Hematopoietic differentiation activity of a recombinant human interleukin-6 (IL-6) isoform resulting from alternatively spliced deletion of the second exon.
Am J Hematol
; 61(3): 169-77, 1999 Jul.
Article
in En
| MEDLINE
| ID: mdl-10398309
ABSTRACT
We have previously identified and cloned an alternatively spliced form of human interleukin-6 mRNA lacking exon II, which encodes amino acid residues known to be important in gp130-mediated signal transduction pathways. We expressed and purified the recombinant protein (rIL6-alt) resulting from this alternatively spliced mRNA and now report the initial characterization of its biologic activities with comparison to full length IL6 (rIL6-full). rIL6-alt was found to have 10(4) to 10(5) fold less activity in proliferation assays with 7TD1 murine plasmacytoma cells and did not competitively inhibit the stimulatory activity of rIL6-full. In addition, like rIL6-full, rIL6-alt had antiproliferative activity toward M1 murine myeloblast cells and was 10-200-fold less active than rIL6-full. In contrast, in assays with human HL60 promyelocytic leukemia cells, rIL6-alt had greater antiproliferative activity than rIL6-full and more strongly upregulated phagocytosis as well as surface expression of the differentiation antigen CD11b. rIL6-full and rIL6-alt upregulated the level of lysozyme mRNA in HL60 cells approximately equally. These findings suggest that IL6-alt, which lacks amino acid residues encoded by the second exon of the gene, is not a natural inhibitor of IL6-full but may be relatively tissue specific and may play a role in modulation of hematopoietic cell growth and differentiation.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Hematopoietic Stem Cells
/
Cell Differentiation
/
Interleukin-6
/
Sequence Deletion
/
Alternative Splicing
Type of study:
Prognostic_studies
Limits:
Animals
/
Humans
Language:
En
Journal:
Am J Hematol
Year:
1999
Document type:
Article
Affiliation country:
Estados Unidos