Combined mutations of the penA with ftsX genes contribute to ceftriaxone resistance in Neisseria gonorrhoeae and peptide nucleic acids targeting these genes reverse ceftriaxone resistance.

OBJECTIVES: To investigate the gene mutations associated with ceftriaxone (CRO) resistance among gonococcal isolates, and to determine the effects of the mutated genes on CRO minimum inhibitory concentrations (MICs) with transformation assays and antisense peptide nucleic acids (asPNAs). METHODS: Ceftriaxone-resistant (CROR) and ceftriaxone-susceptible (CROS) isolates were identified using EUCAST and paired according to similarity in their MICs to other antimicrobials. The two groups of gonococci were sequenced and analysed. Mutated genes that showed a statistical difference between the two groups were transformed into gonococcal reference strains to determine their functions. AsPNAs were designed and transformed into the former transformant to further confirm the effects of the mutated genes. RESULTS: Twenty-two paired CROR and CROS isolates were obtained. The incidence of the penA-A501T and penA-G542S mutations individually, as well as combined mutations (penA-A501T and ftsX-R251H, penA-G542S and ftsX R251H), was statistically different between the two groups. The MIC of ATCC43069 (A43) increased 2 times following transformation with penA-A501T, and the MICs of A43 and ATCC49226 (A49) increased 32 times and 2 times following transformation with penA-A501T and ftsX-R251H, respectively. Antisense PNA-P3 reduced the MIC of the A43 transformant most significantly when transformed individually. PNA-P3 and PNA-F1 (asPNAs of the penA and ftsX) restored CRO susceptibility. CONCLUSIONS: PenA-A501T and penA-G542S mutations are important in CRO resistance among gonococci isolates. The ftsX-R251H mutation is also related to CRO resistance, and combined mutations of ftsX-R251H and penA-A501T comediate a significant reduction in CRO susceptibility. The combined application of PNA-P3 and PNA-F1 could effectively reverse the resistance to CRO in N. gonorrhoeae.

Targeting Tumor Markers with Antisense Peptides: An Example of Human Prostate Specific Antigen.

The purpose of this paper was to outline the development of short peptide targeting of the human prostate specific antigen (hPSA), and to evaluate its effectiveness in staining PSA in human prostate cancer tissue. The targeting of the hPSA antigen by means of antisense peptide AVRDKVG was designed according to a three-step method involving: 1. The selection of the molecular target (hPSA epitope), 2. the modeling of an antisense peptide (paratope) based on the epitope sequence, and 3. the spectroscopic evaluation of sense-antisense peptide binding. We then modified standard hPSA immunohistochemical staining practice by using a biotinylated antisense peptide instead of the standard monoclonal antibody and compared the results of both procedures. Immunochemical testing on human tissue showed the applicability of the antisense peptide technology to human molecular targets. This methodology represents a new approach to deriving peptide ligands and potential lead compounds for the development of novel diagnostic substances, biopharmaceuticals and vaccines.

Inhibiting Methicillin-Resistant Staphylococcus aureus by Tetrahedral DNA Nanostructure-Enabled Antisense Peptide Nucleic Acid Delivery.

One of the biggest obstacles for the use of antisense oligonucleotides as antibacterial therapeutics is their limited uptake by bacterial cells without a suitable carrier, especially in multi-drug-resistant bacteria with a drug efflux mechanism. Existing vectors, such as cell-penetrating peptides, are inefficient and nontargeting, and accordingly are not ideal carriers. A noncytotoxic tetrahedral DNA nanostructure (TDN) with a controllable conformation has been developed as a delivery vehicle for antisense oligonucleotides. In this study, antisense peptide nucleic acids (asPNAs) targeting a specific gene ( ftsZ) were efficiently transported into methicillin-resistant Staphylococcus aureus cells by TDNs, and the expression of ftsZ was successfully inhibited in an asPNA-concentration-dependent manner. The delivery system specifically targeted the intended gene. This novel delivery system provides a better platform for future applications of antisense antibacterial therapeutics and provides a basis for the development of a new type of antibacterial drug for multi-drug-resistant bacterial infections.

Sense-antisense (complementary) peptide interactions and the proteomic code; potential opportunities in biology and pharmaceutical science.

INTRODUCTION: A sense peptide can be defined as a peptide whose sequence is coded by the nucleotide sequence (read 5' → 3') of the sense (positive) strand of DNA. Conversely, an antisense (complementary) peptide is coded by the corresponding nucleotide sequence (read 5' → 3') of the antisense (negative) strand of DNA. Research has been accumulating steadily to suggest that sense peptides are capable of specific interactions with their corresponding antisense peptides. Unfortunately, although more and more examples of specific sense-antisense peptide interactions are emerging, the very idea of such interactions does not conform to standard biology dogma and so there remains a sizeable challenge to lift this concept from being perceived as a peripheral phenomenon if not worse, into becoming part of the scientific mainstream. AREAS COVERED: Specific interactions have now been exploited for the inhibition of number of widely different protein-protein and protein-receptor interactions in vitro and in vivo. Further, antisense peptides have also been used to induce the production of antibodies targeted to specific receptors or else the production of anti-idiotypic antibodies targeted against auto-antibodies. Such illustrations of utility would seem to suggest that observed sense-antisense peptide interactions are not just the consequence of a sequence of coincidental 'lucky-hits'. Indeed, at the very least, one might conclude that sense-antisense peptide interactions represent a potentially new and different source of leads for drug discovery. But could there be more to come from studies in this area? EXPERT OPINION: Studies on the potential mechanism of sense-antisense peptide interactions suggest that interactions may be driven by amino acid residue interactions specified from the genetic code. If so, such specified amino acid residue interactions could form the basis for an even wider amino acid residue interaction code (proteomic code) that links gene sequences to actual protein structure and function, even entire genomes to entire proteomes. The possibility that such a proteomic code should exist is discussed. So too the potential implications for biology and pharmaceutical science are also discussed were such a code to exist.

