Purpose: The immunologic effects of radiation (RT) are influenced by dose and each may be optimiz... more Purpose: The immunologic effects of radiation (RT) are influenced by dose and each may be optimized over a unique dose range. We used brachytherapy (BT) to deliver a heterogeneous RT dose within a single tumor and compared the relative capacities of BT and homogenous dose external beam radiotherapy (EBRT) to enhance the anti-tumor immune response in combination with immune checkpoint inhibition (ICI). Materials and Methods: We used syngeneic murine models of melanoma (B78) and prostate cancer (Myc-CaP). To evaluate the effect of BT on the microenvironment, mice bearing B78 tumors were randomized to receive BT (192Ir source, 2 Gy to tumor edge), sham insertion, or EBRT (2, 8, or 20 Gy). Tumors were harvested 3 days following RT and in the case of BT, punch excisions were taken from the dissected tumor 1, 3, and 5 mm from the source location for gene expression and immune cell infiltration analysis. To evaluate anti-tumor response, we randomized mice bearing B78 tumors on the right fl...
Brain metastases develop in over 60% of advanced melanoma patients and negatively impact quality ... more Brain metastases develop in over 60% of advanced melanoma patients and negatively impact quality of life and prognosis. In a murine melanoma model, we previously showed that an in situ vaccination (ISV) regimen, combining radiation treatment and intratumoral (IT) injection of immunocytokine (IC: anti-GD2 antibody fused to IL2), along with the immune checkpoint inhibitor anti-CTLA-4, robustly eliminates peripheral flank tumors but only has modest effects on co-occurring intracranial tumors. In this study, we investigated the ability of low-dose radiation to the brain to potentiate anti-tumor immunity against a brain tumor when combined with ISV + anti-CTLA-4. B78 (GD2+, immunologically “cold”) melanoma tumor cells were implanted into the flank and the right striatum of the brain in C57BL/6 mice. Flank tumors (50–150 mm3) were treated following a previously optimized ISV regimen [radiation (12 Gy × 1, treatment day 1), IT-IC (50 µg daily, treatment days 6–10), and anti-CTLA-4 (100 µg, treatment days 3, 6, 9)]. Mice that additionally received whole-brain radiation treatment (WBRT, 4 Gy × 1) on day 15 demonstrated significantly increased survival compared to animals that received ISV + anti-CTLA-4 alone, WBRT alone or no treatment (control) (P < 0.001, log-rank test). Timing of WBRT was critical, as WBRT administration on day 1 did not significantly enhance survival compared to ISV + anti-CTLA-4, suggesting that the effect of WBRT on survival might be mediated through immune modulation and not just direct tumor cell cytotoxicity. Modest increases in T cells (CD8+ and CD4+) and monocytes/macrophages (F4/80+) but no changes in FOXP3+ regulatory T cells (Tregs), were observed in brain melanoma tumors with addition of WBRT (on day 15) to ISV + anti-CTLA-4. Cytokine multiplex immunoassay revealed distinct changes in both intracranial melanoma and contralateral normal brain with addition of WBRT (day 15) to ISV + anti-CTLA-4, with notable significant changes in pro-inflammatory (e.g., IFNγ, TNFα and LIX/CXCL5) and suppressive (e.g., IL10, IL13) cytokines as well as chemokines (e.g., IP-10/CXCL10 and MIG/CXCL9). We tested the ability of the alkylphosphocholine analog, NM600, to deliver immunomodulatory radiation to melanoma brain tumors as a targeted radionuclide therapy (TRT). Yttrium-86 (86Y) chelated to NM600 was delivered intravenously by tail vein to mice harboring flank and brain melanoma tumors, and PET imaging demonstrated specific accumulation up to 72 h at each tumor site (∼12:1 brain tumor/brain and ∼8:1 flank tumor/muscle). When NM600 was chelated to therapeutic β-particle-emitting 90Y and administered on treatment day 13, T-cell infiltration and cytokine profiles were altered in melanoma brain tumor, like that observed for WBRT. Overall, our results demonstrate that addition of low-dose radiation, timed appropriately with ISV administration to tumors outside the brain, significantly increases survival in animals co-harboring melanoma brain tumors. This observation has potentially important translational implications as a treatment strategy for increasing the response of tumors in the brain to systemically administered immunotherapies.
