| 1. |
- Bjorck, L., et al.
(författare)
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A deletion in a rat major histocompatibility complex class I gene is linked to the absence of β2-microglobulin-containing serum molecules
- 1986
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424. ; 83:15, s. 5630-5633
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Tidskriftsartikel (refereegranskat)abstract
- Class I major histocompatibility antigens are composed of a heavy chain that is noncovalently associated with β2-microglobulin (β2m). Most class I molecules are membrane bound, but mouse and rat cDNA clones and genes without a functional code for the transmembrane amino acids have been identified. The membrane-associated class I molecules are important in the control of cell-mediated cytotoxicity, while the function of the soluble molecules remains unclear. Previous studies have shown that β2m circulates in rat serum in three different molecular weight classes. The first is free β2m (M(r), 12,000), the second is about M(r) 70,000, and the third is roughly M(r) 200,000. In an inbred subline of immunodeficient, diabetesprone BioBreeding rats (BioBreeding/Hagedorn), previous work detected two restriction fragment polymorphisms in class I major histocompatibility complex genes, one of them a gene deletion on a 7-kilobase BamHI fragment and the other on a 2-kilobase BamHI fragment. In these rats we have found that the third serum β2m-binding size class is absent. Analysis of F1 and F2 individuals following cross-breeding between Bio-Breeding/Hagedorn rats and genetically related (nondiabetic) control BioBreeding w-subline rats demonstrated that the large-size serum peak of β2m was associated with the presence of the class I restriction fragments.
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| 2. |
- Herold, K C, et al.
(författare)
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Derivation of non-lymphopenic BB rats with an intercross breeding
- 1989
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Ingår i: Autoimmunity. - : Informa UK Limited. - 0891-6934 .- 1607-842X. ; 3:2, s. 83-93
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies have suggested that the development of diabetes in the BB rats does not require the expression of T lymphopenia. In order to derive non-lymphopenic diabetic rats and define the relationship between the T cell abnormalities, MHC genotype, and diabetes, we performed a cross between BB/H and diabetes resistant BB/control followed by an intercross of the F1. In the F2, the overall incidence of diabetes and lymphopenia was 30% and 27%, respectively. Lymphopenia was strongly associated with diabetes (p less than 0.001) and was seen in 76% of the diabetic F2's. However, 6 of the diabetic were non-lymphopenic (24%) and 3 of the non-diabetics were lymphopenic (5%). In the non-lymphopenic diabetic animals, all T cell levels were within the normal range, but diabetes occurred at an earlier age than their lymphopenic littermates (p less than 0.001). In contrast to the strong association between the inheritance of lymphopenia and diabetes, no relationship between diabetes and Class I MHC restriction fragment length polymorphisms was found. We conclude: 1) Diabetes and lymphopenia are strongly associated inherited abnormalities in the BB rat and are not associated with Class I RFLP defined genotypes within the RTIu haplotype, 2) Animals in whom diabetes occurs in the absence of lymphopenia can be derived using this breeding approach 3) In our non-lymphopenic rats, diabetes occurred at an earlier age possibly reflecting the restoration of quantitative or qualitative T cell defects found in lymphopenic BB rats.
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| 3. |
- Kastern, W, et al.
(författare)
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Developmental and tissue-specific expression of alpha 1-microglobulin mRNA in the rat
- 1986
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Ingår i: Journal of Biological Chemistry. - 0021-9258. ; 261:32, s. 4-15070
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Tidskriftsartikel (refereegranskat)abstract
- A rat liver cDNA library was constructed in the lambda gt11 expression vector. Three clones expressing alpha 1-microglobulin, an immunosuppressive plasma protein, were detected by screening with rabbit antiserum against rat alpha 1-microglobulin. The alpha 1-microglobulin activity from one of the clones, 6b, was confirmed with monoclonal antibodies in a solid phase radioimmunoassay. The nucleotide sequence of the fragment (165 base pairs) was determined, and the translated amino acid sequence (55 amino acids) showed a 75% homology to human alpha 1-microglobulin (position 122-176). Southern blots of restriction endonuclease-digested rat DNA indicated two distinct genes with alpha 1-microglobulin homology when probed with radioactive cDNA fragment from clone 6b. Northern blots showed the presence of a single mRNA species in rat liver, and the level was low in 1-month-old animals, increased to reach a maximum during adulthood (3 months), and decreased with aging (12 months). The alpha 1-microglobulin concentration in rat serum showed the same age dependence between 1 and 12 months, with the highest values at 3 months. Embryonic development (8.5-day to 17.5-day) was studied using total fetal RNA, and expression of alpha 1-microglobulin mRNA was detected in low amounts only at day 15.5. alpha 1-Microglobulin mRNA levels, studied by an RNA dot blot assay, were high in liver and kidney, low in brain and testis, and none were found in hypothalamus and spleen cells.
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| 4. |
- Lindqvist, A, et al.
(författare)
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Rat alpha 1-microglobulin : co-expression in liver with the light chain of inter-alpha-trypsin inhibitor
- 1992
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Ingår i: Biochimica et Biophysica Acta. - : Elsevier BV. - 0006-3002. ; 1130:1, s. 7-63
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Tidskriftsartikel (refereegranskat)abstract
- A 1162 bp rat liver cDNA clone encoding the immunoregulatory plasma protein alpha 1-microglobulin was isolated and sequenced. The open reading frame encoded a 349 amino acid polyprotein, including alpha 1-microglobulin, 182 amino acids, and bikunin, the light chain of the plasma protein inter-alpha-trypsin inhibitor, 145 amino acids. The alpha 1-microglobulin/bikunin mRNA was found only in the liver when different tissues were examined. Free alpha 1-microglobulin and a polyprotein, containing both alpha 1-microglobulin and inter-alpha-trypsin inhibitor epitopes, were found in the microsomal fraction from rat liver homogenates.
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| 5. |
- Nilson, B H, et al.
(författare)
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Purification of antibodies using protein L-binding framework structures in the light chain variable domain
- 1993
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Ingår i: Journal of Immunological Methods. - 0022-1759. ; 164:1, s. 33-40
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Tidskriftsartikel (refereegranskat)abstract
- Protein L from the bacterial species Peptostreptococcus magnus binds specifically to the variable domain of Ig light chains, without interfering with the antigen-binding site. In this work a genetically engineered fragment of protein L, including four of the repeated Ig-binding repeat units, was employed for the purification of Ig from various sources. Thus, IgG, IgM, and IgA were purified from human and mouse serum in a single step using protein L-Sepharose affinity chromatography. Moreover, human and mouse monoclonal IgG, IgM, and IgA, and human IgG Fab fragments, as well as a mouse/human chimeric recombinant antibody, could be purified from cultures of hybridoma cells or antibody-producing bacterial cells, with protein L-Sepharose. This was also the case with a humanized mouse antibody, in which mouse hypervariable antigen-binding regions had been introduced into a protein L-binding kappa subtype III human IgG. These experiments demonstrate that it is possible to engineer antibodies and antibody fragments (Fab, Fv) with protein L-binding framework regions, which can then be utilized in a protein L-based purification protocol.
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