Systemic antibody responses to the immunodominant p23 antigen and p23 polymorphisms in children with cryptosporidiosis in Bangladesh.
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.
Division of Geographic Medicine and Infectious Disease, Tufts Medical Center, Boston, Massachusetts 02111, USA. anoli.borad@yale.edu
Anoli J
AJ
Borad
Geneve M
GM
Allison
David
D
Wang
Sabeena
S
Ahmed
Mohammad M
MM
Karim
Anne V
AV
Kane
Joy
J
Moy
Patricia L
PL
Hibberd
Sitara Swarna Rao
SS
Ajjampur
Gagandeep
G
Kang
Stephen B
SB
Calderwood
Edward T
ET
Ryan
Elena
E
Naumova
Wasif A
WA
Khan
Honorine D
HD
Ward
D000208:Acute Disease; D000293:Adolescent; D000595:Amino Acid Sequence; D000913:Antibodies, Protozoan / Q000097:blood*; D000917:Antibody Formation; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology*; D001459:Bangladesh / Q000453:epidemiology; D016022:Case-Control Studies; D002648:Child; D003457:Cryptosporidiosis / Q000453:epidemiology / Q000276:immunology*; D003458:Cryptosporidium / Q000472:pathogenicity; D016785:Cryptosporidium parvum / Q000472:pathogenicity; D003967:Diarrhea / Q000150:complications / Q000276:immunology / Q000469:parasitology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016056:Immunodominant Epitopes / Q000276:immunology*; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008969:Molecular Sequence Data; D020641:Polymorphism, Single Nucleotide; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D016415:Sequence Alignment / Q000379:methods; D017422:Sequence Analysis, DNA
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D016056:Immunodominant Epitopes; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011994:Recombinant Proteins