The lncARSR/PTEN/Akt/nuclear factor-kappa B feedback regulatory loop contributes to doxorubicin resistance in hepatocellular carcinoma.

Chemoresistance is a major obstacle to hepatocellular carcinoma (HCC) chemotherapy. Our previous study found that long noncoding RNA lncARSR (lncRNA Activated in RCC with Sunitinib Resistance) activated Akt signaling via repressing phosphatase and tensin homolog (PTEN) during doxorubicin resistance in HCC. The purpose of this study is to further explore lncARSR-mediated mechanisms and roles during doxorubicin resistance in HCC. The expression of lncARSR was detected by real-time quantitative polymerase chain reaction (qPCR). Nuclear factor-kappa B (NF-κB) activity was detected by NF-κB luciferase reporter assays, western blot, and NF-κB transcription factor assays. The effects of NF-κB on lncARSR were detected by chromatin immunoprecipitation assay, promoter luciferase reporter assay, and real-time qPCR. The effects of lncARSR/Akt/NF-κB on doxorubicin resistance were detected by Cell Counting Kit-8 assay, capsase-3 activity assay, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. lncARSR activated NF-κB signaling through activation of Akt. NF-κB transactivated lncARSR through directly binding lncARSR promoter and increasing lncARSR promoter activity. Akt transactivated lncARSR via activating NF-κB signaling. Thus, lncARSR, Akt, and NF-κB formed a positive feedback regulatory loop in HCC. Through this feedback loop, lncARSR auto-regulated its transcription. Drug sensitivity assays showed that the lncARSR/Akt/NF-κB feedback regulatory loop promoted doxorubicin resistance in HCC. These findings identified the lncARSR/Akt/NF-κB feedback regulatory loop in HCC, which represent potential therapeutic targets for improving doxorubicin sensitivity in HCC.

Diagnosis, treatment and genetic analysis of a case of familial aldosteronism type II with WFS1 gene mutation.

Primary aldosteronism (PA) is a disease characterized by hypertension and hypokalemia due to the excessive aldosterone secretion from the adrenal cortex, which leads to the retention of both water and sodium, and the inhibition of the renin-angiotensin system as well. Familial hyperaldosteronism type II (FH-II) is known as an autosomal dominant hereditary disease, which is a scarce cause of PA. In this report, we cllected the clinical data of a patient with repeated hypertension and hypokalemia of uncertain diagnosis since 2014. Nevertheless, we discovered by genetic sequencing in 2021 that the CLCN2 and WFS1 gene mutation of the patient, whose mother belongs to heterozygote genotype and father belongs to wild-type genotype. Combined with a series of endocrine function tests and imaging studies, the patient was finally certified her suffering from FH-II and WFS1 gene mutation. By summarizing and analyzing the characteristics and genetic test results of this case, we recommended gene sequencing for patients with PA whose etiology is difficult to be determined clinically. This case also provides new clinical data for subsequent genetic studies of the disease.

A CD200R-CD28 fusion protein appropriates an inhibitory signal to enhance T-cell function and therapy of murine leukemia.

