title: Augmentation of mouse liver-associated natural killer activity by biologic response modifiers occurs largely via rapid recruitment of large granular lymphocytes from the bone marrow.
abstract: A variety of biologic response modifiers (BRM) can potently augment NK activity in nonlymphoid organs. By using the liver as a model organ, we have shown that this augmentation of organ-associated NK activity is coincident with a 10- to 15-fold increase in the number of large granular lymphocytes (LGL) which can be isolated. The present study was designed to investigate the mechanism by which BRM induce this increase in liver-associated LGL and the coincident increase in hepatic NK activity. Initial studies confirm that a single dose of the pyran copolymer, maleic anhydride divinyl ether (MVE-2), augmented hepatic NK activity and increased the number of liver-associated LGL from 3 x 10(4)/liver to 5 x 10(5)/liver (a 17-fold increase). Multiple injections of MVE-2 further augmented total liver-associated NK activity and LGL number (to 13 x 10(5)/liver). As expected, both the NK activity and detectable LGL were eliminated by treatment of the mice with antiasialo GM1 (asGM1) serum. Three possible mechanisms for the BRM-induced increase in liver-associated LGL have been investigated, including 1) the rapid proliferation of resident hepatic LGL, 2) the redistribution of mature LGL from peripheral sites such as the spleen, or by 3) a rapid output and subsequent hepatic localization of LGL or their precursors recently derived from the bone marrow (BM). Our results demonstrated that the contribution of in situ proliferation to the BRM-induced increase in liver-LGL was relatively small, since the number of cells expressing NK-associated markers (i.e., asGM1, Thy-1.2, and NK1.1) and in G2/M phase (as assessed by propidium iodide uptake) was only 4 to 8%. Further experiments demonstrated that splenectomy before the administration of MVE-2 did not inhibit the augmentation of liver-associated NK activity. This result argued against a recruitment of mature LGL from the spleen. In contrast, selective depletion of the BM following administration of 89Sr decreased the ability of MVE-2 to augment liver-associated NK activity by greater than 80%. This procedure also significantly decreased the ability of Propionibacterium acnes (85%) and multiple doses of IL-2 (49%) to augment liver-associated NK activity. These results demonstrate that the rapid augmentation of liver-associated NK activity by BRM is largely due to localization and accumulation in the liver of LGL recently derived from the BM.
authors.affiliation: Laboratory of Experimental Immunology, National Cancer Institute-Frederick Cancer Research Facility, MD 21701-1013.
authors.forename: R H
authors.initials: RH
authors.lastname: Wiltrout
authors.forename: A M
authors.initials: AM
authors.lastname: Pilaro
authors.forename: M E
authors.initials: ME
authors.lastname: Gruys
authors.forename: J E
authors.initials: JE
authors.lastname: Talmadge
authors.forename: D L
authors.initials: DL
authors.lastname: Longo
authors.forename: J R
authors.initials: JR
authors.lastname: Ortaldo
authors.forename: C W
authors.initials: CW
authors.lastname: Reynolds
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D001853:Bone Marrow / Q000187:drug effects / Q000276:immunology* / Q000528:radiation effects; D002465:Cell Movement / Q000187:drug effects / Q000528:radiation effects; D003602:Cytotoxicity, Immunologic / Q000187:drug effects* / Q000528:radiation effects; D004334:Drug Administration Schedule; D005260:Female; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology* / Q000528:radiation effects; D008099:Liver / Q000187:drug effects / Q000276:immunology*; D008213:Lymphocyte Activation / Q000187:drug effects / Q000528:radiation effects; D051379:Mice; D008810:Mice, Inbred C57BL; D011292:Premedication; D011713:Pyran Copolymer / Q000008:administration & dosage; D013154:Spleen / Q000528:radiation effects; D013156:Splenectomy; D013326:Strontium Radioisotopes / Q000008:administration & dosage
chemical_list: D000276:Adjuvants, Immunologic; D013326:Strontium Radioisotopes; D011713:Pyran Copolymer