International Journal of Molecular Sciences, Apr 14, 2021
Inflammation is the main driver of the tumor initiation and progression in colitis-associated col... more Inflammation is the main driver of the tumor initiation and progression in colitis-associated colorectal cancer (CAC). Recent findings have indicated that the signal transducer and activator of transcription 6 (STAT6) plays a fundamental role in the early stages of CAC, and STAT6 knockout (STAT6 -/-) mice are highly resistant to CAC development. Regulatory T (Treg) cells play a major role in coordinating immunomodulation in cancer; however, the role of STAT6 in the induction and function of Treg cells is poorly understood. To clarify the contribution of STAT6 to CAC, STAT6 -/-and wild type (WT) mice were subjected to an AOM/DSS regimen, and the frequency of peripheral and local Treg cells was determined during the progression of CAC. When STAT6 was lacking, a remarkable reduction in tumor growth was observed, which was associated with decreased inflammation and an increased number of CD4+CD25+Foxp3+ cells in the colon, circulation, and spleen, including an over-expression of TGF-beta, IL-10, and Foxp3, compared to WT mice, during the early stages of CAC development. Conversely, WT mice showed an inverse frequency of Treg cells compared with STAT6 -/-mice, which was followed by intestinal tumor formation. Increased mucosal inflammation, histological damage, and tumorigenesis were restored to levels observed in WT mice when an early inhibition/depletion of Treg cells was performed in STAT6 -/-mice. Thus, with STAT6 deficiency, an increased number of Treg cells induce resistance against tumorigenesis, arresting tumor-promoting inflammation. We reported a direct role of STAT6 in the induction and function of Treg cells during CAC development and suggest that STAT6 is a potential target for the modulation of immune response in colitis and CAC.
A ROLE FOR 17-j-ESTRADIOL IN IMMUNOENDOCRINE REGULATION OF MURINE CYSTICERCOSIS
ABSTRAcr: In experimental murine cysticercosis caused by Taenia crassiceps, parasite reproduction... more ABSTRAcr: In experimental murine cysticercosis caused by Taenia crassiceps, parasite reproduction is favored by thymectomy or by orchidectomy, and restricted by ovariectomy. Hormonal reconstitution experiments showed that 17-fl-estradiol increases parasite numbers whereas 5-a-dihydrotestosterone was ineffective. Parasite numbers decreased with increments in cellular immunity but were insensitive to antibody levels. A possible immunoendocrinological interaction involving estrogen as a depressor of cellular immunity is envisaged in the control of cysticercosis.
Depletion of Treg cells induces an increased activation of T-CD4+ and T-CD8+ cells during colorectal cancer
The Journal of Immunology
Colorectal Cancer (CAC) is the second most commonly diagnosed cancer in women and the third in me... more Colorectal Cancer (CAC) is the second most commonly diagnosed cancer in women and the third in men in North America and Europe. CAC is associated with inflammatory responses where intestinal pathology is caused by a T-cell dysregulation that concludes in an imbalance between T activated (Tact) and T regulatory (Treg) cells. Treg cells are CD4+Foxp3+ cells that actively suppress pathological and physiological immune responses, contributing to the maintenance of immune homeostasis. It has been suggested a tumor-promoting function for Treg cells in CAC, but the kinetics of Treg cells during CAC development is poorly known. Thereby we used a mouse model of CAC induced by azoxymethane and three cycles of dextran sodium sulfate (DSS, 2%). We analyzed the percentage of Treg cells in blood, spleen and mesenteric lymph nodes (MLN) in each cycle. A significant reduction of Treg cells in blood and spleen during the first cycle, but increased percentage of Treg cells during the second and third...
