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The physiological interactions during the course of the immune response to helminthes are complex. As our understanding of the neuroendocrine system grows, it has become increasingly clear that this complex network of neurotransmitters, hormones, and cytokines plays an important role in mediating immunity, in general, but in the case of helminthes this interaction among different systems is crucial. Helminthes present a complex relationship in the host's physiological systems, with neuro and hormonally dependent host factors such as sex, age, and the host physiological status correlated with parasite success. On top of the effect that this particular type of parasites may have on the invaded host, recent experimental evidence suggest that helminth parasites not only actively evade immune response, but are also able to exploit the hormonal microenvironment within their host to favor their establishment, growth and reproduction. The close interaction of the worm with the host's homeostatic systems, the molecules produced by them, and the activation of immune mediated mechanisms to eliminate it, activate a complex neuroendocrine network, that produces strong behavioral changes in the infected host. Understanding how the host's neuroendocrine system can under certain circumstances favor the establishment of a parasitic infection opens interesting perspectives into the host parasite relationship field. This review focuses on the host-parasite neuroendocrine network activated by parasite worm infections. [ABSTRACT FROM AUTHOR]

Mast cells promote the release of cytokines that modify the functioning of various immune subpopulations. These are important in cancer because they have a dual effect in some neoplasms, since they act as protumoral or antitumor factors depending on their micolocalization. Recently, the role of hormonal receptors in these cells has been related to increased metastasis. With this project sought to evaluate the effect of two endocrine disruptors (Benzo [a] pyrene (BaP) and Benzo [a] anthracene (BaA)) on genotoxicity and apoptosis in a human mast cell line (HMC-1). The genotoxic effect was evaluated by the comet assay to observe DNA fragmentation at 1 hour of exposure. Cell death was evaluated in HMC-1 cells by the exposure to these PAH´s for 1 hour, 24 hours and 5 days. In the cell death assays, BaA was shown to have an effect on HMC-1 cells, while BaP showed no effect. In the genotoxicity assays with a higher concentration of BaA there is a higher frequency of comets and a higher percentage of flow intensity. The BaP at a higher concentration there is a lower frequency of comets and the percentage of flow intensity was the same in the four concentrations that we used. Therefore, BaP has no cell death effect on HMC-1 mast cells at 1 hour, 24 hours and 5 days at the concentrations used. On the other hand, BaA did not generate apoptosis at 1 hour and 24 hours, but after 5 days of treatment BaA generate apoptosis. [ABSTRACT FROM AUTHOR]

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En la actualidad, la contaminación ambiental es un serio problema que afecta a todo el mundo. Dentro de los distintos compuestos contaminantes del ambiente podemos encontrar agentes químicos, como el BPA, y contaminantes biológicos como los huevos de distintos parásitos, tal es el caso de Toxocara canis. En el presente trabajo, se evaluó el efecto del BPA administrado durante la etapa perinatal en ratas, sobre la respuesta inmunitaria durante la vida adulta, y la susceptibilidad al parásito zoonótico T. canis. Se analizaron las cargas parasitarias, así como los porcentajes de las subpoblaciones celulares del sistema inmunitario, la expresión de citocinas, y los títulos de anticuerpos contra el parásito. Se observó un aumento en el número de parásitos a nivel hepático y pulmonar. No hubo cambios significativos en los porcentajes de las células de la respuesta inmunitaria analizadas, sin embargo, hubo un aumento en las citocinas Th1 (TNF-α e IFN-γ) y una disminución en las Th2 (Il-4, IL-5 e IL- 13), además de una reducción en los títulos de anticuerpos contra el parásito en las ratas expuestas perinatalmente al BPA. En conclusión, la administración perinatal de BPA, afecta el desarrollo de la respuesta inmunitaria durante la vida adulta, modificando la producción de citocinas y anticuerpos por parte de las células de la respuesta inmune, lo cual ocasiona un aumento en la susceptibilidad a la infección por T. canis. [ABSTRACT FROM AUTHOR]

