Activation Of Systemic Immune Response Research Articles

Immunoantitumor Activity and Oxygenation Effect Based on Iron-Copper-Doped Folic Acid Carbon Dots.

Cancer metastasis and recurrence are closely associated with immunosuppression and a hypoxic tumor microenvironment. Chemodynamic therapy (CDT) and photothermodynamic therapy (PTT) have been shown to induce immunogenic cell death (ICD), effectively inhibiting cancer metastasis and recurrence when combined with immune adjuvants. However, the limited efficacy of Fenton's reaction and suboptimal photothermal effect present significant challenges for successfully inducing ICD through CDT and PTT. This paper described the synthesis and immunoantitumor activity of the novel iron-copper-doped folic acid carbon dots (CFCFB). Copper-doped folic acid carbon dots (Cu-FACDs) were initially synthesized via a hydrothermal method, using folic acid and copper gluconate as precursors. Subsequently, the nanoparticles CFCFB were obtained through cross-linking and self-assembly of Cu-FACDs with ferrocene dicarboxylic acid (FeDA) and 3-bromopyruvic acid (3BP). The catalytic effect of carbon dots in CFCFB enhanced the activity of the Fenton reaction, thereby promoting CDT-induced ICD and increasing the intracellular oxygen concentration. Additionally, 3BP inhibited cellular respiration, further amplifying the oxygen concentration. The photothermal conversion efficiency of CFCFB reached 55.8%, which significantly enhanced its antitumor efficacy through photothermal therapy. Immunofluorescence assay revealed that treatment with CFCFB led to an increased expression of ICD markers, including calreticulin (CRT) and ATP, as well as extracellular release of HMGB-1, indicating the induction of ICD by CFCFB. Moreover, the observed downregulation of ARG1 expression indicates a transition in the tumor microenvironment from an immunosuppressive state to an antitumor state following treatment with CFCFB. The upregulation of IL-2 and CD8 expression facilitated the differentiation of effector T cells, resulting in an augmented population of CD8+ T cells, thereby indicating the activation of systemic immune response.

Abstract 1360: TIGIT blockade combined with local radiotherapy and PD-1 blockade in a murine triple-negative breast cancer model

Abstract Background: Immune checkpoint blockades (ICB) improve outcomes of patients with some solid tumors such has melanoma and lung cancer, however the efficacy of ICB alone showed limited efficacy in many other tumors such as breast cancer. Radiation therapy is a promising combination partner of ICB as a strong immune stimulator so called in situ tumor vaccine, however it also can increase immune suppressive repertoires. TIGIT (T cell Immunoglobulin and ITIM domain) is an inhibitory receptor expressed on activated T cells and NK cells. We evaluated the effects of TIGIT blockade in addition to local RT and PD-1 blockade as a strategy to overcome therapeutic resistance of ICI in a murine breast cancer model. Materials and Methods: 4T1-Luc tumors were treated with various strategies including control, RT, anti-PD-1, anti-TIGIT, RT+anti-PD-1, RT+anti-TIGIT, anti-PD-1+anti-TIGIT, and RT+anti-PD-1+anti-TIGIT. A total of 24 Gy in 3 fractions at 1 week was delivered to the tumor at hindlimb (primary tumor) while the tumor at flank (secondary tumor) was left unirradiated. 10 mg/kg of anti-PD-1 blocking antibodies and 10 mg/kg of anti-TIGIT blocking antibodies were intraperitoneally injected for 6 times for 2 weeks. Flow cytometry, IHC staining, and ELISA were performed to assess the immunologic status after treatments. Results: The triple combination therapy (TCT) group showed the most superior growth delay of primary and secondary tumor growth among treatments. The number of metastatic lung nodule was significantly reduced by TCT as well. Plasma levels of interferon-β and interferon-γ were the highest after TCT. Moreover, TCT significantly increased the proportion of splenic CD8+ dendritic cells among myeloid cells, and effector-memory (CD44+CD62L−) cells among splenic Foxp3− non-regulatory CD4+ and CD8+ T cells. Furthermore, expression of CD226, which is an activating counter-receptor of TIGIT, on splenic CD8+ T cells was elevated by TIGIT blockade, possibly suggesting the activation of systemic immune response by addition of TIGIT blockade to local RT and PD-1 blockade. Meanwhile, TCT decreased splenic Foxp3+ regulatory T cells, as well as the expression of CD39 on splenic Foxp3+ regulatory T cells. The increase of CD8+ T cell infiltration in primary and secondary tumors was most prominent in TCT group. Conclusion: TIGIT blockade elicits systemic immune responses in a murine triple-negative breast cancer model. when combined with local RT and PD-1 blockade, which were correlated with significant delay in the growth of both irradiated and unirradiated tumors. These results suggest that TIGIT blockade could be a viable approach to increase the efficacy of RT and immune checkpoint inhibitors in breast cancer which is a relatively immunologically cold tumor. (Work supported by a grant from National Research Foundation of Korea #2023R1A2C3003782 to In Ah Kim). Citation Format: Seongmin Kim, Seung Hyuck Jeon, In Ah Kim. TIGIT blockade combined with local radiotherapy and PD-1 blockade in a murine triple-negative breast cancer model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1360.

