Therapeutic and diagnostic applications of exosomes in colorectal cancer.

Exosomes play a key role in colorectal cancer (CRC) related processes. This review explores the various functions of exosomes in CRC and their potential as diagnostic markers, therapeutic targets, and drug delivery vehicles. Exosomal long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) significantly influence CRC progression. Specific exosomal lncRNAs are linked to drug resistance and tumor growth, respectively, highlighting their therapeutic potential. Similarly, miRNAs like miR-21, miR-10b, and miR-92a-3p, carried by exosomes, contribute to chemotherapy resistance by altering signaling pathways and gene expression in CRC cells. The review also discusses exosomes' utility in CRC diagnosis. Exosomes from cancer cells have distinct molecular signatures compared to healthy cells, making them reliable biomarkers. Specific exosomal lncRNAs (e.g., CRNDE-h) and miRNAs (e.g., miR-17-92a) have shown effectiveness in early CRC detection and monitoring of treatment responses. Furthermore, exosomes show promise as vehicles for targeted drug delivery. The potential of mesenchymal stem cell (MSC)-derived exosomes in CRC treatment is also noted, with their role varying from promoting to inhibiting tumor progression. The application of multi-omics approaches to exosome research is highlighted, emphasizing the potential for discovering novel CRC biomarkers through comprehensive genomic, transcriptomic, proteomic, and metabolomic analyses. The review also explores the emerging field of exosome-based vaccines, which utilize exosomes' natural properties to elicit strong immune responses. In conclusion, exosomes represent a promising frontier in CRC research, offering new avenues for diagnosis, treatment, and prevention. Their unique properties and versatile functions underscore the need for continued investigation into their clinical applications and underlying mechanisms.

Antigenicity and immunogenicity of fused B-subunit of heat labile toxin of Escherichia coli and colonization factor antigen I polyepitopes.

Linear B-cell epitopes ((93)AKEFEAAAL(101) and (66)PQLTDVLN(73)) of CfaB were genetically fused to ltb-(gly)5-cfaB(1-25). Sera of rabbits immunized with fusion proteins reacted strongly with solid-phase bound ETEC bacteria bearing CFA/I fimbriae. Sera failed to agglutinate or inhibit hemagglutination promoted by CFA/I-positive strain which may be due to solvent inaccessibility of epitope residues on intact fimbriae.

Expression of Shigella flexneri ipaB Gene in Tobacco.

BACKGROUND: Shigellosis is a leading cause of diarrhea in many developing countries and although the disease can be controlled and managed with antibiotics, the constant emergence of resistant species requiring ever newer antibacterial drugs make development of an effective vaccine necessary. The bacteria are highly contagious and since immunity to Shigella is serotype-specific a multi-serotype vaccine is required for adequate protection. Proteins encoded by Shigella invasion plasmid, which are part of the Type Three Secretion System (TTSS) of this bacteria, are good candidate as vaccine targets since they are both immunogenic and conserved between different Shigella species. The advent of molecular farming, which is a low cost system, has opened up new venues for production of recombinant proteins. In view of the difficulties encountered in expressing IpaB in Escherichia coli (E. coli), the feasibility of the expression of this protein in tobacco has been investigated. METHODS: The ipaB gene was cloned in place of the Hygromycin gene in pCambia1304 containing GFP as a reporter gene. The vector was then transferred into competent Agrobacterium tumefaciens (A. tumefaciens) strain LBA4404 which was used for agro-infiltration of Nicotiana tobaccum (N. tobaccum) leaves. Transformation was confirmed by expression of GFP. The gene was also cloned in pBAD/geneIII A and transformed E. coli host containing the construct was induced using different amounts of L-arabinose as inducer. Expression of IpaB gene by both hosts was determined by Western blotting using anti-IpaB monoclonal antibody. RESULTS: The data obtained showed that IpaB was expressed in plant leaves but expression in E. coli was not detectable. CONCLUSION: This study showed that N. tobaccum is capable of expressing this protein without its specific chaperon and in levels detectable by Western blotting.