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We explored the hypothesis that progesterone direct effect on Trichinella spiralis might be mediated indeed by a new steroid-binding parasite protein. Our first results showed that Progesterone decreases the parasite molting rate. We amplify, isolated, cloned and sequenced the PGRMC2 sequence using specific primers from known species. Furthermore, we expressed the protein and developed an antibody to performance immunofluorescent confocal microscopy, where detected that parasite cells showed expression of a P4-binding protein exclusively located at the oocyte and the parasite´s cuticle. Presence of the PGRMC2 protein in these cells was also confirmed by western blot and flow cytometry. Molecular modeling studies accompanied by computer docking using the sequenced protein showed that PGRMC2 is potentially able to bind steroid hormones such as progesterone, estradiol, testosterone, and dihydrodrotestosterone with different affinities. Phylogenetic analysis and sequence alignment clearly demonstrated that Trichinella spiralis PGRMC2 is related to a steroid-binding protein of another platyhelminths. Progesterone may probably act upon Trichinella spiralis oocytes probably by binding to PGRMC2. This research has implications in the field of host-parasite co-evolution as well as the sex-associated susceptibility to this infection. In a more practical matter, present results may contribute to the molecular design of new drugs with anti-parasite actions.

Cysticercosis is a disease caused by the metacestode of the parasite Taenia solium (T. solium). In humans, the most severe complication of the disease is neurocysticercosis. The drug of choice to treat this disease is albendazole; however, the bioavailability and efficacy of the drug are variable. Therefore, new molecules with therapeutic effects against this and other parasitic infections caused by helminths must be developed. Naphthoquinones are naphthalene-derived compounds that possess antibacterial, antifungal, antitumoral, and antiparasitic properties. The aim of this work was to evaluate the in vitro anti-helminthic effect of 2-[(3-chlorophenylamino)phenylmethyl]-3-hydroxy-1,4-naphthoquinone, isolated from a natural source and then synthesized (naphthoquinone 4a), using an experimental model of murine cysticercosis caused by Taenia crassiceps (T. crassiceps). This compound causes paralysis in the cysticerci membrane from day 3 of the in vitro treatment. Additionally, it induces changes in the shape, size, and appearance of the cysticerci and a decrease in the reproduction rate. In conclusion, naphthoquinone 4a has in vitro cysticidal activity on T. crassiceps cysticerci depending on the duration of the treatment and the concentration of the compound. Therefore, it is a promising drug candidate to be used in T. crassiceps and possibly T. solium infections.

Immune tolerance is the state in which the immune system does not generate a response towards otherwise immunogenic antigens. Tolerance is crucial for life and its failures lead to autoimmune diseases. Tolerance may be achieved by preventing autoreactive clones from maturing, early in their development, or either eliminating or suppressing them if they reach periphery. However, there are moments when our own cells happen to be the disease, like with cancer. Herein, we describe the basic mechanism mediating those processes, namely clonal deletion, anergy induction, immunomodulatory cytokines, and regulatory cells. Finally, we comment on the immune recognition of cancer cells and why tolerance is a target for immunotherapy.

Phthalates are endocrine disrupting compounds (EDCs) used as plasticizers in a wide array of daily-use products, from flooring and automotive parts to medical devices and are even present in the childreni?½s toys. Since these compounds are not covalently bound other molecules, they leach from these synthetic products, causing a high level of human exposure to them. EDCs exert several endocrine effects, most typically, reduced biosynthesis of the male hormone, testosterone and disturbances in estrogen, androgen, PPAR-gamma and AhR that control complex immunoendocrine regulatory networks. Besides impacting the developmental processes and long-term adverse effects, since cells of the immune system express endocrine receptors, and synthetize and respond to several hormones and other endocrine ligands, phthalates also cause dysregulation of immune system.

Aims Industrial growth has increased the exposure to endocrine disruptor compounds (EDCs) in all organisms. Bisphenol A (BPA), an EDC, has been demonstrated to be involved in the susceptibility to parasite infections. However, few studies have analysed this connection in more depth. The aim of this study was to determine whether early BPA exposure in female mice affects the systemic immune response and the susceptibility to Taenia crassiceps infection. Methods and results BALB/c mice were exposed to BPA at post-natal day 3. At 6 weeks of age, they were inoculated with T crassiceps larvae and, 2 weeks later, were euthanized. The number of parasites was quantified. By flow cytometry, in the spleen, the peripheral and mesenteric lymph nodes, the different innate and adaptive immune cell modulation was analysed, and RT-PCR cytokine expression was also evaluated. BPA induced a reduction of 40% in parasite load. BPA treatment modulated some lineages of the innate immune response and caused slight changes in cells belonging to the adaptive immune response. Additionally, BPA enhanced the type 2 cytokine profile. Conclusion Neonatal BPA treatment in female mice affects not only the percentage of different immune cells but also their ex vivo cytokine gene expression, decreasing T crassiceps cysticercosis susceptibility.