Involvement in the development of Alzheimer's disease through activation of systemic immune response.

Involvement in the development of Alzheimer's disease through activation of systemic immune response.

Abstract 977: Nano immunotherapeutics crossing blood-brain barrier to activate local brain tumor immune system

Abstract Introduction: Glioblastoma multiforme (GBM) has limited treatment options. Checkpoint inhibitors anti-CTLA-4 and/or anti-PD-1 antibodies (Abs) cannot activate anti-tumor immune response in the brain because of their inability to cross blood-brain barrier (BBB) and modulate brain privileged immunity. A new generation of nano immunotherapeutics (NIT) that pass BBB and activate general and local brain tumor immune systems was developed. Experimental procedures: BBB-crossing NIT were synthesized, based on the poly (β-L-malic acid) polymer (P), P/a-CTLA-4 Ab and P/a-PD-1 Ab, and a-mouse transferring receptor (a-msTfR) Ab or AP-2 peptide for delivery through BBB. Syngeneic GL261 glioma cells were intracranially inoculated into C57/BL mice. Six treatment groups received 5 I.V. injections of PBS, anti-PD1 and anti-CTLA4 Abs (controls), and polymers conjugated with anti-PD-1(P/a-PD-1), anti-CTLA-4 (P/a-CTLA-4) and a combination (P/a-CTLA-4+P/a-PD-1) at 10 mg/kg. Summary of the data: Single NIT treatment (P/a-CTLA-4 or P/a-PD-1) improved brain tumor bearing mice survival vs. free a-CTLA-4 and a-PD-1 (p=0.0076 and 0.0017, respectively). The combination group (P/a-CTLA-4 + P/a-PD-1) showed the best efficacy for survival (p=0.0001). Flow cytometry (FC) analysis of T cell populations in the brain tumor revealed a reduction of total CD4+ T-cells in animals treated with P/anti-PD-1 and P/a-CTLA-4 + P/a-PD-1 combination vs. free anti-PD-1 Ab. The fraction of Tregs (CD4+FOXP3+) was reduced by all polymer treatments compared to free Abs. Activation of CD8+ T cells (CD8+IFN-γ+ and CD8+CD69+) was significantly increased by P/a-CTLA-4 or P/a-PD-1 and combination therapy, vs. free a-CTLA-4 and a-PD-1 Abs. To independently confirm FC data, the local immune response was investigated for CD8 and CD4+FoxP3 positive T-cells, and IFN-γ, iNOS markers for M1 macrophages by immunofluorescence staining using FIJI software. In P/a-CTLA-4 + P/a-PD-1 group vs. PBS the percentage of CD8+ T cells was significantly increased (p=0.0005), together with reduction of CD4+FoxP3+ T cells (p=0.0006) and increase of iNOS-positive macrophages (p=0.0001). FC and histology results confirmed that the NIT treatment stimulated local brain immune system. FC analysis of T-cell population in blood and spleen also demonstrated significant activation of systemic immune response after combination therapy, based on cytokines level: IL-1β, IL-2, IL-10, IL-4, IL-5, TNF-α, IL-6, IL-12, and IFN-γ after treatment. Conclusion: GBM treatment with BBB-crossing polymer-conjugated antibodies a-PD-1 and a-CTLA-4 was able to increase tumor-bearing animal survival, which was supported by immunological results indicating the activation of T cell population systemically and locally in the brain. Support: NIH grants R01 CA206220, R01CA230858 Citation Format: Anna Galstyan, Antonella Chiechi, Tao Sun, Ekaterina S. Shatalova, Rameshwar Patil, Keith L. Black, Eggehard Holler, Alexander V. Ljubimov, Hui Ding, Julia Y. Ljubimova. Nano immunotherapeutics crossing blood-brain barrier to activate local brain tumor immune system [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 977.

Dynamics of inflammation biomarkers C-reactive protein, leukocytes, neutrophils, and CD64 on neutrophils before and after major surgical procedures to recognize potential postoperative infection

Background. Major trauma and soft tissue injuries result in a substantial activation of systemic immune response and post-traumatic complications such as postoperative infections. The aim was to assess the dynamics of expressed inflammatory biomarkers after surgery and to detect possible postoperative infection. Methods. A total of 229 patients were included and separated into three different groups, depending on the procedure they underwent (colorectal, maxillofacial, open heart surgery). Biomarkers CD64 on neutrophils, C-reactive protein (CRP), count of leucocytes and neutrophils were measured to detect postoperative infection. Results. The values of all biomarkers after surgery were generally elevated and had then dropped 48 h after the procedure. The levels were dependent on the type of operation and showed higher levels after more serious procedures. In the patients with postoperative infections the values were considerably higher. Moreover, biomarkers’ cut-off values for positive infection were higher from patients who underwent surgery, compared to the cut-off values from patients with no surgical procedure. CD64 index was the only biomarker that could predict postoperative infection (p < 0.001). Other biomarkers could not statistically predict the infection. Conclusions. Newly acquired postoperative infection is difficult to diagnose using just biomarkers due to the strong activation of immune response. CD64 index with its slightly higher cut-off (> 1.27) is the only biomarker that could be used as a diagnostic tool to rapidly detect postoperative bacterial infection.