Oral administration of PSK can improve the impaired anti-tumor CD4+ T-cell response in gut-associated lymphoid tissue (GALT) of specific-pathogen-free mice

Int J Cancer. 1997 Jan 27;70(3):362-72. doi: 10.1002/(sici)1097-0215(19970127)70:3<362::aid-ijc19>3.0.co;2-h.

Abstract

We investigated both the effect and the mechanism of oral (p.o.) administration of PSK, a protein-bound polysaccharide derived from Basidiomycetes, on the anti-tumor T-cell response in gut-associated lymphoid tissue (GALT). The p.o. administration of PSK significantly suppressed the growth of colon 26 carcinoma (C-26) inoculated into the subserosal space of the cecum (i.c.), and augmented the tumor-neutralizing activity of the draining mesenteric lymph node (LN) cells. PSK treatment also significantly decreased the levels of immunosuppressive factors such as plasma transforming growth factor (TGF)-beta in the i.c. C-26-inoculated mice. We also evaluated the improving effect of PSK on the anti-tumor T-cell response in GALT by utilizing B7-transfected P815 mastocytoma (B7/P815). The PSK treatment promoted the rejection of i.c.-inoculated B7/P815 and restored the CD4+ T-cell-dependent proliferative response of the draining mesenteric LN cells against in vitro restimulation. Furthermore, the treatment also decreased the TGF-beta production but increased the IFN-gamma production of these cells. The p.o. administration of PSK, however, showed no effect in the CD8+ T-cell-dependent cytolytic activity of the draining mesenteric LN cells after in vitro restimulation. Overall, these results indicate that the p.o. administration of PSK can improve the impaired anti-tumor CD4+ T-cell response in GALT, mainly through a suppression of TGF-beta production and a restoration of IFN-gamma production.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Animals
  • Antibiotics, Antineoplastic / administration & dosage
  • Antibiotics, Antineoplastic / pharmacology*
  • CD4-Positive T-Lymphocytes / drug effects*
  • CD4-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / drug effects
  • CD8-Positive T-Lymphocytes / immunology
  • Colonic Neoplasms / blood
  • Colonic Neoplasms / immunology*
  • Female
  • Humans
  • Immunologic Factors / administration & dosage
  • Immunologic Factors / pharmacology*
  • Immunosuppression Therapy
  • Interferon-gamma / metabolism
  • Lymph Nodes / drug effects*
  • Lymph Nodes / immunology
  • Lymph Nodes / metabolism
  • Mesentery
  • Mice
  • Mice, Inbred BALB C
  • Neoplasm Transplantation
  • Proteoglycans / administration & dosage
  • Proteoglycans / pharmacology*
  • Specific Pathogen-Free Organisms
  • Transforming Growth Factor beta / blood

Substances

  • Antibiotics, Antineoplastic
  • Immunologic Factors
  • Proteoglycans
  • Transforming Growth Factor beta
  • polysaccharide-K
  • Interferon-gamma