Data from Lack of STAT6 Attenuates Inflammation and Drives Protection against Early Steps of Colitis-Associated Colon Cancer
Colitis-associated colon cancer (CAC) is one of the most common malignant neoplasms and a leading... more Colitis-associated colon cancer (CAC) is one of the most common malignant neoplasms and a leading cause of death. The immunologic factors associated with CAC development are not completely understood. Signal transducer and activator of transcription 6 (STAT6) is part of an important signaling pathway for modulating intestinal immune function and homeostasis. However, the role of STAT6 in colon cancer progression is unclear. Following CAC induction in wild-type (WT) and STAT6-deficient mice (STAT6–/–), we found that 70% of STAT6–/– mice were tumor-free after 8 weeks, whereas 100% of WT mice developed tumors. STAT6–/– mice displayed fewer and smaller colorectal tumors than WT mice; this reduced tumorigenicity was associated with decreased proliferation and increased apoptosis in the colonic mucosa in the early steps of tumor progression. STAT6–/– mice also exhibited reduced inflammation, diminished concentrations COX2 and nuclear β-catenin protein in the colon, and decreased mRNA expr...
Trypanosoma cruzi is the etiologic agent of Chagas disease, a parasitic disease of great medical ... more Trypanosoma cruzi is the etiologic agent of Chagas disease, a parasitic disease of great medical importance on the American continent. Trypomastigote infection’s initial step in a mammalian host is vital for the parasite’s life cycle. A trypomastigote’s surface presents many molecules, some of which have been proposed to be involved in the infection process, including a glycoprotein family called mucin-associated surface proteins (MASPs). This work describes a 49-kDa molecule (MASP49) that belongs to this family and is expressed mainly on the surfaces of amastigotes and trypomastigotes but can be found in extracts and the membrane-enriched fractions of epimastigotes. This protein is partially GPI-anchored to the surface and has a role during the internalization process, since its blockade with specific antibodies decreases parasite entry into Vero cells by 62%. This work shows that MASP49 binds to peritoneal macrophages and rat cardiomyocytes, undergoes glycosylation via galactose N...
Down-modulation of colitis-associated colorectal cancer development by treatment with helminth-derived molecules
The Journal of Immunology
A role for chronic inflammation in tumor development has been well established and supported in b... more A role for chronic inflammation in tumor development has been well established and supported in both, animal and epidemiological studies. A classic association between inflammation and cancer is colitis-associated colorectal cancer (CAC). Helminth infections and helminth-derived molecules have been recognized as inducers of immunoregulation. Taenia crassiceps modulates inflammatory diseases such as type 1 diabetes, colitis, and autoimmune encephalomyelitis. Here we analyzed the pathophysiologic implication of T. crassiceps excreted/secreted (TcES) products on CAC development. CAC was induced in BALB/c mice with azoxymethane followed by 3 cycles of 2% dextran sodium sulfate exposure to elicit intestinal inflammation. After cycle 1, mice received i.p. TcES (200 μg/mouse 3-times/week) until the end of the experiment. On days 20, 40 and 68 after CAC induction mice were killed to evaluate colonic inflammation, proliferation, and tumorigenesis. Untreated mice developed tumors as early as ...
The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), ha... more The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been one of the most catastrophic diseases observed in recent years. It has reported nearly 550 million cases worldwide, with more than 6.35 million deaths. In Mexico, an increased incidence and mortality of this disease were observed, where the immune response has been involved in the magnitude and severity. A critical version of the disease is accompanied by hyperinflammatory responses, with cytokine and defective cellular responses. A detailed understanding of the role of molecules and cells in the immune response during COVID-19 disease may help to generate effective protection mechanisms, improving those we already have. Here we analyzed blood samples obtained from patients at the Hospital Regional de Alta Especialidad de Ixtapaluca (HRAEI), Mexico, which were classified according to living guidance for clinical management of COVID-19 by the World Health Organization: asymptomatic, mild, severe, and critical disease. We observed increased interleukin (IL)-6 levels and a T-CD8 + and T-CD4 + cell reduction correlated with the critical disease version. Importantly, here, we described a significant reduction of CD11b + CD45 high CD14 low monocytes during severe disease, which displayed a non-classical profile, expressing IL-10, transforming growth factor (TGF)-β, and indoleamine 2,3-dioxygenase (IDO)1 molecule. Moreover, CD11b + CD45 high CD14 low monocytes obtained from infected one-dose vaccinated patients (Pfizer® vaccine) who suffered minimal symptoms showed simultaneously a dual classical and no-classical profile expressing pro-and anti-inflammatory cytokines. These results suggest that blood monocytes expressing a dual pro-and anti-inflammatory profile might be a predictive marker for protection in the Mexican population during COVID-19 disease. • Exacerbated immune response is associated with COVID-19 severe disease. • Dual monocyte activation profile is crucial for predicting protection during COVID-19. • Vaccination is crucial to induce the dual activation profile in monocytes.
