Author(s): Tang YQ, Yeaman MR, Selsted ME
Platelets share structural and functional similarities with granulocytes known to participate in antimicrobial host defense. To evaluate the potential antimicrobial activities of platelet proteins, normal human platelets were stimulated with human thrombin in vitro. Components of the stimulated-platelet supernatants were purified to homogeneity by reversed-phase high-performance liquid chromatography. Purified peptides with inhibitory activity against Escherichia coli ML35 in an agar diffusion antimicrobial assay were characterized by mass spectrometry, amino acid analysis, and sequence determination. These analyses enabled the identification of seven thrombin-releasable antimicrobial peptides from human platelets: platelet factor 4 (PF-4), RANTES, connective tissue activating peptide 3 (CTAP-3), platelet basic protein, thymosin beta-4 (Tbeta-4), fibrinopeptide B (FP-B), and fibrinopeptide A (FP-A). With the exception of FP-A and FP-B, all peptides were also purified from acid extracts of nonstimulated platelets. The in vitro antimicrobial activities of the seven released peptides were further tested against bacteria (E. coli and Staphylococcus aureus) and fungi (Candida albicans and Cryptococcus neoformans). Each peptide exerted activity against at least two organisms. Generally, the peptides were more potent against bacteria than fungi, activity was greater at acidic pHs, and antimicrobial activities were dose dependent. Exceptions to these observations were observed with PF-4, which displayed a bimodal dose-response relationship in microbicidal assays, and Tbeta-4, which had greater activity at alkaline pHs. At concentrations at which they were individually sublethal, PF-4 and CTAP-3 exerted synergistic microbicidal activity against E. coli. Collectively, these findings suggest a direct antimicrobial role for platelets as they are activated to release peptides in response to trauma or mediators of inflammation.
Referred From: https://www.ncbi.nlm.nih.gov/pubmed/12438321
Author(s): Castro MS, Fontes W
Author(s): Strominger JL
Author(s): Zasloff M
Author(s): Riley MA, Chavan MA
Author(s): Cotter PD, Hill C, Ross RP
Author(s): Rodríguez JM, Martínez MI, Kok J
Author(s): da Rocha Pitta MG, da Rocha Pitta MG, Galdino SL
Author(s): Thomas S, Karnik S, Barai RS, Jayaraman VK, Idicula-Thomas S
Author(s): Brogden KA
Author(s): Yount NY, Bayer AS, Xiong YQ, Yeaman MR
Author(s): Kamysz W, Okroj M, Lukasiak J
Author(s): Hale JD, Hancock RE
Author(s): Nicolas P
Author(s): Bowdish DM, Davidson DJ, Lau YE, Lee K, Scott MG, et al.
Author(s): Brown KL, Hancock RE
Author(s): Easton DM, Nijnik A, Mayer ML, Hancock RE
Author(s): Lai Y, Gallo RL
Author(s): Guaní-Guerra E, Santos-Mendoza T, Lugo-Reyes SO, Terán LM
Author(s): Hancock RE, Diamond G
Author(s): Hancock RE, Brown KL, Mookherjee N
Author(s): Bals R, Wilson JM
Author(s): Beauregard KA, Truong NT, Zhang H, Lin W, Beck G
Author(s): Haug T, Kjuul AK, Styrvold OB, Sandsdalen E, Olsen AM, et al.
Author(s): Ghanbari R, Ebrahimpour A, Abdul-Hamid A, Ismail A, Saari N
Author(s): Schillaci D, Arizza V, Parrinello N, Di Stefano V, Fanara S, et al.
Author(s): Huff T, M&uller CS, Otto AM, Netzker R, Hannappel E
Author(s): Safer D, Chowrashi PK
Author(s): Saelee N, Noonin C, Nupan B, Junkunlo K, Phongdara A, et al.
Author(s): Zhang FX, Shao HL, Wang JX, Zhao XF
Author(s): Li C, Haug T, Styrvold OB, JØrgensen TØ, Stensvåg K
Author(s): Selsted ME, Ouellette AJ
Author(s): Daher KA, Selsted ME, Lehrer RI
Author(s): Mandal M, Nagaraj R
Author(s): Li C, Blencke HM, Smith LC, Karp MT, Stensvåg K
Author(s): Li C, Haug T, Moe MK, Styrvold OB, Stensvåg K
Author(s): Bjorn C, HÁkansson J, Myhrman E, Sjostrand V, Haug T, et al.
Author(s): Wilson M
Author(s): Parsek MR, Singh PK
Author(s): Archer NK, Mazaitis MJ, Costerton JW, Leid JG, Powers ME, et al.
Author(s): Obst U, Schwartz T, Volkmann H
Author(s): Horswill AR, Stoodley P, Stewart PS, Parsek MR
Author(s): Spoering AL, Gilmore MS
Author(s): Brogden NK, Brogden KA
Author(s): Huang Y, Huang J, Chen Y
Author(s): Hall-Stoodley L, Stoodley P
Author(s): Landini P, Antoniani D, Burgess JG, Nijland R
Author(s): Pieters RJ, Arnusch CJ, Breukink E
Author(s): Chan DI, Prenner EJ, Vogel HJ
Author(s): Schillaci D, Vitale M, Cusimano MG, Arizza V
Author(s): Hisamatsu K, Tsuda N, Goda S, Hatakeyama T