Molecular transition of SARS-CoV-2 from critical patients during the first year of the COVID-19 pandemic in Mexico City.

Background: The SARS-CoV-2 virus has caused unprecedented mortality since its emergence in late 2019. The continuous evolution of the viral genome through the concerted action of mutational forces has produced distinct variants that became dominant, challenging human immunity and vaccine development. Aim and methods: In this work, through an integrative genomic approach, we describe the molecular transition of SARS-CoV-2 by analyzing the viral whole genome sequences from 50 critical COVID-19 patients recruited during the first year of the pandemic in Mexico City. Results: Our results revealed differential levels of the evolutionary forces across the genome and specific mutational processes that have shaped the first two epidemiological waves of the pandemic in Mexico. Through phylogenetic analyses, we observed a genomic transition in the circulating SARS-CoV-2 genomes from several lineages prevalent in the first wave to a dominance of the B.1.1.519 variant (defined by T478K, P681H, and T732A mutations in the spike protein) in the second wave. Conclusion: This work contributes to a better understanding of the evolutionary dynamics and selective pressures that act at the genomic level, the prediction of more accurate variants of clinical significance, and a better comprehension of the molecular mechanisms driving the evolution of SARS-CoV-2 to improve vaccine and drug development.

Inflammation- and cancer-related microRNAs in rat renal cortex after subchronic exposure to fluoride.

The proximal tubule is a target of subchronic exposure to fluoride (F) in the kidney. Early markers are used to classify kidney damage, stage, and prognosis. MicroRNAs (miRNAs) are small sequences of non-coding single-stranded RNA that regulate gene expression and play an essential role in developing many pathologies, including renal diseases. This study aimed to evaluate the expression of Cytokine-Chemokine molecules (IL-1α/1ß/4/6/10, INF-γ, MIP-1α, MCP-1, RANTES, and TGF ß1/2/3) and inflammation-related miRNAs to evidence the possible renal mechanisms involved in subchronic exposure to F. Total protein and miRNAs were obtained from the renal cortex of male Wistar rats exposed to 0, 15 and 50 mg NaF/L through drinking water during 40 and 80 days. In addition, cytokines-chemokines were analyzed by multiplexing assay, and a panel of 77 sequences of inflammatory-related miRNAs was analyzed by qPCR. The results show that cytokines-chemokines expression was concentration- and time-dependent with F, where the 50 mg NaF/L were the main altered groups. The miRNAs expression resulted in statistically significant differences in thirty-four miRNAs in the 50 mg NaF/L groups at 40 and 80 days. Furthermore, a molecular interaction network analysis was performed. The relevant pathways modified by subchronic exposure to fluoride were related to extracellular matrix-receptor interaction, Mucin type O-glycan biosynthesis, Gap junction, and miRNAs involved with renal cell carcinoma. Thus, F-induced cytokines-chemokines suggest subchronic inflammation; detecting miRNAs related to cancer and proliferation indicates a transition from renal epithelium to pathologic tissue after fluoride exposure.

Dendritic cells drive profibrotic inflammation and aberrant T cell polarization in systemic sclerosis.

