Predicting the clinical efficacy of Natural Killer (NK) cell immunotherapies remains challenging due to functional heterogeneity within effector populations and tumor microenvironment (TME)-mediated suppression. Here, we present a droplet microfluidic platform that couples machine-learning-based, frame-wise K562 target-cell detection and live/dead classification with deterministic temporal event calling to map single-cell cytotoxicity trajectories at scale. These ML-derived target-cell trajectories were integrated with standardized morphology-based NK-cell annotation and effector-target attachment scoring. The resulting framework enabled standardized quantification of NK-cell cytotoxicity, serial-killing capacity, killing-time distributions, and attachment-linked outcomes across thousands of isolated NK-target microenvironments. Using matched donor-derived NK-cell states in defined single-effector droplets containing one to four K562 targets, we resolved how ex vivo expansion and ascites-mediated TME conditioning reshape individual NK-cell function. The results demonstrated that expanded NK cells (exNK) exhibited superior cytotoxic activity, serial killing, and rapid killing dynamics, whereas peripheral blood NK cells (pbNK), especially after exposure to ascites TME (pbNK-asc), showed reduced function across all cytotoxicity metrics. Notably, expanded NK cells exposed to ascites TME (exNK-asc) retained partial functionality, indicating that expansion provides resilience against suppressive factors. This single-cell platform provides insight into NK-cancer cell interactions and offers a scalable framework for optimizing off-the-shelf NK cell-based immunotherapies.

Zika virus (ZIKV) infections have been linked to severe neurological disorders, including microcephaly and Guillain-Barré syndrome in humans as well as mouse models of ZIKV infection. Despite the association, the mechanisms underlying ZIKV-induced neuropathology remain incompletely understood. We have recently shown that antigen independent CD8+ T cells mediate neurological disease in ZIKV-infected mice independent of the amount of infectious virus in the CNS. To further investigate the role of brain viral load and lymphocytes in ZIKV infection we studied the viral kinetics, pathology, and immune responses of ZIKV-infected NOD-Rag1−/−Il2rg−/− mice, which are deficient in lymphoid cells. Despite prolonged high viral titers in the brain, NOD-Rag1−/−IL2rg−/− mice did not develop neurological symptoms following ZIKV infection, contrasting with the infection outcomes of Ifnar1−/− mice which exhibit paralysis despite lower viral load. Notably, we observed significant differences in brain myeloid cells in the presence or absence of lymphoid cells. While Ifnar1−/− mice showed robust infiltration of CD45hiCD11b+ cells in the brain, lymphocyte-deficient NOD-Rag1−/−IL2rg−/− mice exhibited reduced recruitment and activation of these cells. Additionally, we found that CD45hiCD11b+ cells displayed a more inflammatory phenotype in Ifnar1−/− mice compared to NOD-Rag1−/−IL2rg−/− mice. Our study highlights the complex interplay between the immune system and viral infection in ZIKV-induced neuropathology and underscores the importance of considering immune responses in the development of therapeutic interventions for ZIKV.

Glioblastoma multiforme (GBM) is a highly aggressive brain tumor characterized by pervasive tumor recurrence and very poor patient survival. While αβ T cell-based chimeric antigen receptor (CAR) immunotherapies show efficacy in hematologic malignancies, manufacturing delays and potential fatal immune overactivation have prompted the exploration of alternative cell sources, including natural killer (NK) cells. NK cells represent an emerging cell source due to their potent antigen-independent intrinsic cytotoxicity, self-regulating inhibitory mechanisms, and low risk of graft-versus-host disease. In this study, we expanded peripheral blood NK cells using K562 feeder cells expressing membrane-bound IL-21 (K562-mb-IL-21) to produce highly activated and metabolically robust cells targeting both cell lines and patient-derived GBM tumor cells. Furthermore, our in vitro results demonstrate the broad targeting potential of our expanded NK cells, as they exhibit cytotoxicity against a cell line and patient-derived sample of another aggressive brain tumor, medulloblastoma (MB). To enhance tumor-directed cytotoxicity, we utilized CRISPR/Cas9 and adeno-associated virus-based gene delivery to generate stable anti-CD70 CAR-NK cells. CD70 is a promising target due to its minimal expression in healthy tissues and overexpression in recurrent GBM. However, NK cells gain CD70 surface expression upon expansion, causing anti-CD70 CAR-NK cell fratricide. Subsequently, knocking out the CD70 gene enabled large-scale expansion of anti-CD70 CAR-NK cells that were functional against both in vitro and in vivo GBM models.

