Engineered bacteria breach tumor physical barriers to enhance radio-immunotherapy.

Radiotherapy widely applied for local tumor therapy in clinic has been recently reinvigorated by the discovery that radiotherapy could activate systematic antitumor immune response. Nonetheless, the endogenous radio-immune effect is still incapable of radical tumor elimination due to the prevention of immune cell infiltration by the physical barrier in tumor microenvironment (TME). Herein, an engineered Salmonella secreting nattokinase (VNPNKase) is developed to synergistically modulate the physical and immune characteristics of TME to enhance radio-immunotherapy of colon tumors. The facultative anaerobic VNPNKase enriches at the tumor site after systemic administration, continuously secreting abundant NKase to degrade fibronectin, dredge the extracellular matrix (ECM), and inactivate cancer-associated fibroblasts (CAFs). The VNPNKase- dredged TME facilitates the infiltration of CD103+ dendritic cells (DCs) and thus the presentation of tumor-associated antigens (TAAs) after radiotherapy, recruiting sufficient CD8+ T lymphocytes to specifically eradicate localized tumors. Moreover, the pre-treatment of VNPNKase before radiotherapy amplifies the abscopal effect and achieves a long-term immune memory effect, preventing the metastasis and recurrence of tumors. Our research suggests that this strategy using engineered bacteria to breach tumor physical barrier for promoting immune cell infiltration possesses great promise as a translational strategy to enhance the effectiveness of radio-immunotherapy in treating solid tumors.

CD8 + CD103 + iTregs protect against ischemia-reperfusion-induced acute kidney Injury by inhibiting pyroptosis.

The occurrence of acute kidney injury (AKI) is elevated, one of the main causes is ischemia-reperfusion (I/R). However, no specific therapy is currently available to treat I/R-induced AKI (I/R-AKI). Treg cells have been demonstrated to perform an anti-inflammatory role in a range of autoimmune and inflammatory illnesses. However, there is limited available information about the possible functions of CD8 + CD103 + iTregs in I/R-AKI. We utilized renal tubular epithelial cells (RTECs) subjected to hypoxia-reoxygenation (H/R) and I/R-AKI mouse model to investigate whether CD8 + CD103 + iTregs could attenuate AKI and the underlying mechanism. In vitro, co-cultured with CD8 + CD103 + iTregs alleviated H/R-induced cell injury. After treatment of CD8 + CD103 + iTregs rather than control cells, a significant improvement of I/R-AKI was observed in vivo, including decreased serum creatinine (sCr) and blood urea nitrogen (BUN) levels, reduced renal pathological injury, lowered tubular apoptosis and inhibition of the transition from AKI to chronic kidney disease (CKD). Mechanically, CD8 + CD103 + iTregs alleviated H/R-induced cell injury and I/R-AKI partly by suppressing RTECs pyroptosis via inhibiting the NLRP3/Caspase-1 axis. Our study provides a novel perspective on the possibility of CD8 + CD103 + iTregs for the treatment of I/R-AKI.

Tissue-resident memory CD103+CD8+ T cells in colorectal cancer: its implication as a prognostic and predictive liver metastasis biomarker.

BACKGROUND: Tissue-resident memory CD103+CD8+ T cells (CD103+CD8+ TRMs) are important components of anti-tumor immunity. However, the significance of CD103+CD8+ TRMs in colorectal cancer (CRC) and their advantages remain unclear. METHODS: Clinical data and specimens were used to evaluate the significance of CD103+CD8+ TRMs in CRC. A mouse subcutaneous tumorigenesis model and colony-formation assay were conducted to evaluate the anti-tumor effects of CD103+CD8+ TRMs. Finally, the infiltration density and function of CD103+CD8+ TRMs in the tumors were evaluated using flow cytometry. RESULTS: In this study, we showed that highly infiltrated CD103+CD8+ TRMs were associated with earlier clinical stage and negative VEGF expression in CRC patients and predicted a favorable prognosis for CRC/CRC liver metastases patients. Interestingly, we also found that CD103+CD8+ TRMs may have predictive potential for whether CRC develops liver metastasis in CRC. In addition, we found a positive correlation between the ratio of the number of α-SMA+ vessels to the sum of the number of α-SMA+ and CD31+ vessels in CRC, and the infiltration level of CD103+CD8+ TRMs. In addition, anti-angiogenic therapy promoted infiltration of CD103+CD8+ TRMs and enhanced their ability to secrete interferon (IFN)-γ, thus further improving the anti-tumor effect. Moreover, in vivo experiments showed that compared with peripheral blood CD8+ T cells, CD103+CD8+ TRMs infused back into the body could also further promote CD8+ T cells to infiltrate the tumor, and they had a stronger ability to secrete IFN-γ, which resulted in better anti-tumor effects. CONCLUSION: We demonstrated that CD103+CD8+ TRMs have the potential for clinical applications and provide new ideas for combined anti-tumor therapeutic strategies, such as anti-tumor angiogenesis therapy and CAR-T combined immunotherapy.

