Development of Cryptosporidium parvum-induced gastrointestinal neoplasia in severe combined immunodeficiency (SCID) mice: severity of lesions is correlated with infection intensity.
We reported previously that Cryptosporidium parvum was able to induce intestinal tumors in severe combined immunodeficiency (SCID) mice treated with corticoids. To further characterize this Cryptosporidium-induced cell transformation, SCID mice treated with dexamethasone were challenged with C. parvum oocysts, and euthanatized sequentially after infection for histologic examination. Ki-67 was used as a marker of cellular proliferation. Our previous results were confirmed, and it was also found that mice receiving higher inocula (10(6)-10(7)) experienced more severe neoplastic development. Additionally, neoplastic changes were observed not only in the caecum but also in the stomach and duodenum of some animals. Interestingly, SCID mice (6/6) inoculated with 10(5)-10(7) oocysts showed high grade intraepithelial neoplasia or adenomas with high grade dysplasia in the caecum after Day 46 post-infection (PI). Immunohistochemistry for Ki-67 staining indicated the neoplastic process associated to cryptosporidiosis, and evidenced the first immunohistochemical alterations at early stages of the process, even at 3 weeks PI.
Ecologie du Parasitisme (EA3609 Université de Lille 2), IFR 142, Institut Pasteur de Lille, Lille, France. gabriela.certad@pasteur-lille.fr
Gabriela
G
Certad
Colette
C
Creusy
Tramy
T
Ngouanesavanh
Karine
K
Guyot
Nausicaa
N
Gantois
Anthony
A
Mouray
Thierry
T
Chassat
Nicolas
N
Flament
Laurence
L
Fleurisse
Anthony
A
Pinon
Laurence
L
Delhaes
Eduardo
E
Dei-Cas
D000818:Animals; D003457:Cryptosporidiosis / Q000150:complications* / Q000469:parasitology; D016785:Cryptosporidium parvum; D003907:Dexamethasone / Q000494:pharmacology; D005770:Gastrointestinal Neoplasms / Q000150:complications* / Q000469:parasitology; D005786:Gene Expression Regulation; D007166:Immunosuppressive Agents / Q000494:pharmacology; D019394:Ki-67 Antigen / Q000378:metabolism; D051379:Mice; D016513:Mice, SCID
D007166:Immunosuppressive Agents; D019394:Ki-67 Antigen; C498355:Mki67 protein, mouse; D003907:Dexamethasone