The genetically-engineered secretory B27/Q10 chimeric molecule inhibits HLA-B27 restricted alloreactive T-lymphocytes.
OBJECTIVE
Intracellularly persisting bacterial infections and high association with HLA-B27 are the hallmarks of reactive arthritis. Soluble HLA-B27 molecules are induced by bacterial infection; however their biological role in arthritis is unknown. It was the aim of this study to generate soluble HLA-B27 molecule and to analyze its effect on cytotoxic HLA-B27 alloreactive CD8+ T-lymphocytes in order to better understand potential functional links between persistent infection and HLA-B27 association.


METHODS
Using PCR Exons 1 through 4 of HLA-B*2705 were fused to Exon 5 of the soluble murine MHC class I variant Q10 and stably transfected into Hela-cells. Transfectants were analyzed using specific PCR, RT-PCR and intracellular and extracellular staining with anti-HLA-B27 monoclonal antibody ME1. Secretion of B27Q10 in the supernatant was examined by isoelectric focusing (IEF). The effect of B27Q10 on T-cells was analyzed using either HLA-B27- or HLA-A2-restricted alloreactive T-cells in a standard 51Cr-release assay.


RESULTS
PCR and RT-PCR demonstrated the DNA and mRNA of B27Q10 in the transfectants. By intracellular and extracellular staining with ME1 B27Q10-molecule was detected intracellularly but was not expressed in the cell membrane. Using IEF soluble B27Q10-molecules were found in supernatants of transfectants in a concentration of up to 1.342 microg/ml. Soluble B27QJO-molecule inhibited specifically the cytotoxicity of HLA-B27-restricted alloreactive T-cells by about 30%.


CONCLUSIONS
The secretory non-membrane-expressed molecule B27Q10 inhibits HLA-B27 specific T-cells. The inhibition of cytotoxic T-cells by bacteria induced soluble HLA-B27 may thus enable bacterial persistence.
Kuipers
J G
JG
Division of Rheumatology, Medical School, Hannover, Germany. Kuipers.Jens@MH-Hannover.de
Bialowons
A
A
Dollmann
P
P
Jendro
M C
MC
Wagener
N
N
Rebmann
V
V
Ikeda
M
M
Huang
F
F
Grosse-Wilde
H
H
Yu
D T Y
DT
Zeidler
H
H
Märker-Hermann
E
E
D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D003001:Cloning, Molecular; D004247:DNA / Q000032:analysis; D017931:DNA Primers / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D015723:Gene Library; D005818:Genetic Engineering; D015796:HLA-B27 Antigen / Q000235:genetics* / Q000378:metabolism; D006367:HeLa Cells; D015395:Histocompatibility Antigens Class I / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D051379:Mice; D012333:RNA, Messenger / Q000096:biosynthesis / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
D017931:DNA Primers; D015796:HLA-B27 Antigen; D015395:Histocompatibility Antigens Class I; C032907:Q surface antigens; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D004247:DNA