Immunological characteristics of CD103+CD161+ T lymphocytes on chronic rhinosinusitis with nasal polyps.

Chronic rhinosinusitis with nasal polyps (CRSwNPs) is a heterogeneous disease characterized by local inflammation of the upper airway and sinus mucosa. T cell-mediated immune responses play irreplaceable roles in the pathogenesis of nasal polyps. CD161+ T cells have been implicated in the pathology of several diseases through cytokine production and cytotoxic activity. However, the immunological characteristics of CD161+ T cells in nasal mucosa are still not well understood, particularly in CRSwNPs. Our research revealed a notable enrichment of CD161+ T cells in nasal tissues compared to peripheral blood, with a significantly more infiltration of CD161+ T cells in CRSwNPs compared to control nasal samples. Phenotypical analysis found that CD161+ T cells predominantly co-expressed tissue-resident memory surface markers CD103, CD69, and CD45RO. CD161+CD103+ T cells demonstrated complicated effector functions, marked by elevated levels of PD-1, CTLA-4, IL-17, and IFN-γ and diminished expression of FoxP3 and CD25. Interestingly, despite CD161+ T cells was more abundant in polyp tissues compared to normal control tissues, and then further categorizing polyp samples into distinct groups based on clinical characteristics, only the recurrent CRSwNP group showed a significant reduction in CD161+CD8+ T cells compared to the primary CRSwNP group. This finding suggested the necessity for further research to comprehensively understand the underlying mechanisms and the broader significance of CD161+ T cells in the advancement and relapse of CRSwNPs.

Role of chitosan in intestinal integrity: TLR4 and IFNAR signaling in the induction of E-cadherin and CD103 in mice.

Chitin and its derivative chitosan (Q) are abundant structural elements in nature. Q has modulatory and anti-inflammatory effects and also regulates the expression of adhesion molecules. The interaction between cells expressing the αEß7 integrin and E-cadherin facilitates tolerogenic signal transmission and localization of lymphocytes at the frontline for interaction with luminal antigens. In this study we evaluated the ability of orally administered Q to stimulate E-cadherin and CD103 expression in vitro and in vivo. Our findings show that Q promoted epithelial cell migration, accelerated wound healing and increased E-cadherin expression in IEC-18 cells and isolated intestinal epithelial cells (IECs) after Q feeding. The upregulation of E-cadherin was dependent on TLR4 and IFNAR signaling, triggering CD103 expression in lymphocytes. Q reinforced the E-cadherin-αEß7 axis, crucial for intestinal barrier integrity and contributed to the localization of lymphocytes on the epithelium.

Cognate antigen-independent differentiation of resident memory T cells in chronic kidney disease.

