| 1. |
- Aveskogh, Maria, et al.
(författare)
-
Characterization of cDNA clones encoding mouse proteinase 3 (myeloblastine) and cathepsin G
- 1997
-
Ingår i: Immunogenetics. - : Springer Science and Business Media LLC. - 0093-7711 .- 1432-1211. ; 46:3, s. 181-191
-
Tidskriftsartikel (refereegranskat)abstract
- Serine proteases are the most abundant granule constituents of several major hematopoietic cell lineages. Due to their high abundance and their strict tissue specificity they have become important phenotypic cell markers used for studies of various aspects of hematopietic cell development. Using a polymerase chain reaction (PCR)-based strategy for the isolation of trypsin-related serine proteases, we were able to isolate cDNAs for two of the major neutrophil and monocyte serine proteases in the mouse, cathepsin G and mouse protease 3 (myeloblastin). The internal PCR fragments were used as probes to screen a mouse mast cell cDNA library and a cDNA library originating from a mouse monocytic cell line (WEHI-274.1). Full-length cDNAs for mouse cathepsin G and proteinase 3 were isolated and their complete sequences were determined. Northern blot analysis revealed expression of cathepsin G in immature cells of the monocyte macrophage lineage but also in the connective tissue mast cell line MTC. Proteinase 3 was expressed in several cell lines of myelo-monocytic origin and in one B-cell line, but not in any of the other cell lines tested. The isolation of cDNAs for mouse cathepsin G and mouse proteinase 3, together with the previous characterization of the gene for mouse N-elastase, and the entire or partial amino acid sequences for porcine azurocidine, equine N-elastase and proteinase 3, rat, dog, and rabbit cathepsin Gs in evolutionary relatively distantly related mammalian species, indicates that these four members of the serine protease family have been maintained for more than 100 million years of mammalian evolution. This latter finding indicates a strong evolutionary pressure to maintain specific immune functions associated with these neutrophil and monocyte proteases. All amino acid positions of major importance for the cleavage site selection have also been fully conserved between mouse and human proteinase 3 and a few minor changes have occurred between mouse and human cathepsin G.
|
|
| 2. |
- Bemark, Mats, et al.
(författare)
-
Conserved sequence elements in K promoters from mice and humans : Implications for transcriptional regulation and repertoire expression
- 1998
-
Ingår i: Immunogenetics. - : Springer Science and Business Media LLC. - 0093-7711 .- 1432-1211. ; 47:3, s. 183-195
-
Tidskriftsartikel (refereegranskat)abstract
- Promoter region sequences of human and mouse Igk-V genes were aligned and found to be conserved for about 200-300 base pairs (bp) within subgroups/families. No promoter similarity was found between IGKV promoters from different human subgroups. Related mouse Igk-V gene families were conserved in the promoter region but no similarity was evident when promoters from unrelated Igk-V gene families were compared. Most of the human IGKV promoter subgroups were shown to have mouse counterparts with a similarity region that extended about 150 bp upstream of the translational start codon. All promoters contained an octamer sequence element. The consensus octamer/decamer sequence was favored but only seven residues within the octamer element were strictly conserved. Furthermore, there was also sequence conservation immediately 3' of the octamer where either an A or a G residue was conserved. In addition, other DNA elements were also conserved both within the Igk-V subgroups/families and between mouse and human promoters from related subgroups/families. In several of the subgroups/families an E box of the E2A type was conserved 5' of the octamer and a CCCT element was conserved within the IGKV subgroup II and its related mouse Igk-V families. We conclude from this study that conservation of additional sequence elements besides the octamer is a common feature in Igk-V promoters but that distinct elements are conserved only within a given subgroup/family. Thus, the conservation appears to have operated at the level of function rather than at the level of recognition sequence for defined transcription factors.
|
|
| 3. |
- Brenden, N., et al.
