Rickettsia endosymbionts are bacteria that live inside the cells of arthropods, including ticks. These endosymbionts are not pathogenic to their arthropod hosts but can have significant effects on the transmission of other tick-borne pathogens, including human pathogens such as Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever.

One key antigen expressed by Rickettsia endosymbionts is the 17 kDa surface antigen. This protein is found on the surface of the bacteria and is thought to play a role in the interaction between Rickettsia endosymbionts and their arthropod hosts. The 17 kDa surface antigen has also been proposed as a potential target for the development of vaccines to prevent tick-borne diseases.

Another key antigen associated with Rickettsia endosymbionts is the Ixodes scapularis surface antigen (ISSA). This antigen is expressed on the surface of tick cells and is thought to be involved in the interaction between Rickettsia endosymbionts and their tick hosts. ISSA has been shown to elicit an immune response in mice, suggesting that it may be a potential target for the development of vaccines or other therapeutics to prevent tick-borne diseases.

The application of Rickettsia endosymbiont cDNA and recombinant antigen can be used to identify and characterize different strains of Rickettsia, which can be used in the development of diagnostic assays, vaccine development, and strain-specific epidemiological analyses. The cDNA and antigen can also be used to identify and characterize novel proteins and gene products involved in the pathogenesis of Rickettsia infections, which can then be used to develop new strategies to control these infections.

The use of recombinant proteins/cDNA in academic research and therapeutic applications has skyrocketed. However, in heterologous expression systems, successful recombinant protein expression is dependent on a variety of factors, including codon preference, RNA secondary structure, and GC content. When compared to pre-optimization, more and more experimental results demonstrated that the expression level was dramatically increased, ranging from two to hundred times depending on the gene. Bioclone has created a proprietary technology platform that has resulted in the creation of over 6,000 artificially synthesized codon-optimized cDNA clones (cloned in E. coli expression Vector), which are ready for production of the recombinant proteins.