Multiple autoepitope presentation for specific detection of antibodies in primary biliary cirrhosis

Peptide Dendrimer-Based Antibacterial Agents: Synthesis and Applications

Pathogenic bacteria cause the deaths of millions of people every year. With the development of antibiotics, hundreds and thousands of people's lives have been saved. Nevertheless, bacteria can develop resistance to antibiotics, rendering them insensitive to antibiotics over time. Peptides containing specific amino acids can be used as antibacterial agents; however, they can be easily degraded by proteases in vivo. To address these issues, branched peptide dendrimers are now being considered as good antibacterial agents due to their high efficacy, resistance to protease degradation, and low cytotoxicity. The ease with which peptide dendrimers can be synthesized and modified makes them accessible for use in various biological and nonbiological fields. That is, peptide dendrimers hold a promising future as antibacterial agents with prolonged efficacy without bacterial resistance development. Their in vivo stability and multivalence allow them to effectively target multi-drug-resistant strains and prevent biofilm formation. Thus, it is interesting to have an overview of the development and applications of peptide dendrimers in antibacterial research, including the possibility of employing machine learning approaches for the design of AMPs and dendrimers. This review summarizes the synthesis and applications of peptide dendrimers as antibacterial agents. The challenges and perspectives of using peptide dendrimers as the antibacterial agents are also discussed.

Autoimmune Markers in Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease. The most common antibody associated with PBC is the anti-mitochondrial antibody (AMA), present in 90% to 95% of patients. For patients who are AMA-negative, novel biomarkers, such as antinuclear antibody-specific antibodies Sp100 and gp210 and anti-kelch-like-12 and anti-hexokinase-1 antibodies, may further aid in the diagnosis of PBC. Several laboratory methods, including immunofluorescence, enzyme-linked immunosorbent assay, immunoblotting, and bead-based assays, exist to evaluate for the presence of antibodies. This article describes various methods used to evaluate antibodies as well as describe the antibodies present in PBC.

Cross-reactivity and sequence similarity between microbial transglutaminase and human tissue antigens

Microbial transglutaminase (mTG) is a bacterial survival factor, frequently used as a food additive to glue processed nutrients. As a result, new immunogenic epitopes are generated that might drive autoimmunity. Presently, its contribution to autoimmunity through epitope similarity and cross-reactivity was investigated. Emboss Matcher was used to perform sequence alignment between mTG and various antigens implicated in many autoimmune diseases. Monoclonal and polyclonal antibodies made specifically against mTG were applied to 77 different human tissue antigens using ELISA. Six antigens were detected to share significant homology with mTG immunogenic sequences, representing major targets of common autoimmune conditions. Polyclonal antibody to mTG reacted significantly with 17 out of 77 tissue antigens. This reaction was most pronounced with mitochondrial M2, ANA, and extractable nuclear antigens. The results indicate that sequence similarity and cross-reactivity between mTG and various tissue antigens are possible, supporting the relationship between mTG and the development of autoimmune disorders 150W.

Nanomaterials, Autophagy, and Lupus Disease

Nanoscale materials hold great promise in the therapeutic field. In particular, as carriers or vectors, they help bioactive molecules reach their primary targets. Furthermore, by themselves, certain nanomaterials-regarded as protective-can modulate particular metabolic pathways that are deregulated in pathological situations. They can also synergistically improve the effects of a payload drug. These properties are the basis of their appeal. However, nanoscale materials can also have intrinsic properties that limit their use, and this is the case for certain types of nanomaterials that influence autophagy. This property can be beneficial in some pathological settings, but in others, if the autophagic flux is already accelerated, it can be deleterious. This is notably the case for systemic lupus erythematosus (SLE) and other chronic inflammatory diseases, including certain neurological diseases. The nanomaterial-autophagy interaction therefore must be treated with caution for therapeutic molecules and peptides that require vectorization for their administration.

Disease-specific cross-reactivity between mimicking peptides of heat shock protein of Mycobacterium gordonae and dominant epitope of E2 subunit of pyruvate dehydrogenase is common in Spanish but not British patients with primary biliary cirrhosis