Resident memory T cells (TRMs), which are memory T cells that are retained locally within tissues, have recently been described as antigen-specific frontline defenders against pathogens in barrier and nonbarrier epithelial tissues. They have also been noted for perpetuating chronic inflammation. The conditions responsible for TRM differentiation are still poorly understood, and their contributions, if any, to sterile models of chronic kidney disease (CKD) remain a mystery. In this study, we subjected male C57BL/6J mice and OT-1 transgenic mice to five consecutive days of 2 mg/kg aristolochic acid (AA) injections intraperitoneally to induce CKD or saline injections as a control. We evaluated their kidney immune profiles at 2 wk, 6 wk, and 6 mo after treatment. We identified a substantial population of TRMs in the kidneys of mice with AA-induced CKD. Flow cytometry of injured kidneys showed T cells bearing TRM surface markers and single-cell (sc) RNA sequencing revealed these cells as expressing well-known TRM transcription factors and receptors responsible for TRM differentiation and maintenance. Although kidney TRMs expressed Cd44, a marker of antigen experience and T cell activation, their derivation was independent of cognate antigen-T cell receptor interactions, as the kidneys of transgenic OT-1 mice still harbored considerable proportions of TRMs after injury. Our results suggest a nonantigen-specific or antigen-independent mechanism capable of generating TRMs in the kidney and highlight the need to better understand TRMs and their involvement in CKD.NEW & NOTEWORTHY Resident memory T cells (TRMs) differentiate and are retained within the kidneys of mice with aristolochic acid (AA)-induced chronic kidney disease (CKD). Here, we characterized this kidney TRM population and demonstrated TRM derivation in the kidneys of OT-1 transgenic mice with AA-induced CKD. A better understanding of TRMs and the processes by which they can differentiate independent of antigen may help our understanding of the interactions between the immune system and kidneys.

Tertiary Lymphoid Structure-Associated B Cells Enhance CXCL13+CD103+CD8+ Tissue-Resident Memory T-Cell Response to Programmed Cell Death Protein 1 Blockade in Cancer Immunotherapy.

BACKGROUND & AIMS: Although the presence of tertiary lymphoid structures (TLS) correlates with positive responses to immunotherapy in many solid malignancies, the mechanism by which TLS enhances antitumor immunity is not well understood. The present study aimed to investigate the underlying cross talk circuits between B cells and tissue-resident memory T (Trm) cells within the TLS and to understand their role in the context of immunotherapy. METHODS: Immunostaining and H&E staining of TLS and chemokine (C-X-C motif) ligand 13 (CXCL13)+ cluster of differentiation (CD)103+CD8+ Trm cells were performed on tumor sections from patients with gastric cancer (GC). The mechanism of communication between B cells and CXCL13+CD103+CD8+ Trm cells was determined in vitro and in vivo. The effect of CXCL13+CD103+CD8+ Trm cells in suppressing tumor growth was evaluated through anti-programmed cell death protein (PD)-1 therapy. RESULTS: The presence of TLS and CXCL13+CD103+CD8+ Trm cells in tumor tissues favored a superior response to anti-PD-1 therapy in patients with GC. Additionally, our research identified that activated B cells enhanced CXCL13 and granzyme B secretion by CD103+CD8+ Trm cells. Mechanistically, B cells facilitated the glycolysis of CD103+CD8+ Trm cells through the lymphotoxin-α/tumor necrosis factor receptor 2 (TNFR2) axis, and the mechanistic target of rapamycin signaling pathway played a critical role in CD103+CD8+ Trm cells glycolysis during this process. Moreover, the presence of TLS and CXCL13+CD103+CD8+ Trm cells correlated with potent responsiveness to anti-PD-1 therapy in a TNFR2-dependent manner. CONCLUSIONS: This study further reveals a crucial role for cellular communication between TLS-associated B cell and CXCL13+CD103+CD8+ Trm cells in antitumor immunity, providing valuable insights into the potential use of the lymphotoxin-α/TNFR2 axis within CXCL13+CD103+CD8+ Trm cells for advancing immunotherapy strategies in GC.

Activin A levels are raised during human tuberculosis and blockade of the activin signaling axis influences murine responses to M. tuberculosis infection.