OBJECTIVES: SSc is a devastating autoimmune disease characterized by fibrosis and obliterative vasculopathy affecting the skin and visceral organs. While the processes mediating excessive extracellular matrix deposition and fibroblast proliferation are clear, the exact link between autoimmunity and fibrosis remains elusive. Th17 cells have been proposed as critical drivers of profibrotic inflammation during SSc, but little is known about the immune components supporting their pathogenic role. Our aim was to determine cytokine responses of stimulated monocyte-derived dendritic cells (Mo-DCs) and to determine how they influence T-cell cytokine production in SSc. MATERIAL AND METHODS: Dendritic cells (DCs) activate and shape T cell differentiation by producing polarizing cytokines. Hence, we investigated the cytokine responses of monocyte-derived DCs (Mo-DCs) from patients with limited cutaneous SSc (lcSSc), diffuse cutaneous SSc (dcSSc) and healthy controls (HCs) after stimulation with toll-like receptor (TLR) agonists. Also, using co-culture assays, we analysed T cell subpopulations after contact with autologous TLR-activated Mo-DCs. RESULTS: In general, we observed an increased production of Th17-related cytokines like IL-1ß, IL-17F, IL-21 and IL-22 by SSc compared with HC Mo-DCs, with variations between lcSSc vs dcSSc and early- vs late-stage subgroups. Noticeably, we found a significant increment in IL-33 production by Mo-DCs in all SSc cases regardless of their clinical phenotype. Strikingly, T cells displayed Th2, Th17 and dual Th2-Th17 phenotypes after exposure to autologous TLR-stimulated Mo-DCs from SSc patients but not HCs. These changes were pronounced in individuals with early-stage dcSSc and less significant in the late-stage lcSSc subgroup. CONCLUSIONS: Our findings suggest that functional alterations of DCs promote immune mechanisms favouring the aberrant T cell polarization and profibrotic inflammation behind clinical SSc heterogeneity.

Association of the Transmembrane Serine Protease-2 (TMPRSS2) Polymorphisms with COVID-19.

SARS-CoV-2 uses the ACE2 receptor and the cellular protease TMPRSS2 for entry into target cells. The present study aimed to establish if the TMPRSS2 polymorphisms are associated with COVID-19 disease. The study included 609 patients with COVID-19 confirmed by RT-PCR test and 291 individuals negative for the SARS-CoV-2 infection confirmed by RT-PCR test and without antibodies anti-SARS-CoV-2. Four TMPRSS2 polymorphisms (rs12329760, rs2298659, rs456298, and rs462574) were determined using the 5'exonuclease TaqMan assays. Under different inheritance models, the rs2298659 (pcodominant2 = 0.018, precessive = 0.006, padditive = 0.019), rs456298 (pcodominant1 = 0.014, pcodominant2 = 0.004; pdominant = 0.009, precessive = 0.004, padditive = 0.0009), and rs462574 (pcodominant1 = 0.017, pcodominant2 = 0.004, pdominant = 0.041, precessive = 0.002, padditive = 0.003) polymorphisms were associated with high risk of developing COVID-19. Two risks (ATGC and GAAC) and two protectives (GAGC and GAGT) haplotypes were detected. High levels of lactic acid dehydrogenase (LDH) were observed in patients with the rs462574AA and rs456298TT genotypes (p = 0.005 and p = 0.020, respectively), whereas, high heart rate was present in patients with the rs462574AA genotype (p = 0.028). Our data suggest that the rs2298659, rs456298, and rs462574 polymorphisms independently and as haplotypes are associated with the risk of COVID-19. The rs456298 and rs462574 genotypes are related to high levels of LDH and heart rate.

Possible Role of Matrix Metalloproteinases and TGF-ß in COVID-19 Severity and Sequelae.

The costs of coronavirus disease 2019 (COVID-19) are devastating. With millions of deaths worldwide, specific serological biomarkers, antiviral agents, and novel therapies are urgently required to reduce the disease burden. For these purposes, a profound understanding of the pathobiology of COVID-19 is mandatory. Notably, the study of immunity against other respiratory infections has generated reference knowledge to comprehend the paradox of the COVID-19 pathogenesis. Past studies point to a complex interplay between cytokines and other factors mediating wound healing and extracellular matrix (ECM) remodeling that results in exacerbated inflammation, tissue injury, severe manifestations, and a sequela of respiratory infections. This review provides an overview of the immunological process elicited after severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Also, we analyzed available data about the participation of matrix metalloproteinases (MMPs) and transforming growth factor-beta (TGF-ß) in immune responses of the lungs. Furthermore, we discuss their possible implications in severe COVID-19 and sequela, including pulmonary fibrosis, and remark on the potential of these molecules as biomarkers for diagnosis, prognosis, and treatment of convalescent COVID-19 patients. Our review provides a theoretical framework for future research aimed to discover molecular hallmarks that, combined with clinical features, could serve as therapeutic targets and reliable biomarkers of the different clinical forms of COVID-19, including convalescence.

