Biology subjects

Eickhoff, J. C.

Publications and source records attributed to Eickhoff, J. C..

11 recordsLinked to original sources

bioRxiv2026

Low-dose radiopharmaceutical therapy enhances the efficacy of B7-H3 CAR T cells in murine metastatic neuroblastoma

Background: Chimeric antigen receptor (CAR) T cell therapy has had clinical success in hematologic malignancies, but limited efficacy is seen in solid tumors. In this study, we investigated whether systemic CAR T cell therapy could be enhanced in metastatic models of neuroblastoma when combined with radiopharmaceutical therapy (RPT). Methods: Non-irradiated or irradiated tumor cells were co-cultured with CAR T cells (1:1) in vitro and supernatant media was subsequently collected for cytokines analyses. CAR T cell phenotypes were characterized by flow cytometry including checkpoint marker expression. Xenograft models of metastatic neuroblastoma were generated in NOD-Rag1nullIL2rgnull (NRG) mice. Tumor-bearing mice received 1.8 Gy of radiation delivered by 177Lu-NM600 RPT five days after tumor implantation. Nine days after RPT, CAR T cells were administered intravenously. To evaluate tumor burden, mice were imaged weekly for 4 weeks. Results: In models of metastatic neuroblastoma, 177Lu-NM600 RPT significantly increased overall survival when combined with CAR T cell therapy in vivo. Pre-treatment of tumor cells with 177Lu also significantly increased CAR T cell cytotoxicity while decreasing production of IL-4 and IL-10 in vitro. Co-culture of CAR T cells with irradiated tumors led to increases in PD-1+TIM3+LAG3+ T cells, suggesting that further combination with immune checkpoint inhibitors may enhance clinical efficacy. Conclusions: Our findings demonstrate that low-dose RPT can potentiate the anti-tumor efficacy of CAR T cells in metastatic neuroblastoma. To our knowledge, this is the first report of dosimetry-based RPT being combined with CAR T cells in a metastatic solid tumor setting. These findings underscore the potential of combining RPT and CAR T cells to overcome the unique challenges of solid tumors, particularly when treating metastatic disease.

cancer biology↗

bioRxiv2026

Spondweni virus infection in pregnant rhesus macaques causes placental pathology without apparent fetal harm

The 2015-2016 Zika virus (ZIKV) epidemic revealed the potential of flaviviruses to emerge rapidly, cause severe disease, and affect pregnancy outcomes. In 2016, Spondweni virus (SPOV), the closest known relative of ZIKV, was detected in mosquitoes in Haiti, suggesting it may also have the potential to emerge in the Western Hemisphere. The risks that close relatives of ZIKV pose to pregnant individuals are not well understood. Previously, we showed that SPOV can cause fetal demise, placental pathology, and vertical transmission in a mouse model. Here we report SPOVs pathogenic potential in pregnant rhesus macaques. We inoculated four macaques with SPOV at gestational day 30 (early first trimester) and compared their viral loads and fetal outcomes with those of macaques infected in the first trimester with either African-lineage ZIKV (ZIKV-DAK) or an Asian-lineage ZIKV isolate from Puerto Rico (ZIKV-PR) in previous studies. Plasma viremia persisted 10-31 days in SPOV-inoculated dams, whereas viremia resolved within 10-17 days for ZIKV-DAK and 5-52 days for ZIKV-PR. Cesarean deliveries near term (gestational day 152-157) revealed no demise, premature birth, or gross abnormalities in fetuses of dams inoculated with SPOV or ZIKV-PR. In contrast, under near-identical conditions, all ZIKV-DAK-inoculated dams experienced fetal demise between 12 and 20 days post-inoculation. At cesarean section, we did not detect SPOV RNA above the limit of detection in maternal (e.g., spleen, liver), placental, or fetal tissues, in contrast to previous findings with ZIKV-PR. Histological analysis revealed mononuclear/lymphohistiocytic villitis in all placentas of SPOV-exposed macaques, along with other pathological changes in individual placentas. Our findings suggest that SPOV infection of macaques in early pregnancy may result in placental pathology without overt fetal harm. Our results suggest that flaviviruses in the Spondweni serocomplex, which includes ZIKV and SPOV, may vary in their pathogenic potential during pregnancy. Author SummaryZika virus (ZIKV) can cause fetal harm. Does this risk extend to its closest known relative, Spondweni virus (SPOV)? Should SPOV circulate in humans, what risks would it pose in pregnancy? SPOV can injure fetuses in immunocompromised mice, but the physiology of pregnancy in mice differs greatly from that of humans. We therefore infected pregnant rhesus macaques with SPOV during early gestation and compared maternal viremia, placental pathology, and fetal outcomes with macaques infected with African- or Asian-lineage ZIKVs at the same gestational age. All fetuses survived to near-term pregnancy, fetal tissues were negative for SPOV RNA, and fetal growth tracked within expected ranges. Nonetheless, all SPOV-exposed pregnancies showed placental injury, including mononuclear/lymphohistiocytic villitis and maternal vascular malperfusion. Despite the absence of detectable SPOV RNA in fetal tissues, SPOV RNA persisted at term in maternal-fetal interface tissues in two of four animals. These data indicate placental injury without detectable vertical transmission in this translational model. Our results suggest that SPOV and ZIKV display a wide range of risks to the developing fetus. Identifying viral and host factors that increase the potential for fetal harm will be important for assessing risks posed by emerging viruses in this family.