IntroductionInterleukin (IL)-15 is essential for the survival and maturation of natural killer (NK) and CD8+ T cells, and it directly activates macrophages.MethodsIn the present study, we examined the effects of inactivating Il-15 on atherosclerosis in apolipoprotein (apo) E-deficient mice.Results and discussionAs expected, Il-15 deficiency reduced circulating NK and CD8+ T cells in ApoE−/− mice. It also increased body weights in female but not male ApoE−/− mice and increased plasma total cholesterol levels in both. Despite this, the Il-15 knockout reduced spontaneous atherosclerotic plaque development in both male and female ApoE−/− mice (fed a normal diet) at 25 weeks of age, and in female normal diet-fed ApoE−/− mice at 15 weeks but not at 38 weeks of age. Furthermore, Il-15 knockout did not impact the levels of atherosclerosis in 25-week-old female ApoE−/− mice fed a high-fat, high-cholesterol diet for 15 weeks. However, the 6-week treatment with an antibody (M96) that blocks IL-15’s interaction with the IL-2Rβγc complex but does not interfere with its interaction with IL-15Rα reduced spontaneous atherosclerosis in female ApoE−/− mice. ApoE knockout mice in which IL-15 was inactivated or neutralized with an antibody exhibited reduced accumulation of CD11b+ and CD8+ cells within atherosclerotic plaques. These findings demonstrate that interfering with IL-15 signaling through the IL-2Rβγc complex delays spontaneous atherosclerosis development in ApoE-deficient mice.

Glioblastoma multiforme (GBM) and medulloblastoma (MB) are aggressive brain cancers that demonstrate poor patient survival despite intense interventions. Natural Killer (NK) cells are promising in cancer immunotherapy due to their potent antigen-independent cytolytic functions. A chimeric antigen receptor (CAR) can further enhance their tumour specificity. CD70 is a favorable target for CAR-NK cells given its key role in tumor recurrence. Here, we evaluated the in vitro cytotoxicity of ex vivo expanded NK and anti-CD70 CAR-NK cells against GBM and MB. The CAR-NK cells were generated through CRISPR/Cas9 gene editing and adeno-associated viral vector gene delivery. Peripheral blood-derived human NK and CAR-NK cells were expanded using IL-21-expressing feeder cells, and their cytotoxicity was assessed in response to GBM and MB cell lines/patient-derived cells. Expanded NK cells displayed high cell killing of both GBM and MB tumor targets. However, expansion led to rapid surface expression of CD70 on anti-CD70 CAR-NK cells, resulting in their fratricide-mediated depletion. To address this, CD70 knock-out (KO) anti-CD70 CAR-NK cells were generated, which successfully expanded in culture and reliably expressed the CAR receptor. These CAR-NK cells displayed enhanced targeting of highly CD70+ patient-derived GBM cells. This work underscores the in vitro cytotoxic potential of CD70KO anti-CD70 CAR-NK cells against GBM, with their in vivo tumor killing to be further investigated. Supported by a Canadian Institutes of Health Research (CIHR) grant, a Canada Graduate Scholarship - Master’s (CGS-M), and an Ontario Graduate Scholarship (OGS). Immune Mechanisms of Human Disease (HUM)

