scholarly journals Possibility of tuning the differentiation state of tumor associated macrophages towards tumor controlling phenotypes

Author(s):  
Wenfa Ng

Although various immune cells could infiltrate the cellular and tissue environment surrounding a tumor, the tumor microenvironment nevertheless presents immunosuppressive conditions unfavorable for immune cells to conduct large scale attack on cancer cells. For example, T-cells that make it to the tumor microenvironment are typically non-functional in containing tumor growth. On the other hand, macrophages could infiltrate the tumor microenvironment and is an important cell type modulated by and which also modulates the tumor. Specifically, two variants of macrophages with different phenotypes are known to exhibit close interactions with tumors. Known as M1 and M2 macrophages, they present dichotomously different signals to the tumor. Specifically, M1 macrophages control tumor growth while M2 macrophages promote tumor growth. Thus, from a treatment perspective, it would be desirable to tune the phenotypes and cell differentiation program of macrophages towards the M1 subset. To do that, differential gene expression of macrophages in the M1 and M2 lineages must be understood. Such a goal could be achieved with the profiling of tumor associated macrophages from tumor biopsy samples for gene expression patterns characteristic of the two dominant macrophage lineages. Single cell RNA-sequencing conducted after flow cytometry sorting of M1 and M2 macrophages would highlight gene expression patterns associated with each lineage, and the cellular differentiation programs that prompted entry into particular macrophage subtype. Knowledge of gene expression pattern associated with each macrophage lineage is not useful for tuning their differentiation state unless specific transcription factor that trigger the regulon could be identified. To this end, transcription factors that have been upregulated in the differentiation program could be profiled from the transcriptome data, and help inform the design of vectors for targeted overexpression of specific transcription factor for modulating cellular differentiation of macrophage. Given their low immunogenicity, adeno-associated virus (AAV) could serve as vectors for ferrying the gene cassette containing specific transcription factors into macrophages. Delivery methods for the AAV could be via targeted local infusion of vectors to tumors or through the systemic circulation, but the latter approach would result in lower transfection efficiency. Collectively, possibility exists of tuning the differentiation state of macrophage associated with tumors for enabling tumor controlling lineage to be dominant. Such immuno-targeted therapy would harness the body’s macrophages for controlling tumor growth and represents a treatment option that may yield fewer side effects compared to conventional chemotherapy. But, identification of genes that control lineage-specific differentiation program and the delivery of gene cassette to macrophages for modulating their differentiation remain key challenges.

2019 ◽  
Author(s):  
Wenfa Ng

Although various immune cells could infiltrate the cellular and tissue environment surrounding a tumor, the tumor microenvironment nevertheless presents immunosuppressive conditions unfavorable for immune cells to conduct large scale attack on cancer cells. For example, T-cells that make it to the tumor microenvironment are typically non-functional in containing tumor growth. On the other hand, macrophages could infiltrate the tumor microenvironment and is an important cell type modulated by and which also modulates the tumor. Specifically, two variants of macrophages with different phenotypes are known to exhibit close interactions with tumors. Known as M1 and M2 macrophages, they present dichotomously different signals to the tumor. Specifically, M1 macrophages control tumor growth while M2 macrophages promote tumor growth. Thus, from a treatment perspective, it would be desirable to tune the phenotypes and cell differentiation program of macrophages towards the M1 subset. To do that, differential gene expression of macrophages in the M1 and M2 lineages must be understood. Such a goal could be achieved with the profiling of tumor associated macrophages from tumor biopsy samples for gene expression patterns characteristic of the two dominant macrophage lineages. Single cell RNA-sequencing conducted after flow cytometry sorting of M1 and M2 macrophages would highlight gene expression patterns associated with each lineage, and the cellular differentiation programs that prompted entry into particular macrophage subtype. Knowledge of gene expression pattern associated with each macrophage lineage is not useful for tuning their differentiation state unless specific transcription factor that trigger the regulon could be identified. To this end, transcription factors that have been upregulated in the differentiation program could be profiled from the transcriptome data, and help inform the design of vectors for targeted overexpression of specific transcription factor for modulating cellular differentiation of macrophage. Given their low immunogenicity, adeno-associated virus (AAV) could serve as vectors for ferrying the gene cassette containing specific transcription factors into macrophages. Delivery methods for the AAV could be via targeted local infusion of vectors to tumors or through the systemic circulation, but the latter approach would result in lower transfection efficiency. Collectively, possibility exists of tuning the differentiation state of macrophage associated with tumors for enabling tumor controlling lineage to be dominant. Such immuno-targeted therapy would harness the body’s macrophages for controlling tumor growth and represents a treatment option that may yield fewer side effects compared to conventional chemotherapy. But, identification of genes that control lineage-specific differentiation program and the delivery of gene cassette to macrophages for modulating their differentiation remain key challenges.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1011-1011 ◽  
Author(s):  
Haiming Chen ◽  
Mingjie Li ◽  
Eric Sanchez ◽  
Abigail Gillespie ◽  
Cathy Wang ◽  
...  

