Increased Th17 activation and gut microbiota diversity are associated with pembrolizumab-triggered tuberculosis

Integrated single-cell transcriptome and T cell receptor profiling reveals defects of T cell exhaustion in pulmonary tuberculosis

Tuberculosis-affected lungs with chronic inflammation harbor abundant immunosuppressive immune cells but the nature of such inflammation is unclear. Dysfunction in T cell exhaustion, while implicated in chronic inflammatory diseases, remains unexplored in tuberculosis. Given that immunotherapy targeting exhaustion checkpoints exacerbates tuberculosis, we speculate that T cell exhaustion is dysfunctional in tuberculosis. Using integrated single-cell RNA sequencing and T cell receptor profiling we reported defects in exhaustion responses within inflamed tuberculosis-affected lungs. Tuberculosis lungs demonstrated significantly reduced levels of exhausted CD8+ T cells and exhibited diminished expression of exhaustion-related transcripts among clonally expanded CD4+ and CD8+ T cells. Additionally, clonal expansion of CD4+ and CD8+ T cells bearing T cell receptors specific for CMV was observed. Expanded CD8+ T cells expressed the cytolytic marker GZMK. Hence, inflamed tuberculosis-affected lungs displayed dysfunction in T cell exhaustion. Our findings likely hold implications for understanding the reactivation of tuberculosis observed in patients undergoing immunotherapy targeting the exhaustion checkpoint.

Pathogenic Th17 cell-mediated liver fibrosis contributes to resistance to PD-L1 antibody immunotherapy in hepatocellular carcinoma

Understanding the mechanisms of resistance of hepatocellular carcinoma (HCC) to targeted therapies and immune checkpoint blockade is critical for the development of new combination therapies and improving patient survival. Here, we found that in HCC, anti-programmed cell death 1 ligand 1 (PD-L1) therapy reduces liver cancer growth, but the tumors eventually become resistant to continued therapy. Experimental analyses shows that the infiltration of pathogenic T helper 17 (pTh17) cells increases in drug-resistant HCC, and pTh17 cells secrete interleukin-17A (IL-17A), which promotes the expression of PD-L1 on the surface of HCC cells and produces resistance to anti-PD-L1 therapy. Anti-IL-17A combined with PD-L1 blockade significantly increased the infiltration of cytotoxic CD8+ T cells expressing high levels of interferon-γ and reduced treatment resistance in HCC. These results support the combination of anti-PD-L1 and anti-IL-17A as a novel strategy to induce effective T cell-mediated anti-tumor immune responses.

Immune Checkpoint Inhibitors and Tuberculosis Infection in Lung Cancer: A Case Series and Systematic Review With Pooled Analysis

The association between immune checkpoint inhibitors (ICIs) and tuberculosis (TB) infection in patients with lung cancer remains largely elusive. We performed a systematic review and conducted a retrospective analysis of TB infection in patients with lung cancer and ICI exposure to assess the clinical characteristics and outcomes using PubMed, EMBASE, and the Cochrane Library. The time interval from ICI administration to diagnosis of TB between patients with and without a history of TB was compared using Kaplan-Meier analysis. A multivariate Cox regression model was used to identify potential risk factors associated with the time interval of TB development. Twenty-four studies including 53 patients with lung cancer were included. The median age of the patients was 64 years. Eight patients had a history of TB. The median time interval from ICI administration to TB diagnosis was 3 months. In retrospective analysis, 5 (1.16%, 95%CI 0.38% to 2.68%) patients with lung cancer developed TB during ICI treatment. The median time interval was 10.4 months. In a pooled analysis, the median time interval in the without-TB and with-TB groups was 7.00 and 2.35 months, respectively (P = .034). Multivariate Cox regression analyses revealed a history of TB to be an independent factor affecting the time interval of TB activation in patients with lung cancer and ICI exposure (HR 3.59; 95%CI 1.17 to 11.02; P = .026). Therefore, TB infection should be considered in patients with lung cancer during or after ICI treatment. Moreover, we found TB history to be a positive risk factor for a shorter median time interval from ICI to TB diagnosis in patients with lung cancer receiving ICI.

A rare case of miliary tuberculosis in a patient with NSCLC receiving PD1 inhibitor therapy, mimicking autoimmune pneumonitis