Recent studies demonstrated the presence of prolactin and progesterone receptors in larvae of Haemonchus contortus. The parasite infection is more severe in lambs than in adult animals, factors that could be involved in susceptibility could be the effect of growth hormone (GH) in the lambs. The objective of the study was to identify possible GH receptors (GHR) in larvae 3 of H. contortus. Larva cells were obtained and labeled with a primary anti-GHR antibody (Santa Cruz labs.) followed by a secondary anti-mouse IgG antibody (eBioscience labs.) coupled to Alexa 647. The counting of positive cells was performed with a FACScalibur cytometer. Immunolocation of possible GHRs was performed in permeabilized larvae treated with anti-GRH antibody, secondary mouse anti-IgG coupled to FITC (Molecular, Probes ®, USA) and confocal microscopy. Three cell populations were determined by according to granularity and size. Cell population with larger size and granularity have 3.34% of cells positive for GHR. The immunolocation of possible GHRs in the larval intestinal cells, which correspond to cells of large size and granularity was observed. These results indicate that H. contortus larvae express GHR in intestinal cells and possibly have the ability to respond to stimulation with GH as has been observed with other hormones. The identification of GHR in H. contortus larvae strongly suggests the existence of a biological effect of the hormone on the parasite in the host. Supported by PAPIIT-UNAM IN-218018. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is an endocrine disruptor of estrogenic nature. During the early stages of development, any exposure to BPA can have long-term effects. In this work, we study the potential alterations to the humoral antitumor immune (IgM) response in adult life after a single neonatal exposure to BPA. Female syngeneic BALB/c mice were exposed to a single dose of BPA of 250 μg/kg. Once sexual maturity was reached, a breast tumor was induced. After 25 days, the serum was obtained, and the populations of B cells in the spleen and lymph nodes were analyzed by flow cytometry. The reactivity of IgM was evaluated by 2D immunoblots. No significant changes were found in the B cell populations in the peripheral lymph nodes and the spleen. The level of Erα expression was not significantly different. However, the IgM reactivity was affected. In individuals treated with BPA, a decrease in the number of IgMs that recognize tumor antigens was observed. The possibility that these antibodies are the high affinity products of the adaptive response is discussed. The recognition of IgG was also evaluated but a null recognition was found in the controls as in the individuals treated with the 4T1 cells. [ABSTRACT FROM AUTHOR]

Androgens have been shown to exert a cysticidal effect upon Taenia crassiceps, an experimental model of cysticercosis. To further inquire into this matter, the Taenia crassiceps model was used to evaluate the expression of several proteins after testosterone (T4) and dihydrotestosterone (DHT) in vitro treatment. Under 2-D proteomic maps, parasite extracts were resolved into approximately 130 proteins distributed in a molecular weight range of 10-250 kDa and isoelectrical point range of 3-10. The resultant proteomic pattern was analysed, and significant changes were observed in response to T4 and DHT. Based on our experience with electrophoretic patterns and proteomic maps of cytoskeletal proteins, alteration in the expression of isoforms of actin, tubulin and paramyosin and of other proteins was assessed. Considering that androgens may exert their biological activity in taeniids through the non-specific progesterone receptor membrane component (PGRMC), we harnessed bioinformatics to propose the identity of androgen-regulated proteins and establish their hypothetical physiological role in the parasites. These analyses yield a possible explanation of how androgens exert their cysticidal effects through changes in the expression of proteins involved in cytoskeletal rearrangement, dynamic vesicular traffic and transduction of intracellular signals.

