Chemotherapy Shifts the Balance in Favor of CD8+ TNFR2+ TILs in Triple-Negative Breast Tumors

Triple-negative breast cancer (TNBC) is primarily treated via chemotherapy; in parallel, efforts are made to introduce immunotherapies into TNBC treatment. CD4+ TNFR2+ lymphocytes were reported as Tregs that contribute to tumor progression. However, our published study indicated that TNFR2+ tumor-infiltrating lymphocytes (TNFR2+ TILs) were associated with improved survival in TNBC patient tumors. Based on our analyses of the contents of CD4+ and CD8+ TILs in TNBC patient tumors, in the current study, we determined the impact of chemotherapy on CD4+ and CD8+ TIL subsets in TNBC mouse tumors. We found that chemotherapy led to (1) a reduction in CD4+ TNFR2+ FOXP3+ TILs, indicating that chemotherapy decreased the content of CD4+ TNFR2+ Tregs, and (2) an elevation in CD8+ TNFR2+ and CD8+ TNFR2+ PD-1+ TILs; high levels of these two subsets were significantly associated with reduced tumor growth. In spleens of tumor-bearing mice, chemotherapy down-regulated CD4+ TNFR2+ FOXP3+ cells but the subset of CD8+ TNFR2+ PD-1+ was not present prior to chemotherapy and was not increased by the treatment. Thus, our data suggest that chemotherapy promotes the proportion of protective CD8+ TNFR2+ TILs and that, unlike other cancer types, therapeutic strategies directed against TNFR2 may be detrimental in TNBC.

SV40 microRNA miR-S1-3p Downregulates the Expression of T Antigens to Control Viral DNA Replication, and TNFα and IL-17F Expression

SV40-encoded microRNA (miRNA), miR-S1, downregulates the large and small T antigens (LTag and STag), which promote viral replication and cellular transformation, thereby presumably impairing LTag and STag functions essential for the viral life cycle. To explore the functional significance of miR-S1-mediated downregulation of LTag and STag as well as the functional roles of miR-S1, we evaluated viral DNA replication and proinflammatory cytokine induction in cells transfected with simian virus 40 (SV40) genome plasmid and its mutated form lacking miR-S1 expression. The SV40 genome encodes two mature miR-S1s, miR-S1-3p and miR-S1-5p, of which miR-S1-3p is the predominantly expressed form. MiR-S1-3p exerted strong repressive effects on a reporter containing full-length sequence complementarity, but only marginal effect on one harboring a sequence complementary to its seed sequence. Consistently, miR-S1-3p downregulated LTag and STag transcripts with complete sequence complementarity through miR-S1-3p-Ago2-mediated mRNA decay. Transfection of SV40 plasmid induced higher DNA replication and lower LTag and STag transcripts in most of the examined cells compared to that miR-S1-deficient SV40 plasmid. However, miR-S1 itself did not affect DNA replication without the downregulation of LTag transcripts. Both LTag and STag induced the expression of tumor necrosis factor α (TNFα) and interleukin (IL)-17F, which was slightly reduced by miR-S1 due to miR-S1-mediated downregulation of LTag and STag. Forced miR-S1 expression did not affect TNFα expression, but increased IL-17F expression. Overall, our findings suggest that miR-S1-3p is a latent modifier of LTag and STag functions, ensuring efficient viral replication and attenuating cytokine expression detrimental to the viral life cycle.

Oncolytic HSV therapy increases trametinib access to brain tumors and sensitizes them in vivo

BACKGROUND

Hyperactivation of the RAS-RAF-MEK-ERK signaling pathway is exploited by glioma cells to promote their growth and evade apoptosis. MEK activation in tumor cells can increase replication of ICP34.5-deleted herpes simplex virus type 1 (HSV-1), but paradoxically its activation in tumor-associated macrophages promotes a pro-inflammatory signaling that can inhibit virus replication and propagation. Here we investigated the effect of blocking MEK signaling in conjunction with oncolytic HSV-1 (oHSV) for brain tumors.

METHODS

Infected glioma cells co-cultured with microglia or macrophages treated with or without trametinib were used to test trametinib effect on macrophages/microglia. Enzyme-linked immunosorbent assay, western blotting, and flow cytometry were utilized to evaluate the effect of the combination therapy. Pharmacokinetic (PK) analysis of mouse plasma and brain tissue was used to evaluate trametinib delivery to the CNS. Intracranial human and mouse glioma-bearing immune deficient and immune competent mice were used to evaluate the antitumor efficacy.

RESULT

Oncolytic HSV treatment rescued trametinib-mediated feedback reactivation of the mitogen-activated protein kinase signaling pathway in glioma. In vivo, PK analysis revealed enhanced blood-brain barrier penetration of trametinib after oHSV treatment. Treatment by trametinib, a MEK kinase inhibitor, led to a significant reduction in microglia- and macrophage-derived tumor necrosis factor alpha (TNFα) secretion in response to oHSV treatment and increased survival of glioma-bearing mice. Despite the reduced TNFα production observed in vivo, the combination treatment activated CD8+ T-cell mediated immunity and increased survival in a glioma-bearing immune-competent mouse model.

