows them to escape maternal alloimmune attack during pregnancy. However, recent results have demonstrated that such a lack of expression could be reversed in villous cytotrophoblast cells purified from term placenta by in vitro IFN-γ treatment. In this context, we investigated whether both maternal and paternal HLA class Ia antigens were co-dominantly expressed in such trophoblast cells. Using polymerase chain reaction sequence-specific primers for HLA-A and HLA-C alleles, we detected transcripts of both paternal and maternal origins, showing that these genes were not affected by genomic imprinting, at least in term placenta. After in vitro IFN-γ treatment, the polymorphic HLA-A and HLA-B antigens of both parental origins become detectable at the cell surface, as assessed by flow cytometry and/or complement-dependent microtoxicity test. Appearance of paternal antigens on trophoblast cells upon IFN-γ induction raises the question of the in vivo biological consequences of this phenomena, in term of materno-fetal tolerance and in particular of a potential allogeneic cytotoxic immune response.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002510050361
