Experimental infection of immunocompetent and immunodeficient mice with Encephalitozoon cuniculi

Abstract

Abstract. An experimental infection with the microsporidian Encephalitozoon cuniculi Levaditi, Nicolau et Schoen, 1923 was studied using a model of immunocompetent BALB/c mice and immunodeficient SCID mice. The course of infection after intraperitoneal inoculation of E. cuniculi spores was evaluated using the presence of spores in peritoneal macrophages as a criterion. First significant decrease in the proportion of infected cells was recorded on day 9 post infection (p.i.) in BALB/c mice. From day 14 p.i. no spores were observed in macrophages from BALB/c mice, while the number of infected macrophages from SCID mice increased until the death of the mice. The natural killer (NK) cell activity of mouse splenocytes was compared with the production of interferon gamma (IFN-γ ) by these cells. While in BALB/c mice NK activity peaked on days 9 and 14 p.i., in SCID mice the marked increase of NK activity was recorded close before death of mice, on day 21 p.i. in correlation with the production of IFN-γ. Production of specific antibodies was demonstrated from day 9 p.i. in sera from BALB/c mice. It is concluded that intraperitoneal infection of SCID mice with spores of E. cuniculi results in the marked increase in the number of peritoneal exudate cells and in the percentage of infected cells close before death of mice. Neither high activity of NK cells nor increased production of IFN-γ are sufficient for the recovery of SCID mice from an E. cuniculi infection.

Encephalitozoon cuniculi Genotype III Evinces a Resistance to Albendazole Treatment in both Immunodeficient and Immunocompetent Mice

“…The results of the present study confirmed the hypothesis concerning variations in pathology and albendazole resistance of different genotypes of Encephalitozoon that had previously been suggested (11,12,39,40). Although there was a disappearance of E. cuniculi genotype III from many organs during the next several weeks after 20 mg albendazole treatment, the number of positive-testing organs seen in the chronic stage of infection was much higher than that seen under conditions of chronic infection caused by E. cuniculi genotype II after treatment with 0.2 mg, mainly in C57BL/6 mice and derived knockouts (10,12).…”

Efecto de la ciclosporina A en ratones C57BL/6 infectados con Encephalitozoon intestinalis.

“…Lo anterior indica que los ratones inmunosuprimidos e infectados, a pesar de tener una alteración en la respuesta inmune mediada por LT, fueron capaces de controlar la infección, quizá mediante una respuesta inmune innata que fue eficaz en la eliminación del parásito, como ha sido reportado en otras investigaciones realizadas con E. cuniculi (14,17). Además, la respuesta generada por el tejido linfoide asociado a la mucosa intestinal (placas de Peyer, ganglios linfáticos mesentéricos, lámina propia) puede haber contribuido al control del parásito, a la manera de una respuesta inmune local que puede extenderse por todo el sistema o a otras mucosas.…”

“…Se ha reportado que la inmunidad mediada por linfocitos T (LT) juega un papel importante en la defensa de la infección con microsporidios; algunos autores señalan que la respuesta inmune del hospedero contra estos parásitos es del tipo Th1 con producción de IL-2 e INFγ (8)(9)(10)(11)(12)(13)(14)(15)(16)(17).…”

Infectious microorganisms in mice (Mus musculus) purchased from commercial pet shops in Germany

“…14–18 Infections with this parasite trigger humoral and cellular immune responses of the hosts, thereby significantly altering their respective immune parameters. 31,32 Hence, they have the potential to compromise the interpretation of scientific experiments considerably and should be avoided.…”