Previous studies on Spanish patients with Primary Biliary Cirrhosis (PBC) have shown extensive, disease-specific cross-reactivity between the 65-kDa heat shock protein (hsp65) of Mycobacterium gordonae and pyruvate dehydrogenase complex-E2 (PDC-E2), the major target of anti-mitochondrial antibody (AMA). Studies on a British population were unable to substantiate these findings. Having found that there is an excellent and almost unique match between the PDC-E2 autoepitope and a sequence in mycobacterial hsp65s, we tested the corresponding peptides by ELISA for cross-reactivity using sera from 90 PBC patients, 40 Spanish and 50 British, and 84 pathological controls. Reactivity to the MYCGO hsp65(90-104)/human PDC-E2(212-226)pair was present in 19 (47.5%) Spanish PBC patients and in 2 (4%) of the 50 British. Reactivity was not seen in any of the controls. Simultaneous reactivity to mimics was due to cross-reactivity as confirmed by inhibition studies. Three dimensional modelling predicts mycobacterial hsp65(90-104)to be exposed on the surface of the protein. The affinity of anti-hsp65(90-104)antibody was higher than that of anti-PDC-E2(212-226). Hsp65(90-104)is a target of disease-specific cross-reactivity to PDC-E2(212-226). The geographical confinement of this phenomenon is probably the result of complex genetic, environmental and immunological interaction.

Peptide dendrimers: applications and synthesis

Peptide dendrimers are radial or wedge-like branched macromolecules consisting of a peptidyl branching core and/or covalently attached surface functional units. The multimeric nature of these constructs, the unambiguous composition and ease of production make this type of dendrimer well suited to various biotechnological and biochemical applications. Applications include use as biomedical diagnostic reagents, protein mimetics, anticancer and antiviral agents, vaccines and drug and gene delivery vehicles. This review focuses on the different types of peptide dendrimers currently in use and the synthetic methods commonly employed to generate peptide dendrimers ranging from stepwise solid-phase synthesis to chemoselective and orthogonal ligation.

Recent advances in multiple antigen peptides

The goals for the development of multiple antigen peptides (MAP) are to provide a rational and unambiguous system to multimerize different types of synthetic peptide antigens and to attach immunomodulating molecules for targeting and delivery. These goals have been largely realized and new designs of MAPs now permit a broad range of immune responses including CTLs and mucosal IgAs. Furthermore, significant advances by the inventiveness of many laboratories have led to applications of MAPs for serodiagnostic and other biochemical uses including those for drug discovery. An important aspect to accomplish various goals of MAPs is chemistry. New methodologies using unprotected peptides as building blocks have been developed to accommodate new and sophisticated design of MAPs. This review is written based on the personal perspective of my laboratory and will focus on the recent progress in MAPs, together with the chemistry to achieve their synthesis.

Dependence of the murine antibody response to an anti-CDR2 VH peptide on immunogen formulation

A peptide corresponding to the second complementarity determining region of the heavy chain (CDR2 VH) from a murine anti-CD4 monoclonal antibody, designated L202, was synthesized by solid phase methodology in a number of different antigenic forms, for the purpose of comparing the effectiveness of different adjuvant-carrier systems in the induction of a murine antibody response against the immunizing peptide and parent antibody molecule. Two of the synthetic constructs contained the palmitoyl and N-palmitoyl-cysteinyl-S-(2,3-palmitoyloxy)-propanediol (PAM3Cys) moieties, respectively, attached to the peptide amino terminus with the immunogen comprising liposomal formulations of each. A third immunogen consisted of the CDR2 VH peptide admixed with the PAM3Cys non-covalently and incorporated into liposomes (PAM3Cys + CDR2 VH). A fourth composition comprised the CDR2 VH peptide conjugated to KLH via the sulfhydryl of an added N terminal cysteine (KLH-CDR2 VH) and injected with Complete Freund's adjuvant (CFA). A fifth immunogen consisted of the CDR2 VH peptide synthesized on an octameric, branched polylysine core as a multiple antigenic peptide (MAP-CDR2 VH) injected in the presence of Freund's adjuvant. Groups of five mice were injected intramuscularly with each of these immunogens and bled at two week intervals. The highest anti-peptide gamma-immunoglobulin (IgG) responses (against uncoupled peptide by ELISA) after 56 days were obtained with mice receiving the PAM3Cys-CDR2 VH peptide. However, when screened against the CDR2 V(H) peptide present as the MAP derivative by ELISA, IgG raised against the cognate MAP-CDR2 peptide was much more reactive than IgG raised against the liposomal PAM3Cys-CDR2 VH immunogen. In either case, IgG raised against the KLH-CDR2VH conjugate was poorly reactive. These differences in reactivity to the two forms of the CDR2 VH peptide by ELISA did not correspond to major differences in reactivities to the intact L202 Ab by ELISA. Although the IgG against the MAP immunogen was slightly more reactive than the other antisera against the l202 Ab, all titers were less than 1:100. These data illustrate some limitations of using anti-peptide responses as indicators of potential reactivity against the native protein, but suggest that alternate formulations including lipoidal peptides are more effective than corresponding KLH-peptide conjugates in eliciting Ab responses against poorly immunogenic epitopes.