Antibodies and ADCs are mainstays in the treatment of cancer. However, given difficulties in achieving a deep and sustained response, significant improvements are desirable. We report on first in class “Booster” molecules, based on clinically validated ADCC-competent antibodies, equipped with two immunomodulatory domains that are affinity engineered to be functional only when in contact with a tumor cell. We see strong expansion and increased cytotoxicity of immune cells in the presence of cancer cells in vitro, activation of relevant immune cell types ex vivo, and reduction of tumor burden in vivo, with significantly better activity than adoptive cell therapy or control antibody without fusion domains. NRG mice were engrafted with luciferase expressing SKOV3 cells via intraperitoneal injection 7 days prior to treatment. Mice received 1 million NK cells isolated from healthy donors. Compounds were administered biweekly, and low dose IL2 thrice weekly. Blood was collected weekly, and tumor burden monitored weekly via bioluminescence. ex vivo: in situ activation of tumor infiltrating immune populations was evaluated by nanostring in freshly isolated tumor tissue. in vitro: cytotoxicity was measured by quantifying the number of alive tumor cells using automated microscopy. Expansion was performed by stimulating NK cells weekly with tumor cells that were opsonized with Booster or antibody, NK cells were counted weekly to determine expansion. Mice treated with a HER2 targeting Booster demonstrated superior tumor control than trastuzumab treated mice, with near tumor remission by day 35. High NK counts were observed in the blood of Booster treated mice, and no NK cells were detected in that of trastuzumab treated mice. In the peritoneal cavity, NK counts were up to 600x higher in Booster treated mice than in trastuzumab treated mice. Our Booster reprograms the immune microenvironment ex vivo in freshly isolated tumor tissue, transforming a cold tumor into a hot tumor. It activates multiple cytotoxic and IFN-γ pathways, stimulates CD8+ T cell activation, downregulates pro-tumor pathways in Tregs and induces a phenotypic shift in macrophages from the immunosuppressive M2 to the pro-inflammatory M1 phenotype. In separate in vitro assays we saw sustained expansion and enhanced cytotoxicity of NK cells for at least 6 weeks. Cells stimulated with HER2 Booster showed prolonged tumor control, whereas trastuzumab stimulated cells failed to sustain tumor control beyond 21 days. In correlation with extensive in vitro and ex vivo data, we observe a prolonged and significant improvement in tumor control in mice treated with Boosters compared to mice treated with trastuzumab. Work is ongoing to develop these molecules, with the first clinical trial expected to start in 2026. Sophie Poznanski, Erik Slinger, Jarek Juraszek, Fatemeh Vahedi, Marcelo Pereira, Loreto Parga-Vidal, Dean Lee, Ali Ashkar, Robert Friesen. Avidity engineered multispecific antibodies that are highly efficacious in immune cell stimulation in patient tissue and in mice: significantly improved tumor control and turning cold tumors hot [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4876.

Background The use of cannabis during pregnancy is rising following its widespread legalization. Cannabidiol (CBD) is gaining popularity due to the public perception that it is safer than the psychoactive cannabis component Δ9-tetrahydrocannabinol (THC). However, while evidence underpins the harm of THC and cannabis smoke on fetal development, there is minimal research on the safety of CBD and oral cannabis. The current study aims to decipher the safety of oral CBD and THC use during pregnancy. Methods Using a mouse model, we directly compared the effects of oral CBD and THC oil exposure (20 mg/kg body weight) from early to mid-gestation on implantation site remodelling and fetal growth. We examined offspring behaviour and metabolic activity using both traditional and automated cage systems. Lastly, using human and mouse immune cells we assessed how CBD and THC influence angiogenic factor production. Findings We observed impaired maternal spiral artery remodelling in cannabis exposed mice and found that CBD and THC disrupt immune cell angiogenic factor production. Oral consumption of THC or CBD oil also resulted in significant fetal growth impairment and led to long-lasting sex-dependent consequences as male offspring exhibited altered aggression and metabolic activity while females had impaired spatial learning. Interpretation Our results show that oral consumption of either CBD or THC oil during pregnancy in mice results in harm to the developing fetus and causes behavioural changes after birth. Funding The Michael G. DeGroote Centre for Medicinal Cancer Research, the Canadian Institutes of Health Research, and the Canadian Foundation for Innovation.

The consumption of cannabis during pregnancy has increased in recent years following the widespread legalization of recreational cannabis. However, accumulating evidence uncovers the detrimental harm of cannabis and specifically the psychoactive component Δ9-tetrahydrocannabinol (THC) on pregnancy complications and fetal growth. Despite growing concern, the mechanism underlying cannabis-induced pregnancy complications is largely unknown. Given the substantial role of uterine Natural Killer (uNK) cells in maternal tissue remodeling during early pregnancy, we sought to determine if cannabis impacts uNK cell function and ultimately pregnancy outcome. Using a mouse model, we directly compared the effect of oral THC and cannabidiol (CBD) consumption on uNK cell function, decidual remodeling, and fetal growth. We also assessed how THC and CBD impact human NK cell angiogenic capabilities. Strikingly, we observed that both THC and CBD disrupted mouse and human NK cell angiogenic abilities which corresponded to impaired remodeling of vessels at the maternal-fetal interface in cannabis-exposed pregnant mice. Alarmingly, this disruption led to impaired fetal growth in both the CBD and THC-exposed mice. Altogether, our work pinpoints that oral exposure to either THC or CBD leads to compromised uNK cell function and ultimately impaired fetal growth and development in mice. This work is funded by the Michael G. DeGroote Centre for Medicinal Cancer Research and the Canadian Institutes of Health Research. Mucosal and Regional Immunology (MUC)