microbiology↗

bioRxiv2024

Low Dose Radiation by Radiopharmaceutical Therapy Enhances GD2 TRAC-CAR T Cells Efficacy in Localized Neuroblastoma

BackgroundWhile chimeric antigen receptor (CAR) T cells have achieved significant success against hematological malignancies, efficacy against neuroblastoma has been limited. Virus-free CRISPR-edited GD2 TRAC-CAR T cells have been developed as a potential means of improving CAR T efficacy but are not curative. Radiopharmaceutical therapy (RPT) is a promising approach to enhance the effectiveness of immunotherapies, including immune checkpoint inhibitors. However, it remains unclear whether RPT can synergize with GD2 TRAC-CAR T cells to improve outcomes in neuroblastoma. MethodsDosimetry studies were conducted to measure the absorbed radiation dose delivered by lutetium-177 (177Lu) in both in vitro and in vivo models. Tumor-bearing mice were treated sequentially with low dose radiation by 177Lu-NM600, an alkylphosphocholine mimetic radiopharmaceutical agent, followed 9 days later by GD2 TRAC-CAR T cells generated in a virus-free manner by CRISPR/Cas9. Tumor burden was monitored through bioluminescence imaging and tumor size measurements. Mechanistic studies were performed using flow cytometry, multiplex assay and single-cell proteomic analysis. ResultsLow dose radiation delivered by 177Lu-NM600 synergized with GD2 TRAC-CAR T cells in a localized neuroblastoma model, resulting in complete tumor regression in all mice. The optimal combination was dependent on both the radiation dose and timing to minimize the negative impact of radiation on CAR T cell viability. Irradiation of neuroblastoma cells by low-dose RPT before GD2 TRAC-CAR T cells enhanced the release by CAR T cells of perforin, granzyme B and cytokines like TNF- and IL-7 while abrogating TGF-{beta}1 secretion. Additionally, low-dose RPT upregulated Fas on neuroblastoma cells, potentially enabling a CAR-independent killing. ConclusionsThis study demonstrates that low-dose RPT can enhance CAR T cell efficacy to treat a solid tumor. Findings suggest that optimization of radiation dose and timing may be needed for each patient and RPT to account for effects of varied tumor radiosensitivity and dosimetry. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=142 SRC="FIGDIR/small/621668v1_ufig1.gif" ALT="Figure 1"> View larger version (45K): org.highwire.dtl.DTLVardef@153ff5dorg.highwire.dtl.DTLVardef@1a269b7org.highwire.dtl.DTLVardef@1ca9a53org.highwire.dtl.DTLVardef@59f461_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2022

Frequent first-trimester pregnancy loss in rhesus macaques infected with African-lineage Zika virus

In the 2016 Zika virus (ZIKV) pandemic, a previously unrecognized risk of birth defects surfaced in babies whose mothers were infected with Asian-lineage ZIKV during pregnancy. Less is known about the impacts of gestational African-lineage ZIKV infections. Given high human immunodeficiency virus (HIV) burdens in regions where African-lineage ZIKV circulates, we evaluated whether pregnant rhesus macaques infected with simian immunodeficiency virus (SIV) have a higher risk of African-lineage ZIKV-associated birth defects. Remarkably, in both SIV+ and SIV-animals, ZIKV infection early in the first trimester caused a high incidence (78%) of spontaneous pregnancy loss within 20 days. These findings suggest a significant risk for early pregnancy loss associated with African-lineage ZIKV infection and provide the first consistent ZIKV-associated phenotype in macaques for testing medical countermeasures.

