Recombinant EV71 VP0 [His, GST]

Enterovirus 71 (EV71) belongs to the genus enterovirus in the family Picornaviridae, which is highly contagious and can be transmitted through feces, saliva, and respiratory droplets. Humans are the only known host of natural origin. EV71 infections cause patients to develop herpes pharyngitis, hand-foot-mouth disease (HFMD), etc., and are highly lethal and disabling. Because EV71 is highly neurophilic, it can cause central nervous system infections in patients, including aseptic meningitis, acute flaccid paralysis, and brainstem encephalitis.

EV71 is a virus without protrusion and envelope, with a complex capsid structure that includes four protein structures. Three of them (VP1-VP3) are exposed on the surface of the virus, and the other (VP4) is closely attached to the core on the inside of the viral particle, so that the antigen of this virus depends on VP1-VP3. The internal genome is a single-stranded positive-stranded RNA rich in guanine and adenine nucleotides. EV71 single-stranded RNA is invasive, but breaking its 3-terminal PolyA leads to loss of invasiveness.

Figure 1. EV71 virion and genome structure
(Source: Solomon T, et al. 2010)

After EV71 invades the body, if the body fails to produce enough antibodies to clear the virus, the virus circulates in the bloodstream leading to the first viremia. In immunocompromised humans, EV71 invades target organs such as lymph nodes, liver, spleen, and bone marrow, circulates through the bloodstream, and triggers serious lesions. EV71 also causes brain tissue lesions, and researchers hypothesize that the virus may involve the central nervous system through the reverse axonal transport pathway. Viral infection stimulates the body's immune response and releases a variety of cytokines, causing a systemic inflammatory response that leads to multiple organ failure. The development of prophylactic vaccines is the most effective way to control EV71 infections, and inactivated EV71 vaccination has significantly reduced the trend of HFMD. Inactivated EV71 vaccines are usually selected as vaccine candidates from highly virulent strains with good immunogenicity and genetic stability, and are cross-protective in animal studies. Inactivated vaccines currently in the clinic use aluminum as a vaccine adjuvant, which enhances the immunogenicity of the vaccine.

Enterovirus 71 VP0