The in vitro effect of progesterone in T. canis larvae on their enlargement and motility were evaluated, together to the possible presence of progesterone receptors (PRs). T. canis larvae were cultured in RPMI-1640 with different concentrations of progesterone (0, 20, 40, 80, 400 and 800 ng/mL). Enlargement and increases in motility were dependent on the concentration only from 0 to 80 ng/mL (p < 0.05). The mean percentage of PR + cells in newly obtained larvae as measured by flow cytometry was 8.16 ± 0.4. The number of PR + cells increased depending on concentration from 0 to 80 ng/mL (p < 0.001). Cells obtained from larvae stimulated at any of the studied hormone concentrations showed greater mean fluorescence intensity when compared to non-stimulated cells. Additionally, the expression and location of PR + cells were determined in the larvae. The sequence of an amplicon (420-bp) obtained by PCR from T. canis larvae showed 100% homology with a gene fragment that codes for the PR of the dog. PR + cells were immunolocated using confocal microscopy in the intestinal region of the larvae that had been recently obtained. The results of this study show that T. canis larvae can recognize and respond to the presence of progesterone through a molecule possibly able to bind it. Since we previously observed a similar response to prolactin, we suggest that both hormones could participate sequentially in the reactivation of T. canis larvae in pregnant bitches., (Copyright © 2019 Elsevier Inc. All rights reserved.)

We evaluated the direct effects of progesterone on the morphology, maturation and behavior of Haemonchus contortus larvae in vitro. The presence and location of possible progesterone receptors in these larvae were also determined. The addition of 8ng/mL of progesterone to larval cultures over 10days reduced larval enlargement, while the addition of 160ng/mL of the hormone increased the enlargement. Up to 62% and 65% of the H. contortus larvae molted from third-stage larvae (L3) to fourth-stage larvae (L4) when cultured in RPMI-1640 media without hormone for 5 and 10days, respectively. The addition of different progesterone concentrations (1, 8, 16, 80 and 160ng/mL) to the larval cultures significantly inhibited the molting process within the same periods. The addition of 8ng/mL or higher progesterone concentrations to the cultures significantly increased larval motility (p<0.05) compared with unstimulated larvae. Flow cytometry showed the expression of progesterone receptors (P4-R) in 15% of the cells from newly isolated H. contortus larvae. When the larvae were cultured for 5days in the presence of the hormone, the percentage of P 4 -R+ cells remained the same. In contrast, unstimulated larvae showed a significant reduction in the number of P 4 -R+ cells. Using confocal microscopy, a greater concentration of P 4 -Rs was immunolocated in the anterior portion of the alimentary tract of the larvae, suggesting that the cells in this region are targeted by the hormone. The results of the present study show that H. contortus larvae have possible P 4 -Rs and respond to this hormone by inhibiting their molting process, thereby suggesting the participation of progesterone in the larval arrest phenomenon., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The in vitro effect of prolactin (PRL) on the growth and motility of Toxocara canis larvae was assessed. Additionally, the expression and location of prolactin receptors (PRL-Rs) were determined in the larvae. Larvae of T. canis were incubated with different concentrations of PRL for different periods of time. The stimulated larvae accelerated their enlargement and increased their motility. The mean percentage of PRL-R+ cells in non-stimulated larvae, measured by flow cytometry was 7.3±0.3%. Compared with non-stimulated larvae, the mean fluorescence intensity (p<0.05) increased in larvae incubated with 40ng/mL of PRL for 10 days. A 465-bp length fragment was amplified from larvae gDNA by PCR. The sequence of this fragment showed 99% similarity with the gene fragment that codes for the PRL-R of the domestic dog. A high concentration of PRL-Rs was immune-located in the posterior region of the larval intestine; therefore, the intestinal cells in this region were most likely the targets for this hormone. Based on these results, PRL-Rs were identified in T. canis larvae, and the in vitro stimulation with PRL increased the number of these receptors, accelerated the growth and modified the activity of larvae. All of the above suggest that T. canis larvae are evolutionarily adapted to recognize the PRL of their definitive host and furthermore might explain the reactivation of tissue-arrested larvae during the gestation of bitches, which does not occur in gestating females of other species., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Progesterone regulates cancer cell proliferation and invasion through its receptors (PR-A and PR-B), whose phosphorylation modifies their transcriptional activity and induce their degradation. We identified by in silico analysis a putative residue (Ser400) in PR that might be phosphorylated by protein kinase C (PKC), a family of enzymes involved in the proliferation and infiltration of astrocytomas, the most frequent and aggressive brain tumors. A grade III human astrocytoma-derived cell line was used to study the role of PKC in PR phosphorylation, transcriptional activity, and degradation. Treatment with PKC activator [tetradecanoyl phorbol acetate (TPA)] increased PR phosphorylation in Ser400 after 5 minutes, which in turn induced PR transcriptional activity and its subsequent degradation by the 26S proteasome 3-5 hours after treatment. Silencing or inhibition of PKCα and PKCδ blocked PR phosphorylation and degradation induced by TPA. Both PR isoforms were associated with PKCα and reached the maximum association after 5 minutes of TPA addition. These data correlated with immunnofluorescence assays in which nuclear colocalization of PKCα with PR increased after TPA treatment. We observed a 2-fold increase in cell proliferation after PKC activation with TPA that was reduced with the PR antagonist, RU486. The PR S400A mutant revealed that this residue is essential for PKC-mediated PR phosphorylation and degradation. Our results show a key participation of PKCα and PKCδ in PR regulation and function.