Background As a result of human socioeconomic activity, industrial wastes have increased distressingly. Plastic pollution is globally distributed across the world due to its properties of buoyancy and durability. A big health hazard is the sorption of toxicants to plastic while traveling through the environment. Two broad classes of plastic-related chemicals are of critical concern for human health-bisphenols and phthalates. Bisphenol A (BPA) is an endocrine-disruptor compound (EDC) with estrogenic activity. It is used in the production of materials that are used daily. The endocrine modulating activity of BPA and its effects on reproductive health has been widely studied. BPA also has effects on the immune system; however, they are poorly investigated and the available data are inconclusive. Phthalates are also EDCs used as plasticizers in a wide array of daily-use products. Since these compounds are not covalently bound to the plastic matrix, they easily leach out from it, leading to high human exposure. These compounds exert several cell effects through modulating different endocrine pathways, such as estrogen, androgen, peroxisome proliferator-activated receptor gamma, and arylhydrocarbon receptor pathways. The exposure to both classes of plastic derivatives during critical periods has detrimental effects on human health. Methods In this review, we have compiled the most important of their perinatal effects on the function of the immune system and their relationship to the development of different types of cancer. Results/conclusion The administration of bisphenols and phthalates during critical stages of development affects important immune system components, and the immune function; which might be related to the development of different diseases including cancer.

Worldwide breast cancer is the most important type in regard to incidence and prevalence in women. Several risk factors interact to increase the probability of breast cancer development. Biological environmental contaminants such as infectious agents play a significant role in tumor development, and helminths have been recognized as cancer enhancers or inducers due to their ability to regulate the host immune response. However, nothing it is not known in regard to parasites and breast cancer. Toxocara canis is a zoonotic and cosmopolite nematode, with immuno-regulatory abilities. T. canis infection has been related to T helper type-2 cell (Th2 or type 2) and regulatory responses. Type 2 and regulatory immune responses may favor the development of comorbidities that are usually controlled or eliminated through a type 1 response, such as cancer. The aim of this study was to determine if T. canis infection alters mammary tumor growth through modulation of the immune response. Infected mice developed larger tumors. Tumor immune cell milieu analysis revealed that infection reduced CD8+ T lymphocytes, and increased F4/80+ macrophages as well as CD19+ B cells proportions. These changes were accompanied by a type 2 local response represented by increased amounts of IL-4, VEGF, and a regulatory microenvironment associated with higher IL-10 levels. Thus, this study demonstrates that T. canis infection enhances tumor development and suggests that this is through the modulation of tumor immune microenvironment.

Taiep rat is a myelin mutant with a progressive motor syndrome characterized by tremor, ataxia, immobility episodes, epilepsy and paralysis of the hindlimbs, accompanied with differential expression of interleukins and their receptors that correlated with the progressive demyelination that characterize this mutant. Thus, the taiep rat is a suitable model to study neuroimmune alterations. The aim of this study was to investigate the immune alterations present in the mutant taiep rat during the acute infection with Trichinella spiralis. Our results show that there is an important decrease in the number of intestinal larvae in the taiep rat when compared to the Sprague-Dawley control rats. We also found differences in the percentage of innate and adaptive immune cell profile in the mesenteric lymphatic nodes and the spleen associated to the lack of myelin in the taiep rat. Finally, a clear pro-inflammatory cytokine pattern was seen in the infected taiep rat, which may explain the decrease in larvae number. These results sustain the theory that neuroimmune interaction is a fundamental process capable of modulating the immune response, particularly against the parasite Trichinella spiralis in a model of progressive demyelination that could be an important mechanism in autoimmune diseases and parasite infection.Author summaryThe complex communication among the brain and the immune system may be certainly altered during an infection and may be determinant in the resolution of this. We analyze the immune response to a parasite in a rat model in which a demyelinization process occur naturally and found that parasite loads were reduced when comparing with control subjects and this was accompanied to changes in the systemic immune response.

Toxoplasmosis is a zoonotic disease caused by the apicomplexa protozoan parasiteToxoplasma gondii. This disease is a health burden, mainly in pregnant women and immunocompromised individuals, in whom they can cause death. Despite advances in the medical area, nowadays there are no new drugs to treat toxoplasmosis. The standard therapy to toxoplasmosis has not had progress for last seven decades; it is a combination of sulfadiazine-pyrimethamine (S-P); which is co-administered with folic acid due to the adverse effects of the drug. Several studies have shown that the conventional treatment has limited effectiveness and severe adverse effects. Thus, the search of better treatments with greater efficacy and without the adverse effects becomes relevant. In the current work we demonstrate for the first time the parasiticidal effect of dehydroepiandrosterone (DHEA), a steroid hormone produced by many mammals, on extracellular tachyzoites (the infective stage ofT. gondii). In vitro treatment with DHEA reduces the viability of extracellular tachyzoites, and both the active and passive invasion processes. The ultrastructural analysis of treated parasites showed that DHEA alters the cytoskeleton structures, leading in the lost of the organelle structure and organization, as well as, the lost of the cellular shape. On a molecular level, we observed an important reduction of the expression of several proteins that are essential for the motility and virulence of parasites when they were exposed to DHEA. These results suggest that DHEA could be used as an alternative treatment against toxoplasmosis.