Differential Leukocyte Expression of IFITM1 and IFITM3 in Patients with Severe Pandemic Influenza A(H1N1) and COVID-19.

Interferon-induced transmembrane (IFITM) proteins mediate protection against enveloped viruses by blocking membrane fusion at endosomes. IFITM1 and IFITM3 are crucial for protection against influenza, and various single nucleotide polymorphisms altering their function have been linked to disease susceptibility. However, bulk IFITM1 and IFITM3 mRNA expression dynamics and their correlation with clinical outcomes have not been extensively addressed in patients with respiratory infections. In this study, we evaluated the expression of IFITM1 and IFITM3 in peripheral leukocytes from healthy controls and individuals with severe pandemic influenza A(H1N1) or coronavirus disease 2019 (COVID-19). Comparisons between participants grouped according to their clinical characteristics, underlying disease, and outcomes showed that the downregulation of IFITM1 was a distinctive characteristic of severe pandemic influenza A(H1N1) that correlated with outcomes, including mortality. Conversely, increased IFITM3 expression was a common feature of severe pandemic influenza A(H1N1) and COVID-19. Using a high-dose murine model of infection, we confirmed not only the downregulation of IFITM1 but also of IFITM3 in the lungs of mice with severe influenza, as opposed to humans. Analyses in the comparative cohort also indicate the possible participation of IFITM3 in COVID-19. Our results add to the evidence supporting a protective function of IFITM proteins against viral respiratory infections in humans.

GPR55 and GPR119 Receptors Contribute to the Processing of Neuropathic Pain in Rats.

Orphan G-protein-coupled receptors (GPCR) comprise a large number of receptors which are widely distributed in the nervous system and represent an opportunity to identify new molecular targets in pain medicine. GPR55 and GPR119 are two orphan GPCR receptors whose physiological function is unclear. The aim was to explore the participation of spinal GPR55 and GPR119 in the processing of neuropathic pain in rats. Mechanical allodynia was evaluated using von Frey filaments. Protein localization and modulation were measured by immunohistochemistry and western blotting, respectively. Intrathecal administration of CID16020046 (selective GPR55 antagonist) or AS1269574 (selective GPR119 agonist) produced a dose-dependent antiallodynic effect, whereas O1062 (GPR55 agonist) and G-protein antagonist peptide dose-dependently prevented the antiallodynic effect of CID16020046 and AS1269574, respectively. Both GPR55 and GPR119 receptors were expressed in spinal cord, dorsal root ganglia and sciatic nerve, but only GPR119 was downregulated after 14 days of spinal nerve ligation. Data suggest that GPR55 and GPR119 participate in the processing of neuropathic pain and could be useful targets to manage neuropathic pain disorders.

Corrigendum: CXCL17 Is a Specific Diagnostic Biomarker for Severe Pandemic Influenza A(H1N1) That Predicts Poor Clinical Outcome.

[This corrects the article DOI: 10.3389/fimmu.2021.633297.].

Phenotype of Peripheral NK Cells in Latent, Active, and Meningeal Tuberculosis.