Activin A strongly influences immune responses; yet, few studies have examined its role in infectious diseases. We measured serum activin A levels in two independent tuberculosis (TB) patient cohorts and in patients with pneumonia and sarcoidosis. Serum activin A levels were increased in TB patients compared to healthy controls, including those with positive tuberculin skin tests, and paralleled severity of disease, assessed by X-ray scores. In pneumonia patients, serum activin A levels were also raised, but in sarcoidosis patients, levels were lower. To determine whether blockade of the activin A signaling axis could play a functional role in TB, we harnessed a soluble activin type IIB receptor fused to human IgG1 Fc, ActRIIB-Fc, as a ligand trap in a murine TB model. The administration of ActRIIB-Fc to Mycobacterium tuberculosis-infected mice resulted in decreased bacterial loads and increased numbers of CD4 effector T cells and tissue-resident memory T cells in the lung. Increased frequencies of tissue-resident memory T cells corresponded with downregulated T-bet expression in lung CD4 and CD8 T cells. Altogether, the results suggest a disease-exacerbating role of ActRIIB signaling pathways. Serum activin A may be useful as a biomarker for diagnostic triage of active TB or monitoring of anti-tuberculosis therapy. IMPORTANCE: Tuberculosis remains the leading cause of death by a bacterial pathogen. The etiologic agent of tuberculosis, Mycobacterium tuberculosis, can remain dormant in the infected host for years before causing disease. Significant effort has been made to identify biomarkers that can discriminate between latently infected and actively diseased individuals. We found that serum levels of the cytokine activin A were associated with increased lung pathology and could discriminate between active tuberculosis and tuberculin skin-test-positive healthy controls. Activin A signals through the ActRIIB receptor, which can be blocked by administration of the ligand trap ActRIIB-Fc, a soluble activin type IIB receptor fused to human IgG1 Fc. In a murine model of tuberculosis, we found that ActRIIB-Fc treatment reduced mycobacterial loads. Strikingly, ActRIIB-Fc treatment significantly increased the number of tissue-resident memory T cells. These results suggest a role for ActRIIB signaling pathways in host responses to Mycobacterium tuberculosis and activin A as a biomarker of ongoing disease.

Spatial features of specific CD103+CD8+ tissue-resident memory T cell subsets define the prognosis in patients with non-small cell lung cancer.

BACKGROUND: Tissue-resident memory T (TRM) cells can reside in the tumor microenvironment and are considered the primary response cells to immunotherapy. Heterogeneity in functional status and spatial distribution may contribute to the controversial role of TRM cells but we know little about it. METHODS: Through multiplex immunofluorescence (mIF) (CD8, CD103, PD-1, Tim-3, GZMB, CK), the quantity and spatial location of TRM cell subsets were recognized in the tissue from 274 patients with NSCLC after radical surgery. By integrating multiple machine learning methods, we constructed a TRM-based spatial immune signature (TRM-SIS) to predict the prognosis. Furthermore, we conducted a CD103-related gene set enrichment analysis (GSEA) and verified its finding by another mIF panel (CD8, CD103, CK, CD31, Hif-1α). RESULTS: The density of TRM cells was significantly correlated with the expression of PD-1, Tim-3 and GZMB. Four types of TRM cell subsets was defined, including TRM1 (PD-1-Tim-3-TRM), TRM2 (PD-1+Tim-3-TRM), TRM3 (PD-1-Tim-3+TRM) and TRM4 (PD-1+Tim-3+TRM). The cytotoxicity of TRM2 was the strongest while that of TRM4 was the weakest. Compare with TRM1 and TRM2, TRM3 and TRM4 had better infiltration and stronger interaction with cancer cells. The TRM-SIS was an independent prognostic factor for disease-free survival [HR = 2.43, 95%CI (1.63-3.60), P < 0.001] and showed a better performance than the TNM staging system for recurrence prediction. Furthermore, by CD103-related GSEA and mIF validation, we found a negative association between tumor angiogenesis and infiltration of TRM cells. CONCLUSIONS: These findings reveal a significant heterogeneity in the functional status and spatial distribution of TRM cells, and support it as a biomarker for the prognosis of NSCLC patients. Regulating TRM cells by targeting tumor angiogenesis may be a potential strategy to improve current immunotherapy.