Androgens have been shown to exert a cysticidal effect uponTaenia crassiceps, an experimental model of cysticercosis. To further inquire into this matter, theTaenia crassicepsmodel was used to evaluate the expression of several proteins after testosterone (T4) and dihydrotestosterone (DHT)in vitrotreatment. 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.

Background We have previously reported that progesterone (P4) has a direct in vitro effect on the scolex evagination and growth of Taenia solium cysticerci. Here, we explored the hypothesis that the P4 direct effect on T. solium might be mediated by a novel steroid-binding parasite protein. Methods By way of using immunofluorescent confocal microscopy, flow cytometry analysis, double-dimension electrophoresis analysis, and sequencing the corresponding protein spot, we detected a novel PGRMC in T. solium. Molecular modeling studies accompanied by computer docking using the sequenced protein, together with phylogenetic analysis and sequence alignment clearly demonstrated that T. solium PGRMC is from parasite origin. Results Our results show that P4 in vitro increases parasite evagination and scolex size. Using immunofluorescent confocal microscopy, we detected that parasite cells showed expression of a P4-binding like protein exclusively located at the cysticercus subtegumental tissue. Presence of the P4-binding protein in cyst cells was also confirmed by flow cytometry. Double-dimension electrophoresis analysis, followed by sequencing the corresponding protein spot, revealed a protein that was previously reported in the T. solium genome belonging to a membrane-associated progesterone receptor component (PGRMC). Molecular modeling studies accompanied by computer docking using the sequenced protein showed that PGRMC is potentially able to bind steroid hormones such as progesterone, estradiol, testosterone and dihydrodrotestosterone with different affinities. Phylogenetic analysis and sequence alignment clearly demonstrated that T. solium PGRMC is related to a steroid-binding protein of Echinoccocus granulosus, both of them being nested within a cluster including similar proteins present in platyhelminths such as Schistocephalus solidus and Schistosoma haematobium. Conclusion Progesterone may directly act upon T. solium cysticerci probably by binding to PGRMC. This research has implications in the field of host-parasite co-evolution as well as the sex-associated susceptibility to this infection. In a more practical matter, present results may contribute to the molecular design of new drugs with anti-parasite actions. Electronic supplementary material The online version of this article (10.1186/s13071-018-2703-1) contains supplementary material, which is available to authorized users.

In this work, we identified the expression, regulation, and viral targeting of Scribble and Dlg1 in antigen-presenting cells. Scribble and Dlg1 belong to the family of PDZ (postsynaptic density (PSD95), disc large (Dlg), and zonula occludens (ZO-1)) proteins involved in cell polarity. The relevance of PDZ proteins in cellular functions is reinforced by the fact that many viruses interfere with host PDZ-dependent interactions affecting cellular mechanisms thus favoring viral replication. The functions of Scribble and Dlg have been widely studied in polarized cells such as epithelial and neuron cells. However, within the cells of the immune system, their functions have been described only in T and B lymphocytes. Here we demonstrated that Scribble and Dlg1 are differentially expressed during antigen-presenting cell differentiation and dendritic cell maturation. While both Scribble and Dlg1 seem to participate in distinct dendritic cell functions, both are targeted by the viral protein NS1 of influenza A in a PDZ-dependent manner in dendritic cells. Our findings suggest that these proteins might be involved in the mechanisms of innate immunity and/or antigen processing and presentation that can be hijacked by viral pathogens.

Bisphenol A, a very widespread environmental pollutant and endocrine disruptor compound, can interact with several steroid receptors, particularly with estrogen ones. In different studies, it has observed that the endocrine disruption during critical periods of development can trigger alterations in the immune response during the adult life. Male Wistar rats were exposed indirectly to BPA at a dose of 250 μg/kg day during the perinatal period (from day 5 of pregnancy until day 21 postnatal), At the 60 days of age, the adulthood, animals were infected with larvated eggs of the Toxocara canis, and were sacrificed at 7 days post-infection. Parasitic loads in the lung and in the liver were analyzed by artificial digestion. Furthermore, immune cell subpopulations (macrophages, NK cells, Tγδ, total T cells, T helper, T cytotoxic, and B lymphocytes) present in spleen, peripheral and mesenteric lymph nodes were analyzed by flow cytometry. The expression of Th1 and Th2 cytokines at the splenic level was determined by real-time quantitative PCR. Finally, the titers of specific antibodies against to the parasite were analyzed by ELISA. The BPA treatment administrated in the perinatally stage favors a significant increase of the percentage of Toxocara canis larvae in the lungs and liver in the adulthood. Additionally, the exposure to this compound caused a dramatically decrease in the production of specific antibodies against to this parasite, downregulating together Th2 cytokines (IL-4, IL-5 and IL-13), meanwhile upregulated Th1 cytokines (IFN-γ and TNF-α). Perinatal exposure to BPA affects the performance of the immune response during adult life, modifying both cytokines and antibodies production by these cells, which favors the susceptibility to infections, specifically toxocariosis.