Signal transducer and activator of transcription 1 (STAT1) acts as a tumor suppressor molecule in... more Signal transducer and activator of transcription 1 (STAT1) acts as a tumor suppressor molecule in colitis-associated colorectal cancer (CAC), particularly during the very early stages, modulating immune responses and controlling mechanisms such as apoptosis and cell proliferation. Previously, using an experimental model of CAC, we reported increased intestinal cell proliferation and faster tumor development, which were consistent with more signs of disease and damage, and reduced survival in STAT1-/- mice, compared with WT counterparts. However, the mechanisms through which STAT1 might prevent colorectal cancer progression preceded by chronic inflammation are still unclear. Here, we demonstrate that increased tumorigenicity related to STAT1 deficiency could be suppressed by IL-17 neutralization. The blockade of IL-17 in STAT1-/- mice reduced the accumulation of CD11b+Ly6ClowLy6G+ cells resembling granulocytic myeloid-derived suppressor cells (MDSCs) in both spleen and circulation. A...
Inflammation is the main driver of the tumor initiation and progression in colitis-associated col... more Inflammation is the main driver of the tumor initiation and progression in colitis-associated colorectal cancer (CAC). Recent findings have indicated that the signal transducer and activator of transcription 6 (STAT6) plays a fundamental role in the early stages of CAC, and STAT6 knockout (STAT6−/−) mice are highly resistant to CAC development. Regulatory T (Treg) cells play a major role in coordinating immunomodulation in cancer; however, the role of STAT6 in the induction and function of Treg cells is poorly understood. To clarify the contribution of STAT6 to CAC, STAT6−/− and wild type (WT) mice were subjected to an AOM/DSS regimen, and the frequency of peripheral and local Treg cells was determined during the progression of CAC. When STAT6 was lacking, a remarkable reduction in tumor growth was observed, which was associated with decreased inflammation and an increased number of CD4+CD25+Foxp3+ cells in the colon, circulation, and spleen, including an over-expression of TGF-beta...
A close connection between inflammation and the risk of developing colon cancer has been suggeste... more A close connection between inflammation and the risk of developing colon cancer has been suggested in the last few years. It has been estimated that patients diagnosed with some types of inflammatory bowel disease, such as ulcerative colitis or Crohn’s disease, have up to a 30% increased risk of developing colon cancer. However, there is also evidence showing that the activation of anti-inflammatory pathways, such as the IL-4 receptor-mediated pathway, may favor the development of colon tumors. Using an experimental model of colitis-associated colon cancer (CAC), we found that the decrease in tumor development in global IL4Rα knockout mice (IL4RαKO) was apparently associated with an inflammatory response mediated by the infiltration of M1 macrophages (F480+TLR2+STAT1+) and iNOS expression in colon tissue. However, when we developed mice with a specific deletion of IL4Rα in macrophages (LysMcreIL4Rα−/lox mice) and subjected them to CAC, it was found that despite presenting a large in...
Current State of the Art in Cysticercosis and Neurocysticercosis, 2021
In the last decades, we have learned some critical lessons about the relationship between the hum... more In the last decades, we have learned some critical lessons about the relationship between the human body and its interaction with many infectious diseases, where regularly, the immune system has a major role in protection. We learned to differentiate between the immune response occurring in either an intracellular or extracellular parasitic infection, between innate and adaptive immune response, between either inflammatory or anti-inflammatory responses, and finally, we learned to recognize very particular mechanisms, such as the inability of the immune system to respond during very particular scenarios, such as the inability of T cells to both proliferate and produce cytokines even after their exposure to mitogens or specific-antigens. Along with our increase in the knowledge in immunology, we figured out that immunoregulation and immunosuppression are processes used by many parasites to reduce the capacity of the immune system to eliminate them, and to persist in the host favoring...