Acute myeloid leukemia (AML), the most common adult acute leukemia in the United States, has the poorest survival rate, with 26% of patients surviving 5 years. Adoptive immunotherapy with T cells genetically modified to recognize tumors is a promising and evolving treatment option. However, antitumor activity, particularly in the context of progressive leukemia, can be dampened both by limited costimulation and triggering of immunoregulatory checkpoints that attenuate T-cell responses. Expression of CD200 (OX2), a negative regulator of T-cell function that binds CD200 receptor (CD200R), is commonly increased in leukemia and other malignancies and is associated with poor prognosis in leukemia patients. To appropriate and redirect the inhibitory effects of CD200R signaling on transferred CD8+ T cells, we engineered CD200R immunomodulatory fusion proteins (IFPs) with the cytoplasmic tail replaced by the signaling domain of the costimulatory receptor, CD28. An analysis of a panel of CD200R-CD28 IFP constructs revealed that the most effective costimulation was achieved in IFPs containing a dimerizing motif and a predicted tumor-T-cell distance that facilitates localization to the immunological synapse. T cells transduced with the optimized CD200R-CD28 IFPs exhibited enhanced proliferation and effector function in response to CD200+ leukemic cells in vitro. In adoptive therapy of disseminated leukemia, CD200R-CD28-transduced leukemia-specific CD8 T cells eradicated otherwise lethal disease more efficiently than wild-type cells and bypassed the requirement for interleukin-2 administration to sustain in vivo activity. The transduction of human primary T cells with the equivalent human IFPs increased proliferation and cytokine production in response to CD200+ leukemia cells, supporting clinical translation. This trial was registered at www.clinicaltrials.gov as #NCT01640301.

Peripheral CD8+ T cell tolerance to self-proteins is regulated proximally at the T cell receptor.

CD8(+) T cell tolerance, although essential for preventing autoimmunity, poses substantial obstacles to eliciting immune responses to tumor antigens, which are generally overexpressed normal proteins. Development of effective strategies to overcome tolerance for clinical applications would benefit from elucidation of the immunologic mechanism(s) regulating T cell tolerance to self. To examine how tolerance is maintained in vivo, we engineered dual-T cell receptor (TCR) transgenic mice in which CD8(+) T cells recognize two distinct antigens: a foreign viral-protein and a tolerizing self-tumor protein. Encounter with peripheral self-antigen rendered dual-TCR T cells tolerant to self, but these cells responded normally through the virus-specific TCR. Moreover, proliferation induced by virus rescued function of tolerized self-tumor-reactive TCR, restoring anti-tumor activity. These studies demonstrate that peripheral CD8(+) T cell tolerance to self-proteins can be regulated at the level of the self-reactive TCR complex rather than by central cellular inactivation and suggest an alternate strategy to enhance adoptive T cell immunotherapy.

Cell-intrinsic abrogation of TGF-ß signaling delays but does not prevent dysfunction of self/tumor-specific CD8 T cells in a murine model of autochthonous prostate cancer.

Adoptive T cell therapy (ACT) for the treatment of established cancers is actively being pursued in clinical trials. However, poor in vivo persistence and maintenance of antitumor activity of transferred T cells remain major problems. TGF-ß is a potent immunosuppressive cytokine that is often expressed at high levels within the tumor microenvironment, potentially limiting T cell-mediated antitumor activity. In this study, we used a model of autochthonous murine prostate cancer to evaluate the effect of cell-intrinsic abrogation of TGF-ß signaling in self/tumor-specific CD8 T cells used in ACT to target the tumor in situ. We found that persistence and antitumor activity of adoptively transferred effector T cells deficient in TGF-ß signaling were significantly improved in the cancerous prostate. However, over time, despite persistence in peripheral lymphoid organs, the numbers of transferred cells in the prostate decreased and the residual prostate-infiltrating T cells were no longer functional. These findings reveal that TGF-ß negatively regulates the accumulation and effector function of transferred self/tumor-specific CD8 T cells and highlight that, when targeting a tumor Ag that is also expressed as a self-protein, additional substantive obstacles are operative within the tumor microenvironment, potentially hampering the success of ACT for solid tumors.

Abrogation of SRC homology region 2 domain-containing phosphatase 1 in tumor-specific T cells improves efficacy of adoptive immunotherapy by enhancing the effector function and accumulation of short-lived effector T cells in vivo.

