Biomedical subjects

R B Pollard

Publications and source records attributed to R B Pollard.

147 records · Page 9Linked to original sources

PubMedDate not supplied

Antitumor mechanisms of Z-100, an immunomodulatory arabinomannan extracted from Mycobacterium tuberculosis: the importance of lymphocytes infiltrated into tumor sites.

The mechanisms of increased host resistance to tumors following treatment with Z-100, an arabinomannan extracted from Mycobacterium tuberculosis, were investigated in mice bearing syngeneic solid tumors. When BALB/c mice bearing Meth-A solid tumors were treated intralesionally (i.l.) with a 10 mg/kg dose of Z-100, 74% of tumor growth was inhibited in the test group as compared with control mice treated with saline. However, no significant tumor inhibitory activity was observed when these mice were treated with various doses of Z-100 i.p. or i.v. In addition, tumor growth in X-irradiated mice (450 R, whole-body irradiation) and in mice treated with antilymphocyte serum was not suppressed even though Z-100 was administered into the tumor. The number of lymphocytes isolated from Z-100-treated tumor tissues increased 3.2-fold (14 days after the tumor inoculation), whereas no change in the number of tumor-infiltrating lymphocytes was demonstrated in mice treated with Z-100 i.p. or i.v. as compared to controls. When BALB/c mice were inoculated s.c. with a mixture of Meth-A tumor cells (1 x 10(6) cells) and lymphocytes (2 x 10(5) cells) derived from Z-100-treated tumor tissues in a Winn's neutralization test, decreased growth of solid tumors was demonstrated as compared with that of control mice inoculated with tumor cells alone. However, no such inhibition of tumor growth was observed in mice inoculated with a mixture of the tumor cells and lymphocytes obtained from tumor tissues of control mice at the same effector to target cell ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Adjuvants, Immunologic↗

PubMedDate not supplied

Prolongation of concomitant antitumor immunity in mice treated with Z-100, an arabinomannan extracted from Mycobacterium tuberculosis.

The effect of Z-100, a natural immunomodulator extracted from Mycobacterium tuberculosis strain Aoyama B, on concomitant antitumor immunity (CAI) was investigated in mice immunized with Meth-A tumor cells (primary inoculation) in combination with Corynebacterium parvum. CAI, which was observed in mice 10 days after immunization (I10 mice), disappeared in mice 20 days after immunization (I20 mice). However, no growth of secondary inoculated Meth-A tumors was demonstrated in I20 mice treated with Z-100 (IZ20 mice). CAI was demonstrated in tumor-bearing recipients when splenic mononuclear cells (SMNC) from I10 mice or IZ20 mice were transferred to recipients intralesionally. However, CAI was not detected when recipients received SMNC from I20 mice or a SMNC mixture from I10 and I20 mice. The SMNC mixture from I10 and IZ20 mice inhibited the growth of Meth-A solid tumors in the recipients. The activity of non-specific suppressor cells, which were characterized as CD8+ T cells, was demonstrated in SMNC from I20 mice, while SMNC from I10 and IZ20 mice did not show any suppressor cell activities. In addition, clear inhibition of tumor growth was demonstrated in recipient mice which received a SMNC mixture from I20 mice, previously treated with anti-Lyt-2+ MAb plus complement, and I10 mice. These results suggest that Z-100 might be able to prolong CAI observed in I10 mice through the inhibition of Lyt-2+ T suppressor cells detected in SMNC from I20 mice.

Adjuvants, Immunologic↗

PubMedDate not supplied

Keishi-ka-kei-to, a traditional Chinese herbal medicine, inhibits pulmonary metastasis of B16 melanoma.

Keishi-ka-kei-to, a traditional Chinese herbal medicine composed of a mixture of crude extracts from five medicinal plants (Cinnamomi cortex, Paeoniae radix, Zizyphi fructus, Zingiberis rhizoma and Glycyrrhizae radix), inhibited experimental pulmonary metastasis in mice implanted with B16F10 melanoma cells. When 136 to 145 metastatic colonies were produced in lungs of mice inoculated with 1 x 10(5) cells/mouse of melanoma cells, less than 15 metastatic colonies were demonstrated when these tumor-inoculated mice were treated orally with 80 to 320 mg/kg doses of Keishi-ka-kei-to. The most active component in the mixture was shown to be 6-gingerol, derived from the Zingiberis rhizoma extract. The antimetastatic activity of 6-gingerol was expressed through the host's antitumor immune functions, as the growth of B16F10 melanoma cells was not affected by this substance in vitro. The splenic CD8+ T cells from mice treated with the compound showed inhibitory activities on pulmonary metastasis when these T cells were adoptively transferred to mice bearing B16F10 melanoma cells. These results may suggest that Keishi-ka-kei-to inhibits pulmonary metastasis in mice bearing B16F10 melanoma cells through the stimulation of CD8+ T cells.

Animals↗