Relapsed and refractory T cell malignancies are associated with poor clinical outcomes. Although autologous CAR-αβT cells have been employed in the treatment of several cancers, generating CAR-T cells for T cell malignancies remains challenging. The need to obtain enough healthy αβT cells from patients to generate CAR-αβT cells, combined with the problem of shared antigens such as the pan-cancer target CD38 expressed on both malignant and normal T cells, which can lead to fratricide of healthy CAR-αβT has hindered the application of CAR-T therapy for T-ALL. The use of allogeneic αβT and NK cells has also been explored for treating T-ALL. However deletion of the TCRαβ/CD3 complex to avoid graft-versus-host disease (GvHD) for αβT and multiple infusions of NK cells, can increase the cost of manufacturing and logistics. In this study, we genetically engineered polyclonal gamma delta T (γδT) cells as an alternative allogeneic cell source for cancer immunotherapy. γδT share innate immune properties of NK cells and adaptive immunity of αβT cells. Generating CAR γδT would allow us to minimize the cost of generating allogenic TRAC- KO CAR αβT cells and lower the number of infusions needed when NK cells are used. Utilizing a novel expansion protocol in combination with CRISPR/AAV gene editing, we developed CD38 knockout (CD38KO)/CD38-CAR polyclonal γδT cells that target T-ALL. Our editing strategy enabled site-directed, on-target insertion of the CD38-CAR transgene into the CD38 locus, with no evidence of significant random CAR DNA integration (as commonly seen with lentiviral CAR transduction) or chromatin abnormalities resulting from CRISPR editing. This approach effectively mitigated fratricide through simultaneous CD38 disruption and CAR expression. We evaluated the edited γδT cells in vitro across multiple patient-derived T-ALL samples and demonstrated the efficacy of the CD38KO/CD38-CAR γδT cells against both baseline and relapsed samples. In vivo, a single injection of CD38KO/CD38-CAR γδT cells without cytokine support resulted in potent anti-leukemic efficacy Fratricide-resistant CD38KO/CD38-CAR polyclonal γδT cells thus represent a promising off-the-shelf therapeutic platform. They may serve as a bridge to allogeneic hematopoietic stem cell transplantation (allo-HSCT), potentially enabling molecular remission in T cell malignancies and other CD38-expressing cancers such as AML. ### Competing Interest Statement D.A.L., M.N.K., and Y.S. have a provisional patent for the described technology. D.A.L., M.N.K., and M.S.F.P. have received royalties from Sanofi/Kiadis. M.N.K and D.A.L have share in CARTx Therapeutics. Nationwide Children's Hospital and Ohio Development Services Agency, TECG20232876 CancerFree KIDS, https://ror.org/04jme7072, Visionary Society Research Grant - 2023

Cancer cell therapies have primarily focused on engineering autologous αβ T cells with chimeric antigen receptors (CARs), achieving clinical success against hematologic malignancies. However, their effectiveness against solid tumors is limited by challenges such as antigen escape, suppression by the metabolically hostile tumor microenvironment (TME), and manufacturing difficulties. γδ T cells are unconventional T cells with innate tumor-targeting capabilities independent of MHC class I, making them an emerging candidate for allogeneic cell therapy. While the Vδ1 T cell subset has shown promising anti-tumor killing their clinical application has been hindered by difficulties in achieving robust expansion for therapeutic use. Here, we evaluated the potential of K562 feeder cells expressing membrane-bound IL-21 (K562-mb-IL-21) to expand and activate γδ T cells from peripheral blood. Our findings show that this method preferentially expands Vδ1 T cells, resulting in an activated phenotype characterized by enhanced expression of NK cell activation receptors, innate cytotoxicity against breast and ovarian cancer cells, and sustained metabolic function in patient-derived ascites TME. When engineered with a CAR, Vδ1 T cells exhibited further enhanced anti-tumor efficacy in an immunodeficient NRG xenograft model of human ovarian cancer. These findings highlight K562-mb-IL-21 expanded peripheral blood Vδ1 T cells as a promising ‘off-the-shelf’ allogeneic therapy for solid tumors.