microbiology↗

bioRxiv2022

Quantification of Early Gait Development: Expanding the Application of Catwalk Technology to an Infant Rhesus Macaque Model

BackgroundUnderstanding gait development is essential for identifying motor impairments in neurodevelopmental disorders. Defining typical gait development in a rhesus macaque model is critical prior to characterizing abnormal gait. The goal of this study was to 1) explore the feasibility of using the Noldus Catwalk to assess gait in infant rhesus macaques and 2) provide preliminary normative data of gait development during the first month of life. New methodThe Noldus Catwalk was used to assess gait speed, dynamic and static paw measurements, and interlimb coordination in twelve infant rhesus macaques at 14, 21, and 28 days of age. All macaque runs were labeled as a diagonal or non-diagonal walking pattern. ResultsInfant rhesus macaques primarily used a diagonal (mature) walking pattern as early as 14 days of life. Ten infant rhesus macaques (83.3%) were able to successfully walk across the Noldus Catwalk at 28 days of life. Limited differences in gait parameters were observed between timepoints because of the variability within the group at 14, 21, and 28 days. Comparison with existing methods: No prior gait analysis system has been used to provide objective quantification of gait parameters for infant macaques. ConclusionsThe Catwalk system can be utilized to quantify gait in infant rhesus macaques less than 28 days old. Future applications to infant rhesus macaques could provide a better understanding of gait development and early differences within various neurodevelopmental disorders. Highlights- Infant rhesus macaque gait parameters can successfully be captured by the Catwalk - At 14 days of life, macaques were consistently using a diagonal walking pattern - Limited developmental change occurs in gait parameters over the first month of life - Infant macaque gait parameters had high within group variability at each timepoint Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=190 HEIGHT=200 SRC="FIGDIR/small/516450v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@6185edorg.highwire.dtl.DTLVardef@9fa472org.highwire.dtl.DTLVardef@e54919org.highwire.dtl.DTLVardef@12231cc_HPS_FORMAT_FIGEXP M_FIG C_FIG Note: Brown and grey-colored macaques were created in biorender

animal behavior and cognition↗

bioRxiv2022

Fetal loss in pregnant rhesus macaques infected with high-dose African-lineage Zika virus

Countermeasures against Zika virus (ZIKV), including vaccines, are frequently tested in nonhuman primates (NHP). Macaque models are important for understanding how ZIKV infections impact human pregnancy due to similarities in placental development. The lack of consistent adverse pregnancy outcomes in ZIKV-affected pregnancies poses a challenge in macaque studies where group sizes are often small (4-8 animals). Studies in small animal models suggest that African-lineage Zika viruses can cause more frequent and severe fetal outcomes. No adverse outcomes were observed in macaques inoculated with a low dose of African-lineage ZIKV at gestational day (GD) 45. Here, we inoculate eight pregnant rhesus macaques with a higher dose of African-lineage ZIKV at GD 45 to test the hypothesis that adverse pregnancy outcomes are dose-dependent. Three of eight pregnancies ended prematurely with fetal death. ZIKV was detected in both fetal and placental tissues from all cases of early fetal loss. Further refinements of this challenge system (e.g., varying the dose and timing of infection) could lead to an even more consistent, unambiguous fetal loss phenotype for assessing ZIKV countermeasures in pregnancy. These data demonstrate that high-dose inoculation with African-lineage ZIKV causes pregnancy loss in macaques and also suggest that ZIKV-induced first trimester pregnancy could be strain-specific. Author summaryAlthough pregnant rhesus macaques are susceptible to infection with Zika virus (ZIKV), fetal phenotypes can be subtle and variable. Most macaque studies of ZIKV have involved infection with Asian-lineage viruses because these viruses caused Western Hemisphere outbreaks beginning in 2015. African-lineage ZIKV yields more severe adverse fetal outcomes in small animal models. Here, we provide evidence that pregnant macaques infected late in the first trimester using a high dose of African-lineage ZIKV have frequent ZIKV-associated pregnancy loss. This severe phenotype establishes a new model for evaluating countermeasures and reinforces the idea that African-lineage ZIKV infection may be a frequent cause of pregnancy loss in areas where it is endemic depending on the amount of transmitted virus during infection.

pathology↗

bioRxiv2021

Integrating Subclonal Response Heterogeneity to Define Cancer Organoid Therapeutic Sensitivity

