A novel glycoprotein obtained from Chlorella vulgaris strain CK22 shows antimetastatic immunopotentiation

Abstract

A glycoprotein extract (CVS), derived from the unicellular green alga Chlorella vulgaris, strain CK22, exhibited a pronounced antitumor effect against both spontaneous and experimentally induced metastasis in mice. Inhibition of tumor metastasis was enhanced when intratumor administration of CVS was followed by s.c. injection of CVS. Anti-metastatic immunopotentiation was observed in euthymic mice, but not in athymic nude mice. The antitumor activity of CVS was reflected in antigen-specific, T-cell-mediated immunity. Both CD4 and CD8 T cells contributed to the antimetastatic effects, as shown by in vivo depletion experiments with anti-T-cell subset antibodies. Furthermore, CVS caused the recruitment of T cells to the regional lymph nodes and their proliferation in these organs. The CD4-positive population, following CVS injection at the time of tumor rechallenge, displayed a pronounced increase in the proportion of T cells that were CD18 bright, CD44 bright, CD25+, CD54+, CD69+ or CD71+ in the lymph nodes. Thus, CVS induces T cell activation in peripheral lymph nodes in tumor-bearing mice. We conclude that CVS augments antimetastatic immunity through T cell activation in lymphoid organs and enhances recruitment of these cells to the tumor sites. Presurgical treatment with CVS might prevent metastasis or tumor progression.

Purification and characterization of a novel haemagglutinin from Chlorella pyrenoidosa

“…These characteristics make Chlorella a good choice for use in the lab [31]. In addition, Chlorella cells are rich in protein and contain special functional compounds, making them an ideal health food source [17,23,28]. Thus, scientists have sought to investigate Chlorella cellular biology for both laboratory and commercial applications.…”

Effect of a hot water extract of Chlorella vulgaris on proliferation of IEC-6 cells

“…The Chlorella polysaccharide, β-1,3-glucan, exerts important biological effects, including immunomodulatory activities (1), free radical scavenging, and reduction of blood lipid levels (2). Thus, various healthpromoting effects have been suggested, including dioxin excretion (3), cadmium detoxification (4), hepatoprotection (5), and antitumor (6) and immunomodulatory activities (1). A hot water extract of Chlorella vulgaris (CVE) had an antitumor effect (7) and immunomodulatory activity (8,9).…”

Analysis of the agglutinating activity from unicellular algae

“…Several reports indicate that microalgae contain agglutinins that agglutininate human and animal erythrocytes to varying degrees (Hori et al 1996;Liao and Huang 2000;Sato et al 2000). Some agglutinins have shown pronounced antitumor effects, such as a glycoprotein from Chlorella vulgaris (Tanaka et al 1998). They also exhibit unique structure and characteristics, as shown in extracts from Microcystis aeruginosa, M. viridis, Oscillatoria agardhii and related species (Sakamoto et al 1996;Yamaguchi et al 1998Yamaguchi et al , 1999Sato et al 2000).…”