The mechanisms underlying the immunopathology of tuberculous meningitis (TBM), the most severe clinical form of extrapulmonary tuberculosis (TB), are not understood. It is currently believed that the spread of Mycobacterium tuberculosis (Mtb) from the lung is an early event that occurs before the establishment of adaptive immunity. Hence, several innate immune mechanisms may participate in the containment of Mtb infection and prevent extrapulmonary disease manifestations. Natural killer (NK) cells participate in defensive processes that distinguish latent TB infection (LTBI) from active pulmonary TB (PTB). However, their role in TBM is unknown. Here, we performed a cross-sectional analysis of circulating NK cellCID="C008" value="s" phenotype in a prospective cohort of TBM patients (n = 10) using flow cytometry. Also, we addressed the responses of memory-like NK cell subpopulations to the contact with Mtb antigens in vitro. Finally, we determined plasma levels of soluble NKG2D receptor ligands in our cohort of TBM patients by enzyme-linked immunosorbent assay (ELISA). Our comparative groups consisted of individuals with LTBI (n = 11) and PTB (n = 27) patients. We found that NK cells from TBM patients showed lower absolute frequencies, higher CD69 expression, and poor expansion of the CD45RO+ memory-like subpopulation upon Mtb exposure in vitro compared to LTBI individuals. In addition, a reduction in the frequency of CD56brightCD16- NK cells characterized TBM patients but not LTBI or PTB subjects. Our study expands on earlier reports about the role of NK cells in TBM showing a reduced frequency of cytokine-producing cells compared to LTBI and PTB.

Clinical and Immunological Factors That Distinguish COVID-19 From Pandemic Influenza A(H1N1).

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), is a global health threat with the potential to cause severe disease manifestations in the lungs. Although COVID-19 has been extensively characterized clinically, the factors distinguishing SARS-CoV-2 from other respiratory viruses are unknown. Here, we compared the clinical, histopathological, and immunological characteristics of patients with COVID-19 and pandemic influenza A(H1N1). We observed a higher frequency of respiratory symptoms, increased tissue injury markers, and a histological pattern of alveolar pneumonia in pandemic influenza A(H1N1) patients. Conversely, dry cough, gastrointestinal symptoms and interstitial lung pathology were observed in COVID-19 cases. Pandemic influenza A(H1N1) was characterized by higher levels of IL-1RA, TNF-α, CCL3, G-CSF, APRIL, sTNF-R1, sTNF-R2, sCD30, and sCD163. Meanwhile, COVID-19 displayed an immune profile distinguished by increased Th1 (IL-12, IFN-γ) and Th2 (IL-4, IL-5, IL-10, IL-13) cytokine levels, along with IL-1ß, IL-6, CCL11, VEGF, TWEAK, TSLP, MMP-1, and MMP-3. Our data suggest that SARS-CoV-2 induces a dysbalanced polyfunctional inflammatory response that is different from the immune response against pandemic influenza A(H1N1). Furthermore, we demonstrated the diagnostic potential of some clinical and immune factors to differentiate both diseases. These findings might be relevant for the ongoing and future influenza seasons in the Northern Hemisphere, which are historically unique due to their convergence with the COVID-19 pandemic.

CXCL17 Is a Specific Diagnostic Biomarker for Severe Pandemic Influenza A(H1N1) That Predicts Poor Clinical Outcome.

The C-X-C motif chemokine ligand 17 (CXCL17) is chemotactic for myeloid cells, exhibits bactericidal activity, and exerts anti-viral functions. This chemokine is constitutively expressed in the respiratory tract, suggesting a role in lung defenses. However, little is known about the participation of CXCL17 against relevant respiratory pathogens in humans. Here, we evaluated the serum levels and lung tissue expression pattern of CXCL17 in a cohort of patients with severe pandemic influenza A(H1N1) from Mexico City. Peripheral blood samples obtained on admission and seven days after hospitalization were processed for determinations of serum CXCL17 levels by enzyme-linked immunosorbent assay (ELISA). The expression of CXCL17 was assessed by immunohistochemistry (IHQ) in lung autopsy specimens from patients that succumbed to the disease. Serum CXCL17 levels were also analyzed in two additional comparative cohorts of coronavirus disease 2019 (COVID-19) and pulmonary tuberculosis (TB) patients. Additionally, the expression of CXCL17 was tested in lung autopsy specimens from COVID-19 patients. A total of 122 patients were enrolled in the study, from which 68 had pandemic influenza A(H1N1), 24 had COVID-19, and 30 with PTB. CXCL17 was detected in post-mortem lung specimens from patients that died of pandemic influenza A(H1N1) and COVID-19. Interestingly, serum levels of CXCL17 were increased only in patients with pandemic influenza A(H1N1), but not COVID-19 and PTB. CXCL17 not only differentiated pandemic influenza A(H1N1) from other respiratory infections but showed prognostic value for influenza-associated mortality and renal failure in machine-learning algorithms and regression analyses. Using cell culture assays, we also identified that human alveolar A549 cells and peripheral blood monocyte-derived macrophages increase their CXCL17 production capacity after influenza A(H1N1) pdm09 virus infection. Our results for the first time demonstrate an induction of CXCL17 specifically during pandemic influenza A(H1N1), but not COVID-19 and PTB in humans. These findings could be of great utility to differentiate influenza and COVID-19 and to predict poor prognosis specially at settings of high incidence of pandemic A(H1N1). Future studies on the role of CXCL17 not only in severe pandemic influenza, but also in seasonal influenza, COVID-19, and PTB are required to validate our results.

