Overexpression, Purification, and Immunogenicity of Recombinant Porin Proteins of Salmonella enterica Serovar Typhi (S. Typhi)

Abstract

Porin proteins of Gram-negative bacteria are outer membrane proteins that act as receptors for bacteriophages and are involved in a variety of functions like solute transport, pathogenesis, and immunity. Salmonella enterica serovar Typhi (S. Typhi), a Gram-negative bacterium, is the causative agent of typhoid fever. Porins of S. Typhi have been shown to have a potential role in diagnostics and vaccination. In the present study, the major outer membrane proteins OmpF and OmpC from S. Typhi were cloned in pQE30UA vector and expressed in E. coli. The immunogenic nature of the recombinant porin proteins were evaluated by ELISA by raising hyperimmune sera in Swiss Albino mice with three different adjuvants (i.e., Freund's adjuvant and two human-compatible adjuvants like montanide and aluminium hydroxide gel) and proved to be immunogenic. The recombinant OmpF and OmpC generated in this work may be used for further studies for vaccination and diagnostics.

Cloning, Sequencing and In Silico Characterization of OmpF Protein of Salmonella typhimurium for its Immune-Potential

“…It has been previously reported that, OmpF protein is resistant to high temperature and denaturing agents and preferably expressing at low osmolar conditions (Verma et al, 2009 (47-50, 83-86, 127-130, 258-261, 263-266), single tyrosine kinase phosphorylation site (52-58), N-myristoylation site at nine locations (104-109, 141-146, 154-159, 166-171, 172-175, 194-199, 207-212, 288-293, 305-310), three protein kinase phosphorylation sites (150-152, 158-160, 215-217) and N-glycosylation sites at three locations (184-187, 156-259, 272-275). Antigenic characterization of translated protein sequence was done by VaxiJen v2.0 antigen prediction server (Doytchinova and Flower, 2007) and OmpF protein was found to be antigenic in nature with an overall antigen prediction score of 0.85.…”

Peptides representing the specific variable regions but not the full porin proteins can be useful for antibody based diagnosis of typhoid fever

“…The recombinant OmpC (rOmpC) and recombinant OmpF (rOmpF) were prepared according to Verma et al (2009). The ompC and ompF genes were amplified by PCR and cloned in pQEUA vector.…”

Heterogeneous expression and functional evaluation of in silico characterized recombinant OmpC of Salmonella Typhimurium as a functional poultry vaccine to eradicate zoonotic transmission

“…It was found that OmpC of S. Typhimurium folds in a similar way as OmpF of E. coli and OmpC of S. Typhi (Arockiasamy et al, 2004b;Kumar and Krishnaswamy, 2005). The expression of OmpC during infection (Puente et al, 1989;Verma et al, 2009) and its capacity to display heterologous epitopes on the cell surface (Puente et al, 1995) make it an important candidate antigen with potential applications in immunology and vaccine design. Studies using Salmonella porin specific monoclonal antibodies (Muthukkaruppan et al, 1992) showed that S. Typhi OmpC is the major surface antigen with unique exposed epitopes.…”

“…Maximum survival was seen in the animals immunized with 49 kDa protein (100%), followed by 37 kDa (66.7%), 33 kDa (50%) and 15kDa (33.3%) (Hamid and Jain, 2008). Verma et al (2009) evaluated the immunogenicity of the recombinant porins, in Swiss albino mice with three different adjuvants. In contrast to OmpF, the high titer (p < 0.05) of recombinant OmpCspecific IgG antibody was observed in mice immunized with aluminium hydroxide gel followed by Freund's adjuvant and montanide.…”

“…al., 2006). The immunogenic potential was earlier studied and it was observed to be imunodominant and thermostable protein (Verma et al, 2009;Jailkhani et al, 2007). Hence, OmpC is considered as a potential candidate for the development of a subunit vaccine against Salmonellosis (Prejit et al, 2013).…”