ABSTRACT

Immune checkpoint inhibitors (ICIs) are widely used for the treatment of various types of cancer. One of the possible immune-related adverse effects of ICI is pneumonitis, which is a life-threatening condition that can present as a variety of radiographic patterns, so it can be difficult to differentiate from infectious cases of pneumonia based on radiological findings alone. We present a rare case of miliary tuberculosis (M. tuberculosis) in a patient receiving programmed death-1 (PD-1) inhibitor therapy mimicking autoimmune pneumonitis and possible pathophysiological mechanisms of this unexpected event. We presented a 52-year-old patient with stage IV non-small-cell lung carcinoma (NSCLC) who was admitted to the hospital with radiological and clinical signs of pneumonitis caused by immunotherapy-Pembrolizumab. During hospitalization, she was clinically, laboratory, and microbiologically processed and her diagnosis of M. tuberculosis was confirmed. Initial treatment started with corticosteroids as a pneumonitis treatment, and because there was no adequate response, and the diagnosis of tuberculosis was confirmed, treatment with a four-regimen antituberculotic drug started. On a control, CT scan regression in distribution and number of changes in lungs occurred. After a while, patient died due to hepatic failure. There are not many reported cases of pulmonary tuberculosis in patients receiving immunotherapy; to our knowledge, no cases of M. tuberculosis in a patient with lung cancer were described. Since there is a different approach to the treatment of tuberculosis and pneumonitis, we presented our dilemmas and literature review in this article. A multidisciplinary approach (oncologist, radiologist, microbiologist, etc.) is essential in a case like this.

IL-17A aggravates asthma-induced intestinal immune injury by promoting neutrophil trafficking

With the concept of the gut-lung axis reinforced in recent years, emerging evidence has shown that intestinal homeostasis is vital for lung health. Nevertheless, the impacts of lung homeostasis on intestinal tracts and their mechanism are rarely studied. Our results showed that papain-induced asthmatic mice exhibited apparent colonic injuries compared with controls, including increased intestinal permeability, neutrophil and Th17 infiltration in the colonic lamina propria. Moreover, the intranasal administration of papain aggravated such colonic injuries in mice with dextran sulfate sodium-induced colitis, as evidenced by increased occult blood scores, shortened colon length, and accumulated neutrophils. The level of IL-17A was also higher in the serum of asthmatic mice than wild-type mice. Interestingly, the pathologic scores, the proportion of Th17 cells, and neutrophil infiltration in the colon were markedly reduced after IL-17A blocking. Similarly, longer length, lower pathologic scores, and fewer neutrophils were also observed in the colon of IL-17-deficient asthmatic mice. More importantly, we demonstrated that severe gastrointestinal symptoms could accompany clinical asthmatics. The frequencies of Th17 cells and the mRNA expression of IL-17A in the peripheral blood of these patients were significantly enhanced. Besides, the gastrointestinal symptom rating scale scores positively correlated with the frequencies of Th17 in asthmatics. These findings enlighten that IL-17A aggravates asthma-induced intestinal immune injury by promoting neutrophil trafficking, which facilitates the exploration of new potential biomarkers to treat asthma.

Checkpoint Inhibitor Pneumonitis Induced by Anti-PD-1/PD-L1 Therapy in Non-Small-Cell Lung Cancer: Occurrence and Mechanism

Immune checkpointty inhibitors (ICIs), particularly those targeting programmed death 1 (PD-1) and anti-programmed death ligand 1 (PD-L1), enhance the antitumor effect by restoring the function of the inhibited effector T cells and produce durable responses in a large variety of metastatic and late patients with non-small-cell lung cancer. Although often well tolerated, the activation of the immune system results in side effects known as immune-related adverse events (irAEs), which can affect multiple organ systems, including the lungs. The occurrence of severe pulmonary irAEs, especially checkpoint inhibitor pneumonitis (CIP), is rare but has extremely high mortality and often overlaps with the respiratory symptoms and imaging of primary tumors. The development of CIP may be accompanied by radiation pneumonia and infectious pneumonia, leading to the simultaneous occurrence of a mixture of several types of inflammation in the lungs. However, there is a lack of authoritative diagnosis, grading criteria and clarified mechanisms of CIP. In this article, we review the incidence and median time to onset of CIP in patients with non-small-cell lung cancer treated with PD-1/PD-L1 blockade in clinical studies. We also summarize the clinical features, potential mechanisms, management and predictive biomarkers of CIP caused by PD-1/PD-L1 blockade in non-small-cell lung cancer treatment.

Pulmonary tuberculosis associated with immune checkpoint inhibitors: a pharmacovigilance study

We examined case reports of immune checkpoint inhibitors (ICIs) associated pulmonary tuberculosis (PT) using data from the Food and Drug Administration Adverse Event Reporting System database. Disproportionality analysis was performed by using the reporting OR (ROR) with relevant 95% CI. A total of 74 cases of PT related to ICIs therapy were identified. ICIs were significantly associated with over-reporting frequencies of PT (ROR=3.16, 95% CI: 2.51 to 3.98), while the signal was differed between anti-programmed death-1/ligand-1 and anti-cytotoxic T lymphocyte antigen-4 agents. Most indications were lung cancer (64.9%), the median onset age was 70 years, the median time to onset of PT was 70 days, ICIs were discontinued in most cases (85.2%).

The safety and efficacy of immunotherapy with anti-programmed cell death 1 monoclonal antibody for lung cancer complicated with Mycobacterium tuberculosis infection

Background

Anti-programmed cell death 1 (PD-1)/programmed cell death-ligand 1 (PD-L1) immunotherapy has boosted the prognosis in advanced lung cancer. Meanwhile, accumulating cases showed the correlation between tuberculosis (TB) reactivation and anti-PD-1/PD-L1 immunotherapy. However, the safety and efficacy of anti-PD-1/PD-L1 immunotherapy for lung cancer complicated with TB infection could only be learned from real-world data.