Expression of Surfactant Protein D Distinguishes Severe Pandemic Influenza A(H1N1) from Coronavirus Disease 2019.

The differentiation between influenza and coronavirus disease 2019 (COVID-19) could constitute a diagnostic challenge during the ongoing winter owing to their clinical similitude. Thus, novel biomarkers are required to enable making this distinction. Here, we evaluated whether the surfactant protein D (SP-D), a collectin produced at the alveolar epithelium with known immune properties, was useful to differentiate pandemic influenza A(H1N1) from COVID-19 in critically ill patients. Our results revealed high serum SP-D levels in patients with severe pandemic influenza but not those with COVID-19. This finding was validated in a separate cohort of mechanically ventilated patients with COVID-19 who also showed low plasma SP-D levels. However, plasma SP-D levels did not distinguish seasonal influenza from COVID-19 in mild-to-moderate disease. Finally, we found that high serum SP-D levels were associated with death and renal failure among severe pandemic influenza cases. Thus, our studies have identified SP-D as a unique biomarker expressed during severe pandemic influenza but not COVID-19.

Risk factors associated with the development of interstitial lung abnormalities.

BACKGROUND: Around 8-10% of individuals over 50 years of age present interstitial lung abnormalities (ILAs), but their risk factors are uncertain. METHODS: From 817 individuals recruited in our lung ageing programme at the Mexican National Institute of Respiratory Diseases, 80 (9.7%) showed ILAs and were compared with 564 individuals of the same cohort with normal high-resolution computed tomography to evaluate demographic and functional differences, and with 80 individuals randomly selected from the same cohort for biomarkers. We evaluated MUC5B variant rs35705950, telomere length, and serum levels of matrix metalloproteinase (MMP)-1, MMP-2, MMP-3, MMP-7, MMP-8, MMP-9, MMP-12, MMP-13, interleukin (IL)-6, surfactant protein (SP)-D, α-Klotho and resistin. RESULTS: Individuals with ILAs were usually males (p<0.005), older than controls (p<0.0001), smokers (p=0.01), with a greater frequency of MUC5B rs35705950 (OR 3.5, 95% CI 1.3-9.4; p=0.01), and reduced diffusing capacity of the lung for carbon monoxide and oxygen saturation. Resistin, IL-6, SP-D, MMP-1, MMP-7 and MMP-13 were significantly increased in individuals with ILAs. Resistin (12±5 versus 9±4 ng·mL-1; p=0.0005) and MMP-13 (357±143 versus 298±116 pg·mL-1; p=0.004) were the most increased biomarkers. On follow-up (24±18 months), 18 individuals showed progression which was associated with gastro-oesophageal reflux disease (OR 4.1, 95% CI 1.2-12.9; p=0.02) and in females with diabetes mellitus (OR 5.3, 95% CI 1.0-27.4; p=0.01). CONCLUSIONS: Around 10% of respiratory asymptomatic individuals enrolled in our lung ageing programme show ILAs. Increased serum concentrations of pro-inflammatory molecules and MMPs are associated with ILAs.

Antigens of Mycobacterium tuberculosis Stimulate CXCR6+ Natural Killer Cells.

