Mitogenic Response Research Articles

Aging alters the cell cycle control and mitogenic signaling responses of human hematopoietic stem cells

AbstractHuman hematopoietic stem cells (HSCs), like their counterparts in mice, comprise a functionally and molecularly heterogeneous population of cells throughout life that collectively maintain required outputs of mature blood cells under homeostatic conditions. In both species, an early developmental change in the HSC population involves a postnatal switch from a state in which most of these cells exist in a rapidly cycling state and maintain a high self-renewal potential to a state in which the majority of cells are in a quiescent state with an overall reduced self-renewal potential. However, despite the well-established growth factor dependence of HSC proliferation, whether and how this mechanism of HSC regulation might be affected by aging has remained poorly understood. To address this knowledge gap, we isolated highly HSC-enriched CD34+CD38−CD45RA−CD90+CD49f+ (CD49f+) cells from cord blood, adult bone marrow, and mobilized peripheral blood samples obtained from normal humans spanning 7 decades of age and then measured their functional and molecular responses to growth factor stimulation in vitro and their regenerative activity in vivo in mice that had undergone transplantation. Initial experiments revealed that advancing donor age was accompanied by a significant and progressively delayed proliferative response but not the altered mature cell outputs seen in normal older individuals. Importantly, subsequent dose-response analyses revealed an age-associated reduction in the growth factor–stimulated proliferation of CD49f+ cells mediated by reduced activation of AKT and altered cell cycle entry and progression. These findings identify a new intrinsic, pervasive, and progressive aging-related alteration in the biological and signaling mechanisms required to drive the proliferation of very primitive, normal human hematopoietic cells.

FASCIA Method in the Assessment of Lymphocyte Mitogen Responses in the Laboratory Diagnostics of Primary Immunodeficiencies

Lymphocyte responses to mitogens constitute a key part of the diagnostics of combined immunodeficiency (CID). Currently, mostly radioactive thymidine incorporation and carboxyfluorescein diacetate succinimidyl ester (CFSE) dilution methods are used. Flow-cytometric assay for specific cell-mediated immune-response in activated whole blood (FASCIA) has been put forth as an easy-to-perform option for the measurement of lymphocyte responses with the advantage of recognizing different lymphocyte subtypes and avoiding the use of radioactive reagents. Our aim was to analyze retrospectively the usefulness of FASCIA in the diagnostics of CID. We included all lymphocyte stimulation tests done with FASCIA in HUSLAB (Helsinki, Finland) between February 2015 and September 2018 in our analysis. The cohort was divided into two groups according to the patients’ final diagnoses: CID (n = 30) or non-CID (n = 159). We evaluated the stimulation responses with a combined FASCIA score (the average of all mitogen responses). The FASCIA score was significantly lower among the CID group compared to the other patients (p = 0.002), and in the ROC analysis, the AUC was 0.75 (p < 0.001) for the FASCIA score. When the three mitogens were analyzed separately, phytohemagglutinin (PHA) was best in separating patients with CID from non-CID (in the ROC analysis AUC 0.71, p = 0.001). Immunosuppressive medication affected the FASCIA result significantly and needs to be considered when evaluating the results. In conclusion, FASCIA can reliably detect the CID patients in the absence of immunosuppressive medication. It emerges as a method with many benefits compared to tests requiring radioactive reagents or the complicated CFSE staining.

Interleukin-4 activates divergent cell-intrinsic signals to regulate retinal cell proliferation induced by classical growth factors

In the developing retina, precise coordination of cell proliferation, differentiation, and survival is essential for proper retinal maturation and function. We have previously reported evidence that interleukin-4 (IL-4) plays critical roles in neuronal differentiation and survival during retinal development. However, little is known about the role of IL-4 on retinal cell proliferation. In the current study, we investigated if IL-4 regulates cell proliferation induced by epidermal growth factor (EGF) and by fibroblast growth factor 2 (FGF2) in primary retinal cell cultures obtained from newborn rats. First, we show that EGF and FGF2 act as mitogens for glial cells, increasing proliferation of these cells in the retina. EGF- and FGF2-induced mitogenesis requires activation of distinct cell-intrinsic signals. In retinal cells exposed to FGF2, IL-4 downregulates p53 levels (a protein whose activation induces cell-cycle arrest) and increases mitogenic responsiveness to FGF2 through activation of protein kinase A (PKA) pathway. Conversely, in retinal cells exposed to EGF, IL-4 downregulates cyclin D1 levels (a protein required for cell-cycle progression), upregulates p53 levels, and decreases mitogenic responsiveness to EGF. The inhibitory effect induced by IL-4 on retinal cells exposed to EGF requires activation of Janus kinase 3 (JAK3), but not activation of PKA. Based on previous and current findings, we propose that IL-4 serves as a node of signal divergence, modulating multiple cell-intrinsic signals (e.g., cyclin D1, p53, JAK3, and PKA) and mitogenic responsiveness to cell-extrinsic signals (e.g., FGF2 and EGF) to control cell proliferation, differentiation, and survival during retinal development.