Background: Andrographis paniculata (AP) (Burm. F) Nees, belongs to the family Acanthaceae, it is... more Background: Andrographis paniculata (AP) (Burm. F) Nees, belongs to the family Acanthaceae, it is also known as a highly bitter plant. In South East Asia this plant is commonly used for cold, cough and respiratory tract infections. Andrographolide (ANG), 14-deoxy-11, 12-didehydroandrographolide (DDA) are the major bioactive diterpenoid lactone compounds of the plant shown vasorelaxant effect, anticancer, anti-inflammatory, and to treat variety of diseases which is well-documented. Materials and Methods: The high-performance liquid chromatography (HPLC) and 1H-NMR analysis of AP chloroform extract (APCE) revealed the presence of ANG, 14-deoxyandrographolide (DA), and DDA. The main advantage of 1H-NMR is simple, rapid and successfully applied to quantify the active diterpenoids and an alternative to HPLC method to check the presence of various bioactive compounds and its presence in the active raw materials of AP. Results: The results revealed that most active bioactive compounds such as ANG, DA, and DDA are present in the APCE portion of the AP. The chemical shifts of various groups confirmed through 1H-NMR that all the three ANG, DA, and DDA has potent vasorelaxant effect and majority of these compounds are present in the APCE portion and not in the methanol or aqueous fractions. The 1H-NMR study confirmed that diterpenoids such as ANG, DA, and DDA from APCE has vasorelaxant effect on the animal study.
A neurodegenerative disease (ND) is defined as an irreversible disorder in most cases, leading to... more A neurodegenerative disease (ND) is defined as an irreversible disorder in most cases, leading to progressive loss of neurons and intellectual abilities. ND can lead to fatality in most circumstances, and the elderly above the age of sixty-five (65) constitute the major risk category. The most common type of ND includes Alzheimer's disease (AD), and Parkinson's disease (PD). Other NDs are Huntington's disease (HD), motor neuron disease (MND), spinocerebellar ataxia (SCA), spinal muscular atrophy (SMA), and prion disease. ND strikes mainly in the middle to late life incidence expected to rise as the population ages.
BackgroundImmune checkpoint inhibition (ICI) alone is not efficacious for a large number of patie... more BackgroundImmune checkpoint inhibition (ICI) alone is not efficacious for a large number of patients with melanoma brain metastases. We previously established an in situ vaccination (ISV) regimen combining radiation and immunocytokine to enhance response to ICIs. Here, we tested whether ISV inhibits the development of brain metastases in a murine melanoma model.MethodsB78 (GD2+) melanoma ‘primary’ tumors were engrafted on the right flank of C57BL/6 mice. After 3–4 weeks, primary tumors were treated with ISV (radiation (12 Gy, day 1), α-GD2 immunocytokine (hu14.18-IL2, days 6–10)) and ICI (α-CTLA-4, days 3, 6, 9). Complete response (CR) was defined as no residual tumor observed at treatment day 90. Mice with CR were tested for immune memory by re-engraftment with B78 in the left flank and then the brain. To test ISV efficacy against metastases, tumors were also engrafted in the left flank and brain of previously untreated mice. Tumors were analyzed by quantitative reverse transcripti...
Purpose: The immunologic effects of radiation (RT) are influenced by dose and each may be optimiz... more Purpose: The immunologic effects of radiation (RT) are influenced by dose and each may be optimized over a unique dose range. We used brachytherapy (BT) to deliver a heterogeneous RT dose within a single tumor and compared the relative capacities of BT and homogenous dose external beam radiotherapy (EBRT) to enhance the anti-tumor immune response in combination with immune checkpoint inhibition (ICI). Materials and Methods: We used syngeneic murine models of melanoma (B78) and prostate cancer (Myc-CaP). To evaluate the effect of BT on the microenvironment, mice bearing B78 tumors were randomized to receive BT (192Ir source, 2 Gy to tumor edge), sham insertion, or EBRT (2, 8, or 20 Gy). Tumors were harvested 3 days following RT and in the case of BT, punch excisions were taken from the dissected tumor 1, 3, and 5 mm from the source location for gene expression and immune cell infiltration analysis. To evaluate anti-tumor response, we randomized mice bearing B78 tumors on the right fl...