Natural killer (NK) cells participate in immunity against several pathogens by exerting cytotoxic and cytokine-production activities. Some NK cell subsets also mediate recall responses that resemble memory of adaptive lymphocytes against antigenic and non-antigenic stimuli. The C-X-C motif chemokine receptor 6 (CXCR6) is crucial for the development and maintenance of memory-like responses in murine NK cells. In humans, several subsets of tissue-resident and circulating NK cells with different functional properties express CXCR6. However, the role of CXCR6+ NK cells in immunity against relevant human pathogens is unknown. Here, we addressed whether murine and human CXCR6+ NK cells respond to antigens of Mycobacterium tuberculosis (Mtb). For this purpose, we evaluated the immunophenotype of hepatic and splenic CXCR6+ NK cells in mice exposed to a cell-wall (CW) extract of Mtb strain H37Rv. Also, we characterized the expression of CXCR6 in peripheral NK cells from active pulmonary tuberculosis (ATB) patients, individuals with latent TB infection (LTBI), and healthy volunteer donors (HD). Furthermore, we evaluated the responses of CXCR6+ NK cells from HD, LTBI, and ATB subjects to the in vitro exposure to CW preparations of Mtb H37Rv and Mtb HN878. Our results showed that murine hepatic CXCR6+ NK cells expand in vivo after consecutive administrations of Mtb H37Rv CW to mice. Remarkably, pooled hepatic and splenic, but not isolated splenic NK cells from treated mice, enhance their cytokine production capacity after an in vitro re-challenge with H37Rv CW. In humans, CXCR6+ NK cells were barely detected in the peripheral blood, although slightly significative increments in the percentage of CXCR6+, CXCR6+CD49a-, CXCR6+CD49a+, and CXCR6+CD69+ NK cells were observed in ATB patients as compared to HD and LTBI individuals. In contrast, the expansion of CXCR6+CD49a- and CXCR6+CD69+ NK cells in response to the in vitro stimulation with Mtb H37Rv was higher in LTBI individuals than in ATB patients. Finally, we found that Mtb HN878 CW generates IFN-γ-producing CXCR6+CD49a+ NK cells. Our results demonstrate that antigens of both laboratory-adapted and clinical Mtb strains are stimulating factors for murine and human CXCR6+ NK cells. Future studies evaluating the role of CXCR6+ NK cells during TB are warranted.

A unique immune signature of serum cytokine and chemokine dynamics in patients with Zika virus infection from a tropical region in Southern Mexico.

OBJECTIVES: To describe the kinetics of circulating cytokines and chemokines in humans with ZIKAV infection. METHODS: Serum levels of different immune mediators in patients with ZIKAV infection were measured at distinct stages of the disease, as well as in culture supernatants from human monocytes infected with a clinical ZIKAV isolate. We also looked for clinical features associated with specific immune signatures among symptomatic patients. RESULTS: We evaluated 23 ZIKAV-infected patients. Their mean age was 32 ± 8.3 years and 65% were female. ZIKAV patients showed elevated IL-9, IL-17A, and CXCL10 levels at acute stages of the disease. At day 28, levels of CCL4 and CCL5 were increased, whereas IL-1RA, CXCL8 and CCL2 were decreased. At baseline, IL-7 was increased among patients with headache, whereas CCL2, and CCL3 were decreased in patients with bleeding and rash, respectively. Our clinical ZIKAV isolate induced a broad immune response in monocytes that did not resemble the signature observed in ZIKAV patients. CONCLUSIONS: We showed a unique immune signature in our cohort of ZIKAV-infected patients. Our study may provide valuable evidence helpful to identify immune correlates of protection against ZIKAV.

MicroRNA Expression in Cutaneous Lupus: A New Window to Understand Its Pathogenesis.

