Soluble branched (1,4)‐β‐D‐glucans from Acetobacter species enhance antitumor activities against MHC class I‐negative and ‐positive malignant melanoma through augmented NK activity and cytotoxic T‐cell response
Open Access
- 11 May 2005
- journal article
- research article
- Published by Wiley in International Journal of Cancer
- Vol. 115 (5), 769-776
- https://doi.org/10.1002/ijc.20934
Abstract
We previously found that an extracellular polysaccharide, AC-1, produced by Acetobacter polysaccharogenes composed of (1,4)-β-D-glucan with branches of glucosyl residues showed a strong activity to induce production of interleukin (IL)-12 p40 and tumor necrosis factor-α by macrophage cell lines in vitro via Toll-like receptor-4 signaling. In the present study, we examined the effects of oral administration of AC-1 on protection against 2 types of murine B16 melanoma lines, major histocompatibility complex (MHC) class I-negative B16L and MHC class I gene-transfected B16Kb cells. Mice were inoculated subcutaneously with B16L or B16Kb cells on day 0 and administrated intragastrically with AC-1 or PBS once every 5 days from 1 day before tumor inoculation. The tumor growth was severely retarded in AC-1-treated mice after subcutaneous inoculation with B16L or B16Kb cells. The AC-1-treated mice showed augmented natural killer (NK) cell activity against B16L cells, and in vivo depletion of NK cells by antiasialoGM1 antibody (Ab) treatment abrogated the antitumor activity in AC-1-treated mice. On the other hand, AC-1-treated mice inoculated with B16Kb cells developed a significantly higher level of cytotoxic T-lymphocyte response against B16Kb cells, and in vivo depletion of CD8+ T cells by anti-CD8 mAb treatment abrogated the antitumor activity. Thus, AC-1 augmented antitumor activity against different tumors via augmentation of different antitumor mechanisms. These results suggest a possible prophylactic application of AC-1 for human neoplasms irrespective of expression levels of their MHC class I molecules.Keywords
This publication has 55 references indexed in Scilit:
- Interleukin-12 and the regulation of innate resistance and adaptive immunityNature Reviews Immunology, 2003
- Two subsets of memory T lymphocytes with distinct homing potentials and effector functionsNature, 1999
- NK CELL RECEPTORSAnnual Review of Immunology, 1998
- Mouse liver T cells: Their change with aging and in comparison with peripheral T cellsHepatology, 1997
- Loss of HLA class I antigens by melanoma cells: molecular mechanisms, functional significance and clinial relevanceImmunology Today, 1995
- Fate and distribution of an antitumor protein-bound polysaccharide PSK (Krestin®)International Journal of Immunopharmacology, 1988
- Antitumor mechanisms of orally administered shiitake fruit bodies.CHEMICAL & PHARMACEUTICAL BULLETIN, 1987
- Effect of a protein bound polysaccharide (PS-K) on tumor development and infections in splenectomized rats and miceInternational Journal of Immunopharmacology, 1986
- Extracellular polysaccharides produced by acetic acid bacteria. Part II. Structure of an acidic polysaccharide from Acetobacter sp. NBI 1022.Agricultural and Biological Chemistry, 1985
- Extracellular polysaccharides produced by acetic acid bacteria. Part I. Isolation and characterization of a new polysaccharide-producing Acetobacter sp.Agricultural and Biological Chemistry, 1984