ImmunoPET provides a novel way to visualize the CD103+ tissue-resident memory T cell to predict the response of immune checkpoint inhibitors.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have made significant progress in oncotherapy improving survival of patients. However, the benefits are limited to only a small subgroup of patients who could achieve durable responses. Early prediction of response may enable treatment optimization and patient stratification. Therefore, developing appropriate biomarkers is critical to monitoring efficacy and assessing patient response to ICIs. MAIN BODY: Herein, we first introduce a new potential biomarker, CD103, expressed on tissue-resident memory T cells, and discuss the potential application of CD103 PET imaging in predicting immune checkpoint inhibitor treatment. In addition, we describe the current targets of ImmunoPET and compare these targets with CD103. To assess the benefit of PET imaging, a comparative analysis between ImmunoPET and other imaging techniques commonly employed for tumor diagnosis was performed. Additionally, we compare ImmunoPET and immunohistochemistry (IHC), a widely utilized clinical method for biomarker identification with respect to visualizing the immune targets. CONCLUSION: CD103 ImmunoPET is a promising method for determining tumor-infiltrating lymphocytes (TILs) load and response to ICIs, thereby addressing the lack of reliable biomarkers in cancer immunotherapy. Compared to general T cell markers, CD103 is a specific marker for tissue-resident memory T cells, which number increases during successful ICI therapy. ImmunoPET offers noninvasive, dynamic imaging of specific markers, complemented by detailed molecular information from immunohistochemistry (IHC). Radiomics can extract quantitative features from traditional imaging methods, while near-infrared fluorescence (NIRF) imaging aids tumor detection during surgery. In the era of precision medicine, combining such methods will offer a more comprehensive approach to cancer diagnosis and treatment.

Short-term administration of Qipian®, a mixed bacterial lysate, inhibits airway inflammation in ovalbumin-induced mouse asthma by modulating cellular, humoral and neurogenic immune responses.

AIMS: Qipian® is a commercialized agent composed of extracts of three genera of commensal bacteria, and its mechanism of action on asthma is unclear. This study aimed to examine the impact of Qipian® on airway inflammation and investigate the underlying mechanisms. MATERIALS AND METHODS: Qipian® or dexamethasone (DEX) was administered before OVA challenge in an ovalbumin-induced asthma mouse model, and then asthmatic symptoms were observed and scored. Samples of lung tissues, blood, and bronchoalveolar lavage fluid (BALF) were collected, and eosinophils (Eos), immunoglobins (Igs), and type 1 T helper (Th1)/Th2 cell cytokines were measured. Mucus production in the lung was assessed by periodic acid-Schiff (PAS) staining. The effects of Qipian® on dendritic and T regulatory (Treg) cells were investigated using flow cytometry. KEY FINDINGS: The short-term administration of Qipian® significantly inhibited the cardinal features of allergic asthma, including an elevated asthmatic behaviour score, airway inflammation and immune response. Histological analysis of the lungs showed that Qipian® attenuated airway inflammatory cell infiltration and mucus hyperproduction. Qipian® restored Th1/Th2 imbalance by decreasing interleukin (IL)-4, IL-5, and IL-13 while increasing interferon (IFN)-γ and IL-10. Further investigation revealed that Qipian® treatment induced the upregulation of CD4+CD25+Foxp3+ Treg cells and CD103+ DCs and downregulation of tachykinins neurokinin A (NKA) and NKB in the lung. SIGNIFICANCE: Our findings suggested that short-term treatment with Qipian® could alleviate inflammation in allergic asthma through restoring the Th1/Th2 balance by recruiting Treg cells to airways and inducing the proliferation of CD103+ DCs, which actually provides a new treatment option for asthma.

Spatial Distribution and Densities of CD103+ and FoxP3+ Tumor Infiltrating Lymphocytes by Digital Analysis for Outcome Prediction in Breast Cancer.

BACKGROUND: The evaluation of tumor-infiltrating lymphocytes (TILs) for breast cancer prognosis is now established. However, the clinical value for their spatial distributions of specific immune subsets, namely CD103+ tissue-resident memory T cells FoxP3+ regulatory T ells, have not been thoroughly examined. METHOD: Representative whole sections of breast cancers were subjected to CD103 and FoxP3 double staining. Their density, ratio, and spatial features were analyzed in tumor area and tumor-stromal interface. Their associations with clinicopathological parameters and patient's prognosis were analyzed. RESULTS: CD103 TILs were closer to tumor nests than FoxP3 TILs in the tumor-stromal interface. Their densities were associated with high-grade disease, TNBC, and stromal TILs. High stromal FoxP3 (sFoxP3) TILs and close proximity of sCD103 TILs to tumor were independently associated with better survival at multivariate analysis. Subgroup analysis showed the high FoxP3 TILs density associated better survival was seen in HER2-OE and TNBC subtypes while the proximity of CD103 TILs to tumor nests associated better survival was seen in luminal cancers. CONCLUSION: The prognostic impact of CD103 and FoxP3 TILs in breast cancer depends on their spatial localization. High sFoxP3 TIL density and the lower distance of CD103 TILs from the tumor nests had independent favorable prognostic values.

