Immunogenicity of the Recombinant Cryptococcus neoformans HSP70, a Potential Candidate for Developing an ELISA Kit

Cryptococcus neoformans is an encapsulated fungal pathogen that causes life-threatening meningoencephalitis in immunocompromised patients. This yeast secretes several potent immunogenic proteins by secretory vesicular mechanisms, such as HSP70 chaperone.

The PCR-amplified HSP70 gene was cloned into a PET-28a(+) expression vector. The purified recombinant HSP70  (rHSP70) was evaluated by western blotting using an anti-His Tag-HRP antibody and then used for immunization of a rabbit. The serum of the immunized rabbit was tested against the whole lysate of C. neoformans in ELISA.

The antibodies in the rabbit’s serum recognized lysate of C. neoformans yeast. The highest antibody levels were achieved after the third booster injection.

The rHSP70 showed to be a reliable candidate for the designing and development of an ELISA kit for early detection of cryptococcosis, and to screen a large number of specimens.