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 &mu, g/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 ER&alpha, 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.

Aims The zoonotic nematode Toxocara canis causes larva migrans syndrome that induces an immune response characterized by the production of antibodies and eosinophilia. A Th2 polarization has been associated with the infection, but there are still details of the cellular and humoral immune response that need to be described. Thus, the aim of this study was to describe the systemic host immune response to T canis chronic infection in a mouse model. Methods and results BALB/c mice were inoculated once with 500 T canis embryonated eggs, per os. After 49 days, the amounts of larval found in brain and muscle tissues were statistically two and four times higher, respectively, than the amounts found in lung, liver, kidney or heart tissues. Splenic proportions of F4/80+ cells, as well as B, cytotoxic T and CD4+ Foxp3+ lymphocytes, were statistically higher (P ≤ .05, P ≤ .01, P ≤ .001 and P ≤ .001, respectively) as compared with control mice. In lymph nodes, some of these proportions changed, with the exception of F4/80+ cells. IgG1 levels in infected mice sera were increased. IL-4, IL-10 and VEGF levels were statistically higher in spleen (P ≤ .05, all) and sera (P ≤ .01, P ≤ .05 and P ≤ .05, respectively) in the infected mice. Also, in infected animals, IL-5 serum levels were increased (P ≤ .01). Conclusion These results suggest that T canis chronic infection in BALB/c mice results in a type 2 response with an incipient regulatory response.

Bisphenol A (BPA) is an endocrine disruptor compound with estrogenic activity, possessing affinity for both nuclear (ERα and ERβ) and membrane estrogen receptors. The main source of BPA exposure comes from the contamination of food and water by plastic storage containers or disposable bottles, among others, in which case BPA is easily ingested. Exposure to BPA during early pregnancy leads to lifelong effects; however, its effect on the immune system has not been fully studied. Since endocrine and immune systems interact in a bidirectional manner, the disruption of the former may cause permanent alterations of the latter, thus affecting a future anti-parasitic response. In this study, neonate BALB/c mice were exposed to a single dose of BPA (250 μg/kg); once sexual maturity was reached, they were orally infected with Trichinella spiralis (T. spiralis). The analyses performed after 5 days of infection revealed a decreased parasitic load in the duodenum of mice in the BPA-treated group. Flow cytometry analyses also revealed changes in the immune cell subpopulations of the infected animals when compared to the BPA-treated group. RT-PCR analyses of duodenum samples showed an increased expression of TNF-α, IFN-γ, IL-4, IL-5, and IL-9 in the BPA-treated group. These findings show a new aspect whereby early-life exposure to BPA contributes to the protection against T. spiralis by modulating the anti-parasitic immune response.

Toxoplasmosis is a zoonotic disease caused by the apicomplexa protozoan parasite Toxoplasma gondii. This disease is a health burden, mainly in pregnant women and immunocompromised individuals. Dehydroepiandrosterone (DHEA) has proved to be an important molecule that could drive resistance against a variety of infections, including intracellular parasites such as Plasmodium falciparum and Trypanozoma cruzi, among others. However, to date, the role of DHEA on T. gondii has not been explored. Here, we demonstrated for the first time the toxoplasmicidal effect of DHEA on extracellular tachyzoites. Ultrastructural analysis of treated parasites showed that DHEA alters the cytoskeleton structures, leading to the loss of the organelle structure and organization as well as the loss of the cellular shape. In vitro treatment with DHEA reduces the viability of extracellular tachyzoites and the passive invasion process. Two-dimensional (2D) SDS-PAGE analysis revealed that in the presence of the hormone, a progesterone receptor membrane component (PGRMC) with a cytochrome b5 family heme/steroid binding domain-containing protein was expressed, while the expression of proteins that are essential for motility and virulence was highly reduced. Finally, in vivo DHEA treatment induced a reduction of parasitic load in male, but not in female mice.