Abstract Introduction: The bone marrow (BM) microenvironment plays an important role in multiple myeloma (MM). The BM niche is composed of multiple cell types including macrophages. Macrophages polarize into pro-inflammatory macrophage-1 (M1) or alternative M2 states that promote tumor growth and metastasis. We evaluated the proportion of M2 macrophages in BM from MM pts either showing complete response (CR) or progressive disease (PD), the effects of MM cells on M1 and M2 differentiation, and the role of Trib1 in M2 differentiation in MM BM. Since the JAK-STAT signaling pathway plays key roles in macrophages, we also evaluated the effects of the JAK2 inhibitor ruxolitinib (RUX) on M2 polarization in MM. Methods: Using immunofluorescence (IFC), we determined the proportion of M1 and M2 macrophages in BM biopsies and aspirates from MM pts with PD or CR. The BM biopsy samples were stained with antibodies directed against human iNOS and CD86 for M1 and arginase 1(ARG1) and CD36 for M2 cells. MM BM aspirates were also examined using flow cytometric analysis (FCA). Human monocytes isolated from healthy subjects or the THP1 monocyte cell line were co-cultured with MM cell lines (RPMI8226 and U266) or primary MM tumor cells. The effects of RUX at low concentrations (IC20) on M2 polarization were determined. The percentages of M1 and M2 macrophages were determined using FCA. Total RNA was extracted from monocytes. Quantitative PCR was measured with TaqMan technology. For the in vivo studies, human MM tumors (LAGκ-2) were surgically implanted into the left superficial gluteal muscle of SCID mice and tumor volume measured on a weekly basis. Results: The proportion of M2 macrophages (CD36+/ARG1+) was markedly increased in BM biopsies or mononuclear cells from MM pts with PD compared with those in CR using IFC staining. FCA also showed the percentage of M2 macrophages in BM was significantly increased in MM pts with PD (n=25) compared to those in CR (n=10; P=0.005) whereas there was no difference in the percentage of M1 (CD86+/iNOS+) macrophages in BM derived from MM pts with PD compared to those in CR. Trib1 gene mRNA levels were higher among pts with PD compared to those in CR whereas the gene expression of Trib2 and Trib3 was not different. Next, we co-cultured MM cell lines (U266) or fresh MM BMMCs with purified healthy human monocytes for one week. The percentage of M2 cells markedly increased and the proportion of M1 cells decreased. Trib1 gene expression increased during co-culture whereas there was no change in expression of the other two Tribs. When direct cell-to-cell contact occurred between the MM tumor cells and the monocytes, the percentage of M2 macrophages markedly increased. We investigated the effects of the JAK2 inhibitor RUX on M2 differentiation induced with MM tumor cells. After exposure to a low concentration of RUX, the percentage of M2 cells decreased when the monocytes were co-cultured with MM tumor cells. Trib1 gene expression of the monocytes treated with RUX was also notably reduced compared with cells not treated with the JAK2 inhibitor. Using our human MM xenograft model LAGκ-2, RUX (1.5mg/kg) reduced tumor growth and decreased the proportion of M2 macrophages in the tumor tissue of MM tumor-bearing SCID mice. Conclusion: M2 cells are present at high levels in BM derived from MM pts with PD compared to those in CR, MM cells induce monocytes to become M2 macrophages and increase Trib1 gene expression. This induces monocyte differentiation into M2 macrophages that support MM tumor cell growth.. Notably, the JAK2 inhibitor RUX inhibits both M2 macrophage polarization and Trib1 gene expression in MM, and reduces tumor growth in SCID mice bearing human MM. These results suggest that RUX may be effective for treating MM pts. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2006 ◽  
Vol 109 (5) ◽  
pp. 2066-2077 ◽  
Author(s):  
Octavio Ramilo ◽  
Windy Allman ◽  
Wendy Chung ◽  
Asuncion Mejias ◽  
Monica Ardura ◽  
...  