Expression of active B-Raf proto-oncogene in kidney collecting ducts induces cyst formation in normal mice and accelerates cyst growth in mice with polycystic kidney disease

Polycystic kidney disease (PKD) is characterized by the formation and progressive enlargement of fluid-filled cysts due to abnormal cell proliferation. Cyclic AMP agonists, including arginine vasopressin, stimulate ERK-dependent proliferation of cystic cells, but not normal kidney cells. Previously, B-Raf proto-oncogene (BRAF), a MAPK kinase kinase that activates MEK-ERK signaling, was shown to be a central intermediate in the cAMP mitogenic response. However, the role of BRAF on cyst formation and enlargement invivo had not been demonstrated. To determine if active BRAF induces kidney cyst formation, we generated transgenic mice that conditionally express BRAFV600E, a common activating mutation, and bred them with Pkhd1-Cre mice to express active BRAF in the collecting ducts, a predominant site for cyst formation. Collecting duct expression of BRAFV600E (BRafCD) caused kidney cyst formation as early as three weeks of age. There were increased levels of phosphorylated ERK (p-ERK) and proliferating cell nuclear antigen, a marker for cell proliferation. BRafCD mice developed extensive kidney fibrosis and elevated blood urea nitrogen, indicating a decline in kidney function, by ten weeks of age. BRAFV600E transgenic mice were also bred to Pkd1RC/RC and pcy/pcy mice, well-characterized slowly progressive PKD models. Collecting duct expression of active BRAF markedly increased kidney weight/body weight, cyst number and size, and total cystic area. There were increased p-ERK levels and proliferating cells, immune cell infiltration, interstitial fibrosis, and a decline in kidney function in both these models. Thus, our findings demonstrate that active BRAF is sufficient to induce kidney cyst formation in normal mice and accelerate cystic disease in PKD mice.

Comparison of the oxidative respiratory burst and mitogen-induced leukocyte responses of camels, goats, sheep, and cows.

Background and Aim:The reports from the Ministry of Agriculture and Fisheries suggest that camels suffer less compared to goats, sheep, and cows from a number of common infectious diseases in Oman. However, there is no immunological evidence to substantiate this claim. This present study is, therefore, an attempt to study the immunological responses of camels, goats, sheep, and cows by comparing their oxidative respiratory burst of peripheral blood leukocytes (PBLs) as a marker of innate immunity occurring during phagocytosis and the mitogenic responses of their peripheral blood mononuclear leukocytes (PBMLs) as a marker of their adaptive immune response.Materials and Methods:Ten female adult animals (n = 10) were selected from each species (goats, sheep, and cows). The goats, sheep, and cows were maintained at the Agricultural Experiment Station, while camels were kept at the Royal Camel Corps (RCC). Blood samples were collected from the jugular vein in 7 mL of heparin and ethylenediaminetetraacetic acid vacutainer tubes. The oxidative respiratory burst of PBLs was measured using a chemiluminescence (CL) assay. Reactants consisted of 75 mL of whole blood diluted (1:50), 75 mL of luminol/isoluminol, and 75 mL of zymosan opsonized with non-heat inactivated serum/heat-inactivated serum or non-opsonized zymosan. CL responses were measured as relative light units and expressed as the mean count per minute and peak CL values. The mitogenic response of PBMLs to concanavalin A (Con-A), phytohemagglutinin (PHA), and pokeweed mitogen (PWM) was tested using a WST-8 assay and read spectrophotometrically at 450 nm.Results:The present findings showed that camel PBLs generate significantly higher CL responses, both intracellularly as well as extracellularly, with zymosan opsonized with autologous serum. Camel PBLs demonstrated a significantly higher (p = 0.001) response when stimulated with zymosan opsonized with heat-inactivated serum compared to those of goat, sheep, and cow lymphocytes from camels exhibited significantly higher (p = 0.001) stimulation indices (SI) with Con-A, PHA, and PWM.Conclusion:The present study suggests that camels are capable of mounting both superior innate as well as adaptive immune responses and provide immunological evidence supporting the belief of some authors, who have proposed that camels are less susceptible to a number of common infectious diseases than other domesticated ruminants.