Breast cancer is one of the most common malignancies and the second leading cause of death in women. Despite efforts for its early detection, its worldwide incidence continues to increase. Thus, identification of risk factors for its development and new targets for its therapy are of vital importance. Environmental pollutants derived from human activity have been associated with predisposition to the development of cancer. Bisphenol A (BPA) is an endocrine disruptor compound (EDC) widely used in the manufacture of polycarbonates, and it has affinity for the estrogen receptor (ER). Scientific evidence has proposed an association between increased incidence of breast cancer and BPA exposure at lower doses. Among worldwide concerns with BPA exposure, different industries proceeded to replace BPA with analogs such as bisphenol S (BPS), which is now employed in products labelled as BPA-free. Nevertheless, recent studies exhibit that its exposure results in altered mammary gland development and morphogenesis; and promotes breast cancer cell proliferation. Of note, most of the effects of both BPA and BPS have been performed in estrogen-dependent breast cancer models. However, gaps in knowledge still exist on the roles and mechanisms that both compounds, specifically BPS, may play in cancer initiation and development in hormone-dependent and other types of breast cancer. Thus, the aim of the present study was to deepen the understanding of biological targets modulated by these ubiquitous pollutants in different breast cancer cell lines, representing two scenarios of this pathology: hormone-dependent and hormone-independent breast cancer. Results point out that both compounds induced proliferation in ER positive cells, not showing this effect in the ER-negative breast cancer cells. Different targets modified at the proteomic level in both breast cancer scenarios were also identified. Stem cell markers (eg. CD44) and invasion proteins (eg. MMP-14) were importantly increased by BPA and BPS in ER-positive breast cancer cells. In contrast, growth factors and associated receptors such as EGFR and TGF-β were induced by BPS in the ER-negative breast cancer cells; both pollutants induced an increase of vascular endothelial growth factor (VEGF) protein secretion. This finding suggests that the use of BPS must be considered with more caution than BPA, since it can act independently of the presence of the hormonal receptor. These findings show new evidence that BPA and BPS exposure can contribute to breast cancer development and progression. Our results suggest that both BPA and BPS must be considered equally as outstanding risk factors for this pathology.

It is well known that sex hormones play an important role during Taenia solium infection; however, to our knowledge no studies exist concerning the immune response following complete or lobe-specific removal of the pituitary gland during T. solium infection. Thus, the aim of this work was to analyze in hamsters, the effects of lack of pituitary hormones on the duodenal immune response, and their impact on T. solium establishment and development. Thus, in order to achieve this goal, we perform anterior pituitary lobectomy (AL, n = 9), neurointermediate pituitary lobectomy (NIL, n = 9) and total hypophysectomy (HYPOX, n = 8), and related to the gut establishment and growth of T. solium, hematoxylin-eosin staining of duodenal tissue and immunofluorescence of duodenal cytokine expression and compared these results to the control intact (n = 8) and control infected group (n = 8). Our results indicate that 15 days post-infection, HYPOX reduces the number and size of intestinally recovered T. solium adults. Using semiquantitative immunofluorescent laser confocal microscopy, we observed that the mean intensity of duodenal IFN-γ and IL-12 Th1 cytokines was mildly expressed in the infected controls, in contrast with the high level of expression of these cytokines in the NIL infected hamsters. Likewise, the duodenum of HYPOX animals showed an increase in the expression of Th2 cytokines IL-5 and IL-6, when compared to control hamsters. Histological analysis of duodenal mucosa from HYPOX hamsters revealed an exacerbated inflammatory infiltrate located along the lamina propria and related to the presence of the parasite. We conclude that lobe-specific pituitary hormones affect differentially the T. solium development and the gut immune response.

Taiep rat is a myelin mutant with a progressive motor syndrome characterized by tremor, ataxia, immobility episodes, epilepsy and paralysis of the hindlimbs. Taiep had an initial hypomyelination followed by a progressive demyelination associated with an increased expression of some interleukins and their receptors. The pathology correlated with an increase in nitric oxide activity and lipoperoxidation. In base of the above evidences taiep rat is an appropriate model to study neuroimmune interactions. The aim of this study was to analyze the immune responses in male taiep rats after acute infection with Trichinella spiralis. Our results show that there is an important decrease in the number of intestinal larvae in the taiep rat with respect to Sprague-Dawley control rats. We also found differences in the percentage of innate and adaptive immune cell profile in the mesenteric lymphatic nodes and the spleen that correlated with the demyelination process that took place on taiep subjects. Finally, a clear pro-inflammatory cytokine pattern was seen on infected taiep rats, that could be responsible of the decrement in the number of larvae number. These results sustain the theory that neuroimmune interaction is a fundamental process capable of modulating the immune response, particularly against the parasite Trichinella spiralis in an animal model of progressive demyelination due to tubulinopathy, that could be an important mechanism for the clinical course of autoimmune diseases associated with parasite infection.

Cerebral malaria (CM) is the major complication associated with death in malaria patients, and its pathogenesis is associated with excessive proinflammatory cytokine production. Notably, the severity and mortality of natural infections with Plasmodium are higher in males than females, suggesting that sexual hormones influence both the pathogenesis of and immune response in CM. However, no studies on inflammation mediators in the brains of both sexes have been reported. In this work, the mRNA expression levels of the proinflammatory cytokines IL-1β, IFN-γ, TNF-α, and IL-2 were measured in the preoptic area, hypothalamus, hippocampus, olfactory bulb, frontal cortex, and lateral cortex regions of gonadectomized female and male CBA/Ca mice infected with P. berghei ANKA (a recognized experimental CM model). Our findings demonstrate that both infection with P. berghei ANKA and gonadectomy trigger a cerebral sex dimorphic mRNA expression pattern of the cytokines IL-1β, TNF-α, IFN-γ, and IL-2. This dimorphic cytokine pattern was different in each brain region analysed. In most cases, infected males exhibited higher mRNA expression levels than females, suggesting that sexual hormones differentially regulate the mRNA expression of proinflammatory cytokines in the brain and the potential use of gonadal steroids or their derivates in the immunomodulation of cerebral malaria.

