Molecular cloning of a new immunomodulatory protein from Anoectochilus formosanus which induces B cell IgM secretion through a T-independent mechanism

• Published in: PloS one 2011-06, Vol.6 (6), p.e21004-e21004
• Main Authors: Kuan, Yen-Chou, Wu, Tsai-Jen, Kuo, Che-Yu, Hsu, Ju-Chun, Chang, Wen-Ying, Sheu, Fuu
• Format: Article
• Language: English
• Subjects: Allium sativum; Amino Acid Sequence; Amino acids; Animals; Anoectochilus; Anoectochilus formosanus; Antigens; B cells; B-Lymphocytes - immunology; Base Sequence; Biology; Blotting, Western; CD69 antigen; Cell activation; Cell growth; Cell proliferation; Chemistry; Cloning; Cloning, Molecular; Cytokines; DNA, Complementary; Electrophoresis, Capillary; Electrophoresis, Polyacrylamide Gel; Gene expression; Homology; Horticulture; Humoral immunity; Immune system; Immunity; Immunoglobulin M; Immunoglobulin M - metabolism; Immunoglobulins; Immunomodulation; Lectins; Lymphocyte Activation; Lymphocytes; Lymphocytes B; Lymphocytes T; Major histocompatibility complex; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Molecular Sequence Data; Momordica charantia; Narcissus tazetta; Orchidaceae - metabolism; Peptides; Plant Proteins - genetics; Plant Proteins - physiology; Proteins; Seeds; Sequence Homology, Amino Acid; Spleen; Staphylococcus aureus; Studies; T cells; T-Lymphocytes - immunology
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0021004

An immunomodulatory protein (IPAF) was purified and cloned from Anoectochilus formosanus, an Orchidaceae herbal plant in Asia. The major targeting immune cells of IPAF and its modulating effects toward B lymphocytes were investigated. Rapid amplification of cDNA ends (RACE) was conducted to clone the IPAF gene, and the obtained sequence was BLAST compared on the NCBI database. MACS-purified mouse T and B lymphocytes were stimulated with IPAF and the cell proliferation, activation, and Igs production were examined. IPAF comprised a 25 amino acids signal peptide and a 138 amino acids protein which was homologous to the lectins from Orchidaceae plant. IPAF selectively induced the cell proliferation in mouse splenic B lymphocytes but not T lymphocytes. The IPAF-induced B cells exhibited increased CD69 and MHC class II expression, and a dose- and time-dependent enhancement in IgM production. These results suggested potential benefits of IPAF to strengthen the humoral immunity.