Ciro Estrada-Chávez

High-Level Expression of NRAMP1 in Peripheral Blood Cells and Tuberculous Granulomas from Mycobacterium bovis-Infected Bovines

ABSTRACT By Western blotting, we demonstrate high-level expression of NRAMP1 proteins in peripheral blood cells and granulomas ofMycobacterium bovis-infected bovines. Immunohistochemistry of granulomatous lesions showed heavily labeled epithelioid macrophages and Langhans cells. These data suggest that M. bovisinfection enhances NRAMP1 expression and that active tuberculosis can occur despite this response.

Lipopolysaccharide induces the expression of an autocrine prolactin loop enhancing inflammatory response in monocytes

BackgroundProlactin from pituitary gland helps maintain homeostasis but it is also released in immune cells where its function is not completely understood. Pleiotropic functions of prolactin (PRL) might be mediated by different isoforms of its receptor (PRLr).MethodsThe aim of this study was to investigate the relationship between the eventual synthesis of PRL and PRLr isoforms with the inflammatory response in monocytes. We used THP-1 and monocytes isolated from healthy subjects stimulated with lipopolysaccharide (LPS). Western blot, real time PCR and immunocytochemistry were performed to identify both molecules. The bioactivity of the PRL was assessed using a bioassay and ELISA to detect pro inflammatory cytokines.ResultsPRLr mRNA and PRL mRNA were synthesized in THP-1 monocytes activated with LPS with peaks of 300-fold and 130-fold, respectively. The long (100 kDa) and the intermediate (50 kDa) isoforms of PRLr and big PRL (60 kDa) were time-dependent upregulated for monocytes stimulated with LPS. This expression was confirmed in monocytes from healthy subjects. The PRLr intermediate isoform and the big PRL were found soluble in the culture media and later in the nucleus in THP-1 monocytes stimulated with LPS. Big PRL released by monocytes showed bioactivity in Nb2 Cells, and both PRL and PRLr, synthesized by monocytes were related with levels of nitrites and proinflammatory citokines.ConclusionsOur results suggest the expression of a full-autocrine loop of PRL enhances the inflammatory response in activated monocytes. This response mediated by big PRL may contribute to the eradication of potential pathogens during innate immune response in monocytes but may also contribute to inflammatory disorders.

Prolactin in Inflammatory Response

Prolactin (PRL) is a peptide hormone produced by the pituitary gland and diverse extrapituitary sites, which triggers activation of various signaling pathways after binding to its receptor (PRLr) resulting in the activation of specific genes associated with the pleiotropic activities of PLR. To date, various PRLr isoforms have been described, generated by post-transcriptional or post-translational processes. PRL has been associated with the modulation of a variety of actions in the immune response and inflammatory processes in several physiologic and pathologic conditions. However, PRL can have opposite effects, which might be regulated by interaction with the various isoforms of PRLR and PRL variants, as well as the cellular and molecular microenvironment influence.

High expression of prolactin receptor is associated with cell survival in cervical cancer cells

BackgroundThe altered expression of prolactin (PRL) and its receptor (PRLR) has been implicated in breast and other types of cancer. There are few studies that have focused on the analysis of PRL/PRLR in cervical cancer where the development of neoplastic lesions is influenced by the variation of the hormonal status. The aim of this study was to evaluate the expression of PRL/PRLR and the effect of PRL treatment on cell proliferation and apoptosis in cervical cancer cell lines.ResultsHigh expression of multiple PRLR forms and PRLvariants of 60–80 kDa were observed in cervical cancer cell lines compared with non-tumorigenic keratinocytes evaluated by Western blot, immunofluorecence and real time PCR. Treatment with PRL (200 ng/ml) increased cell proliferation in HeLa cells determined by the MTT assay at day 3 and after 1 day a protective effect against etoposide induced apoptosis in HeLa, SiHa and C-33A cervical cancer cell lines analyzed by the TUNEL assay.ConclusionsOur data suggests that PRL/PRLR signaling could act as an important survival factor for cervical cancer. The use of an effective PRL antagonist may provide a better therapeutic intervention in cervical cancer.

An approach to the immunophenotypic features of circulating CD4⁺NKG2D⁺ T cells in invasive cervical carcinoma.