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

Mast cells (MCs) are versatile effector and regulatory cells in various physiologic, immunologic, and pathologic processes. In addition to the well-characterized IgE/FcεRI-mediated degranulation, a variety of biological substances can induce MCs activation and release of their granule content. Sex steroids, mainly estradiol and progesterone, have been demonstrated to elicit MCs activation. Most published studies have been conducted on MCs lines or freshly isolated peritoneal and bone marrow-derived MC without addressing gender impact on MC response. Our goal was to investigate if the effect of estradiol, progesterone, testosterone, and dihydrotestosterone (DHT) on MCs may differ depending on whether female or male rats are used as MCs donors. Our results demonstrated that effect of sex steroids on MCs histamine release is dose- and gender-dependent and can be direct, synergistic, or inhibitory depending on whether hormones are used alone or to pretreat MCs followed by substance P-stimulation or upon IgE-mediated stimulation. In contrast, sex steroids did not have effect on the MC expression of the IgE high affinity receptor, FcεRI, no matter female or male rats were used. In conclusion, MCs degranulation is modulated by sex hormones in a gender-selective fashion, with MC from females being more susceptible than MC from males to the effects of sex steroids.

Toxocara canis is the helminth causing Toxocariasis, a parasitic disease with medical and veterinary implications. Their final host are members of the family Canidae and as paratenic hosts, most of the mammals are sensitive (man, rat, mouse, among others). It has been reported that a pituitary hormone, prolactin, it is responsible for reactivation and migration of larvae to the uterus and mammary gland during the last third of gestation in bitches. In addition, this hormone has been shown to play an important role in the regulation of the immune response. Thus, the aim of this study, was to evaluate the effect of hypophysectomy in the rat model of Toxocariasis, on the immune response against this parasite during a chronic infection, for which parasite loads were analyzed in different organs (lung and brain). Furthermore, serum specific antibody titers, and percentages of different cells of the immune system were also determined. The results showed a decrease in the number of larvae recovered from lung and brain in the hypophysectomized animals. In this same group of animals, there was no production of specific antibodies against the parasite. As for the percentages of the cells of the immune system, there are differences in some subpopulations due to surgery and others due to infection. Our results demonstrated that the lack of pituitary hormones alters parasite loads and the immune response to the helminth parasite Toxocara canis.

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

BPA is an oestrogenic endocrine disrupting chemical compound. Exposure to BPA in as early as pregnancy leads to lifelong effects. Since endocrine and immune systems interact in a bidirectional manner, endocrine disruption may cause permanent alterations of the immune system, affecting a future anti-tumoral response. Neonate (PND 3) female syngeneic BALB/c mice were exposed to a single dose of 250 µg/kg BPA. Once sexual maturity was reached, a mammary tumour was induced injecting 4T1 cells in situ, these cells are derived from a spontaneous adenocarcinoma in a BALB/c mouse and therefore allows for an immunocompetent recipient. After 25 days of injection, showing no major endocrine alterations, BPA-exposed mice developed larger tumours. Tumour leukocytic infiltrate analysis revealed a higher proportion of regulatory T lymphocytes in the BPA-exposed group. RT-PCR analysis of tumour samples showed a decreased expression of TNF-α and IFN-γ, as well as the M2 macrophage marker Fizz-1 in the BPA-exposed group. Flow cytometry analysis revealed differences in ERα expression by T lymphocytes, macrophages and NK cells, both associated to BPA exposure and tumour development. These findings show a new aspect whereby early life BPA exposure can contribute to breast cancer development and progression by modulating the anti-tumoral immune response.

We examined the effects of oestradiol (E2) and progesterone (P4) on cytoskeletal protein expression in the helminth Taenia crassiceps - specifically actin, tubulin and myosin. These proteins assemble into flame cells, which constitute the parasite excretory system. Total protein extracts were obtained from E2- and P4-treated T. crassiceps cysticerci and untreated controls, and analysed by one- and two-dimensional protein electrophoresis, flow cytometry, immunofluorescence and videomicroscopy. Exposure of T. crassiceps cysticerci to E2 and P4 induced differential protein expression patterns compared with untreated controls. Changes in actin, tubulin and myosin expression were confirmed by flow cytometry of parasite cells and immunofluorescence. In addition, parasite morphology was altered in response to E2 and P4 versus controls. Flame cells were primarily affected at the level of the ciliary tuft, in association with the changes in actin, tubulin and myosin. We conclude that oestradiol and progesterone act directly on T. crassiceps cysticerci, altering actin, tubulin and myosin expression and thus affecting the assembly and function of flame cells. Our results increase our understanding of several aspects of the molecular crosstalk between host and parasite, which might be useful in designing anthelmintic drugs that exclusively impair parasitic proteins which mediate cell signaling and pathogenic reproduction and establishment.

