Streptococcus suis is a Gram-positive pathogen that causes serious diseases in pigs. In addition to S. suis serotype 2 （SS2）, S. suis serotype 9 （SS9） is another prevalent serotype, which is frequently isolated fr...Streptococcus suis is a Gram-positive pathogen that causes serious diseases in pigs. In addition to S. suis serotype 2 （SS2）, S. suis serotype 9 （SS9） is another prevalent serotype, which is frequently isolated from the organs of diseased pigs in China. An immunoproteomic-based approach was developed to identify antigens common to SS2 and SS9 for vaccine development. Cell wall proteins extracted from SS2 strain HA9801 were screened by two-dimensional Western blot using anti-SS2 sera, anti-SS9 sera, or pre-immune sera pooled from specific pathogen free （SPF） mice. Protein spots on preparative gels were excised and identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry, which led to the identification of four shared immunogenic proteins （arginine deiminase, translation elongation factor-Ts, o-acetylserine lyase, and 1-phosphofructokinase）. The genes encoding these four proteins from SS9 strain GZ0565 were cloned and their proteins were overexpressed in Escherichia coli BL21. Western blot analysis of these recombinant proteins using the convalescent serum of an SPF mini-pig inoculated with the SS2 strain, anti-SS2 sera, and anti-SS9 sera pooled from SPF mice further confirmed the immunogenicity of these proteins. These immunogenic proteins, which are encoded by genes that are reasonably conserved among SS2 and SS9 strains, could be developed as vaccine candidates.展开更多
Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibi...Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibitory environment for axonal regeneration. Among these inhibitory molecules, myelinassociated inhibitors, including neurite outgrowth inhibitor A, oligodendrocyte myelin glycoprotein, myelin-associated glycoprotein, chondroitin sulfate proteoglycans and repulsive guidance molecule A are of particular importance. Due to their inhibitory nature, they represent exciting molecular targets to study axonal inhibition and regeneration after central injuries. These molecules are mainly produced by neurons, oligodendrocytes, and astrocytes within the scar and in its immediate vicinity. They exert their effects by binding to specific receptors, localized in the membranes of neurons. Receptors for these inhibitory cues include Nogo receptor 1, leucine-rich repeat, and Ig domain containing 1 and p75 neurotrophin receptor/tumor necrosis factor receptor superfamily member 19(that form a receptor complex that binds all myelin-associated inhibitors), and also paired immunoglobulin-like receptor B. Chondroitin sulfate proteoglycans and repulsive guidance molecule A bind to Nogo receptor 1, Nogo receptor 3, receptor protein tyrosine phosphatase σ and leucocyte common antigen related phosphatase, and neogenin, respectively. Once activated, these receptors initiate downstream signaling pathways, the most common amongst them being the Rho A/ROCK signaling pathway. These signaling cascades result in actin depolymerization, neurite outgrowth inhibition, and failure to regenerate after spinal cord injury. Currently, there are no approved pharmacological treatments to overcome spinal cord injuries other than physical rehabilitation and management of the array of symptoms brought on by spinal cord injuries. However, several novel therapies aiming to modulate these inhibitory proteins and/or their receptors are under investigation in ongoing clinical trials. Investigation has also been demonstrating that combinatorial therapies of growth inhibitors with other therapies, such as growth factors or stem-cell therapies, produce stronger results and their potential application in the clinics opens new venues in spinal cord injury treatment.展开更多
基金the fund of the Priority Academic Program Development of Jiangsu Higher Education Institutions, China (PAPD)the Natural Science Foundation of Jiangsu Province, China (BK2011644)+2 种基金the Youth Foundation of National Natural Science Foundation of China (31101828)the Youth Foundation of Nanjing Agricultural University, China (KJ2011012)the Specialized Research Funds for the Doctoral Program of Higher Education of China (20110097120016, 20110097130003)
文摘Streptococcus suis is a Gram-positive pathogen that causes serious diseases in pigs. In addition to S. suis serotype 2 （SS2）, S. suis serotype 9 （SS9） is another prevalent serotype, which is frequently isolated from the organs of diseased pigs in China. An immunoproteomic-based approach was developed to identify antigens common to SS2 and SS9 for vaccine development. Cell wall proteins extracted from SS2 strain HA9801 were screened by two-dimensional Western blot using anti-SS2 sera, anti-SS9 sera, or pre-immune sera pooled from specific pathogen free （SPF） mice. Protein spots on preparative gels were excised and identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry, which led to the identification of four shared immunogenic proteins （arginine deiminase, translation elongation factor-Ts, o-acetylserine lyase, and 1-phosphofructokinase）. The genes encoding these four proteins from SS9 strain GZ0565 were cloned and their proteins were overexpressed in Escherichia coli BL21. Western blot analysis of these recombinant proteins using the convalescent serum of an SPF mini-pig inoculated with the SS2 strain, anti-SS2 sera, and anti-SS9 sera pooled from SPF mice further confirmed the immunogenicity of these proteins. These immunogenic proteins, which are encoded by genes that are reasonably conserved among SS2 and SS9 strains, could be developed as vaccine candidates.
基金a Ph D fellowship by FCT-Fundacao para a Ciência Tecnologia (SFRH/BD/135868/2018)(to SSC)。
文摘Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibitory environment for axonal regeneration. Among these inhibitory molecules, myelinassociated inhibitors, including neurite outgrowth inhibitor A, oligodendrocyte myelin glycoprotein, myelin-associated glycoprotein, chondroitin sulfate proteoglycans and repulsive guidance molecule A are of particular importance. Due to their inhibitory nature, they represent exciting molecular targets to study axonal inhibition and regeneration after central injuries. These molecules are mainly produced by neurons, oligodendrocytes, and astrocytes within the scar and in its immediate vicinity. They exert their effects by binding to specific receptors, localized in the membranes of neurons. Receptors for these inhibitory cues include Nogo receptor 1, leucine-rich repeat, and Ig domain containing 1 and p75 neurotrophin receptor/tumor necrosis factor receptor superfamily member 19(that form a receptor complex that binds all myelin-associated inhibitors), and also paired immunoglobulin-like receptor B. Chondroitin sulfate proteoglycans and repulsive guidance molecule A bind to Nogo receptor 1, Nogo receptor 3, receptor protein tyrosine phosphatase σ and leucocyte common antigen related phosphatase, and neogenin, respectively. Once activated, these receptors initiate downstream signaling pathways, the most common amongst them being the Rho A/ROCK signaling pathway. These signaling cascades result in actin depolymerization, neurite outgrowth inhibition, and failure to regenerate after spinal cord injury. Currently, there are no approved pharmacological treatments to overcome spinal cord injuries other than physical rehabilitation and management of the array of symptoms brought on by spinal cord injuries. However, several novel therapies aiming to modulate these inhibitory proteins and/or their receptors are under investigation in ongoing clinical trials. Investigation has also been demonstrating that combinatorial therapies of growth inhibitors with other therapies, such as growth factors or stem-cell therapies, produce stronger results and their potential application in the clinics opens new venues in spinal cord injury treatment.
