Empty and peptide-containing conformers of class I major histocompatibility complex molecules expressed in Drosophila melanogaster cells.

Abstract

Transfected DrosophUa melanogaster cellscan express large quantities of class I major histocompatibility complex molecules. Such molecules lack endogenous peptides because the Drosophila cells are devoid ofproteins necessary for intracellular peptide loading. The empty molecules are efficiently expressed on the cell surface and can acquire extracellular peptides. The conformation and stability ofempty murine class I molecules are determined by the source of P2-microglobulin. All ,2-microglobulin-induced conformers of empty heavy chains seem to be unified in a common rigid conformation on peptide binding.

Abundant empty class II MHC molecules on the surface of immature dendritic cells

“…The presence of such empty MHC class II molecules on the surface of DC was unexpected, because previous work in B cells suggested that MHC class II molecules that do not acquire peptide are retained intracellularly and degraded (21,48). However, we note that empty class II MHC proteins are stable at physiological temperature (37,49), unlike empty class I MHC proteins (49)(50)(51), and that class II MHC proteins can be produced in an empty or functionally empty form in several insect and mammalian cell lines (19,52,53). Thus, the intracellular retention of empty molecules observed in B cells may be caused by B-cell-specific mechanism rather than an intrinsic instability of empty class II MHC proteins.…”

Coexpression of CD58 or CD48 with Intercellular Adhesion Molecule 1 on Target Cells Enhances Adhesion of Resting NK Cells

“…All cDNAs were verified by sequencing. Three million SC2 cells (1 ϫ 10 6 /ml) in a well of a six-well plate were transfected with a total of 30 g of recombinant DNA and 1 g of the selection vector pNeofly (20) (a gift from L. Teyton) using a calcium phosphate transfection kit (Invitrogen, Carlsbad, CA). Stable transfectants were selected and maintained in 0.5 mg/ml G418 (Life Technologies).…”

Heparin-binding EGF-like growth factor contributes to reduced glomerular filtration rate during glomerulonephritis in rats

“…The PCR product amplified by the second set of primers was fused with the sequence coding for 6× histidines and was subcloned into pRM-Ha for expression in Drosophila melanogaster cells (SC2) (41). The recombinant pRM-Ha, pRM-HB-EGF, was transfected into SC2 cells by phosphate methods.…”