T cell expression of inhibitory proteins can be a critical component for the regulation of immunopathology owing to self-reactivity or potentially exuberant responses to pathogens, but it may also limit T cell responses to some malignancies, particularly if the tumor Ag being targeted is a self-protein. We found that the abrogation of Src homology region 2 domain-containing phosphatase-1 (SHP-1) in tumor-reactive CD8(+) T cells improves the therapeutic outcome of adoptive immunotherapy in a mouse model of disseminated leukemia, with benefit observed in therapy employing transfer of CD8(+) T cells alone or in the context of also providing supplemental IL-2. SHP-1(-/-) and SHP-1(+/+) effector T cells were expanded in vitro for immunotherapy. Following transfer in vivo, the SHP-1(-/-) effector T cells exhibited enhanced short-term accumulation, followed by greater contraction, and they ultimately formed similar numbers of long-lived, functional memory cells. The increased therapeutic effectiveness of SHP-1(-/-) effector cells was also observed in recipients that expressed the tumor Ag as a self-antigen in the liver, without evidence of inducing autoimmune toxicity. SHP-1(-/-) effector CD8(+) T cells expressed higher levels of eomesodermin, which correlated with enhanced lysis of tumor cells. Furthermore, reduction of SHP-1 expression in tumor-reactive effector T cells by retroviral transduction with vectors that express SHP-1-specific small interfering RNA, a translatable strategy, also exhibited enhanced antitumor activity in vivo. These studies suggest that abrogating SHP-1 in effector T cells may improve the efficacy of tumor elimination by T cell therapy without affecting the ability of the effector cells to persist and provide a long-term response.

An Integrated Analytical Approach for Screening Functional Post-Translational Modification Sites in Metabolic Enzymes.

Post-translational modifications (PTMs) are pivotal in the orchestration of diverse physiological and pathological processes. Despite this, the identification of functional PTM sites within the vast amount of data remains challenging. Conventionally, those PTM sites are discerned through labor-intensive and time-consuming experiments. Here, we developed an integrated analytical approach for the identification of functional PTM sites on metabolic enzymes via a screening process. Through gene ontology (GO) analysis, we identified 269 enzymes with lysine 2-hydroxyisobutyrylation (Khib) from our proteomics data set of Escherichia coli. The first round of screening was performed based on the enzyme structures/predicted structures using the TM-score engineer, a tool designed to evaluate the impact of PTM on the protein structure. Subsequently, we examined the influence of Khib on the enzyme-substrate interactions through both static and dynamic analyses, molecular docking, and molecular dynamics simulation. Ultimately, we identified NfsB K181hib and ThiF K83hib as potential functional sites. This work has established a novel analytical approach for the identification of functional protein PTM sites, thereby contributing to the understanding of Khib functions.

Multilevel factors associated with HIV-related stigma among women living with HIV in Guangdong Province, China: a social-ecological model-informed study.

BACKGROUND: HIV-related stigma continues to hinder optimal HIV care, and its determinants should be understood at multiple levels. Based on the social-ecological model, this study aimed to explore factors associated with HIV-related stigma among women living with HIV in Guangdong Province, China. METHODS: A cross-sectional study was conducted from July to August 2022 to recruit newly reported women living with HIV with a history of pregnancy or current pregnancy in 2021 in 21 cities in Guangdong Province. HIV-related stigma was assessed using an abbreviated Chinese version of Berger's HIV Stigma Scale. Univariate and multivariable hierarchical regression analyses based on the social-ecological model were conducted to explore factors associated with HIV-related stigma and its four dimensions (personalized stigma, disclosure concerns, negative self-image and concerns about public attitudes) at the community/hospital, interpersonal, and individual levels. RESULTS: A moderate level of HIV-related stigma was found among the 360 participants included, with a mean score of 45.26. Multivariable hierarchical regression analysis showed that at the community/hospital-level, individuals were more likely to experience high levels of HIV-related stigma if they had experienced the discriminatory behaviors from health care workers (aOR = 2.34, 95%CI: 1.48-3.70) and if they rated serostatus disclosure services as less helpful (aOR = 0.69, 95%CI: 0.48-0.98). At the interpersonal-level, individuals with an HIV-positive partner (aOR = 1.71, 95%CI: 1.01-2.90) were more likely to experience high levels of HIV-related stigma than those with an HIV-negative or unknown partner. Individuals with high resilience (aOR = 0.22, 95%CI: 0.13-0.35) had lower levels of HIV-related stigma at the individual-level. In addition, ever experiencing discriminatory behaviors from health care workers, thinking serostatus disclosure services helpful, having ever seen publicity about personal interest protection services and complaint channels for people living with HIV(PLHIV), knowing about care and support services for PLHIV from social organizations at the community/hospital-level, partner notification and support at the interpersonal-level, and violations of personal interests, resilience at the individual-level were also associated with different dimensions of HIV-related stigma. CONCLUSIONS: HIV-related stigma was moderate among women living with HIV. The social-ecological model can facilitate a better understanding of factors associated with HIV-related stigma. Multilevel intervention strategies need to be tailored to reduce HIV-related stigma.