BackgroundNKG2D, an activating immunoreceptor, is primarily restricted to NK cells and CD8+ T cells. The existence of an atypical cytotoxic CD4+NKG2D+ T cell population has also been found in patients with autoimmune dysfunctions. Nonetheless, contradictory evidence has categorized this population with a regulatory rather than cytotoxic role in other situations. These confounding data have led to the proposal that two distinct CD4+NKG2D+ T cell subsets might exist. The immune response elicited in cervical cancer has been characterized by apparent contradictions concerning the role that T cells, in particular T-helper cells, might be playing in the control of the tumor growth. Interestingly, we recently reported a substantial increase in the frequency of CD4+NKG2D+ T cells in patients with cervical intraepithelial neoplasia grade-1. However, whether this particular population is also found in patients with more advanced cervical lesions or whether they express a distinctive phenotype remains still to be clarified. In this urgent study, we focused our attention on the immunophenotypic characterization of CD4+NKG2D+ T cells in patients with well-established cervical carcinoma and revealed the existence of at least two separate CD4+NKG2D+ T cell subsets defined by the co-expression or absence of CD28.ResultsPatients with diagnosis of invasive cervical carcinoma were enrolled in the study. A group of healthy individuals was also included. Multicolor flow cytometry was used for exploration of TCR alpha/beta, CD28, CD158b, CD45RO, HLA-DR, CD161, and CD107a. A Luminex-based cytokine kit was used to quantify the levels of pro- and anti-inflammatory cytokines. We found an increased percentage of CD4+NKG2D+ T cells in patients with cervical cancer when compared with controls. Accordingly with an increase of CD4+NKG2D+ T cells, we found decreased CD28 expression. The activating or degranulation markers HLA-DR, CD161, and CD107a were heterogeneously expressed. The levels of IL-1beta, IL-2, TNF-alpha, and IL-10 were negatively correlated with the percentages of CD4+NKG2D+ T cells in patients with cervical carcinoma.ConclusionsTaken together, our results reveal the existence of two separate CD4+NKG2D+ T cell subsets defined by the co-expression or absence of CD28, the latter more likely to be present in patients with cervical cancer.

The extrapituitary prolactin promoter polymorphism is associated with rheumatoid arthritis and anti-CCP antibodies in Mexican population

Prolactin (PRL) is a hormone-cytokine that has been involved in autoimmunity due to its immunoregulatory and lymphoproliferative effects. It is produced by various extrapituitary sites including immune cells, under control of a superdistal promoter that contains a single nucleotide polymorphism -1149 G/T previously associated with rheumatoid arthritis (RA) susceptibility in European population. The aim of this study was to investigate the association of the extrapituitary PRL -1149 G/T promoter polymorphism with clinical parameters, clinical activity and disability indices in RA patients from Western Mexico and to analyze the PRL mRNA expression according to the PRL -1149 G/T promoter polymorphism in total leucocytes from RA patients and controls. We conducted a case-control study that included 258 RA patients and 333 control subjects (CS). The DNA samples were genotyped using the PCR-RFLP method and the PRL mRNA expression was determined by quantitative real time PCR. PRL serum levels and antibodies to cyclic citrullinated peptides (anti-CCP) were measured with ELISA. We found significant differences in the genotype (p=0.022) and allelic (p=0.046) distribution of the polymorphism between RA patients and control subjects. According to the dominant genetic model, there is an association between the T allele (GT+TT genotypes) and decreased RA susceptibility in comparison to the G allele carriers (GG genotype) (OR 0.64, 95% CI 0.45-0.92; p=0.011). The T allele carriers (GT+TT genotypes) had lower titers of anti-CCP antibodies in comparison to the G allele carriers (GG genotype) (median, 66 U/mL vs. 125 U/mL; p=0.03). Furthermore, the GG homozygotes had higher PRL mRNA expression in comparison to the GT heterozygotes, and this latter with respect to the TT homozygotes, in both groups (RA: 1>0.72>0.19; CS: 1>0.54>0.28). However, PRL serum levels were similar in both groups. Our results suggest that the PRL -1149 T allele is a genetic marker for decreased RA susceptibility and is associated with lower titers of anti-CCP antibodies in Mexican population. We also suggest influence of genotype upon PRL mRNA expression.

Prolactin modulates cytokine production induced by culture filtrate proteins of M. bovis through different signaling mechanisms in THP1 cells

The immunomodulatory functions of prolactin (PRL) are well recognized. Augmented PRL plasma levels were observed in patients with advanced tuberculosis (TB). Recently, we have reported that LPS and Mycobacterium bovis (M. bovis) induced differential expression of PRL receptor (PRLR) isoforms in THP-1 cells and bovine macrophages, respectively. The aim of this work was to determine whether PRL should be considered as a potential modulator of the signaling pathways and cytokine synthesis, induced by culture filtrate protein (CFP) from M. bovis in THP-1 monocytes. The THP-1 cells were stimulated with PRL (20ng/mL), M. bovis CFP (50μg/mL). PRLR as well as phosphorylated STAT3, STAT5, Akt1/2/3, ERK1/2 and p38 expression were evaluated by Western blot. IL1-β, TNF-α, IL-6, IL-12, IL-8, and IL-10 concentrations were measured by ELISA. Our results demonstrated that the expression pattern of PRLR short isoforms is induced by M. bovis CFP. M bovis CFP induced phosphorylation of Akt2, ERK1/2, p38, STAT3, and STAT5 pathways. In turn, PRL only activated the JAK2/STAT3-5 signaling pathway. However, when combined both stimuli, PRL significantly increased STAT3-5 phosphorylation and downregulated Akt2, ERK1/2, and p38 phosphorylation. As expected, M. bovis CFP induced substantial amounts of IL1-β, IL-6, TNF-α, IL-8, IL-12, and IL-10. However, the PRL costimulation considerably decreased IL1-β, TNF-α, and IL-12 secretion, and increased IL-10 production. This results suggest that up-regulation of IL-10 by PRL might be modulating the pro-inflammatory response against mycobacterial antigens through the MAPK pathway.