Beyond QuantiFERON-TB Results, the Added Value of a Weak Mitogen Response.

IntroductionWhile QuantiFERON-TB gold (QFT) is frequently used, little attention is paid to the mitogen response. How it could be impacted and associated with outcomes is poorly known.MethodsRetrospective, case-control study in hospitalized patients who underwent QFT testing in two hospitals between 2016 and 2019. We defined two groups of cases with either negative [interferon (IFN)-γ ≤ 0.5 IU/ml, official threshold] or weak (0.5–2 IU/ml) mitogen response, and one group of controls with normal (>2 IU/ml) mitogen response.ResultsA total of 872 patients were included. An ongoing infection was independently associated with both a negative (RR = 4.34; 95% CI = 2.94–6.41) and a weak mitogen response (RR = 2.44; 95% CI = 1.66–3.58). Among tuberculosis patients, a weak mitogen response was associated with a false-negative QFT result (75%) compared to a normal response (20%). Decreasing mitogen response (normal, weak and negative, respectively) was associated with increasing length of hospital stay [median (interquartile range) 5 (3–13), 11 (5–21) and 15 (10–30) days; p < 0.001] and increasing hospital mortality (3, 7, and 15%; p < 0.001).ConclusionClinicians should take notice of the mitogen response since IFN-γ concentrations lower than <2 IU/ml were associated with false-negative QFT results in tuberculosis patients, independently associated with ongoing infections, and could be associated with worse prognosis.

Autism NPCs from both idiopathic and CNV 16p11.2 deletion patients exhibit dysregulation of proliferation and mitogenic responses.

SummaryNeural precursor cell (NPC) dysfunction has been consistently implicated in autism. Induced pluripotent stem cell (iPSC)-derived NPCs from two autism groups (three idiopathic [I-ASD] and two 16p11.2 deletion [16pDel]) were used to investigate if proliferation is commonly disrupted. All five individuals display defects, with all three macrocephalic individuals (two 16pDel, one I-ASD) exhibiting hyperproliferation and the other two I-ASD subjects displaying hypoproliferation. NPCs were challenged with bFGF, and all hyperproliferative NPCs displayed blunted responses, while responses were increased in hypoproliferative cells. mRNA expression studies suggest that different pathways can result in similar proliferation phenotypes. Since 16pDel deletes MAPK3, P-ERK was measured. P-ERK is decreased in hyperproliferative but increased in hypoproliferative NPCs. While these P-ERK changes are not responsible for the phenotypes, P-ERK and bFGF response are inversely correlated with the defects. Finally, we analyzed iPSCs and discovered that 16pDel displays hyperproliferation, while idiopathic iPSCs were normal. These data suggest that NPC proliferation defects are common in ASD.

Roles for CCN proteins in Lysophosphatidic Acid and Sphingosine 1‐Phosphate Signaling in Prostate Cancer Cells

IntroductionCysteine rich angiogenic factor (CCN1/Cyr61) and connective tissue growth factor (CCN2/CTGF) are members of the CCN family of matricellular proteins. These secreted proteins interact with extracellular matrix proteins and integrins to modulate cell signaling. CCN proteins have been implicated in survival and other mitogenic responses in various cancers. CCN1 and CCN2 are the two early inducible genes in this family. Lysophosphatidic acid (LPA) and sphingosine‐1‐phosphate (S1P) are lipid growth factors known to contribute to tumor progression in prostate cancer. In previous work, our group showed that LPA stimulates proliferation and migration in prostate cancer cells via the G protein‐coupled receptor LPAR1. Free fatty acid receptor 4 (FFAR4) agonists, inhibit LPA‐induced responses in prostate cancer cells. We also demonstrated that CCN1 expression is induced by LPA in human prostate cancer cells. However, the roles of CCN1 and CCN2 in cancer cell signaling have not been fully elucidated.HypothesisWe hypothesize that CCN proteins contribute to LPA‐ and S1P‐induced adhesion and mitogenic signaling in prostate cancer cells.Methods and ResultsPC‐3 human prostate cancer cells were used in the current study. For all experiments, cells were serum starved for 24 hours and then treated with and without 10 µM LPA or S1P. Immunoblotting showed that CCN1 and CCN2 were induced by LPA after 2‐5 hours in PC‐3 cells. The response was inhibited by the LPA receptor antagonist Ki1625. TUG‐891, an FFAR4 agonist, inhibited LPA‐induced CCN1 expression in PC‐3 cells. S1P also induced CCN1 expression in PC‐3 cells. In related experiments, whole cell extracts, and extracellular matrix were subjected to immunoblotting for CCN1, and immunofluorescence microscopy was used to localize the induced CCN1. CCN1 protein levels in extracellular matrix were increased 2‐5 hours after LPA treatment, as compared to untreated controls, and CCN1 was detected outside the cells by confocal microscopy. In cell adhesion assays, LPA‐treated PC‐3 cells exhibited an increase in adhesion to fibronectin‐coated 96‐well plates that was detected by 2 hours. Erk MAPK activation in response to LPA was biphasic, with the later phase occurring after CCN1/2 induction.ConclusionThe results of this study suggest that CCN proteins may play roles in LPA‐ and S1P‐induced signaling in prostate cancer cells and are thus potential therapeutic targets.