[Retracted] MicroRNA­625 inhibits the progression of non­small cell lung cancer by directly targeting HOXB5 and deactivating the Wnt/ß­catenin pathway.

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that certain of the flow cytometric data shown in Fig. 2C and the images of tumors shown in Fig. 7B were strikingly similar to data appearing in different form in other articles by different authors. Owing to the fact that the contentious data in the above article had already been published elsewhere, or were already under consideration for publication, prior to its submission to International Journal of Molecular Medicine, the Editor has decided that this paper should be retracted from the Journal. Independently of this investigation, the authors also requested a retraction of this article owing to the fact that the manuscript had been published without permission from one of the authors. The Editor apologizes to the readership for any inconvenience caused. [the original article was published in International Journal of Molecular Medicine 44: 346­356, 2019; DOI: 10.3892/ijmm.2019.4203].

YiaC and CobB regulate lysine lactylation in Escherichia coli.

Lysine lactylation (Kla) has recently been reported to participate in regulating transcription in human cells. However, the characterization, regulatory mechanism and functional consequence of Kla in prokaryotes remain unclear. Here, we report that YiaC functions as a lysine lactylase and that CobB serves as a lysine delactylase in the regulation of metabolism. We demonstrate that YiaC catalyzes the addition of Kla, while CobB erases this PTM both in vitro and intracellularly. Moreover, we show that YdiF can catalyze the formation of a lactyl-coenzyme A, which donates lactyl group for Kla. Quantitative proteomic analysis further reveals 446 endogenous Kla sites targeted by CobB and 79 candidates targeted by YiaC in Escherichia coli (E. coli). Furthermore, we present that Kla can influence the functions of metabolic enzymes. Interestingly, we demonstrate that CobB can specifically modulate the activity of PykF by regulating K382la, promoting glycolysis and bacterial growth. Our study identifies the regulatory enzymes and functional network of Kla and reveals a Kla-mediated molecular mechanism catalyzed by CobB for glycolysis regulation in E. coli.

Incidence and Risk of Hypertension in Cancer Patients Treated With Atezolizumab and Bevacizumab: A Systematic Review and Meta-Analysis.

