Sex hormone changes induced by the parasite lead to feminization of the male host in murine Taenia crassiceps cysticercosis

Larralde, Carlos; Morales, J.; Terrazas, Luis I.; Govezensky, Tzipe; Romano, M.C.

doi:10.1016/0960-0760(95)00062-5

Cited by 144 publications

(149 citation statements)

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“…Concomitantly, infected male mice progressively decrease their normal sexual behavior, loosing first the ejaculation response, then the intromission response, and finally, at 16 wk of infection, the mount response is totally abolished (20). Because sexual behavior is completely restored after testosterone or dihydrotestosterone restitution of parasitized mice, the disturbances in sexual behavior observed have been related to the high estradiol and low androgens levels detected (19,20). The changes in steroid production and sexual behavior are also associated with tissue damage in the reproductive system (21) together with a specific change in mRNA levels for the enzymes involved in normal male steroid metabolism: a decrease in the expression of 5␣-reductase (the enzyme in charge of the conversion from testosterone to dihydrotestosterone (DHT) 3 ) and an increase in the expression of aromatase (which is responsible for the conversion from testosterone to estradiol) (22).…”

mentioning

confidence: 95%

“…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). Concomitantly, infected male mice progressively decrease their normal sexual behavior, loosing first the ejaculation response, then the intromission response, and finally, at 16 wk of infection, the mount response is totally abolished (20).…”

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confidence: 99%

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

Morales‐Montor

Baig

Mitchell

et al. 2001

The Journal of Immunology

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Taenia crassiceps cysticercosis results in an impressive feminization in male mice during chronic infection, characterized by increased serum estradiol levels 100 times their normal values, while those of testosterone and dihydrotestosterone are decreased by 85 and 95% respectively. Concomitantly, the levels of follicle-stimulating hormone and IL-6 are increased 70 and 90 times their normal values in the infected male mice. Since a specific Th1/Th2 shift of the immune response has been previously reported during the chronic infection, and this shift may be associated with the feminization process, we proposed that this shift is induced by immunoendocrine interactions during the disease, and this gives way to a change in the initial resistance to the infection in the male mice, which become as susceptible as female mice. To confirm this hypothesis, we depleted immune system activity in two different ways: total body irradiation and neonatal thymectomy. Our results show that when immune system activity is depleted using either strategy, the male mice do not feminize, and the levels of follicle-stimulating hormone and IL-6 are inhibited. Depletion of IL-6 using IL-6−/− knockout mice does not produce the feminization process stated above, while restitution of the IL-6−/− knockout, irradiated, and thymectomized mice with murine recombinant IL-6 restores the feminization process. Expression of the IL-6 gene was found only in the testes and spleen of infected animals. Our results illustrate the importance of immunoendocrine interactions during a parasitic disease and show a possible new mechanism of parasite establishment in an initially resistant host.

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confidence: 95%

mentioning

confidence: 99%

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

Morales‐Montor

Baig

Mitchell

et al. 2001

The Journal of Immunology

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“…Infection with viruses, including rabies virus and hantaviruses, increases aggression and, presumably, transmission within host populations (Klein, 2003). Parasites may alter the behavior of vertebrates by infecting and killing neurons in the brain (Dietzschold et al, 2001), altering neurotransmission (Ceccaldi, et al, 1993;Lancaster et al, 2007), or influencing the synthesis of steroids in peripheral organs (Larralde et al, 1995).…”

Section: Introductionmentioning

confidence: 99%

Elevated testosterone and reduced 5-HIAA concentrations are associated with wounding and hantavirus infection in male Norway rats

Easterbrook

Kaplan

Glass

et al. 2007

Hormones and Behavior

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Among rodents that carry hantaviruses, males are more likely to engage in aggression and to be infected than females. One mode of hantavirus transmission is via the passage of virus in saliva during wounding. The extent to which hantaviruses cause physiological changes in their rodent host that increase aggression and, therefore, virus transmission has not been fully documented. To assess whether steroid hormones and neurotransmitters contribute to the correlation between aggression and Seoul virus infection, Norway rats were trapped in Baltimore, Maryland and wounding, infection status, steroid hormones, and concentrations of neurotransmitters, including norepinephrine (NE), dopamine (DA), 3,4-dihydroxyphenol acetic acid (DOPAC), serotonin (5-HT), and 5-hydroxyindole-3-acetic acid (5-HIAA) in select brain regions were examined. Older males and males with high-grade wounds were more likely to have anti-Seoul virus IgG and viral RNA in organs than either juveniles or adult males with less severe wounds. Wounded males had higher circulating testosterone, lower hypothalamic 5-HIAA, and lower NE in the amygdala than males with no wounds. Infected males had higher concentrations of testosterone, corticosterone, NE in the hypothalamus, and DOPAC in the amygdala than uninfected males, regardless of wounding status. In the present study, wounded males that were infected with Seoul virus had elevated testosterone and reduced 5-HIAA concentrations, suggesting that these neuroendocrine mechanisms may contribute to aggression and the likelihood of transmission of hantavirus in natural populations of male Norway rats.

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“…The target organs for testosterone action, testes and seminal vesicles, have a 50% weight reduction (Larralde et al, 1995). At the same time, the cellular immune response (Th1) is markedly diminished in both sexes, and the humoral (Th2) response is enhanced (Terrazas et al, 1998).…”

Section: Role Of Sex Steroids In Cysticercosismentioning

confidence: 98%

“…Gonadectomy alters this resistance pattern and makes intensities equal in both sexes by increasing that of males and diminishing it in females (Huerta et al, 1992), whilst the serum sex steroids level are not detectable in these animals. However, the absence of estrogens does not prevent parasite growth in both genders, demonstrating that although estradiol favours Taenia crassiceps development, it is not indispensable for rapid parasite growth (Larralde et al, 1995).…”

Section: Role Of Sex Steroids In Cysticercosismentioning

confidence: 99%

The Role of Sex Steroids in the Host-Parasite Interaction

Nava-Castro¹,

Hernández-Bello²,

Muñiz-Hernández³

et al. 2012

Sex Steroids

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Sex hormone changes induced by the parasite lead to feminization of the male host in murine Taenia crassiceps cysticercosis

Cited by 144 publications

References 22 publications

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

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

Elevated testosterone and reduced 5-HIAA concentrations are associated with wounding and hantavirus infection in male Norway rats

The Role of Sex Steroids in the Host-Parasite Interaction

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