Brain metastases develop in over 60% of advanced melanoma patients and negatively impact quality ... more Brain metastases develop in over 60% of advanced melanoma patients and negatively impact quality of life and prognosis. In a murine melanoma model, we previously showed that an in situ vaccination (ISV) regimen, combining radiation treatment and intratumoral (IT) injection of immunocytokine (IC: anti-GD2 antibody fused to IL2), along with the immune checkpoint inhibitor anti-CTLA-4, robustly eliminates peripheral flank tumors but only has modest effects on co-occurring intracranial tumors. In this study, we investigated the ability of low-dose radiation to the brain to potentiate anti-tumor immunity against a brain tumor when combined with ISV + anti-CTLA-4. B78 (GD2+, immunologically “cold”) melanoma tumor cells were implanted into the flank and the right striatum of the brain in C57BL/6 mice. Flank tumors (50–150 mm3) were treated following a previously optimized ISV regimen [radiation (12 Gy × 1, treatment day 1), IT-IC (50 µg daily, treatment days 6–10), and anti-CTLA-4 (100 µg, treatment days 3, 6, 9)]. Mice that additionally received whole-brain radiation treatment (WBRT, 4 Gy × 1) on day 15 demonstrated significantly increased survival compared to animals that received ISV + anti-CTLA-4 alone, WBRT alone or no treatment (control) (P < 0.001, log-rank test). Timing of WBRT was critical, as WBRT administration on day 1 did not significantly enhance survival compared to ISV + anti-CTLA-4, suggesting that the effect of WBRT on survival might be mediated through immune modulation and not just direct tumor cell cytotoxicity. Modest increases in T cells (CD8+ and CD4+) and monocytes/macrophages (F4/80+) but no changes in FOXP3+ regulatory T cells (Tregs), were observed in brain melanoma tumors with addition of WBRT (on day 15) to ISV + anti-CTLA-4. Cytokine multiplex immunoassay revealed distinct changes in both intracranial melanoma and contralateral normal brain with addition of WBRT (day 15) to ISV + anti-CTLA-4, with notable significant changes in pro-inflammatory (e.g., IFNγ, TNFα and LIX/CXCL5) and suppressive (e.g., IL10, IL13) cytokines as well as chemokines (e.g., IP-10/CXCL10 and MIG/CXCL9). We tested the ability of the alkylphosphocholine analog, NM600, to deliver immunomodulatory radiation to melanoma brain tumors as a targeted radionuclide therapy (TRT). Yttrium-86 (86Y) chelated to NM600 was delivered intravenously by tail vein to mice harboring flank and brain melanoma tumors, and PET imaging demonstrated specific accumulation up to 72 h at each tumor site (∼12:1 brain tumor/brain and ∼8:1 flank tumor/muscle). When NM600 was chelated to therapeutic β-particle-emitting 90Y and administered on treatment day 13, T-cell infiltration and cytokine profiles were altered in melanoma brain tumor, like that observed for WBRT. Overall, our results demonstrate that addition of low-dose radiation, timed appropriately with ISV administration to tumors outside the brain, significantly increases survival in animals co-harboring melanoma brain tumors. This observation has potentially important translational implications as a treatment strategy for increasing the response of tumors in the brain to systemically administered immunotherapies.
Background: Andrographis paniculata (AP) (Burm. F) Nees, belongs to the family Acanthaceae, it is... more Background: Andrographis paniculata (AP) (Burm. F) Nees, belongs to the family Acanthaceae, it is also known as a highly bitter plant. In South East Asia this plant is commonly used for cold, cough and respiratory tract infections. Andrographolide (ANG), 14-deoxy-11, 12-didehydroandrographolide (DDA) are the major bioactive diterpenoid lactone compounds of the plant shown vasorelaxant effect, anticancer, anti-inflammatory, and to treat variety of diseases which is well-documented. Materials and Methods: The high-performance liquid chromatography (HPLC) and 1H-NMR analysis of AP chloroform extract (APCE) revealed the presence of ANG, 14-deoxyandrographolide (DA), and DDA. The main advantage of 1H-NMR is simple, rapid and successfully applied to quantify the active diterpenoids and an alternative to HPLC method to check the presence of various bioactive compounds and its presence in the active raw materials of AP. Results: The results revealed that most active bioactive compounds such as ANG, DA, and DDA are present in the APCE portion of the AP. The chemical shifts of various groups confirmed through 1H-NMR that all the three ANG, DA, and DDA has potent vasorelaxant effect and majority of these compounds are present in the APCE portion and not in the methanol or aqueous fractions. The 1H-NMR study confirmed that diterpenoids such as ANG, DA, and DDA from APCE has vasorelaxant effect on the animal study.
A neurodegenerative disease (ND) is defined as an irreversible disorder in most cases, leading to... more A neurodegenerative disease (ND) is defined as an irreversible disorder in most cases, leading to progressive loss of neurons and intellectual abilities. ND can lead to fatality in most circumstances, and the elderly above the age of sixty-five (65) constitute the major risk category. The most common type of ND includes Alzheimer's disease (AD), and Parkinson's disease (PD). Other NDs are Huntington's disease (HD), motor neuron disease (MND), spinocerebellar ataxia (SCA), spinal muscular atrophy (SMA), and prion disease. ND strikes mainly in the middle to late life incidence expected to rise as the population ages.
BackgroundImmune checkpoint inhibition (ICI) alone is not efficacious for a large number of patie... more BackgroundImmune checkpoint inhibition (ICI) alone is not efficacious for a large number of patients with melanoma brain metastases. We previously established an in situ vaccination (ISV) regimen combining radiation and immunocytokine to enhance response to ICIs. Here, we tested whether ISV inhibits the development of brain metastases in a murine melanoma model.MethodsB78 (GD2+) melanoma ‘primary’ tumors were engrafted on the right flank of C57BL/6 mice. After 3–4 weeks, primary tumors were treated with ISV (radiation (12 Gy, day 1), α-GD2 immunocytokine (hu14.18-IL2, days 6–10)) and ICI (α-CTLA-4, days 3, 6, 9). Complete response (CR) was defined as no residual tumor observed at treatment day 90. Mice with CR were tested for immune memory by re-engraftment with B78 in the left flank and then the brain. To test ISV efficacy against metastases, tumors were also engrafted in the left flank and brain of previously untreated mice. Tumors were analyzed by quantitative reverse transcripti...
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Papers by Raghava Sriramaneni