title: Rv1268c protein peptide inhibiting Mycobacterium tuberculosis H37Rv entry to target cells.
abstract: Tuberculosis (TB) remains one of the most worrying infectious diseases affecting public health around the world; 8.7 million new TB cases were reported in 2011. The search for an Mycobacterium tuberculosis H37Rv protein sequence which is functionally important in host-pathogen interaction has been proposed for developing a new vaccine which will allow efficient and safe control of the spread of this disease. The present study thus reports the results obtained for the Rv1268c protein described in the M. tuberculosis H37Rv genome as a hypothetical unknown, probably secreted, protein based on a highly robust, specific, sensitive and functional approach to the search for potential epitopes to be included in an anti-tuberculosis vaccine. Rv1268c presence was determined by immunoblotting after obtaining polyclonal sera against mycobacterial total sonicate or subcellular fractions. Such sera were used in electron immunomicroscopy (EIM) for confirming protein localisation on the M. tuberculosis envelop by recognising colloidal gold-labelled immunoglobulin. Screening assays revealed the presence of two sequences having high binding activity: one binding A549 alveolar epithelial cells ((141)TGMAALEQYLGSGHAVIVSI(160)) and other binding U937 monocyte-derived macrophages ((21)AVALGLASPADAAAGTMYGD(40)). Such sequences' ability to inhibit mycobacterial entry during in vitro assays was analysed. The structure of synthetic peptides binding to target cells was also determined, bearing in mind the structure-function relationship. These results, together with those obtained for other proteins, have been involved in selecting peptides which might be included in a subunit-based anti-tuberculosis vaccine.
authors.affiliation: Fundacion Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26-20, Bogotá, Colombia; Universidad del Rosario, Carrera 24 No. 63C-69, Bogotá, Colombia. Electronic address: marisol.ocampo@urosario.edu.co.
authors.forename: Marisol
authors.initials: M
authors.lastname: Ocampo
authors.forename: Deisy Carolina
authors.initials: DC
authors.lastname: Rodríguez
authors.forename: Jorge
authors.initials: J
authors.lastname: Rodríguez
authors.forename: Maritza
authors.initials: M
authors.lastname: Bermúdez
authors.forename: Claudia Marina
authors.initials: CM
authors.lastname: Muñoz
authors.forename: Manuel Alfonso
authors.initials: MA
authors.lastname: Patarroyo
authors.forename: Manuel Elkin
authors.initials: ME
authors.lastname: Patarroyo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D045744:Cell Line, Tumor; D002942:Circular Dichroism; D006046:Gold / Q000737:chemistry; D054884:Host-Pathogen Interactions; D006801:Humans; D007136:Immunoglobulins / Q000276:immunology; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000502:physiology*; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000276:immunology; D011817:Rabbits; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology
chemical_list: D001426:Bacterial Proteins; D007136:Immunoglobulins; D010455:Peptides; D011994:Recombinant Proteins; D006046:Gold
keywords: Anti-tuberculosis vaccine; Entry inhibition; Receptor–ligand interaction; Rv1268c; Sub-cellular localization; Synthetic peptides; Target cell