Tissue-resident memory T cells exhibit phenotypically and functionally heterogeneous in human physiological and pathological nasal mucosa.

Pathogens commonly enter mucosal barrier tissues and tissue-resident memory T cells (TRM) are essential for preventing mucosal lesions. However, the immunological properties of TRM cells in nasal mucosa are poorly known. In comparison with control tissues, decreasing CD103+ TRM cells were observed in Chronic rhinosinusitis with nasal polyps (CRSwNPs) and sinonasal inverted papilloma (SNIP), which presented high capability to produce effector cytokines. In CRSwNPs, we found that CD103+ TRM cells with higher cytokine and Granzyme B coexpressed high PD-1, CD103- TRM cells expressed higher IL-10. Homogenates isolated from CRSwNPs induced CD103 expression on peripheral T cells which could be inhibited by blocking TGF-ß. The frequencies of CD103+ TRM cells in CRSwNPs were extremely negatively correlated with neutrophil infiltration. CD103+ TRM cells from Staphylococcus aureus positive CRSwNPs had a stronger response to SEB. Taken together, two phenotypically and functionally distinct subsets of TRM cells exist in nasal tissues and play critical roles in the progress of CRSwNPs and SNIPs.

Usefulness of Biopsy Specimens for Evaluating CD103+ Tumor-resident Memory T Cells in Esophageal Cancer.

BACKGROUND/AIM: CD103+ tissue-resident memory T cells (TRM) in tumor sites are associated with a favorable prognosis and predict the effectiveness of immune checkpoint inhibitors. The detection of CD103+ TRM infiltration in biopsy samples could be beneficial for patients without surgical indications. However, the usefulness of TRM detection in biopsy tissue and the difference in TRM status between biopsy and surgical specimens' post-neoadjuvant chemotherapy have not been elucidated. In the present study, we aimed to elucidate whether we can detect TRM in biopsy specimens and the impact of chemotherapy on TRM infiltration. MATERIALS AND METHODS: Tissue sections were obtained from 46 patients with esophageal cancer who received neoadjuvant chemotherapy and underwent radical esophagectomy in 2017. Immunohistochemistry was performed using an anti-CD103 antibody for biopsy and surgical specimens. We examined the relationship between CD103 expression, clinicopathological features, and prognosis for each patient. RESULTS: TRM infiltration was detected in the biopsy specimens. CD103 expression in biopsy specimens correlated with that in surgical specimens. Although there was no statistical significance in clinicopathological findings between CD103high and CD103low, patients with CD103high biopsy specimens exhibited favorable prognosis. The number of CD103+ cells was increased by chemotherapy: though with no survival benefit. CONCLUSION: Regardless of surgical indication, we were able to determine the TRM status even in biopsy specimens. CD103 evaluation at biopsy may be more useful and practical than evaluation in surgical specimens, enabling prediction of prognosis and response to immune therapy.

Nanosecond pulsed electric field stimulates CD103+ DC accumulation in tumor microenvironment via NK-CD103+ DC crosstalk.

CD103+ DC is crucial for antitumor immune response. As a promising local therapy on cancers, nanosecond pulsed electric field (nsPEF) has been widely reported to stimulate anti-tumor immune response, but the underlying relationship between intratumoral CD103+ DC and nsPEF treatment remains enigmatic. Here, we focused on the behavior of CD103+ DC in response to nsPEF treatment and explored the underlying mechanism. We found that the nsPEF treatment led to the activation and accumulation of CD103+ DC in tumor. Depletion of CD103+ DC via Batf3-/- mice demonstrated CD103+ DC was necessary for intratumoral CD8+ T cell infiltration and activation in response to nsPEF treatment. Notably, NK cells recruited CD103+ DC into nsPEF-treated tumor through CCL5. Inflammatory array revealed CD103+ DC-derived IL-12 mediated the CCL5 secretion in NK cells. In addition, the boosted activation and infiltration of intratumoral CD103+ DC were abolished by cGAS-STING pathway inhibition, following IL-12 and CCL5 decreasing. Furthermore, nsPEF treatment promoting CD103+ DC-mediated antitumor response enhanced the effects of CD47 blockade strategy. Together, this study uncovers an unprecedented role for CD103+ DC in nsPEF treatment-elicited antitumor immune response and elucidates the underlying mechanisms.

