Expression of xenogeneic MHC class II molecules in HLA-DR(+) and -DR(-) cells: influence of retrovirus vector design and cellular context.

baboon combination. Successful down-regulation of T cell responses appeared, however, to be contingent on a tight lineage-specific expression of transferred class II molecules. The present studies were, therefore, designed to evaluate the influence of construct design and cellular environment on expression of retrovirally transferred xenogeneic class II cDNAs. Proviral genomes for pig class II SLA-DR expression, differing only at the marker neo(r) or enhanced green fluorescent protein (EGFP) gene, showed increased membrane SLA-DR density on HLA-DR(-) fibroblasts as well as HLA-DR(+), TF-1 erythroleukemia cells. More importantly, HLA-DR(+) human B cell lines, although efficiently transduced with pig DR retroviruses, exhibited unstable surface pig DR. Surface pig DR- B cells, nevertheless, stimulated autologous human T cells pre-sensitized to pig Ags, a proliferation likely occurring through presentation of class II-derived peptides. Collectively, these data suggest that surface expression of transferred class II molecules is not related to the ability of recipient cells to synthesize xenogeneic class II molecules but rather to their Ag processing capacities. -->
Grant Information: 2R01-AI33053 United States AI NIAID NIH HHS
Substance Nomenclature: 0 (HLA-DR Antigens)
0 (Histocompatibility Antigens Class II)
Entry Date(s): Date Created: 20020319 Date Completed: 20020819 Latest Revision: 20191105
Update Code: 20231215
DOI: 10.1034/j.1399-3089.2002.1o038.x
PMID: 11897004
Autor: Denaro M; BioTransplant Incorporated, Charlestown Navy Yard, Charlestown, MA, USA., Kolber-Simonds D, Schad V, Muthukumar S, Germana S, White-Scharf ME, Banerjee PT, LeGuern C, Andersson G
Jazyk: angličtina
Zdroj: Xenotransplantation [Xenotransplantation] 2002 Mar; Vol. 9 (2), pp. 115-24.
DOI: 10.1034/j.1399-3089.2002.1o038.x
Abstrakt: We recently established that molecular chimeras of major histocompatibility complex (MHC) class II molecules, created via retroviral transfer of allogeneic class II cDNAs into bone marrow cells (BMCs), alleviated complications associated with mixed BMC chimeras while leading to T cell tolerance to renal grafts sharing the transferred class II. Initially demonstrated for allogeneic transplants in miniature swine, this concept was extended to T-dependent antibody (Ab) responses to xenogeneic antigens (Ags) in the pig --> baboon combination. Successful down-regulation of T cell responses appeared, however, to be contingent on a tight lineage-specific expression of transferred class II molecules. The present studies were, therefore, designed to evaluate the influence of construct design and cellular environment on expression of retrovirally transferred xenogeneic class II cDNAs. Proviral genomes for pig class II SLA-DR expression, differing only at the marker neo(r) or enhanced green fluorescent protein (EGFP) gene, showed increased membrane SLA-DR density on HLA-DR(-) fibroblasts as well as HLA-DR(+), TF-1 erythroleukemia cells. More importantly, HLA-DR(+) human B cell lines, although efficiently transduced with pig DR retroviruses, exhibited unstable surface pig DR. Surface pig DR- B cells, nevertheless, stimulated autologous human T cells pre-sensitized to pig Ags, a proliferation likely occurring through presentation of class II-derived peptides. Collectively, these data suggest that surface expression of transferred class II molecules is not related to the ability of recipient cells to synthesize xenogeneic class II molecules but rather to their Ag processing capacities.
Databáze: MEDLINE
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