Many viral infections have been linked to the development of debilitating neurological disorders. However, the mechanism governing virus-induced neuropathology remains poorly understood, particularly when the virus is not directly neuropathic. Using a mouse model of Zika virus (ZIKV) infection, we find that brain ZIKV titers do not correlate with the severity of neurological disease. Instead, ZIKV-infected brains exhibit microglial activation and infiltration of ‘bystander activated’ CD8+ T cells expressing the NK cell receptor, NKG2D. To assess the role of these T cells in virus-induced neuropathology, we treated ZIKV-infected mice with antibodies to deplete CD8+ T cells or block NKG2D signaling. Both treatments completely prevented against the development of paralysis without altering the viral load in the serum or brain, suggesting that bystander activated T cells mediate virus-induced neurological disease. Interestingly, depletion of brain-resident microglia using the drug PLX3397 also prevented development of neurological disease. However, microglia depletion did not reduce bystander activated T cell numbers in the brain, suggesting that microglia influence bystander T cell function rather than recruitment. Overall, we have identified a novel mechanism where microglia promote bystander activation and function of CD8+ T cells neurological disease. Our findings reveal several strategies for further investigation of treatments for virus-induced neurological diseases. Canadian Institutes for Health Research Viral Immunology (VIR)

Successful host defense during viral infection requires tight control of inflammation to mount an effective immune response while limiting damage to the host. Loss of immune regulation can result in a cytokine storm leading to major immunopathology and serious disease consequences. Evidence has shown that the pathology of acute viral infections is not mediated by viral load, but rather this hyperinflammatory response. Cellular metabolism plays a key role in immune activation as immune cells have specific metabolic requirements that dictate their functional fate. Thus, metabolic processes can shape the intensity of the inflammatory response. Nevertheless, the mechanisms driving cytokine storm remain poorly understood. Here we investigated how metabolism in the local tissue environment regulates the inflammatory response to viral infection. We and others found that mice deficient in the type I IFN receptor (Ifnar-/-) are more susceptible to cytokine storm from influenza A virus (IAV) infection than wild-type (WT) mice, independent of viral load. We show that Ifnar-/- mice have a significantly altered lung metabolite profile during IAV infection, compared to WT mice. These early metabolic changes are associated with heightened glucose metabolism in immune cells, contributing to the development of immune-mediated pathology. Importantly, these results highlight the therapeutic potential of modulating immune metabolism to effectively treat cytokine storm. Supported by Canadian Institute of Health Research (CIHR) project grant and a CIHR Canada Graduate Scholarship - Master’s (CGS-M) Immune Response Regulation: Cellular Mechanisms (IRC)

The recent COVID-19 pandemic has highlighted a significant sex bias in disease outcome, where male sex is associated with greater disease severity and mortality. Interestingly, studies have also identified a role for antigen-independent "bystander-activated" CD8+ T cells in the severity of COVID-19 and other viral infections. However, whether biological sex contributes to the magnitude of bystander T cell activation has not been investigated. To assess sex differences in bystander CD8+ T cell activation, we isolated PBMCs from age-matched male and female donors and stimulated the cells with cytokines IL-12/15/18 to induce bystander T cell activation. Male CD8+ T cells stimulated with IL-15 exhibited greater bystander activation, including increased NKG2D expression and greater antigen-independent cytotoxicity against tumor cells compared with female CD8+ T cells. In contrast, IL-12/18 and IL-12/15/18 stimulation of CD8+ T cells did not reveal evidence of sex differences in bystander IFN-γ production. Our data suggest that underlying sex differences in bystander CD8+ T cell activation and cytotoxicity may contribute to the observed sex biases in disease severity of viral infections.