Abstract Each infectious agent represents a unique combination of pathogen-associated molecular patterns that interact with specific pattern-recognition receptors expressed on immune cells. Therefore, we surmised that the blood immune cells of individuals with different infections might bear discriminative transcriptional signatures. Gene expression profiles were obtained for 131 peripheral blood samples from pediatric patients with acute infections caused by influenza A virus, Gram-negative (Escherichia coli) or Gram-positive (Staphylococcus aureus and Streptococcus pneumoniae) bacteria. Thirty-five genes were identified that best discriminate patients with influenza A virus infection from patients with either E coli or S pneumoniae infection. These genes classified with 95% accuracy (35 of 37 samples) an independent set of patients with either influenza A, E coli, or S pneumoniae infection. A different signature discriminated patients with E coli versus S aureus infections with 85% accuracy (34 of 40). Furthermore, distinctive gene expression patterns were observed in patients presenting with respiratory infections of different etiologies. Thus, microarray analyses of patient peripheral blood leukocytes might assist in the differential diagnosis of infectious diseases.


2020 ◽  
Vol 12 ◽  
pp. 175883592091379 ◽  
Author(s):  
David W. Doo ◽  
Selene Meza-Perez ◽  
Angelina I. Londoño ◽  
Whitney N. Goldsberry ◽  
Ashwini A. Katre ◽  
...  

Background: The Wnt/β-catenin pathway is linked to tumorigenesis in a variety of tumors and promotes T cell exclusion and resistance to checkpoint inhibitors. We sought to determine whether a small molecule inhibitor of this pathway, WNT974, would impair tumor growth, affect gene expression patterns, and improve the immune response in human and murine ovarian cancer models. Methods: Human ovarian cancer cells were treated with WNT974 in vitro. RNAseq libraries were constructed and differences in gene expression patterns between responders and nonresponders were compared to The Cancer Genome Atlas (TCGA). Mice with subcutaneous or intraperitoneal ID8 ovarian cancer tumors were treated with WNT974, paclitaxel, combination, or control. Tumor growth and survival were measured. Flow cytometry and β-TCR repertoire analysis were used to determine the immune response. Results: Gene expression profiling revealed distinct signatures in responders and nonresponders, which strongly correlated with T cell infiltration patterns in the TCGA analysis of ovarian cancer. WNT974 inhibited tumor growth, prevented ascites formation, and prolonged survival in mouse models. WNT974 increased the ratio of CD8+ T cells to T regulatory cells (Tregs) in tumors and enhanced the effector functions of infiltrating CD4+ and CD8+ T cells. Treatment also decreased the expression of inhibitory receptors on CD8+ T cells. Combining WNT974 with paclitaxel further reduced tumor growth, prolonged survival, and expanded the T cell repertoire. Conclusions: These findings suggest that inhibiting the Wnt/β-catenin pathway may have a potent immunomodulatory effect in the treatment of ovarian cancer, particularly when combined with paclitaxel.


Pneumologie ◽  
2018 ◽  
Vol 72 (S 01) ◽  
pp. S8-S9
Author(s):  
M Bauer ◽  
H Kirsten ◽  
E Grunow ◽  
P Ahnert ◽  
M Kiehntopf ◽  
...  

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