(författare)
-
Differential MHC expression requirements for positive selection of separate TCR Vb families
- 1999
-
Ingår i: Immunogenetics. - : Springer Science and Business Media LLC. - 0093-7711 .- 1432-1211. ; 49:1, s. 1-6
-
Tidskriftsartikel (refereegranskat)abstract
- Positive selection has been proposed to be involved in protection from diabetes. We examined positive selection by fluorescence-activated cell sorter analyses in thymocytes of protected and susceptible E-transgenic and non-transgenic NOD mice. Three Vb families showed positive selection in E-transgenic mice. Vb6+CD4+ and Vb10+CD4+ thymocytes were found at higher frequencies in both protected NOD-Ea and susceptible NOD-DY mice. The increased frequencies of Vb13+CD8+ thymocytes were found in protected NOD-Ea mice only, and not in susceptible NOD-DY transgenic mice. These three Vb families were further examined in bone-marrow chimeras between NOD-Ea and non-transgenic NOD mice, where we could examine the contribution of E-expressing bone-marrow-derived cells in positive selection. We find that NOD-Ea→NOD-Ea chimeras have an increased positive selection of Vb13+CD8+ cells and that positive selection is more efficient when both thymic epithelium and bone-marrow-derived cells express the E molecule. This was also seen for Vb6+CD4+ cells. However, for Vb6, bone-marrow-derived cells alone were also capable of positive selection. Positive selection of Vb10+CD4+ cells was restricted to E-expressing thymic epithelium only. For Vb13+CD8+ cells, we found that positive selection is most efficient with E-expression on both thymic epithelium and bone-marrow-derived cells, although positive selection also occurs with E-positive epithelium only. For Vb6+CD4+ cells, the dominating selecting cells are bone-marrow-derived cells, and Vb10+CD4+ cells seem to be selected exclusively by the thymic epithelium. Thus, the conditions for positive selection seem to vary considerably between different Vb families.
|
|
| 4. |
- Högstrand, K., et al.
(författare)
-
Gene conversion of major histocompatibility complex genes is associated with CpG-rich regions
- 1999
-
Ingår i: Immunogenetics. - : Springer Science and Business Media LLC. - 0093-7711 .- 1432-1211. ; 49:5, s. 446-455
-
Tidskriftsartikel (refereegranskat)abstract
- We examined 32 DNA sequences of mouse and human major histocompatibility complex (MHC) genes believed to have been subjected to gene conversion events. All regions of the mouse H2 genes as well as the human HLA genes which have been implied to be involved in gene conversion events had elevated levels of CpG dinucleotides, whereas the rest of the genes showed extensive CpG suppression. Mouse MHC genes which have been suspected but not directly implied to be involved in gene conversion events also showed elevated levels of CpG dinucleotides. Moreover, both mouse and human MHC genes which have never been suspected of undergoing gene conversion had low levels of CpG throughout the genes. These results indicate that high CpG levels are correlated with gene conversion rather than with polymorphism, as non-polymorphic genes that have been implicated as gene conversion donors also have elevated levels of CpG dimers in the involved regions whereas polymorphic genes which have never been considered to undergo gene conversion events have a low level of CpG dinucleotides. We also studied the methylation pattern of CpG dimers in the Abk gene by restriction enzyme digestion of mouse testis DNA followed by Southern blot and hybridization to an Abk-specific probe. The examined CpG dimers in prepubescent mice, where the latest germline stages are spermatogonia, leptene, or pachytene, are respectively non-methylated. Accordingly, the CpG dimers appear to be non-methylated in germline DNA from the testis of prepubescent mice, where gene conversions have been reported to occur.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Rabbani, H, et al.
(författare)
-
Polymorphism of the IGHG3 gene in cattle
- 1997
-
Ingår i: Immunogenetics. - : Springer Science and Business Media LLC. - 0093-7711 .- 1432-1211. ; 46:4, s. 326-331
-
Tidskriftsartikel (refereegranskat)
|
|
| 8. |
|
|
| 9. |
- Westerdahl, Helena, et al.
(författare)
-
Polymorphism and transcription of Mhc class I genes in a passerine bird, the great reed warbler
- 1999
-
Ingår i: Immunogenetics. - : Springer Science and Business Media LLC. - 1432-1211 .- 0093-7711. ; 49:3, s. 158-170
-
Tidskriftsartikel (refereegranskat)abstract
- The class I genes of the major histocompatibility complex (Mhc) are here investigated for the first time in a passerine bird. The great reed warbler is a rare species in Sweden with a few semi-isolated populations. Yet, we found extensive Mhc class I variation in the study population. The variable exon 3, corresponding to the alpha(2) domain, was amplified from genomic DNA with degenerated primers. Seven different genomic class I sequences were detected in a single individual. One of the sequences had a deletion leading to a shift in the reading frame, indicating that it was not a functional gene. A randomly selected clone was used as a probe for restriction fragment length polymorphism (RFLP) studies in combination with the restriction enzyme Pvu II. The RFLP pattern was complex with 21-25 RFLP fragments per individual and extensive variation. Forty-nine RFLP genotypes were detected in 55 tested individuals. To study the number of transcribed genes, we isolated 14 Mhc class I clones from a cDNA library from a single individual. We found eight different sequences of four different lengths (1.3-2.2 kilobases), suggesting there are at least four transcribed loci. The number of nonsynonymous substitutions (d(N)) in the peptide binding region of exon 3 were higher than the number of synonymous substitutions (d(S)), indicating balancing selection in this region. The number of transcribed genes and the numerous RFLP fragments found so far suggest that the great reed warbler does not have a "minimal essential Mhc" as has been suggested for the chicken.
|
|
| 10. |
|
|
