Cryptosporidium parvum is an obligate protozoan parasite responsible for the diarrheal illness
cryptosporidiosis in humans and animals. Although C. parvum is particularly pathogenic in immunocompromised hosts, the molecular mechanisms by which C. parvum invades the host epithelial cells are not well understood. Characterization of molecular-based antigenic targets of C. parvum is required to improve the specificity of detection, viability assessments, and
immunotherapy (treatment). A number of zoite surface (glyco)
proteins are known to be expressed during, and believed to be involved in, invasion and
infection of host epithelial cells. In the absence of protective treatments for this illness,
antibodies targeted against these zoite surface (glyco)
proteins offers a rational approach to
therapy. Monoclonal, polyclonal and recombinant
antibodies represent useful immunotherapeutic means of combating
infection, especially when highly immunogenic C. parvum
antigens are utilized as targets. Interruption of life cycle stages of this parasite via
antibodies that target critical surface-exposed
proteins can potentially decrease the severity of disease symptoms and subsequent
re-infection of host tissues. In addition, development of
vaccines to this parasite based on the same
antigens may be a valuable means of preventing
infection. This paper describes many of the zoite
surface glycoproteins potentially involved in
infection, as well as summarizes many of the immunotherapeutic studies completed to date. The identification and characterization of
antibodies that bind to C. parvum-specific
cell surface antigens of the oocyst and sporozoite will allow researchers to fully realize the potential of molecular-based
immunotherapy to this parasite.