Development of [89Zr]Zr-hCD103.Fab01A and [68Ga]Ga-hCD103.Fab01A for PET imaging to noninvasively assess cancer reactive T cell infiltration: Fab-based CD103 immunoPET.

BACKGROUND: CD103 is an integrin specifically expressed on the surface of cancer-reactive T cells. The number of CD103+ T cells significantly increases during successful immunotherapy and might therefore be an attractive biomarker for noninvasive PET imaging of immunotherapy response. Since the long half-life of antibodies preclude repeat imaging of CD103+ T cell dynamics early in therapy, we therefore here explored PET imaging with CD103 Fab fragments radiolabeled with a longer (89Zr) and shorter-lived radionuclide (68Ga). METHODS: Antihuman CD103 Fab fragment Fab01A was radiolabeled with 89Zr or 68Ga, generating [89Zr]Zr-hCD103.Fab01A and [68Ga]Ga-hCD103.Fab01A, respectively. In vivo evaluation of these tracers was performed in male nude mice (BALB/cOlaHsd-Foxn1nu) with established CD103-expressing CHO (CHO.CD103) or CHO-wildtype (CHO.K1) xenografts, followed by serial PET imaging and ex vivo bio-distribution. RESULTS: [89Zr]Zr-hCD103.Fab01A showed high tracer uptake in CD103+ xenografts as early as 3 h post-injection. However, the background signal remained high in the 3- and 6-h scans. The background was relatively low at 24 h after injection with sufficient tumor uptake. [68Ga]Ga-hCD103.Fab01Ashowed acceptable uptake and signal-to-noise ratio in CD103+ xenografts after 3 h, which decreased at subsequent time points. CONCLUSION: [89Zr]Zr-hCD103.Fab01A demonstrated a relatively low background and high xenograft uptake in scans as early as 6 h post-injection and could be explored for repeat imaging during immunotherapy in clinical trials. 18F or 64Cu could be explored as alternative to 68Ga in optimizing half-life and radiation burden of the tracer.

Significance of CD103+ tissue-resident memory T cells for predicting the effectiveness of immune checkpoint inhibitors in esophageal cancer.

BACKGROUND: Immune checkpoint inhibitors (ICIs), including nivolumab, have been approved to treat esophageal cancer. However, these remedies are not fit for all patients with esophageal cancer; therefore, a predictive surrogate marker is needed to assess their effectiveness. CD103+CD8+ tumor-infiltrating lymphocytes, defined as tissue-resident memory T cells (TRM), are promising indicators of response to ICIs, but it remains to be elucidated. This study investigated the association between the efficacy of ICIs and TRM. METHODS: The relationships between TRM infiltrating esophageal cancer, clinicopathological features, and prognosis after nivolumab initiation were examined using immunostaining. Tissue samples were obtained from surgically resected specimens of 37 patients with esophageal cancer who received nivolumab as a secondary or subsequent therapy. In addition, TRM infiltration was compared with programmed death-ligand 1 (PD-L1) expression and blood count parameters as predictors of nivolumab effectiveness. RESULTS: TRM-rich patients had a significant survival benefit after nivolumab initiation (12-months overall survival 70.8% vs 37.2%, p = 0.0485; 12-months progression-free survival 31.2% vs 0%, p = 0.0153) and experienced immune-related adverse events more frequently than TRM-poor patients (6 vs 2 patients). TRM infiltration was weakly correlated with PD-L1 positivity (r = 0.374, p = 0.022), but TRM may indicate more sensitive response to ICIs than PD-L1 expression in this study. Some blood test parameters also weakly correlated with TRM but did not impact prognosis. CONCLUSIONS: TRM-rich patients have a favorable prognosis after nivolumab initiation. Our results suggest that TRM are vital for antitumor immunity and are a promising predictor of ICIs effectiveness.