PURPOSE: This study aims to inform previous clinical assessments to better understand the total risk of hypertension with atezolizumab and bevacizumab (hereafter referred to as "A-B") in cancer patients, and reduce future incidence of hypertension-related cardiovascular complications. METHODS: Databases, including PubMed, Embase, Cochrane, and Web of Science were searched to identify relevant studies, which were retrieved from inception to March 6, 2021. Studies focused on cancer patients treated with A-B that provided data on hypertension were included. Statistical analyses were conducted to calculate hypertension incidence and relative risk (RR) with a random-effects or fixed-effects model, hinging on heterogeneity status. RESULTS: Ten studies including 2106 patients with renal cell carcinoma (RCC), hepatocellular carcinoma (HCC), ovarian cancer, anal cancer, neuroendocrine tumors (NETs), and cervical cancer were selected for this meta-analysis. For patients treated with A-B, the all-grade and high-grade (grade 3) hypertension incidence were 31.1% (95% CI: 25.5-37.3) and 14.1% (95% CI: 10.9-18.1), respectively. No significant difference was observed in all-grade hypertension incidence between RCC and a non-RCC patients (32.9% [95% CI: 25.3-42.6] v.s. 29.2% [95% CI: 19.7-39.6)]). However, the number of high-grade hypertension incidence in RCC patients (9.4% [95% CI: 4.1-21.3]) was lower than that of non-RCC patients (15.6% [95% CI: 12.8-19.1]). RCC or HCC patients who received the A-B treatment were associated with significantly increased risk of all-grade hypertension with a RR of 7.22 (95% CI: 3.3-15.7; p = 0.6) compared with patients treated with atezolizumab. CONCLUSIONS: Cancer Patients treated with atezolizumab and bevacizumab have a significantly increased risk of hypertension. Sufficient monitoring is highly recommended to prevent the consequences of treatment-induced hypertension and other cardiovascular complications.

Overexpression of microRNA-124-5p sensitizes non-small cell lung cancer cells to treatment with 5-fluorouracil via AEG-1 regulation.

Chemotherapeutic resistance represents a major obstacle for the treatment of patients with non-small cell lung cancer (NSCLC); however, the associated molecular mechanisms underpinning the development of resistance remain poorly characterized. In the current study, 5-fluorouracil (5-FU)-resistant A549 cells (A549/5-FU) were generated from A549 cells. Reverse transcription-quantitative PCR and western blotting were used to detect microRNA(miR)-124-5p and astrocyte elevated gene 1 (AEG-1) expression levels in cells and tumor tissues. In addition, the cytotoxic effect of 5-FU on the cells was determined using the Cell Counting Kit-8 assay, and the Dual-luciferase reporter assay was used to validate AEG-1 as a target gene of miR-124-5p. Transfection with a miR-124-5p mimic enhanced inhibition of cell viability induced by 5-FU in A549/5-FU cells, whereas miR-124-5p inhibitor transfection partially reversed 5-FU-induced cell viability inhibition in A549 and H1299 cells. A decrease in miR-124-5p expression level was observed in A549/5-FU cells compared with the parental A549 cells. Furthermore, AEG-1 was predicted as a target gene of miR-124-5p, and its expression was increased in A549/5-FU cells compared with A549 cells. Additionally, the upregulation of miR-124-5p was associated with lower expression levels of AEG-1 in A549/5-FU cells, compared with parental A549 cells. Moreover, the Dual-luciferase reporter assay confirmed the ability of miR-124-5p to bind directly to the 3'-untranslated region of AEG-1 mRNA. Notably, the overexpression of AEG-1 reversed the ability of the miR-124-5p mimic to increase the sensitivity of A549/5-FU cells to 5-FU treatment. Additionally, a significant negative correlation between miR-124-5p expression and AEG-1 mRNA levels was detected in 40 pairs of NSCLC tissues and their corresponding adjacent paracancerous tissues. The results of the present study indicated that miR-124-5p may regulate the chemotherapeutic sensitivity of NSCLC cells, and may therefore represent a promising biomarker or therapeutic target for patients with NSCLC.

Adoptive immunotherapy of disseminated leukemia with TCR-transduced, CD8+ T cells expressing a known endogenous TCR.

Adoptive T-cell immunotherapy has shown promise in the treatment of human malignancies, but the challenge of isolating T cells with high avidity for tumor antigens in each patient has limited application of this approach. The transfer into T cells of T-cell receptor (TCR) genes encoding high-affinity TCRs recognizing defined tumor-associated antigens can potentially circumvent this obstacle. Using a well-characterized murine model of adoptive T-cell immunotherapy for widely disseminated leukemia, we demonstrate that TCR gene-modified T cells can cure mice of disseminated tumor. One goal of such adoptive therapy is to establish a persistent memory response to prevent recurrence; however, long-term function of transferred TCR-transduced T cells is limited due to reduced expression of the introduced TCR in vivo in quiescent resting T cells. However, by introducing the TCR into a cell with a known endogenous specificity, activation of these T cells by stimulation through the endogenous TCR can be used to increase expression of the introduced TCR, potentially providing a strategy to increase the total number of tumor-reactive T cells in the host and restore more potent antitumor activity.