A review of the biomaterials technologies for infection-resistant surfaces.

Anti-infective biomaterials need to be tailored according to the specific clinical application. All their properties have to be tuned to achieve the best anti-infective performance together with safe biocompatibility and appropriate tissue interactions. Innovative technologies are developing new biomaterials and surfaces endowed with anti-infective properties, relying either on antifouling, or bactericidal, or antibiofilm activities. This review aims at thoroughly surveying the numerous classes of antibacterial biomaterials and the underlying strategies behind them. Bacteria repelling and antiadhesive surfaces, materials with intrinsic antibacterial properties, antibacterial coatings, nanostructured materials, and molecules interfering with bacterial biofilm are considered. Among the new strategies, the use of phages or of antisense peptide nucleic acids are discussed, as well as the possibility to modulate the local immune response by active cytokines. Overall, there is a wealth of technical solutions to contrast the establishment of an implant infection. Many of them exhibit a great potential in preclinical models. The lack of well-structured prospective multicenter clinical trials hinders the achievement of conclusive data on the efficacy and comparative performance of anti-infective biomaterials.

Synthesis of DR5-derived complementary peptide FR-11 and its inhibitory effect on TRAIL-mediated cell apoptosis / 第二军医大学学报

Objective: To synthesize DR5-derived complementary peptide(s) that can influence the function of TRAIL and to observe its(their) inhibitory effect on TRAIL-mediated cell death. Methods: A software was designed to identify the matching domains of two known peptide sequences according to the theory of Proteomic Code. The antisense homology box sequences between DR5 and its ligand TRAIL were searched by the designed software. Possibly active peptide(s) was/were selected and synthesized based on the structural information of TRAIL-DR5 complex. The binding between TRAIL molecule and the selected peptide(s) was examined by ELISA; the inhibitory effect of the selected peptide(s) against TRAIL-induced cell death was studied by cellular experiments. Results: Ten complementary peptide sequences were obtained based on software selection and structural analyzing. One active DR5-derived peptide FR-11 was selected with ligand-binding analysis using ELISA; FR-11 showed specific binding to TRAIL in a dose-dependant manner and blocked the binding of TRAIL with DR5. The matching rate between FR-11 and TRAIL 97-103aa was higher than 50%. Computer analysis showed that FR-11 corresponded to the extracellular domain of DRS, a key binding site to TRAIL. Further study indicated that FR-11 inhibited TRAIL-induced apoptosis of SW1990 cells and L929 cells in a dose-dependant manner; the inhibitory effect of FR-11 was more potent when the concentration of TRAIL was low, suggesting that it inhibited the binding between TRAIL and death receptor. Conclusion: The software designed based on the theory of Proteomic Code can be used to select complementary peptides which influence the interaction between ligand and receptor. The selected peptide FR-11 can bind to the ligand TRAIL and subsequently inhibit the biological function of the ligand.

Study on the inhibition of allogeneic transplantation rejection by the B7 antisense peptide / 中国免疫学杂志

95%,WT= 1 271 6 .Lymphoproliferation reaction of the splenocytes derived from BALB/C mice was inhibited by stimulating with the antisense peptide pre treatment of allogeneic splenic cells and cardiac cells of C57 mice.The inhibition rates up to 38 4% and 36 6%.Pre treatment of allogeneic cardiac grafts resulted in prolonging the survival of cardiac transplantation 5 4 days more than the control group(n=6,P

Immune regulation of antisense peptides of thyrotropin receptor activity fragments / 中华内分泌代谢杂志

Objective To study the immune regulation of antisense peptide in rats by observing immune function of activity fragments of thyrotropin receptor (TSHR) and their corresponding antisense peptides. Methods TSHR peptides TR1, TR2, TR3 and their antisense peptides RT1, RT2, RT3, and three pairs of complementary peptides were injected into rats of different groups respectively, and the serum levels of TT_3, TT_4, TSHR antibody (TRAb), thyroid stimmulating antibody, thyroid blocking antibody and TSH antibody (TSHAb) and pathological changes in thyroid tissue were investigated. Results Serum TRAb could be induced when each of three fragments of TSHR was injected into rats; TRAb and TSHAb were induced by RT1 or RT2; epithelial hyperplasia and lymphocytic infiltration observed in thyroid tissue of rats injected with TR2 could be abated by injecting RT2 subsequently. Conclusion The results suggest that all 3 TSHR fragments are shown to be immunogenic and are capable to induce TRAb; both RT1 and RT2 show their effect on immune regulation and are idiotypic of TSHR peptides; On the other hand, the humoural and cell immunities are ameliarated by injection of antisense peptides. Therefore, it is possible that antisense peptides may be involved in immune regulation via immune network.

The screening of C5a antagonist by optic biosensor technique / 中国免疫学杂志

Objective:To screen the antagonist of C5a anaphylatoxin,and further to study the dinetic characteristics of interaction between C5a and its anti-sense peptides.Methods:The anti-sense peptides were screened that can interact with C5a selectively by means of dinetic analysis,via biosensor technique.Results:There is one piece of anti-sense peptide(R4) being screened from these four synthesized peptides.The dissociation equilibrium constant(K D) between R4 and the immobilized hC5a is 6.62?10 -6 mol/L and the K D between R4 and L2 is 7.02?10 -7 . Conclusion:Based on the results obtained,it was concluded that the optic biosensor is a ideal and powerful tool to facilitate the kinetic analysis of interaction between sense peptide and its anti-sense peptide and to screen antagonist of biologic activity molecule.