Macrophage galactose-C type lectin (MGL)1 receptor is involved in the recognition of Trypanosoma ... more Macrophage galactose-C type lectin (MGL)1 receptor is involved in the recognition of Trypanosoma cruzi (T. cruzi) parasites and is important for the modulation of the innate and adaptive immune responses. However, the mechanism by which MGL1 promotes resistance to T. cruzi remains unclear. Here, we show that MGL1 knockout macrophages (MGL1−/− Mφ) infected in vitro with T. cruzi were heavily parasitized and showed decreased levels of reactive oxygen species (ROS), nitric oxide (NO), IL-12 and TNF-α compared to wild-type macrophages (WT Mφ). MGL1−/− Mφ stimulated in vitro with T. cruzi antigen (TcAg) showed low expression of TLR-2, TLR-4 and MHC-II, which resulted in deficient splenic cell activation compared with similar co-cultured WT Mφ. Importantly, the activation of p-ERK1/2, p-c-Jun and p-NF-κB p65 were significantly reduced in MGL1−/− Mφ exposed to TcAg. Similarly, procaspase 1, caspase 1 and NLRP3 inflammasome also displayed a reduced expression that was associated with low IL...
Glutathione (GSH) transferase (GST) is an essential enzyme in cestodes for the detoxification of ... more Glutathione (GSH) transferase (GST) is an essential enzyme in cestodes for the detoxification of xenobiotics. In Taenia solium, two GSTs (Ts25GST and Ts26GST kDa) were isolated as a fraction (SGSTF) by GSH-Sepharose-4B. Both are located on the tegument. Immunization assays with SGSTF reduced up to 90% of the parasitic load in a murine model of cysticercosis. It prompted us to investigate how SGSTF induces this protective immune response. To test it, we exposed peritoneal macrophages to SGSTF for 24 h; such exposure favored the production of IL-12, TNF, and IL-10 as well as the expression of nitric oxide synthase 2 inducible (Nos2) and CD86, but did not induce the expression of chitinase-like 3 (Chil3). Confocal microscopy showed that the macrophages internalize the SGSTF which co-localized after 1 h with MHC-II in their plasma membranes. Macrophages exposed to SGSTF and co-cultured with anti-CD3 pre-activated T CD4+ cells, enhanced the proliferation of CD4+ cells, induced high inter...
Colorectal cancer (CRC) is an important health issue worldwide, accounting for the third place of... more Colorectal cancer (CRC) is an important health issue worldwide, accounting for the third place of cancer incidence. Chronic inflammation, as seen in Crohn's disease and ulcerative colitis, is the most important risk factor for developing CRC, as it favours neoplastic transformation by enhancing epithelial cell turnover in the colonic mucosa. Treatments for CRC need to be improved; currently they are not specific and have several secondary effects in patients. The main objective of this work was to evaluate a new therapeutic strategy against a colitis-related colorectal cancer in vivo and in vitro by targeting mTOR-signaling and lactate dehydrogenase A. Together, these mechanisms directly affect tumor energetics. In this study we evaluated a better and more efficient triple therapy against a chronic inflammation-associated CRC in vivo and in vitro. After the development of tumors, mice were treated intraperitoneally during a forty-day period with single drugs or different combinations of Metformin, Sodium Oxamate and Doxorubicin. Targeted inhibition of the mTOR pathway, lactate dehydrogenase A and the concurrent use of Doxorubicin (called in this work as triple therapy), leaded to a notable reduction in the number and size of tumors in mice, and, a significant pro-inflammatory cytokines reduction Besides, we showed that treated cells were induced to early autophagy, and apoptosis cell death. Our results represent a novel and robust therapeutic strategy for overcoming CRC by means of targeting central molecular pathways in cancer by the combination of Metformin, Oxamate, and Doxorubicin leading to a rapid tumor growth inhibition and a dramatic colorectal crypt restoration. Besides, drug combination resulted in a notable reduction of anti-inflammatory cytokines.
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Papers by Luis Terrazas