AIM:Maternal excess adiposity (i.e., overweight/obesity) is linked to impaired uteroplacental perfusion, compromised placental development, and increased risk of adverse pregnancy outcomes. Inflammation and immune dysregulation accompanying excess adiposity may disrupt leukocyte-mediated tissue remodeling and immunoregulation, contributing to placental dysfunction. However, the impacts of excess adiposity on populations of innate lymphoid cells and macrophages orchestrating these processes, and on the decidual microenvironment, remain understudied. Here, we used a mouse model of high-fat, high-sucrose (HFHS) diet-feeding to study the impacts of excess adiposity on decidual immune dynamics during placental development. METHODS:Uteroplacental tissues were collected at mid-gestation (E10.5) from mice fed a control chow (CON) or HFHS diet before and during pregnancy. Multicolour flow cytometry was used to profile decidual leukocyte composition. Spiral artery remodeling was measured using (immuno)histochemistry. Multiplex immunoassays were used to compare systemic and decidual cytokine and growth factor levels. Comparative gene expression was measured in placental tissues using a NanoString nCounter array. RESULTS:HFHS pregnancies had elevated decidual leukocyte abundance, with increased tissue-resident and conventional-like NK cells, and MHC-II+ macrophages. This was not associated with abnormal spiral artery remodeling but coincided with increased decidual proinflammatory cytokine and chemokine expression, and greater elevations in mediators of angiogenesis, endothelial activation, and coagulation. Despite this, placental gene expression was largely unaltered at mid-gestation. CONCLUSION:These findings point towards decidual vascular inflammation and dysregulated angiogenesis during early placentation in pregnancies complicated by excess adiposity. This may stem from or induce shifts in resident immune cells, contributing to later placental dysfunction.

Natural Killer (NK) cells are a promising adoptive cell therapy given their ability to target tumors in an antigen independent manner. NK cells can be expanded ex vivo using membrane bound IL-21 (mbIL-21) feeder cells enhancing their anti-tumor activity. We have also shown that expanded NK cells are metabolically reprogrammed, allowing them to withstand the metabolically hostile tumor microenvironment. While this approach to expand NK cells has demonstrated promising results in preclinical models and early clinical trials, ex vivo expansion requires resources and GMP-grade manufacturing facilities, increasing the cost and accessibility of this treatment. To overcome these challenges, we are developing a tri-specific killer engagers (TriKE) to activate and expand NK cells directly in cancer patients. Our TriKE consists of a HER-2 protein binding domain, an NKp30 binding domain, and an activating cytokine, IL-21 to induce NK activation and cytotoxicity against HER-2+ cancers. We demonstrate that in vitro, the TriKE elicits robust STAT-3 mediated signaling. Additionally, in a mouse model for HER-2 positive ovarian cancer, following adoptive transfer of human NK cells, mice treated with the TriKE showed increased NK cell accumulation in the peritoneum compared to untreated mice. Overall, we provide evidence that our TriKE is a promising strategy to expand NK cells in vivo to target solid tumors. Vaccines and Immunotherapy (VAC)

Type I Interferons (IFN-I) are crucial in restricting the proliferation and pathology of the murine hepatitis virus (MHV). Macrophages in the liver highly express the MHV receptor, CEACAM-1, thus we were interested in understanding how macrophages mediate the antiviral effects of IFN-I during MHV infection. So, wildtype (WT) and IFNAR-/- C57BL/6 mice were infected with MHV-A58 via i.p., intranasal, and oral routes. Compared to WT mice, IFNAR-/- mice developed an acute infection and hepatitis within 3 days following i.p. injection of MHV-A58, while they were less susceptible to intranasal and oral routes of administration. The susceptibility was dependent on peritoneal macrophages, as their depletion in IFNAR-/- mice completely prevented acute liver pathology and significantly reduced viral load in both the serum and liver. Peritoneal macrophages in IFNAR-/-mice were depleted using Clodronate liposomes, followed by intraperitoneal administration of MHV. Cytokine array analysis revealed reduced inflammatory response cytokine profiles in both the serum and liver of macrophage-depleted IFNAR-/- mice, similar to those observed in WT mice. In vitro apoptosis studies using poly I:C stimulation showed that macrophages from IFNAR-/- mice exhibit greater resistance to apoptosis and viral replication. These findings clearly show Type I IFN signalling is crucial in preventing liver pathology against MHV through controlling MHV replication and regulating macrophage apoptosis. CIHR Viral Immunology (VIR)