Download The Immune Response to the Hypervariable Domain of

Poster No. 21
Title:
The Immune Response to the Hypervariable Domain of Cryptosporidium Glycoprotein gp40
Authors:
Adam Baghban, Roberta O’Connor, Honorine Ward
Presented by:
Adam Baghban
Department:
Division of Geographic Medicine and Infectious Disease, Tufts Medical Center
Abstract:
Cryptosporidium is a genus of protozoan intestinal parasites which are prevalent worldwide. Cryptosporidium
parvum and Cryptosporidium hominis are the species which most commonly infect humans. In
immunocompetent hosts, Cryptosporidium infection is often asymptomatic or self limiting.
In contrast,
Cryptosporidium infection in immunocompromised patients such as those with AIDS, and in malnourished
children, may result in serious and life-threatening diarrheal disease.
There is currently no vaccine for
Cryptosporidium and treatment options are limited. The Cryptosporidium glcyoprotein gp40 is important in the
interaction between the parasite and host epithelial cells. However, there are extensive polymorphisms in the
amino acid sequence of gp40 among Cryptosporidium parvum and Cryptosporidium hominis isolates, possibly
because of selective immune pressure. In order to develop an assay to study the antibody response to the
hypervariable domains of gp40 from both species, primers specific to this domain from C. hominis subtype IA
and C. parvum subtype II were designed. Following PCR amplification from genomic DNA, these sequences
were cloned into the pET 46 vector and expressed in E. coli BL21. Recombinant proteins were purified and
used as antigen in ELISA to detect antibody responses to gp40 in sera from Bangladeshi children who had acute
cryptosporidiosis. Initial results of such experiments showed that the antibody response to the hypervariable
domain of gp40 may occur across 2 species and subtypes. However, further experiments are necessary to
confirm these findings.
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