Unlabelled: Helminthic infections are important causes of morbidity and mortality in many developing countries, where children bear the greatest health burden. The ability of parasites to cause behavioral changes in the host has been observed in a variety of host-parasite systems, including the Taenia crassiceps-mouse model. In murine cysticercosis, mice exhibit a disruption in the sexual, aggressive and avoidance predator behaviors., Objective: The present study was conducted to characterize short-term memory and depression-like behavior, as well as levels of neurotransmitters and cytokines in the hippocampus of cysticercotic male and female mice., Methods: Cytokines were detected by RT-PCR and neurotransmitters were quantified by HPLC., Results: Chronic cysticercosis infection induced a decrease in short-term memory in both male and female mice, having a more pronounced effect in females. Infected females showed a significant increase in forced swimming tests with a decrease in immobility. In contrast, male mice showed an increment in total activity and ambulation tests. Serotonin levels decreased by 30% in the hippocampus of infected females whereas noradrenaline levels significantly increased in infected males. The hippocampal expression of IL-4 increased in infected female mice, but decreased in infected male mice., Conclusion: Our study suggests that intraperitoneal chronic infection with cysticerci in mice leads to persistent deficits in tasks dependent on the animal's hippocampal function. Our findings are a first approach to elucidating the role of the neuroimmune network in controlling short-term memory and mood in T. crassiceps-infected mice.

Macrophages are critically involved in the interaction between T. crassiceps and the murine host immune system. Also, a strong gender-associated susceptibility to murine cysticercosis has been reported. Here, we examined the sex-associated expression of molecules MHC-II, CD80, CD86, PD-L1, and PD-L2 on peritoneal F4/80(hi) macrophages of BALB/c mice infected with Taenia crassiceps. Peritoneal macrophages from both sexes of mice were exposed to T. crassiceps total extract (TcEx). BALB/c Females mice recruit higher number of macrophages to the peritoneum. Macrophages from infected animals show increased expression of PDL2 and CD80 that was dependent from the sex of the host. These findings suggest that macrophage recruitment at early time points during T. crassiceps infection is a possible mechanism that underlies the differential sex-associated susceptibility displayed by the mouse gender.

During the helminth infections, the immune system tends to be modulated by host's sex hormones. Actually, many studies show the reciprocal relationship between sex steroids, the immune system and the elimination or establishment of helminth parasites. Is well known that innate immune response determines the type of adaptive immune response, so the effects in the innate immune response by hormones may affect subsequent adaptive immunity. The sex steroids as estrogens, progesterone and testosterone regulate growth, differentiation, survival and function of many cell types that could be involved in process like homeostasis and immunity, but also have a direct effect on the helminthes, that may probably be mediated by specific receptors on these parasites. Sex steroids, parasites and immunity are closely connected, and their interconnection is involved in the maintenance of elimination or establishment of helminthes in an immunocompetent host. For that reason, understanding the action's mechanisms of sex steroids on immune cells and its direct effect on helminth parasites is important for further progress in the development of novel therapies for chronic helminth diseases associated to immune dysregulation. In this review, we will describe the effects of sex steroids on the immune response during helminth infections as well as the direct effect in these parasites, and the possible implications of these effects on the incidence of several helminth infections.