Tumor heterogeneity is predicted to confer inferior clinical outcomes, however modeling heterogeneity in a manner that still represents the tumor of origin remains a formidable challenge. Sequencing technologies are limited in their ability to identify rare subclonal populations and predict response to the multitude of available treatments for patients. Patient-derived organotypic cultures have significantly improved the modeling of cancer biology by faithfully representing the molecular features of primary malignant tissues. Patient-derived cancer organoid (PCO) cultures contain numerous individual organoids with the potential to recapitulate heterogeneity, though PCOs are most commonly studied in bulk ignoring any diversity in the molecular profile or treatment response. Here we demonstrate the advantage of evaluating individual PCOs in conjunction with cellular level optical metabolic imaging to characterize the largely ignored heterogeneity within these cultures to predict clinical therapeutic response, identify subclonal populations, and determine patient specific mechanisms of resistance.

cancer biology↗

bioRxiv2021

Prior dengue immunity enhances Zika virus infection of the maternal-fetal interface in rhesus macaques

Concerns have arisen that pre-existing immunity to dengue virus (DENV) could enhance Zika virus (ZIKV) disease, due to the homology between ZIKV and DENV and the observation of antibody-dependent enhancement (ADE) among DENV serotypes. To date, no study has examined the impact of pre-existing DENV immunity on ZIKV pathogenesis during pregnancy in a translational non-human primate model. Here we show that prior DENV-2 exposure enhanced ZIKV infection of maternal-fetal interface tissues in macaques. However, pre-existing DENV immunity had no detectable impact on ZIKV replication kinetics in maternal plasma, and all pregnancies progressed to term without adverse outcomes or gross fetal abnormalities detectable at delivery. Understanding the risks of ADE to pregnant women worldwide is critical as vaccines against DENV and ZIKV are developed and licensed and as DENV and ZIKV continue to circulate.

microbiology↗

bioRxiv2020

African-lineage Zika virus replication dynamics and maternal-fetal interface infection in pregnant rhesus macaques

Following the Zika virus (ZIKV) outbreak in the Americas, ZIKV was causally associated with microcephaly and a range of neurological and developmental symptoms, termed congenital Zika syndrome (CZS). The isolates responsible for this outbreak belonged to the Asian lineage of ZIKV. However, in-vitro and in-vivo studies assessing the pathogenesis of African-lineage ZIKV demonstrated that African-lineage isolates often replicated to high titer and caused more severe pathology than Asian-lineage isolates. To date, the pathogenesis of African-lineage ZIKV in a translational model, particularly during pregnancy, has not been rigorously characterized. Here we infected four pregnant rhesus macaques with a low-passage strain of African-lineage ZIKV and compared its pathogenesis to a cohort of four pregnant rhesus macaques infected with an Asian-lineage isolate and a cohort of mock-infected controls. Viral replication kinetics were not significantly different between the two experimental groups and both groups developed robust neutralizing antibody titers above levels considered to be protective. There was no evidence of significant fetal head growth restriction or gross fetal harm at delivery in either group. However, a significantly higher burden of ZIKV vRNA was found in maternal-fetal interface tissues in the macaques exposed to an African-lineage isolate. Our findings suggest that ZIKV isolates of any genetic lineage pose a threat to women and their infants. IMPORTANCEZIKV was first identified over 70 years ago in Africa, but most of our knowledge of ZIKV is based on studies of the distinct Asian genetic lineage, which caused the outbreak in the Americas in 2015-16. In its most recent update, the WHO stated that improved understanding of African-lineage pathogenesis during pregnancy must be a priority. Recent detection of African-lineage isolates in Brazil underscores the need to understand the impact of these viruses. Here we provide the first comprehensive assessment of African-lineage ZIKV infection during pregnancy in a translational non-human primate model. We show African-lineage isolates replicate with similar kinetics to Asian-lineage isolates and are capable of infecting the placenta. However, there was no evidence of more severe outcomes with African-lineage isolates. Our results highlight both the threat that African-lineage ZIKV poses to women and their infants and the need for future epidemiological and translational in-vivo studies with African-lineage ZIKV.

microbiology↗

bioRxiv2020

Discovery of a novel simian pegivirus in common marmosets (Callithrix jacchus) with lymphocytic enteritis