A novel mutation in TRAC in a patient with abnormal newborn screening for severe combined immunodeficiency

Background: The T cell receptor (TCR)-α chain plays a key role in TCR structure and function. Biallelic mutations in TRAC, encoding the constant region of the TCR-α chain, obliterates TCR expression and results in immunodeficiency. TCR-α chain deficiency presents at infancy or childhood with repeated viral and bacterial infections, enlarged liver, spleen, and lymph nodes as well as autoimmune features and lymphoma (OMIM #615387). Aim: To broaden the genotypic and phenotypic spectrum of TCR-α chain deficiency. Methods: We present a case report of a patient with severe combined immunodeficiency (SCID) due to a novel autosomal recessive mutation in TRAC. Results: Our patient was identified at 13 days of life due to abnormal T cell receptor excision circle levels detected by newborn screening (NBS). Immune evaluation revealed profound lymphopenia, depressed responses to the mitogen PHA and a skewed T cell repertoire, all consistent with SCID. The patient was found to carry a novel homozygous mutation in the TRAC gene. Conclusion: A novel homozygous mutation in the TRAC gene caused profound T cell lymphopenia and aberrant in vitro mitogenic response, the hallmarks of SCID. Statement of Novelty: TCR-α chain deficiency is a rare and relatively new condition and not very well defined. We herein report a novel mutation in TRAC resulting in SCID.

Clinical and Epidemiological Correlates of Low IFN-Gamma Responses in Mitogen Tube of QuantiFERON Assay in Tuberculosis Infection Screening During the COVID-19 Pandemic: A Population-Based Marker of COVID-19 Mortality?

BackgroundThe clinical and epidemiological implications of abnormal immune responses in COVID-19 for latent tuberculosis infection (LTBI) screening are unclear. MethodsWe reviewed QuantiFERON TB Gold Plus (QFT-Plus) results (36,709 patients) from July 2016 until October 2021 in Asturias (Spain). We also studied a cohort of ninety hospitalized patients with suspected/confirmed COVID-19 pneumonia and a group of elderly hospitalized patients with COVID-19 who underwent serial QFT-Plus and immune profiling testing. ResultsThe indeterminate QFT-Plus results rate went from 1.4% (July 2016 to November 2019) to 4.2% during the COVID-19 pandemic. The evolution of the number of cases with low/very low interferon-gamma (IFN-gamma) response in the mitogen tube paralleled the disease activity and number of deaths during the pandemic waves in our region (from March 2020 to October 2021). The percentages of positive QFT-plus patients did not significantly change before and during the pandemic (13.9% vs. 12.2%). Forty-nine patients from the suspected/confirmed COVID-19 pneumonia cohort (54.4%) had low/very low IFN-gamma response to mitogen, 22 of them (24.4%) had severe and critical pneumonia. None received immunosuppressants prior to testing. Abnormal radiological findings (P=0.01) but not COVID-19 severity was associated with low mitogen response. Immune profiling showed a reduction of CD8+T cells and a direct correlation between the number of EMRA CD8+T-cells and IFN-gamma response to mitogen (P=0.03). ConclusionLow IFN-gamma responses in mitogen tube of QFT-Plus often occur in COVID-19 pneumonia, which is associated with a low number of an effector CD8+T-cell subset and does not seem to affect LTBI screening; however, this abnormality seems to parallel the dynamics of COVID-19 at the population level and its mortality.