Detection of Mycobacterium tuberculosis complex by PCR in fresh cheese from local markets in Hidalgo, Mexico.

The objective of this study was to identify the presence of Mycobacterium tuberculosis complex bacterial DNA in samples extracted from fresh cheeses; 95 samples of fresh cheese were obtained from municipal markets in the state of Hidalgo, in central Mexico, and were analyzed in triplicate. The exogenous control for the amplification was the mitochondrial gene for cytochrome b (cyt-b). M. tuberculosis complex DNA was detected by nested-PCR amplification of a fragment of the mpb70 gene in six samples, four of which were obtained from regions with enzootic bovine tuberculosis. These results suggest that cheeses prepared with raw milk contaminated with M. bovis are being sold and consumed by humans, which may cause tuberculosis.

Mycobacterium bovis DNA Detection in Colostrum as a Potential Indicator of Vaccination Effectiveness against Bovine Tuberculosis

ABSTRACT Bovine tuberculosis (bTB) remains a problem on many dairy farms in Mexico, as well as a public health risk. We previously found a high frequency of Mycobacterium bovis DNA in colostrum from dairy cows using a nested PCR to detect mpb70. Since there are no reliable in vivo tests to determine the effectiveness of booster Mycobacterium bovis BCG vaccination against bTB, in this work we monitored M. bovis DNA in colostrum by using this nested PCR. In order to decrease the risk of adverse reactions in animals likely containing viable M. bovis, a single application of BCG and a subunit vaccine (EEP-1) formulated with M. bovis culture filtrate proteins (CFP) and a copolymer as the adjuvant was performed in tuberculin skin test-negative cattle (TST−), while TST reactor animals (TST+) received EEP-1 only. Booster immunization using EEP-1 was applied to both groups, 2 months after primary vaccination to whole herds and 12 months later to lactating cows. Colostrum samples were collected from 6 farms where the cows were vaccinated over a 12-month period postvaccination and, for comparison, from one control farm where the cows were not vaccinated with comparable bTB prevalence. We observed an inverse relationship between the frequency of M. bovis DNA detection and time postvaccination at the first (P < 0.001) and second (P < 0.0001) 6-month periods. Additionally, the concentration of gamma interferon (IFN-γ) was higher in mpb70 PCR-positive colostrum samples (P = 0.0003). These results suggest that M. bovis DNA frequency in colostrum could be a potentially useful biomarker for bTB vaccine efficacy on commercial dairy farms.

Divergent macrophage responses to Mycobacterium bovis among naturally exposed uninfected and infected cattle

Mycobacterium bovis, the causative agent of bovine tuberculosis (TB), is a successful pathogen that remains an important global threat to livestock. Cattle naturally exposed to M. bovis normally become reactive to the M. bovis‐purified protein derivative (tuberculin) skin test; however, some individuals remain negative, suggesting that they may be resistant to infection. To better understand host innate resistance to infection, 26 cattle from herds with a long history of high TB prevalence were included in this study. We investigated the bactericidal activity, the production of reactive oxygen and nitrogen species and the TB‐related gene expression profile after in vitro M. bovis challenge of monocyte‐derived macrophages from cattle with TB (n=17) and from non‐infected, exposed cattle (in‐contacts, n=9). The disease status was established based on the tuberculin skin test and blood interferon‐gamma test responses, the presence of visible lesions at inspection on abattoirs and the histopathology and culture of M. bovis. Although macrophages from TB‐infected cattle enabled M. bovis replication, macrophages from healthy, exposed cattle had twofold lower bacterial loads, overproduced nitric oxide and had lower interleukin (IL)‐10 gene expression (P⩽0.05). Higher mRNA expression levels of inducible nitric oxide synthase, C‐C motif chemokine ligand 2 and IL‐12 were observed in macrophages from all in‐contact cattle than in macrophages from their TB‐infected counterparts, which expressed more tumour necrosis factor‐α; however, the differences were not statistically significant owing to individual variation. These results confirm that macrophage bactericidal responses have a crucial role in innate resistance to M. bovis infection in cattle.