Systemic Antibody Responses to the Immunodominant p23 Antigen and p23 Polymorphisms in Children with Cryptosporidiosis in Bangladesh

Abstract

Abstract. Cryptosporidium is a major cause of diarrhea in children in developing countries. However, there is no vaccine available and little is known about immune responses to protective antigens. We investigated antibody responses to p23, a putative vaccine candidate, in children in Bangladesh with cryptosporidiosis and diarrhea (cases) and uninfected children with diarrhea (controls), and p23 gene polymorphisms in infecting species. Serum IgM, IgG, and IgA responses to p23 were significantly greater in cases than controls after three weeks of follow-up. Cases with acute diarrhea had significantly greater serum IgA and IgM responses than those with persistent diarrhea, which suggested an association with protection from prolonged disease. The p23 sequences were relatively conserved among infecting species and subtype families. Although most children were infected with Cryptosporidium hominis, there was a cross-reactive antibody response to C. parvum antigen. These results support further development of p23 as a vaccine candidate.

Cryptosporidiosis in HIV/AIDS Patients in Kenya: Clinical Features, Epidemiology, Molecular Characterization and Antibody Responses

“…35 It is therefore interesting to note that responses to the homotypic antigen were associated with protection from diarrhea. Antibody responses to the Cp23 antigen, which is highly conserved among C. parvum or C. hominis isolates, 36,66 were also associated with protection from diarrhea.…”

“…33 Serum enzyme-linked immunosorbent assays (ELISA). Serum immunoglobulin G (IgG) and IgM responses to Cryptosporidium antigens were assessed by ELISA as previously described [34][35][36] ; briefly, 96-well plates were coated overnight at 4 C with 0.5 μg/well of the following recombinant (r) C. parvum (Cp) and C. hominis (Ch) antigens in phosphate buffered saline (PBS): rCp23, rChgp15, rCpgp15, rChgp40, rCpgp40, or control antigen. Plates were washed three times with PBS, pH 7.2, containing 0.05% Tween 20 (PBST) and blocked with 0.25% bovine serum albumin (BSA) in PBS (BSA/PBS) for 2 hours at 37 C. Sera diluted 1:100 in 0.25% BSA/PBS were added to the wells and the plates incubated for 1 hour at 37 C, followed by washing three times with PBST.…”

Rapid microfluidic immunoassay for surveillance and diagnosis of Cryptosporidium infection in human immunodeficiency virus-infected patients

“…[9][10][11][12] In some immunoassays, P23 (also known as Cp23, p27, or 27-kDa antigen) was used as a captured antigen, which is a major target of antibody responses elicited by infective stages of the parasite, and many studies have verified its value in epidemiologic studies of C. parvum infections. 11,13,14 However, immunoassays such as Western blotting and ELISA are always the drawbacks for the relatively time and labor-intensive protocols which require highly skilled operators. Recently, microfluidic system which manipulates small volumes of fluids within microscale channels has been demonstrated as an efficient detection platform for rapid and automatic diagnosis of samples.…”

Avaliação clínica, sorológica e parasitológica de serpentes naturalmente infectadas com Cryptosporidium serpentis

“…Durante o curso da criptosporidiose em serpentes é comum a intermitência e variação na quantidade de oocistos eliminados em amostras fecais (GRACZYK et al, 1996b; Mesmo que haja reatividade cruzada no ELISA indireto, devido à existência antígenos comuns entre diferentes espécies de Cryptosporidium (GRACZYK et al, 1996a;ALLISON et al, 2011;TEIXEIRA et al, 2011;BORAD et al, 2012), a probabilidade dos anticorpos detectados pelo ELISA indireto serem produzidos contra outra espécie que não seja C. serpentis é pouco provável. Infecção por…”

“…Métodos sorológicos não são comumente utilizados para diagnóstico de criptosporidiose, pois mesmo com utilização de antígenos pouco conservados um resultado positivo indica somente exposição ao gênero Cryptosporidium ou a espécies muito próximas geneticamente, já que há antígenos comuns entre diferentes espécies do parasito (GRACZYK et al, 1996a;ALLISON et al, 2011;TEIXEIRA et al, 2011;BORAD et al, 2012). Além disso, os anticorpos contra Cryptosporidium podem persistir por mais de 12 meses pós-infecção (O´DONOGHUE, 1995).…”