From 2010 to 2015, 73 common marmosets (Callithrix jacchus) housed at the Wisconsin National Primate Research Center (WNPRC) were diagnosed postmortem with lymphocytic enterocolitis. We used unbiased deep-sequencing to screen the blood of deceased enterocolitis-positive marmosets for the presence of RNA viruses. In five out of eight marmosets with lymphocytic enterocolitis, we discovered a novel pegivirus that was not present in ten subsequently deep-sequenced matched, clinically-normal common marmosets with no evidence of lymphocytic enterocolitis. The novel virus, which we have named Southwest bike trail virus (SOBV), is most closely related (68% nucleotide identity) to a strain of simian pegivirus A that was previously isolated from a three-striped night monkey (Aotus trivirgatus). To determine the prevalence of this novel virus within the WNPRC marmoset colony, we screened 146 living animals and found an overall prevalence of 34% (50/146). Over the next four years, 85 of the 146 screened marmosets died or were euthanized and were examined histologically for lymphocytic enterocolitis. Out of these 85 animals, 27 SOBV-positive common marmosets had developed lymphocytic enterocolitis, compared to 42 SOBV-negative common marmosets, indicating no evidence of an association between this virus and development of enterocolitis in this cohort (p=0.0798). The novel pegivirus was also found in two of 32 (6%) clinically-normal common marmosets screened while in quarantine during the transfer from the New England Primate Research Center to the WNPRC, suggesting SOBV has different prevalence at different centers and could exert confounding influences on the comparison of marmoset studies from multiple centers. ImportanceCommon marmosets (Callithrix jacchus) are a valuable model species. We discovered two variants of a novel simian pegivirus, which we named the Southwest bike trail virus (SOBV), in common marmosets which had postmortem histologic diagnosis of lymphocytic enterocolitis. The virus was not present in ten matched, clinically-normal controls. We screened 146 live healthy common marmosets in the Wisconsin National Primate Research Center colony and found 34% (50/146) of the animals were SOBV-positive. SOBV was also present in two of 32 (6%) clinically-normal common marmosets from the New England Primate Research Center. These findings could have confounding effects in animal studies, especially those in which infection-free animals are desired, and they demonstrate the need for further investigations into SOBV transmission, the length of time of SOBV persistence, and SOBV prevalence at other primate centers, in order to increase understanding of the effects of SOBV and of this viral genus.

microbiology↗

bioRxiv2018

Antibody responses to the Zika virus polyprotein in pregnant and non-pregnant macaques

The specificity of the antibody response against Zika virus (ZIKV) is not well-characterized. This is due, in part, to the antigenic similarity between ZIKV and closely related dengue virus (DENV) serotypes. Since these and other similar viruses co-circulate, are spread by the same mosquito species, and can cause similar acute clinical syndromes, it is difficult to disentangle ZIKV-specific antibody responses from responses to closely-related arboviruses in humans. Here we use high-density peptide microarrays to profile anti-ZIKV antibody reactivity in pregnant and non-pregnant macaque monkeys with known exposure histories and compare these results to reactivity following DENV infection. We also compare cross-reactive binding of ZIKV-immune sera to the full proteomes of 28 arboviruses. We independently confirm a purported ZIKV-specific IgG antibody response targeting ZIKV nonstructural protein 2B (NS2B) that was recently reported in ZIKV-infected people and we show that antibody reactivity in pregnant animals can be detected as late as 127 days post-infection (dpi). However, we also show that these responses wane over time, sometimes rapidly, and in one case the response was elicited following DENV infection in a previously ZIKV-exposed animal. These results suggest epidemiologic studies assessing seroprevalence of ZIKV immunity using linear epitope-based strategies will remain challenging to interpret due to susceptibility to false positive results. However, the method used here demonstrates the potential for rapid profiling of proteome-wide antibody responses to a myriad of neglected diseases simultaneously and may be especially useful for distinguishing antibody reactivity among closely related pathogens.\n\nAuthor summaryZIKV has emerged as a vector-borne pathogen capable of causing serious illness in infected adults and congenital birth defects. The vulnerability of communities to future ZIKV outbreaks will depend, in part, on the prevalence and longevity of protective immunity, thought to be mediated principally by antibodies. We currently lack diagnostic assays able to differentiate ZIKV-specific antibodies from antibodies produced following infection with closely related DENV, and we do not know how long anti-ZIKV responses are detectable. Here we profile antibodies recognizing linear epitopes throughout the entire ZIKV polyprotein, and we profile cross-reactivity with the proteomes of other co-endemic arboviruses. We show that while ZIKV-specific antibody binding can be detected, these responses are generally weak and ephemeral, and false positives may arise through DENV infection. This may complicate efforts to discern ZIKV infection and to determine ZIKV seroprevalence using linear epitope-based assays. The method used in this study, however, has promise as a tool for profiling antibody responses for a broad array of neglected tropical diseases and other pathogens and in distinguishing serology of closely-related viruses.

microbiology↗