title: Anti-lymphoproliferative activity of alpha-2-macroglobulin in the plasma of hibernating 13-lined ground squirrels and woodchucks.
abstract: Plasma from hibernating (HIB) woodchucks (Marmota monax) or 13-lined ground squirrels (Ictidomys tridecemlineatus) suppressed (3)H-thymidine uptake in mouse spleen cell cultures stimulated with Concanavalin A (ConA); plasma from non-hibernating animals were only slightly inhibitory. Maximum inhibition occurred when HIB plasma was added to the cultures prior to ConA. After HPLC size exclusion chromatography of the HIB ground squirrel plasma, a single fraction (fraction-14) demonstrated inhibitory activity. Assay of fraction-14 from 8 HIB squirrels showed inhibition ranging from 13 to 95%; inhibition was correlated to the time the squirrels were exposed to cold prior to hibernation. Western blot analysis showed the factor to be a large molecular weight protein (>300 kDa), and mass spectrometry identified sequences that were 100% homologous with alpha-2-macroglobulin from humans and other species. These findings indicate a hibernation-related protein that may be responsible for immune system down regulation.
authors.affiliation: Naval Medical Research Center, Silver Spring, MD 20910, United States. Electronic address: donna.sieckmann@med.navy.mil.
authors.forename: Donna G
authors.initials: DG
authors.lastname: Sieckmann
authors.affiliation: LNC-NINDS Protein/Peptide Sequencing Facility, NINDS, NIH, Bethesda, MD 20892, United States.
authors.forename: Howard
authors.initials: H
authors.lastname: Jaffe
authors.affiliation: Naval Medical Research Center, Silver Spring, MD 20910, United States.
authors.forename: Susanne
authors.initials: S
authors.lastname: Golech
authors.affiliation: Stroke Branch, NINDS, NIH, Bethesda, MD 20892, United States.
authors.forename: DeCheng
authors.initials: D
authors.lastname: Cai
authors.affiliation: Stroke Branch, NINDS, NIH, Bethesda, MD 20892, United States.
authors.forename: John M
authors.initials: JM
authors.lastname: Hallenbeck
authors.affiliation: Naval Medical Research Center, Silver Spring, MD 20910, United States; Department of Pathology, USUHS, Bethesda, MD 20814, United States. Electronic address: richard.mccarron@med.navy.mil.
authors.forename: Richard M
authors.initials: RM
authors.lastname: McCarron
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D003208:Concanavalin A; D005260:Female; D006605:Hibernation / Q000502:physiology*; D008214:Lymphocytes / Q000187:drug effects*; D051379:Mice; D008934:Mitogens; D012589:Sciuridae / Q000097:blood* / Q000502:physiology*; D013154:Spleen / Q000166:cytology; D000511:alpha-Macroglobulins / Q000494:pharmacology* / Q000502:physiology
chemical_list: D008934:Mitogens; D000511:alpha-Macroglobulins; D003208:Concanavalin A
keywords: 13-Lined ground squirrel; Alpha-2-macroglobulin; Hibernation; Lymphocyte proliferation; Serine proteinase inhibitors; Woodchuck