Stronger T Cell Immunogenicity of Ovalbumin Expressed Intracellularly in Gram-Negative than in Gram-Positive Bacteria
نویسندگان
چکیده
This study aimed to clarify whether Gram-positive (G+) and Gram-negative (G-) bacteria affect antigen-presenting cells differently and thereby influence the immunogenicity of proteins they express. Lactobacilli, lactococci and Escherichia coli strains were transformed with plasmids conferring intracellular ovalbumin (OVA) production. Murine splenic antigen presenting cells (APCs) were pulsed with washed and UV-inactivated OVA-producing bacteria, control bacteria, or soluble OVA. The ability of the APCs to activate OVA-specific DO11.10 CD4(+) T cells was assessed by measurments of T cell proliferation and cytokine (IFN-γ, IL-13, IL-17, IL-10) production. OVA expressed within E. coli was strongly immunogenic, since 500 times higher concentrations of soluble OVA were needed to achieve a similar level of OVA-specific T cell proliferation. Furthermore, T cells responding to soluble OVA produced mainly IL-13, while T cells responding to E. coli-expressed OVA produced high levels of both IFN-γ and IL-13. Compared to E. coli, G+ lactobacilli and lactococci were poor inducers of OVA-specific T cell proliferation and cytokine production, despite efficient intracellular expression and production of OVA and despite being efficiently phagocytosed. These results demonstrate a pronounced difference in immunogenicity of intracellular antigens in G+ and G- bacteria and may be relevant for the use of bacterial carriers in vaccine development.
منابع مشابه
Synthesis and Charactrization of Au Nanocomposits by Green Capping Agent: Pomegranate juice For Antibacterial Activity
Objective(s): In this work, pomegranate juice was used as a capping agent for self- assembly to form particles-like Au nanostructures in the presence of AuHCl4.3H2O as aurate source. Besides, to investigate the concentration effect of pomegranate juice as the green capping agent on the morphology and particle size of final products several experiments were...
متن کاملTwo Proteins from Snake Venom have Potent Antibacterial Effects against Bacillus anthracis and Streptococcus pneumoniae
Background: Antibacterial proteins are widely expressed in snake venoms. Previously, we have isolated two immunodominant proteins with molecular weights of 14 and 65kD from the snake venom of Naja naja oxiana (N. oxiana). It was demonstrated that they had potent inhibitory effects against gram-positive bacteria, S. aureus and B. subtilis but were less effective against gram-negative bacteria, s...
متن کاملEvaluation of antibacterial activity of new N-piperazinyl quinolone derivatives with 1,3,4.thiadiazole group
quinolones are broad-spectrum antibacterial agents.they have many clinical uses which are increasing.quinolones exert antibacterial activity primarily by inhibiting bacterial DNA gyrase.the inhibition of DNA gyrase by the quinolones are greatly influenced by the nature of the C-7 substituent on the quinolones molecule.substitution of bulky functional groupd is also possible in C-7 position.furt...
متن کاملGROWTH INHIBITION OF PATHOGENS BY LACTIC ACID BACTERIA PRODUCING INHIBITORY SUBSTANCES
71 samples of milk and dairy products were collected from 18 cities throughout Iran. 93 strains of lactic acid bacteria (LAB) were isolated and assayed against four opportunistic patho gens including E. coli, proteus and klebsiella as gram-negative and S. aureus as a gram-positive organism. All indicators (organisms) were hospital strains. Among isolated bacteria, lactobacilli (37 isolates)...
متن کامل