CONCLUSION

This study provides a rationale for combining oHSV with trametinib for the treatment of brain tumors.

Novel apoE receptor mimetics reduce LPS-induced microglial inflammation

Apolipoprotein E (apoE) and apoE-mimetic peptides exert prominent anti-inflammatory effects. We determined the anti-inflammatory effects of novel apoE receptor mimetics, composed of the LDL receptor-binding domain of apoE (aa 133-152, ApoEp) or ApoEp with 6 lysines (6KApoEp) or 6 aspartates added at the N-terminus (6DApoEp). BV2 microglia and human THP-1 monocytes were treated with lipopolysaccharide (LPS) in the absence or presence of ApoEp, 6KApoEp or 6DApoEp, followed by determination of pro-inflammatory tumor necrosis factor α (TNFα) and interleukin-6 (IL-6) release by ELISA. As signaling intermediates of inflammation, Signal Transducer and Activator of Transcription 3 (STAT3), Janus-Activated Kinase2 (JAK2) and p38 and p44/42 MAPK phosphorylation levels were determined by Western blot analysis. In addition, we isolated splenocytes from female htau mice treated with 6KApoEp or 6K for 28 weeks, followed by determination of concanavalinA (conA)-mediated interferon gamma (IFNγ) release. 6KApoEp starting at 2.5 µM significantly reduced LPS-mediated TNFα and IL-6 secretion in BV2 and THP-1 cells in a dose-dependent manner. In BV2 cells, 6KApoEp reduced TNFα secretion more effectively than 6DApoEp and ApoEp, which was blocked by PCSK9 treatment, suggesting a role for LDL receptors. 6KApoEp also inhibited LPS-induced p44/42 MAPK, JAK2 and STAT3 phosphorylation, while enhancing p38 MAPK phosphorylation. In addition, conA induced significantly less IFNγ release in splenocytes derived from htau mice treated with 6KApoEp compared with those treated with 6K. Thus, 6KApoEp most effectively reduces LPS-mediated neuroinflammation by interacting with LDL receptors, thus representing a novel anti-inflammatory agent for treatment of neurodegenerative disease.

Oncogenic Role of Tumor Necrosis Factor α-Induced Protein 8 (TNFAIP8)

Tumor necrosis factor (TNF)-α-induced protein 8 (TNFAIP8) is a founding member of the TIPE family, which also includes TNFAIP8-like 1 (TIPE1), TNFAIP8-like 2 (TIPE2), and TNFAIP8-like 3 (TIPE3) proteins. Expression of TNFAIP8 is strongly associated with the development of various cancers including cancer of the prostate, liver, lung, breast, colon, esophagus, ovary, cervix, pancreas, and others. In human cancers, TNFAIP8 promotes cell proliferation, invasion, metastasis, drug resistance, autophagy, and tumorigenesis by inhibition of cell apoptosis. In order to better understand the molecular aspects, biological functions, and potential roles of TNFAIP8 in carcinogenesis, in this review, we focused on the expression, regulation, structural aspects, modifications/interactions, and oncogenic role of TNFAIP8 proteins in human cancers.

Structural basis for tumor necrosis factor blockade with the therapeutic antibody golimumab

Tumor necrosis factor α (TNFα) is a proinflammatory cytokine, and elevated levels of TNFα in serum are associated with various autoimmune diseases, including rheumatoid arthritis (RA), ankylosing spondylitis (AS), Crohn's disease (CD), psoriasis, and systemic lupus erythaematosus. TNFα performs its pleiotropic functions by binding to two structurally distinct transmembrane receptors, TNF receptor (TNFR) 1 and TNFR2. Antibody-based therapeutic strategies that block excessive TNFα signaling have been shown to be effective in suppressing such harmful inflammatory conditions. Golimumab (Simponi®) is an FDA-approved fully human monoclonal antibody targeting TNFα that has been widely used for the treatment of RA, AS, and CD. However, the structural basis underlying the inhibitory action of golimumab remains unclear. Here, we report the crystal structure of the Fv fragment of golimumab in complex with TNFα at a resolution of 2.73 Å. The resolved structure reveals that golimumab binds to a distinct epitope on TNFα that does not overlap with the binding residues of TNFR2. Golimumab exerts its inhibitory effect by preventing binding of TNFR1 and TNFR2 to TNFα by steric hindrance. Golimumab does not induce conformational changes in TNFα that could affect receptor binding. This mode of action is specific to golimumab among the four anti-TNFα therapeutic antibodies currently approved for clinical use.