It has been widely reported that the incidence and the severity of natural parasitic infections are different between males and females of several species, including humans. This sexual dimorphism involves a distinct exposure of males and females to various parasite infective stages, differential effects of sex steroids on immune cells, and direct effects of these steroids on parasites, among others. Typically, for a large number of parasitic diseases, the prevalence and intensity is higher in males than females; however, in several parasitic infections, males are more resistant than females. In the present work, we review the effects of sex hormones on immunity to protozoa and helminth parasites, which are the causal agents of several diseases in humans, and discuss the most recent research related to the role of sex steroids in the complex host-parasite relationship., (© 2012 New York Academy of Sciences.)

The role of an estrogen-binding protein similar to a known mammalian estrogen receptor (ER) is described in the estradiol-dependent reproduction of the helminth parasite Taenia crassiceps. Previous results have shown that 17-β-estradiol induces a concentration-dependent increase in bud number of in vitro cultured cysticerci. This effect is inhibited when parasites are also incubated in the presence of an ER binding-inhibitor (tamoxifen). RT-PCR assays using specific oligonucleotides of the most conserved ER sequences, showed expression by the parasite of a mRNA band of molecular weight and sequence corresponding to an ER. Western blot assays revealed reactivity with a 66 kDa protein corresponding to the parasite ER protein. Tamoxifen treatment strongly reduced the production of the T. crassiceps ER-like protein. Antibody specificity was demonstrated by immunoprecipitating the total parasite protein extract with anti-ER-antibodies. Cross-contamination by host cells was discarded by flow cytometry analysis. ER was specifically detected on cells expressing paramyosin, a specific helminth cell marker. Parasite cells expressing the ER-like protein were located by confocal microscopy in the subtegumental tissue exclusively. Analysis of the ER-like protein by bidimensional electrophoresis and immunoblot identified a specific protein of molecular weight and isoelectric point similar to a vertebrates ER. Sequencing of the spot produced a small fragment of protein similar to the mammalian nuclear ER. Together these results show that T. crassiceps expresses an ER-like protein which activates the budding of T. crassiceps cysticerci in vitro. To the best of our knowledge, this is the first report of an ER-like protein in parasites. This finding may have strong implications in the fields of host-parasite co-evolution as well as in sex-associated susceptibility to this infection, and could be an important target for the design of new drugs., (Copyright © 2011 Elsevier Inc. All rights reserved.)

We evaluated the in vitro effects of estradiol, progesterone, and testosterone on the molting process, which is the initial and crucial step in the development of the muscular larvae (ML or L1) to adult worm. Testosterone had no significative effect on the molting rate of the parasite, however, progesterone decreased the molting rate about a 50% in a concentration- and time-independent pattern, while estradiol had a slight effect (10%). The gene expression of caveolin-1, a specific gene used as a marker of parasite development, showed that progesterone and estradiol downregulated its expression, while protein expression was unaffected. By using flow citometry, a possible protein that is recognized by a commercial antiprogesterone receptor antibody was detected. These findings may have strong implications in the host-parasite coevolution, in the sex-associated susceptibility to this infection and could point out to possibilities to use antihormones to inhibit parasite development.

In parasitology, particularly in helminthes studies, several methods have been used to look for the expression of specific molecules, such as RT-PCR, western blot, 2D-electrophoresis, and microscopy, among others. However, these methods require homogenization of the whole helminth parasite, preventing evaluation of individual cells or specific cell types in a given parasite tissue or organ. Also, the extremely high interaction between helminthes and host cells (particularly immune cells) is an important point to be considered. It is really hard to obtain fresh parasites without host cell contamination. Then, it becomes crucial to determine that the analyzed proteins are exclusively from parasitic origin, and not a consequence of host cell contamination. Flow cytometry is a fluorescence-based technique used to evaluate the expression of extra-and intracellular proteins in different type cells, including protozoan parasites. It also allows the isolation and recovery of single-cell populations. Here, we describe a method to isolate and obtain purified helminthes cells.