Methods

We retrospectively analyzed 562 patients with advanced lung cancer who received anti-PD-1/PD-L1 immunotherapy at Shanghai Pulmonary Hospital from 2015 to 2019, including 13 patients with TB infection. Besides, relevant literature reviews were performed online to analyze the safety and efficacy of immunotherapy and to explore the appropriate treatment strategies in this specific population.

Results

In our cohort, the initiation of anti-PD-1/PD-L1 immunotherapy was from June 2015 to December 2019. Among them, 13 patients had TB infection prior to immunotherapy including 11 latent TB and 2 active TB, and all of them were treated with anti-PD-1 immunotherapy. Patients with active TB infection were treated with concurrent anti-TB and anti-PD-1 treatments, and the remaining received either mono-immunotherapy or combined immunotherapy. Neither reactivation of latent TB nor progression of active TB was monitored in our cohort during immunotherapy. Severe immune-related adverse events (irAEs) were diagnosed in two patients. Treatment strategies such as discontinuation of immunotherapy and administration of corticosteroids were provided timely, and one with latent TB infection got gradually improved, but the other one with active TB died quickly. The median progression-free survival (PFS) was 5.5 months for tumor immunotherapy in our cohort. However, the PFS of immunotherapy was merely 2.1 and 2.2 months in lung cancer patients with active TB infection.

Conclusions

Immunotherapy is relatively safe for lung cancer patients complicated with previously treated latent TB, and the efficacy of immunotherapy in this specified population is not inferior to that in lung cancer patients without TB infection. TB screening before anti-PD-1/PD-L1 immunotherapy is strongly recommended, and irAEs should be monitored more cautiously in lung cancer patients with active TB infection.

The Role of Gut Microbiota in Lung Cancer: From Carcinogenesis to Immunotherapy

The influence of microbiota on host health and disease has attracted adequate attention, and gut microbiota components and microbiota-derived metabolites affect host immune homeostasis locally and systematically. Some studies have found that gut dysbiosis, disturbance of the structure and function of the gut microbiome, disrupts pulmonary immune homeostasis, thus leading to increased disease susceptibility; the gut-lung axis is the primary cross-talk for this communication. Gut dysbiosis is involved in carcinogenesis and the progression of lung cancer through genotoxicity, systemic inflammation, and defective immunosurveillance. In addition, the gut microbiome harbors the potential to be a novel biomarker for predicting sensitivity and adverse reactions to immunotherapy in patients with lung cancer. Probiotics and fecal microbiota transplantation (FMT) can enhance the efficacy and depress the toxicity of immune checkpoint inhibitors by regulating the gut microbiota. Although current studies have found that gut microbiota closely participates in the development and immunotherapy of lung cancer, the mechanisms require further investigation. Therefore, this review aims to discuss the underlying mechanisms of gut microbiota influencing carcinogenesis and immunotherapy in lung cancer and to provide new strategies for governing gut microbiota to enhance the prevention and treatment of lung cancer.

Therapeutic implications of SARS-CoV-2 dysregulation of the gut-brain-lung axis

The emergence and rapid spread of novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused over 180 million confirmed cases resulting in over 4 million deaths worldwide with no clear end in sight for the coronavirus disease 19 (COVID-19) pandemic. Most SARS-CoV-2 exposed individuals experience mild to moderate symptoms, including fever, cough, fatigue, and loss of smell and taste. However, many individuals develop pneumonia, acute respiratory distress syndrome, septic shock, and multiorgan dysfunction. In addition to these primarily respiratory symptoms, SARS-CoV-2 can also infiltrate the central nervous system, which may damage the blood-brain barrier and the neuron's synapses. Resultant inflammation and neurodegeneration in the brain stem can further prevent efferent signaling to cranial nerves, leading to the loss of anti-inflammatory signaling and normal respiratory and gastrointestinal functions. Additionally, SARS-CoV-2 can infect enterocytes resulting in gut damage followed by microbial dysbiosis and translocation of bacteria and their byproducts across the damaged epithelial barrier. As a result, this exacerbates pro-inflammatory responses both locally and systemically, resulting in impaired clinical outcomes. Recent evidence has highlighted the complex interactions that mutually modulate respiratory, neurological, and gastrointestinal function. In this review, we discuss the ways SARS-CoV-2 potentially disrupts the gut-brain-lung axis. We further highlight targeting specific responses to SARS-CoV-2 for the development of novel, urgently needed therapeutic interventions. Finally, we propose a prospective related to the individuals from Low- and Middle-Income countries. Here, the underlying propensity for heightened gut damage/microbial translocation is likely to result in worse clinical outcomes during this COVID-19 pandemic.