ISSN:
1744-313X
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
,
Medicine
Notes:
The expression of HLA class I(-like) genes was studied in two human developmental turnour cell lines representing embryonic (Tera-2) and extra-embryonic (Jeg-3) origins. Neither cell line expresses polymorphic HLA-A, -B, -C antigens as determined by standard serological typing. Tera-2 cells express the HLA class I-like T cell system A (TCA) determinants; Jeg-3 cells are TCA negative. Northern blot analysis using an HLA class I α3 domain specific probe revealed markedly reduced levels of HLA class I(-like) transcripts in both cell lines, which can be upregulated in Tera-2 cells by incubation with gamma interferon (γIFN). Immunoprecipitation studies with a large panel of HLA class I/beta-2 microglobulin (β2m) monoclonal antibodies (mAbs), detect low quantities of regular HLA class I heavy chains that are not associated with β2m on the surface of Tera-2 cells. In contrast, Jeg-3 cells express significant amounts of cell membrane β2m associated molecules of 41 and 45 kilodalton (kD). Screening of a Tera-2 cDNA library, yielded 30 clones that hybridize to a full length HLA class I cDNA probe. Sixteen have been characterized and represent HLA class I sequences, consistent with the haplotype of Tera-2. A similar screening of a Jeg-3 cDNA library isolated clones representing a single novel HLA-C-like sequence; this probably codes for the 45 kD cell surface molecules of Jeg-3. The 41 kD molecule may be encoded by the HLA-6.0 gene since this is constitutively expressed in Jeg-3 cells.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1744-313X.1989.tb00486.x
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