BACKGROUND: The role of miRNAs in the pathogenesis of cutaneous lupus has not been studied. OBJECTIVE: It was to assess the levels of a selected panel of circulating miRNAs that could be involved in the regulation of the immune response, inflammation, and fibrosis in cutaneous lupus. METHODS: It was a cross-sectional study. We included 22 patients with subacute (SCLE) and 20 with discoid (DLE) lesions, and 19 healthy donors (HD). qRT-PCR for miRNA analysis, flow cytometry in peripheral blood, and skin immunohistochemistry were performed to determine the distribution of CD4 T cells and regulatory cells and their correlation with circulating miRNAs. RESULTS: miR-150, miR-1246, miR-21, miR-23b, and miR-146 levels were downregulated in SCLE vs. HD. miR-150, miR-1246, and miR-21 levels were downregulated in DLE vs. HD. miR-150, miR-1246, and miR-21 levels were downregulated in DLE γ + with miR-1246 in SCLE, whereas CD123+/CD196+/IDO+ cells were positively associated with miR-150 in DLE. In the tissue, CD4+/IL-4+ and CD20+/IL-10+ cells were positively associated with miR-21 and CD4+/IFN-γ + with miR-1246 in SCLE, whereas CD123+/CD196+/IDO+ cells were positively associated with miR-150 in DLE. In the tissue, CD4+/IL-4+ and CD20+/IL-10+ cells were positively associated with miR-21 and CD4+/IFN-ß, thyroid hormone, and cancer signaling pathways were shared between miR-21, miR-31, miR-23b, miR-146a, miR-1246, and miR-150. CONCLUSIONS: A downregulation of miR-150, miR-1246, and miR-21 in both CLE varieties vs. HD. miR-150, miR-1246, and miR-21 levels were downregulated in DLE.

Deregulated MicroRNAs in Cancer-Associated Fibroblasts from Front Tumor Tissues of Lung Adenocarcinoma as Potential Predictors of Tumor Promotion.

Cancer-associated fibroblasts (CAFs) are the main component of the tumor stroma and promote tumor progression through several mechanisms. Recent evidence indicates that small noncoding RNAs, microRNAs (miRNAs), play key roles in CAF tumor-promoting properties; however, the role of miRNAs in lung cancer-associated fibroblasts remains poorly defined. We characterized the differential miRNA expression profile of fibroblasts isolated from matched tumor front (F-CAFs), inner tumor (In-CAFs), and normal adjacent (NFs) tissues from four lung adenocarcinoma patients (ADs) using microarray analysis. Proliferation and invasion assays of A549 human lung cancer cells in the presence of conditioned medium from F-CAFs, In-CAFs or NFs were performed to assess tumorigenic properties. Ten identified candidate miRNAs in F-CAFs, In-CAFs and NFs from 12 ADs were then validated by RT-PCR. Both F-CAFs and In-CAFs enhanced the proliferation and invasion of A549 cells compared with NFs; moreover, F-CAFs showed a significantly stronger effect than In-CAFs. RT-PCR validation demonstrated three downregulated miRNAs in F-CAFs compared with NFs (miR-145-3p, miR-299-3p, and miR-505-3p), two in F-CAFs compared with In-CAFs (miR-410-3p and miR-485-5p), but no differentially expressed miRNAs between In-CAFs and NFs. Further target-gene prediction and pathway enrichment analysis indicated that deregulated miRNAs in F-CAFs showed significant associations with "pathways in cancer" (miR-145-3p, miR-299-3p and miR-410-3p), "Wnt signaling pathway" (miR-410-3p and miR-505-3p), and "TGF-beta signaling pathway" (miR-410-3p). Importantly, a tumor-promoting growth factor targeted by those miRNAs, VEGFA, was upregulated in F-CAFs compared with NFs, as judged by RT-PCR. In conclusion, deregulated miRNAs in F-CAFs are potentially associated with CAF tumor-promoting properties.

Interleukin-17 limits hypoxia-inducible factor 1α and development of hypoxic granulomas during tuberculosis.