MicroRNA-625 inhibits the progression of non­small cell lung cancer by directly targeting HOXB5 and deactivating the Wnt/ß-catenin pathway.

Numerous microRNAs (miRs) are dysregulated in non­small cell lung cancer (NSCLC), serving pivotal roles in its formation and progression. miR­625 is dysregulated in several types of human cancer, but its involvement in the formation and development of NSCLC remains poorly understood. In the present study, we aimed to investigate miR­625 expression in NSCLC and its role in regulating NSCLC cell behavior. miR­625 expression in NSCLC tissues and cell lines was detected using reverse transcription­quantitative polymerase chain reaction. The effects of miR­625 overexpression on NSCLC cell proliferation, apoptosis, migration and invasion in vitro were assessed using an MTT assay, flow cytometry, and cell migration and invasion assays, respectively. The effects of miR­625 upregulation on NSCLC growth were evaluated in an in vivo xenograft model. The molecular mechanisms underlying the tumor­suppressing roles of miR­625 in NSCLC were explored in detail. miR­625 expression was determined to be downregulated in NSCLC tissues and cell lines. This decreased expression was associated with advanced clinical features and poor overall survival of patients with NSCLC. Exogenous miR­625 expression suppressed NSCLC cell proliferation, migration and invasion, and induced apoptosis in vitro. miR­625 upregulation hindered NSCLC tumor growth in vivo. Homeobox B5 (HOXB5) was proposed to be the direct target gene of miR­625 in NSCLC cells. The tumor­suppressing effects of HOXB5 silencing were similar to those of miR­625 overexpression in NSCLC cells. In rescue experiments, HOXB5 overexpression partially reversed the inhibitory effects of miR­625 in NSCLC cells. miR­625 upregulation directly targeted HOXB5 to deactivate the Wnt/ß­catenin signaling pathway in NSCLC cells in vitro and in vivo. miR­625 was determined to be associated with HOXB5 suppression and Wnt/ß­catenin pathway deactivation, which in turn inhibited the aggressive behavior of NSCLC cells in vitro and in vivo.

MicroRNA-150 modulates intracellular Ca 2+ levels in naïve CD8+ T cells by targeting TMEM20.

Regulation of intracellular Ca2+ signaling is a major determinant of CD8+ T cell responsiveness, but the mechanisms underlying this regulation of Ca2+ levels, especially in naïve CD8+ T cells, are not fully defined. Here, we showed that microRNA-150 (miR-150) controls intracellular Ca2+ levels in naïve CD8+ T cells required for activation by suppressing TMEM20, a negative regulator of Ca2+ extrusion. miR-150 deficiency increased TMEM20 expression, which resulted in increased intracellular Ca2+ levels in naïve CD8+ T cells. The subsequent increase in Ca2+ levels induced expression of anergy-inducing genes, such as Cbl-b, Egr2, and p27, through activation of NFAT1, as well as reduced cell proliferation, cytokine production, and the antitumor activity of CD8+ T cells upon antigenic stimulation. The anergy-promoting molecular milieu and function induced by miR-150 deficiency were rescued by reinstatement of miR-150. Additionally, knockdown of TMEM20 in miR-150-deficient naïve CD8+ T cells reduced intracellular Ca2+ levels. Our findings revealed that miR-150 play essential roles in controlling intracellular Ca2+ level and activation in naïve CD8+ T cells, which suggest a mechanism to overcome anergy induction by the regulation of intracellular Ca2+ levels.