Industrial growth has increased the exposition to endocrine disruptor compounds (EDC’s), which are exogenous agents with agonist or antagonist action of endogenous steroid hormones that may affect the course of parasite infections. We wanted to determine if the exposure to diethylstilbestrol (DES), an estrogen agonist, to both male and female mice affected the immune response and their susceptibility toT. crassicepscysticercosis. In all infected groups, females showed higher parasite loads than males, and neonatal DES administration did not modify this pattern. In the spleen, noninfected mice showed sex-related differences in the percentage of the CD8+ subpopulation, but DES decreased the percentage of CD3+, CD19+, and CD8+ subpopulations in infected mice. In the mesenteric lymphatic node (MNL), DES showed a dimorphic effect in the percentage of CD19+ cells. Regarding estrogen receptor alpha (ER-α) expression, DES treatment induced a reduction in the expression of this receptor in both noninfected female and male mice in the spleen, which was decreased only in males in CD3+ and CD8+ lymphocytes in MNL cell subpopulations. Our study is the first one to demonstrate that DES neonatal treatment in male and female mice affects the immune cell percentage, without effect on the susceptibility toT. crassicepscysticercosis.

Breast cancer is a disease in which abnormal cell proliferation leads to uncontrolled growth of breast tissue. Breast cancer can start in various areas of the breast, such as the ducts, lobes, and, in some cases, the intervening tissue. For many years, inflammatory infiltrates in tumors have been suggested to reflect the origin of cancer; however, little is known about the function of chronic inflammation in malignant transformation. Sex hormones are associated with many types of cancer, such as colon, cervical, and especially breast. Estrogen-dependent breast cancer (EDBC) constitutes approximately 50% to 80% of all cases of breast cancer. Furthermore, estrogen-dependency is linked to the initiation of malignancy by promoting the growth and proliferation of mammary cells and it is related to prognosis and treatment. The correlation between sex hormones and breast cancer has been recognized for decades, but the mechanisms of this association remain unknown. In recent years, a more enriched landscape of this relationship has emerged. Intervention by the immune system in cancer begins with the detection of transformed cells and their proliferation-—not with the defense and effort to restrain an established tumoral mass. In the late 1950s, Burnet introduced the immunosurveillance theory, which proposes that immune system cells detect and attack transformed cells, eliciting an adaptive response that succeeds and eliminates them or fails, leading to the formation of a tumoral mass and cancer onset. Conversely, sex hormones are important modulators of the immune system. Growing evidence demonstrates a reciprocal relationship between sex steroids and the immune system. Because the innate immune response determines the type of adaptive immunity that develops, hormonal effects on the former can affect adaptive responses. The sex steroids estrogens, progesterone, and testosterone regulate the growth, differentiation, survival, and function of many cell types that mediate homeostasis, immunity, and breast cancer. The presence of sex steroid receptors on immune cells indicates that sex steroids exert their effects by binding to them. Sex steroids and immunity are inextricably linked, and their mutual regulation influences the maintenance of the immune balance. Understanding the mechanisms of action of sex steroids on immune cells is paramount to developing novel therapies for chronic diseases that are associated to immune dysregulation, such as breast cancer. This chapter describes the risk factors in breast cancer, the hormonal factors that are involved, the immunological response toward cancer, and the effects of sex steroids on immune system cells and their implications for the incidence of breast cancer.

Chemokines are small proteins that primarily regulate the traffic of leukocytes under homeostatic conditions and during specific immune responses. The chemokine-chemokine receptor system comprises almost 50 chemokines and approximately 20 chemokine receptors; thus, there is no unique ligand for each receptor and the binding of different chemokines to the same receptor might have disparate effects. Complicating the system further, these effects depend on the cellular milieu. In cancer, although chemokines are associated primarily with the generation of a protumoral microenvironment and organ-directed metastasis, they also mediate other phenomena related to disease progression, such as angiogenesis and even chemoresistance. Therefore, the chemokine system is becoming a target in cancer therapeutics. We review the emerging data and correlations between chemokines/chemokine receptors and breast cancer, their implications in cancer progression, and possible therapeutic strategies that exploit the chemokine system.

Macrophages are critically involved in the interaction betweenT. crassicepsand 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 F4/80himacrophages of BALB/c mice infected withTaenia crassiceps. Peritoneal macrophages from both sexes of mice were exposed toT. crassicepstotal 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 duringT. crassicepsinfection is a possible mechanism that underlies the differential sex-associated susceptibility displayed by the mouse gender.

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

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.

We evaluated thein vitroeffects 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.

