MurineTaenia crassiceps cysticercosis: H-2 complex and sex influence on susceptibility

Abstract

Several inbred strains of mice were infected by intraperitoneal injection of ten Taenia crassiceps cysticerci per mouse. Genes linked with the major histocompatibility complex (H-2) were found to influence parasite growth greatly, as demonstrated by the different parasite loads of H-2 congenic mice with BALB background: BALB/c (H-2d) mice were the most susceptible, whereas BALB/k (H-2k) and BALB/b (H-2b) animals were comparatively resistant. Non-H-2 genes had no significant effect on susceptibility in H-2d strains, as reflected by the similar parasite loads in BALB/c, DBA/2, and (BALB/c x DBA/2)F1 mice. Using the H-2b (BALB/b, C57BL/6J) and H-2k (C3H/HeJ, BALB/k, and C3HeB/FeJ) strains, we found that non-H-2 background genes caused a small but significant influence on parasite load. A recombinant mouse strain alleles (Kk, Ik, Sd, Dd) was also susceptible, indicating that S and/or D regions of the H-2d complex are probably involved in the control of resistance to murine cysticercosis. Females of all mouse strains were more susceptible than males. The same effects were observed for H-2 genes and sex, with two strains of T. crassiceps differing in their rate of growth.

Immunoendocrine Interactions During Chronic Cysticercosis Determine Male Mouse Feminization: Role of IL-6

“…LH and FSH were extracted and concentrated from mouse sera using a C 18 Sep-Pak equilibrated column (Advanced ChemTech, Louisville, KY). After injection into the column, the samples were eluted using 3 ml HPLC grade 0.1% trifluoroacetic acid (Baker, Phillipsburg, NJ) diluted in HPLC grade water (Baker).…”

“…Particularly, during T. crassiceps cysticercosis, females of all strains of mice studied sustain larger intensities of infection than males (18), but during chronic infection (Ͼ4 wk) these differences disappear, and the males of BALB/c AnN strain show a feminization process characterized by high serum estradiol levels (200 times their normal values), while those of testosterone are 90% decreased (19). Gonads are required for the increased estradiol synthesis, because gonadectomized and infected male mice had no detectable changes in blood levels of these hormones (19).…”

Taenia crassiceps cysticercosis: immune response in susceptible and resistant BALB/c mouse substrains

“…cdT cells, on the other hand, seem to play a less important role in controlling the infection (Toenjes et al 1999;Lo´pez-Briones et al 2001). In addition, host susceptibility and the intensity of the infection depend on a combination of additional factors such as genetic makeup (Sciutto et al 1991;Fragoso et al, 1996) and gender (Culbreth et al 1972;Larralde et al 1995). The importance of the genetic background is more apparent at the initial stages of the infection; some strains show high susceptibility whereas others are comparatively resistant (Sciutto et al 1991;Fragoso et al 1996).…”

“…Recently, it was shown that STAT6 )/) mice, unable to develop a Th2 response, efficiently control parasite growth (Rodriguez-Sosa et al 2002). In addition, the absence of either CD4 + or TCRab T cells greatly increases host susceptibility in terms of parasite load and leads to the death of knockout mice (Lo´pez-Briones et al 2001), an outcome of infection that has not been observed in wild-type mice (Sciutto et al 1991;Fragoso et al 1996). cdT cells, on the other hand, seem to play a less important role in controlling the infection (Toenjes et al 1999;Lo´pez-Briones et al 2001).…”

Feminization and reduction of testicular weight in mouse sparganosis

“…The endocrine system of the host's gender is of great consequence for the rate of reproduction of some parasites. For example, T. crassiceps-infected females carry larger parasite loads than males in early infection, but males also become massively parasitized in very chronic infections (Sciutto et al, 1991). Some findings are suggestive of estrogen-mediated immunoendocrinological modulation in favor of Th2-mediated immune responses (humoral responses) and depression of Th1 type immunity (cellular responses) in T. crassiceps infection (Terrazas et al, 1994).…”