KEAP1 mutation in lung adenocarcinoma promotes immune evasion and immunotherapy resistance.

Lung cancer treatment has benefited greatly through advancements in immunotherapies. However, immunotherapy often fails in patients with specific mutations like KEAP1, which are frequently found in lung adenocarcinoma. We established an antigenic lung cancer model and used it to explore how Keap1 mutations remodel the tumor immune microenvironment. Using single-cell technology and depletion studies, we demonstrate that Keap1-mutant tumors diminish dendritic cell and T cell responses driving immunotherapy resistance. This observation was corroborated in patient samples. CRISPR-Cas9-mediated gene targeting revealed that hyperactivation of the NRF2 antioxidant pathway is responsible for diminished immune responses in Keap1-mutant tumors. Importantly, we demonstrate that combining glutaminase inhibition with immune checkpoint blockade can reverse immunosuppression, making Keap1-mutant tumors susceptible to immunotherapy. Our study provides new insight into the role of KEAP1 mutations in immune evasion, paving the way for novel immune-based therapeutic strategies for KEAP1-mutant cancers.

Immunological characteristics of CD103+CD8+ Tc cells in the liver of C57BL/6 mouse infected with plasmodium NSM.

CD103 is an important marker of tissue-resident memory T cells (TRM) which play important roles in fighting against infection. However, the immunological characteristics of CD103+ T cells are not thoroughly elucidated in the liver of mouse infected with Plasmodium. Six- to eight-week-old C57BL/6 mice were infected with Plasmodium yoelii nigeriensis NSM. Mice were sacrificed on 12-16 days after infection and the livers were picked out. Sections of the livers were stained, and serum aspartate aminotransferase (AST) and alanine transaminase (ALT) levels were measured. Moreover, lymphocytes in the liver were isolated, and the expression of CD103 was determined by using qPCR. The percentage of CD103 on different immune cell populations was dynamically observed by using flow cytometry (FCM). In addition, the phenotype and cytokine production characteristics of CD103+CD8+ Tc cell were analyzed by using flow cytometry, respectively. Erythrocyte stage plasmodium infection could result in severe hepatic damage, a widespread inflammatory response and the decrease of CD103 expression on hepatic immune cells. Only CD8+ Tc and γδT cells expressed higher levels of CD103 in the uninfected state.CD103 expression in CD8+ Tc cells significantly decreased after infection. Compared to that of CD103- CD8+ Tc cells, CD103+ CD8+ Tc cells from the infected mice expressed lower level of CD69, higher level of CD62L, and secreted more IL-4, IL-10, IL-17, and secreted less IFN-γ. CD103+CD8+ Tc cells might mediate the hepatic immune response by secreting IL-4, IL-10, and IL-17 except IFN-γ in the mice infected with the erythrocytic phase plasmodium, which could be involved in the pathogenesis of severe liver damage resulted from the erythrocytic phase plasmodium yoelii nigeriensis NSM infection.

PEDV promotes the differentiation of CD4+T cells towards Th1, Tfh, and Treg cells via CD103+DCs.

Porcine epidemic diarrhea virus (PEDV) can infect all ages of pigs, particularly newborn piglets with a mortality almost reaching to 80-100%, causing significant economic losses to the global pig industry. The mucosal immune response is crucial for PEDV prevention, in which specific dendritic cells (DCs) and differentiated T cells play vital roles. In this study, CD103+DCs were differentiated successfully with retinoic acid (RA) treatment in vitro. PEDV could not replicate efficiently in differentiated CD103+DCs but could promote maturation of CD103+DCs by up-regulating the expression of SLA-DR, CD1a, CD86, and cytokines of IL-1ß and IL-10. In addition, PEDV-infected CD103+DCs and CD4+T cells were co-cultured, and the results showed that the differentiation of CD4+T cells toward Th1, Tfh, and Treg, but not Th2. These results demonstrate that PEDV-infected CD103+DCs could promote the differentiation of CD4+T cells, which provided the basis for further study of mucosal response induced by PEDV via CD103+DCs.