Interferon-gamma expression in jejunal biopsies in experimental human cryptosporidiosis correlates with prior sensitization and control of oocyst excretion.
To investigate the role of interferon (IFN)-gamma in human cryptosporidiosis, jejunal biopsies from experimentally infected volunteers and chronically infected AIDS patients were examined for IFN-gamma expression by in situ hybridization. IFN-gamma expression was compared with oocyst excretion, baseline serum anti-Cryptosporidium antibody, and symptoms. IFN-gamma mRNA was detected in biopsies from 13 of 26 volunteers after experimental infection but not in biopsies taken before C. parvum exposure or in biopsies from patients with AIDS-associated cryptosporidiosis. After challenge, 9 of 10 volunteers with baseline C. parvum antibody produced IFN-gamma, compared with 4 of 16 volunteers without baseline antibody (P<.01). Furthermore, IFN-gamma mRNA was detected in 9 of 13 volunteers who did not excrete oocysts, compared with 4 of 13 with organisms (P<.05). Thus, expression of IFN-gamma in the jejunum was associated with prior sensitization and absence of oocyst shedding. IFN-gamma production may explain the resistance to infection noted in sensitized persons but may not be involved in control of human primary infection.
White
A C
AC
Infectious Diseases Section, Dept. of Medicine, Baylor College of Medicine, Houston, TX 77030. arthurw@bcm.tmc.edu
Robinson
P
P
Okhuysen
P C
PC
Lewis
D E
DE
Shahab
I
I
Lahoti
S
S
DuPont
H L
HL
Chappell
C L
CL
D017088:AIDS-Related Opportunistic Infections / Q000276:immunology / Q000469:parasitology; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D001706:Biopsy; D003457:Cryptosporidiosis / Q000276:immunology* / Q000469:parasitology* / Q000473:pathology; D016785:Cryptosporidium parvum / Q000254:growth & development / Q000276:immunology*; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007371:Interferon-gamma / Q000096:biosynthesis* / Q000235:genetics; D007583:Jejunum / Q000276:immunology* / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism
D000913:Antibodies, Protozoan; D016207:Cytokines; D012333:RNA, Messenger; D007371:Interferon-gamma