The effects of testosterone (T4) and dihydrotestosterone (DHT) on the survival of the helminth cestode parasite Taenia crassiceps, as well as their effects on actin, tubulin and myosin expression and their assembly into the excretory system of flame cells are described in this paper. In vitro evaluations on parasite viability, flow cytometry, confocal microscopy, video-microscopy of live flame cells, and docking experiments of androgens interacting with actin, tubulin, and myosin were conducted. Our results show that T4 and DHT reduce T. crassiceps viability in a dose- and time-dependent fashion, reaching 90% of mortality at the highest dose used (40 ng/ml) and time exposed (10 days) in culture. Androgen treatment does not induce differences in the specific expression pattern of actin, tubulin, and myosin isoforms as compared with control parasites. Confocal microscopy demonstrated a strong disruption of the parasite tegument, with reduced assembly, shape, and motion of flame cells. Docking experiments show that androgens are capable of affecting parasite survival and flame cell morphology by directly interacting with actin, tubulin and myosin without altering their protein expression pattern. We show that both T4 and DHT are able to bind actin, tubulin, and myosin affecting their assembly and causing parasite intoxication due to impairment of flame cell function. Live flame cell video microscopy showing a reduced motion as well changes in the shape of flame cells are also shown. In summary, T4 and DHT directly act on T. crassiceps cysticerci through altering parasite survival as well as the assembly and function of flame cells.

Intraperitoneal infection with Taenia crassiceps cysticerci in mice alters several behaviors, including sexual, aggressive, and cognitive function. Cytokines and their receptors are produced in the central nervous system (CNS) by specific neural cell lineages under physiological and pathological conditions, regulating such processes as neurotransmission. This study is aimed to determine the expression patterns of cytokines in various areas of the brain in normal and T. crassiceps-infected mice in both genders and correlate them with the pathology of the CNS and parasite counts. IL-4, IFN-γ, and TNF-α levels in the hippocampus and olfactory bulb increased significantly in infected male mice, but IL-6 was downregulated in these regions in female mice. IL-1β expression in the hippocampus was unaffected by infection in either gender. Our novel findings demonstrate a clear gender-associated pattern of cytokine expression in specific areas of the brain in mammals that parasitic infection can alter. Thus, we hypothesize that intraperitoneal infection is sensed by the CNS of the host, wherein cytokines are important messengers in the host-parasite neuroimmunoendocrine network.

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.

Susceptibility to malaria differs between females and males, and this sexual dimorphism may have important implications for the effects of vaccines and drugs. However, little is known about the mechanisms mediating these sexual differences. Because the main differences between sexes are dictated by sex hormones, we studied the effect of gonadal steroids on immune responses to malaria in CBA/Ca mice. We decreased sex hormones levels by gonadectomy and evaluated the splenic index and the cells involved in the immune response, including T cells (CD3(+), CD4(+), CD8(+) and NK(+)), B cells and macrophages (Mac-3(+)) in the spleens of female and male mice infected with Plasmodium berghei ANKA. In addition, we measured antibody and cytokine levels in blood. Gonadectomy increased T(+) and B(+) splenic cells in both sexes but increased Mac-3(+) cells only in male mice. By contrast, gonadectomy decreased the NK(+) cell population only in male mice. In general, female mice developed higher antibody levels than males. Contrary to our expectations, gonadectomy increased the synthesis of IgG1, IgG2b, IgG3, and total IgG in female mice, indicating negative regulation of antibody production by female sex hormones. Gonadectomy increased the synthesis of tumour necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) only in female mice, suggesting that female sex hormones have anti-inflammatory properties. This work demonstrates that the levels of sex hormones affect the immune response and should be considered when designing malaria vaccines.

Cytokines are highly inducible, secretory proteins that mediate intercellular communication in the immune system. They are grouped into several protein families that are referred to as tumor necrosis factors, interleukins, interferons, and colony-stimulating factors. In recent years, it has become clear that some of these proteins as well as their receptors are produced in the organisms under physiological and pathological conditions. The exact initiation process of breast cancer is unknown, although several hypotheses have emerged. Inflammation has been proposed as an important player in tumor initiation, promotion, angiogenesis, and metastasis, all phenomena in which cytokines are prominent players. The data here suggest that cytokines play an important role in the regulation of both induction and protection in breast cancer. This knowledge could be fundamental for the proposal of new therapeutic approaches to particularly breast cancer and other cancer-related disorders.

In the Acknowledgments section, an antibody donation has been left out, so it should be disclosed. It is corrected as follows.

Karen Nava-Castro1, Romel Hernandez-Bello2, Sae Muniz-Hernandez3 and Jorge Morales-Montor2 1Departamento de Infectologia e Inmunologia, Instituto Nacional de Perinatologia, Secretaria de Salud 2Departamento de Inmunologia, Instituto de Investigaciones Biomedicas, Universidad Nacional Autonoma de Mexico 3Subdireccion de Investigacion Basica, Instituto Nacional de Cancerologia, Secretaria de Salud Mexico

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.

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.