Abstract
An immunoregulatory factor (IRL) that suppresses Con A-mediated peripheral blood mononuclear cell (PBM) prolieferative responses was partially purified by DEAE anion exchange chromatography and affinity chromatography from a 3 M KCl extract of a human liposarcoma. The factor (m.w. = 70K) co-purified with albumin, monitored by two-dimensional gel electrophoresis, and demonstrated a heterogeneous isoelectric point (pI 7.6-7.8). Xenoantisera produced against the DEAE-purified fraction and coupled to Affigel 10 removed suppressive activity that could subsequently be eluted by glycine-HCl, pH 3.5. An anti-albumin column partially removed activity, but the unbound 70K factor could still be detected in the column effluent. A xenoantiserum to this 70K effluent coupled to acrylamide beads completely removed the immunosuppressive activity in immunodepletion experiments. Further direct binding enzyme-linked immunoassays (ELISA) and solid-phase immunoabsorption experiments with monoclonal antibodies to human anti-HLA-DR framework determinants and a constant region of the IgM μ-chain demonstrated determinants on the 70K factor recognized by these antibodies.
Original language | English (US) |
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Pages (from-to) | 303-308 |
Number of pages | 6 |
Journal | Journal of Immunology |
Volume | 130 |
Issue number | 1 |
State | Published - 1983 |
ASJC Scopus subject areas
- Immunology and Allergy
- Immunology