Accuracy of interferon gamma release assays for the COVID-19 immunity assessment

Emerging evidence suggests that T-cells play a significant role in COVID-19 immunity both in the context of natural infection and vaccination. Easy to use IGRA assays including QFN SARS are considered attractive alternatives to more “traditional” but laborious methods for detection of SARS-CoV-2-specific T-cell responses.In our Letter we are proposing explanations to an apparently lower than expected T-cell responses (44 % reactive individuals) reported by Krüttgen et al in a small cohort of healthy double vaccinated individuals. These results could have been affected by reporting raw optical density values instead of calculated Interferon-ɣ concentrations which is supported by unexpectedly low mitogen responses in healthy individuals.This study highlights an importance of adhering to good laboratory practice principles as well as overall importance of accurate T-cell immunity assessment using IGRA assays.

Interferon Gamma Release Assay Mitogen Responses in COVID-19

Background Elevated cytokine release and T cell exhaustion have been associated with COVID-19 disease severity. T cell activity may be indirectly measured through interferon gamma release assays (IGRAs), which use mitogen stimulation of T lymphocytes as a positive control. In our institution, an unexpectedly high rate of indeterminate IGRAs was noted in COVID-19–positive patients. We aimed to evaluate the clinical characteristics associated with indeterminate IGRA results and the difference in mitogen responses between COVID-19–positive and COVID-19–negative patients. Methods We reviewed all patients, regardless of COVID status, who were admitted between March 1, 2020, and May 31, 2020, and for whom an IGRA was collected. For COVID-19–positive individuals, we evaluated the statistical association of their IGRA results and clinical characteristics, including demographics, laboratory values, comorbidities, and hospitalization-related outcomes. For both COVID-19–positive and COVID-19–negative individuals, we evaluated IGRA mitogen control values relative to COVID-19 status as stratified by absolute lymphocyte count. Results In COVID-19–positive patients, indeterminate IGRA results were statistically associated with white blood cell count and other markers of inflammation. When comparing COVID-19–positive and COVID-19–negative patients, we noted a statistically significant difference in IGRA mitogen control values when stratified by absolute lymphocyte count. Conclusions Indeterminate IGRA results were associated with higher levels of inflammatory markers. Furthermore, when comparing mitogen responses between COVID-19–positive and COVID-19–negative patients, there was an observed difference in T cell reactivity between the groups. The mitogen response in IGRAs may serve as a surrogate for T cell function and a marker of disease severity in COVID-19.

309. TB Quantiferon Testing Predicts Mortality in Patients with COVID-19

BackgroundFinding reliable clinical predictors for severity of COVID-19 has been challenging. Interferon gamma (IFNG) plays an important role in viral replication. QuantiFERON-TB (QFT) test relies on IFNG release in response to antigens. A positive or negative test signifies adequate IFNG response, whereas an indeterminate result is obtained when such a response is lacking. In this study, we have attempted to see if an indeterminate QFT result can provide prognostic information on patients with COVID–19.Survival Probability in patients with Covid - 19 and an indeterminate TB Quantiferon test result MethodsThis is a retrospective study of patients who were admitted at our institute with COVID–19 and had a QFT done within one month of the positive SARS-CoV-2 nucleic acid amplification test result. Patient charts were analyzed for clinical course and outcomes, including in-hospital mortality (primary outcome), 90-day mortality, respiratory failure, requirement for intubation and other complications that would portend a more severe disease course.ResultsA total of 120 patient charts were analyzed, out of which 43 (35.8%) had an indeterminate QFT. All the indeterminate results were due to an inadequate mitogen response. The indeterminate QFT group had a 41.86% (18/43) in-hospital mortality vs. 9.09% (7/77) in the negative or positive QFT group (p-value of < 0.001). The 90-day mortality was similar between the two groups. Patients with indeterminate QFT also had a higher incidence of respiratory failure (97.7% vs. 75.3%; p-value = 0.020), requirement for mechanical ventilation (55.8% vs. 23.4%; p-value < 0.001), requirement of ECMO (25.58% vs. 0%; p-vale < 0.001), requirement of pressor (48.83% vs. 14.28%; p-value < 0.001) and requirement for renal replacement therapy (32.5% vs. 1.3%; p-value < 0.001), when compared to patients with a negative or positive QFT. Patients in indeterminate group had a higher hospital length of stay than the other group (p-value = 0.035). ConclusionOur study indicates that patients with COVID-19 who fail to mount an adequate IFNG mitogen response in QFT assay have worse clinical outcomes and a more complicated and protracted clinical course. Evaluating cell-mediated immune responses through commercially available IFNG release assays may yield a promising strategy to predict COVID-19 clinical outcomes. Disclosures All Authors: No reported disclosures