T Cells Engineered against a Native Antigen Can Surmount Immunologic and Physical Barriers to Treat Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinomas (PDAs) erect physical barriers to chemotherapy and induce multiple mechanisms of immune suppression, creating a sanctuary for unimpeded growth. We tested the ability of T cells engineered to express an affinity-enhanced T cell receptor (TCR) against a native antigen to overcome these barriers in a genetically engineered model of autochthonous PDA. Engineered T cells preferentially accumulate in PDA and induce tumor cell death and stromal remodeling. However, tumor-infiltrating T cells become progressively dysfunctional, a limitation successfully overcome by serial T cell infusions that resulted in a near-doubling of survival without overt toxicities. Similarly engineered human T cells lyse PDA cells in vitro, further supporting clinical advancement of this TCR-based strategy for the treatment of PDA.

Abrogating Cbl-b in effector CD8(+) T cells improves the efficacy of adoptive therapy of leukemia in mice.

The clinical use of adoptive immunotherapy with tumor-reactive T cells to treat established cancers is limited in part by the poor in vivo survival and function of the transferred T cells. Although administration of exogenous cytokines such as IL-2 can promote T cell survival, such strategies have many nonspecific activities and are often associated with toxicity. We show here that abrogating expression of Casitas B-lineage lymphoma b (Cbl-b), a negative regulator of lymphocyte activation, in tumor-reactive CD8(+) T cells expanded ex vivo increased the efficacy of adoptive immunotherapy of disseminated leukemia in mice. Mechanistically, Cbl-b abrogation bypassed the requirement for exogenous IL-2 administration for tumor eradication in vivo. In addition, CD8(+) T cells lacking Cbl-b demonstrated a lower threshold for activation, better survival following target recognition and stimulation, and enhanced proliferative responses as a result of both IL-2-dependent and -independent pathways. Importantly, siRNA knockdown of Cbl-b in human CD8(+)CD28- effector T cell clones similarly restored IL-2 production and proliferation following target recognition independent of exogenous IL-2, enhanced IFN-γ production, and increased target avidity. Thus, abrogating Cbl-b expression in effector T cells may improve the efficacy of adoptive therapy of some human malignancies.

Local role for tumor necrosis factor alpha in the pulmonary inflammatory response to Mycobacterium tuberculosis infection.

The local intrapulmonary role of tumor necrosis factor alpha (TNF-alpha) in a protective host response during acute and chronic infection with Mycobacterium tuberculosis is incompletely understood. To directly assess its role in the intrapulmonary immune response, we compared the responses of transgenic mice with a local pulmonary blockade of TNF-alpha (SPCTNFRIIFc mice) to mice with globally inhibited TNF-alpha (TNFRKO mice) and mice with normal immune systems (control mice). Consistent with previous reports, 100% of TNFRKO mice died by 28 days after aerosol infection, and these mice had markedly increased numbers of bacteria and widespread tissue necrosis in their lungs compared to controls. The median survival time of the SPCTNFRIIFc mice was 142 days, and 75% died by 180 days. Even though the numbers of bacteria in the lungs of the SPCTNFRIIFc mice were marginally increased compared to controls, these mice had a persistent neutrophilic inflammatory response and increased expression of proinflammatory cytokines (interleukin-1 alpha/beta [IL-1 alpha/beta], IL-18, gamma interferon, IL-6, and macrophage migration inhibitory factor) and chemokines (eotaxin, macrophage inflammatory protein 1 alpha/beta, gamma interferon-inducible protein 10, macrophage chemotaxic protein 1, and TCA-3) in their lungs. These studies with the SPCTNFRIIFc mice provide direct evidence for the local importance of TNF-alpha in the proper regulation of host defense to M. tuberculosis. The studies also suggest that when the local actions of TNF-alpha are selectively impaired in the lungs, tissue destruction and death ensue, at least in part, due to persistent expression of proinflammatory mediators that would normally be downregulated.