Effects of angiogenin on granulosa and theca cell function in cattle

Angiogenin is a member of the ribonuclease A superfamily of proteins that has been implicated in stimulating angiogenesis but whether angiogenin can directly affect ovarian granulosa or theca cell function is unknown. Therefore, the objective of these studies was to determine the effect of angiogenin on proliferation and steroidogenesis of bovine granulosa and theca cells. In experiments 1 and 2, granulosa cells from small (1 to 5 mm diameter) follicles and theca cells from large (8 to 22 mm diameter) follicles were cultured to evaluate the dose-response effect of recombinant human angiogenin on steroidogenesis. At 30 and 100 ng/ml, angiogenin inhibited (P0.10) granulosa cell estradiol production or theca cell progesterone production, and did not affect numbers of granulosa or theca cells. In experiments 3 and 4, granulosa and theca cells from both small and large follicles were cultured with 300 ng/ml of angiogenin to determine if size of follicle influenced responses to angiogenin. At 300 ng/ml, angiogenin increased large follicle granulosa cell proliferation but decreased small follicle granulosa cell progesterone and estradiol production and large follicle theca cell progesterone production. In experiments 5 and 6, angiogenin stimulated (P<0.05) proliferation and DNA synthesis in large follicle granulosa cells. In experiment 7, 300 ng/ml of angiogenin increased (P<0.05) CYP19A1 messenger RNA (mRNA) abundance in granulosa cells but did not affect CYP11A1 mRNA abundance in granulosa or theca cells and did not affect CYP17A1 mRNA abundance in theca cells. We conclude that angiogenin appears to target both granulosa and theca cells in cattle, but additional research is needed to further understand the mechanism of action of angiogenin in granulosa and theca cells, as well as its precise role in folliculogenesis.

Peripheral T cell lymphoma, not otherwise specified with myelofibrosis: report of a case with review of the literature

A 68-year-old man presented to us with pancytopenia, erythroderma, and multiple lymphadenopathies. Lymph node biopsy led to the diagnosis of peripheral T-Cell lymphoma-not otherwise specified (PTCL-NOS). Immunostaining of the lymph node biopsy specimens for cytokines revealed that the tumor cells were positive for plated-derived growth factor (PDGF), basic fibroblast growth factor (b-FGF), vascular endothelial growth factor (VEGF), tumor necrosis factor α (TNF-α), interferon-γ (IFN-γ), interleukin-1β (IL-1β), interleukin-2 (IL-2), and transforming growth factor-β (TGF-β). Bone marrow biopsy revealed infiltration by the PTCL-NOS and myelofibrosis (MF). Bone marrow blood was negative for JAK-2V617F. Bone marrow immunostaining for cytokines showed that the tumor cells were positive for PDGF, b-FGF, VEGF, TNF-α, IFN-γ, IL-1β, IL-2, and TGF-β. The patient was initiated on treatment, and after the first course of CHOP therapy, the bone marrow infiltration by the PTCL-NOS and MF improved. Repeat immunostaining of bone marrow biopsy specimens for cytokines showed that the tumor cells had become negative for PDGF, VEGF, TNF-α and TGF-β. However, after the second course of CHOP therapy, the bone marrow infiltration by the PTCL-NOS and MF worsened. Immunostaining of bone marrow specimens for cytokines again revealed positive staining results of the tumor cells for PDGF, TNF-α, and TGF-β. At the completion of the first course of treatment, the infiltration by the PTCL-NOS improved, but not the pancytopenia.

Inflammatory cytokine tumor necrosis factor α suppresses neuroprotective endogenous erythropoietin from astrocytes mediated by hypoxia-inducible factor-2α

Interest in erythropoietin (EPO) as a neuroprotective mediator has grown since it was found that systemically administered EPO is protective in several animal models of disease. However, given that the blood-brain barrier limits EPO entry into the brain, alternative approaches that induce endogenous EPO production in the brain may be more effective clinically and associated with fewer untoward side-effects. Astrocytes are the main source of EPO in the central nervous system. In the present study we investigated the effect of the inflammatory cytokine tumor necrosis factor α (TNFα) on hypoxia-induced upregulation of EPO in rat brain. Hypoxia significantly increased EPO mRNA expression in the brain and kidney, and this increase was suppressed by TNFα in vivo. In cultured astrocytes exposed to hypoxic conditions for 6 and 12 h, TNFα suppressed the hypoxia-induced increase in EPO mRNA expression in a concentration-dependent manner. TNFα inhibition of hypoxia-induced EPO expression was mediated primarily by hypoxia-inducible factor (HIF)-2α rather than HIF-1α. The effects of TNFα in reducing hypoxia-induced upregulation of EPO mRNA expression probably involve destabilization of HIF-2α, which is regulated by the nuclear factor (NF)-κB signaling pathway. TNFα treatment attenuated the protective effects of astrocytes on neurons under hypoxic conditions via EPO signaling. The effective blockade of TNFα signaling may contribute to the maintenance of the neuroprotective effects of EPO even under hypoxic conditions with an inflammatory response.

Neural control of inflammation by the greater splanchnic nerves

The brain influences immune function through a powerful neural reflex that suppresses the release of a key pro-inflammatory cytokine, tumor necrosis factor α, after immune challenge. The efferent motor pathway of this reflex is in the splanchnic nerves, not the vagi. This reflex regulates inflammation but does not suppress fever.