Mycobacterium tuberculosis (Mtb) is a global health threat, compounded by the emergence of drug-resistant strains. A hallmark of pulmonary tuberculosis (TB) is the formation of hypoxic necrotic granulomas, which upon disintegration, release infectious Mtb. Furthermore, hypoxic necrotic granulomas are associated with increased disease severity and provide a niche for drug-resistant Mtb. However, the host immune responses that promote the development of hypoxic TB granulomas are not well described. Using a necrotic Mtb mouse model, we show that loss of Mtb virulence factors, such as phenolic glycolipids, decreases the production of the proinflammatory cytokine IL-17 (also referred to as IL-17A). IL-17 production negatively regulates the development of hypoxic TB granulomas by limiting the expression of the transcription factor hypoxia-inducible factor 1α (HIF1α). In human TB patients, HIF1α mRNA expression is increased. Through genotyping and association analyses in human samples, we identified a link between the single nucleotide polymorphism rs2275913 in the IL-17 promoter (-197G/G), which is associated with decreased IL-17 production upon stimulation with Mtb cell wall. Together, our data highlight a potentially novel role for IL-17 in limiting the development of hypoxic necrotic granulomas and reducing disease severity in TB.

Angiotensin II Type 1 receptor (AGTR1) gene polymorphisms are associated with vascular manifestations in patients with systemic sclerosis (SSc).

INTRODUCTION: Systemic sclerosis (SSc) shows variable clinical expression in different ethnic groups; vascular abnormalities are a prominent feature of this disease and its clinical expression may be influenced by genetic factors. PATIENTS AND METHODS: Herein, we describe 15 polymorphisms of the renin-angiotensin-aldosterone pathway in 170 Mexican admixed SSc patients (defined as patients with Mexican ancestry for at least 3 generations) and 199 healthy controls. We determined the presence of angiotensin II Type 1 receptor (AGTR1), angiotensin converting enzyme (ACE) and Endothelin 1 single nucleotide polymorphisms (SNPs) using 5' exonuclease TaqMan genotyping assays on a 7900HT real-time fast polymerase chain reaction (PCR) system. RESULTS: These polymorphisms had a similar distribution between SSc patients and controls, but we found that the AGTR1 G-680T (rs275652) (p = 0.02; OR 3.5; 95%CI 1.2-10.4) and AGTR1 A-119G (rs275653) (p = 0.008; OR 4.2; 95% CI 1.5-12.1) polymorphisms were associated with severe vascular involvement in our SSc patients. CONCLUSIONS: This is the first report of the association of these polymorphisms with vasculopathy in Mexican admixed SSc patients. Our findings suggested that the angiotensin II Type 1 receptor genotype may influence the clinical expression of vasculopathy in these patients. Functional analyses should follow.

High levels of anti-tuberculin (IgG) antibodies correlate with the blocking of T-cell proliferation in individuals with high exposure to Mycobacterium tuberculosis.

OBJECTIVES: To determine the effect of anti-tuberculin antibodies in the T-cell proliferation in response to tuberculin and Candida antigens in individuals with different levels of tuberculosis (TB) risk. METHODS: Sixteen high-risk TB individuals, 30 with an intermediate TB risk (group A), and 45 with a low TB risk (group B), as well as 49 control individuals, were studied. Tuberculin skin test (TST) results were analyzed and serum levels of antibodies (IgG and IgM) against purified protein derivative (PPD) were measured by ELISA. Tuberculin and Candida antigens were used to stimulate T-cell proliferation in the presence of human AB serum or autologous serum. RESULTS: High levels of anti-tuberculin IgG antibodies were found to be significantly associated with the blocking of T-cell proliferation responses in cultures stimulated with tuberculin but not with Candida antigens in the presence of autologous serum. This phenomenon was particularly frequent in high-risk individuals with high levels of anti-tuberculin IgG antibodies in the autologous serum when compared to the other risk groups, which exhibited lower levels of anti-tuberculin antibodies. CONCLUSIONS: Although cellular immunity plays a central role in the protection against TB, humoral immunity is critical in the control of Mycobacterium tuberculosis infection in high-risk individuals with latent TB infection.