Timing and Immune Status after Cellular Therapies Predict Response to COVID-19 Vaccines

BACKGROUNDCellular therapies (allogeneic hematopoietic cell transplantation, allo-HCT, autologous hematopoietic cell transplantation, auto-HCT, and chimeric antigen receptor T cell therapy, CAR T) render patients severely immunocompromised for extended periods post-therapy. Emerging data suggest reduced immune responses to COVID-19 vaccines among patients with hematologic malignancies, but data for cellular therapy recipients are sparse. We therefore assessed immune responses to mRNA COVID-19 vaccines among patients who underwent cellular therapies at our center to identify predictors of response.PATIENT AND METHODSIn this observational prospective study, anti-SARS-CoV-2 spike IgG antibody titers and circulating neutralizing antibodies were measured at 1 and 3 months after the 1 st dose of vaccination. CD4, CD19, mitogen, and IgG levels from patient samples collected prior to initiation of vaccination in a subset of patients were used to assess immune recovery and association with response. A concurrent healthy donor (HD) cohort provided control response rates.RESULTSAllo-HCT (N=149), auto HCT (N=61), and CAR T (N=7) patients vaccinated between 12/22/2020- 2/28/2021 with mRNA vaccines and 69 HD participated in this study. At 3 months, 188 pts (87%) had a positive anti-SARS-CoV-2 spike IgG levels (median 5,379 AU/mL, IQR 451-15,750), and 139 (77%) had a positive neutralization Ab assay (median 93%, IQR 36-96%). All HD (100%) had a positive anti-SARS-CoV-2 spike IgG and a positive neutralization Ab assay with median levels of 8,011 AU/mL (IQR 4573-11,159) and 96% (IQR 78- 96%), respectively.Time from vaccination to cellular therapy was associated with response; 67% of patients vaccinated in the first 12 months post-cellular therapy (N=42) mounted a serologic response, compared with patients vaccinated between 12-24 (89%) (N=45), 24-36 (91%) (N=32) and >36 (93%) (N=98) months post-treatment, p= 0.001 (figure 1). Patients with immune parameters below the recommended threshold for vaccinations post-cellular therapies were also less likely to mount a response (figure 2): CD4+ T-cell count < 200 vs >200 cells/μL, 66% vs 87% (p=0.012); CD19+ B-cell count <50 vs >50 cells/μL; 33% vs 95% (p<0.001), phytohemagglutinin mitogen response <40% vs >40%, 42% vs 89% (p<0.001), and IgG <500 vs >500 mg/dl, 71% vs 91% (p=0.003). Patient age, gender, prior COVID-19 infection, treatment with IVIG, and type of mRNA COVID-19 vaccine were not associated with the likelihood of serologic response.CONCLUSIONThis largest cohort to date, demonstrates that COVID-19 vaccine responses of cellular therapy recipients are reduced compared to healthy control and response varies based on time interval from cellular therapy and immune function at the time of vaccination, underscoring the importance of monitoring immune status parameters, as well as qualitative measures (neutralizing Ab) of vaccine response, in informing clinical decisions, including the indication for booster vaccines. [Display omitted] DisclosuresPolitikos: Merck: Research Funding; ExcellThera, Inc: Other: Member of DSMB - Uncompensated. Vardhana: Immunai: Membership on an entity's Board of Directors or advisory committees. Perales: Equilium: Honoraria; Cidara: Honoraria; Sellas Life Sciences: Honoraria; Miltenyi Biotec: Honoraria, Other; Celgene: Honoraria; MorphoSys: Honoraria; Takeda: Honoraria; Incyte: Honoraria, Other; Karyopharm: Honoraria; Kite/Gilead: Honoraria, Other; Merck: Honoraria; NexImmune: Honoraria; Novartis: Honoraria, Other; Medigene: Honoraria; Omeros: Honoraria; Servier: Honoraria; Bristol-Myers Squibb: Honoraria; Nektar Therapeutics: Honoraria, Other. Shah: Amgen: Research Funding; Janssen Pharmaceutica: Research Funding.

257 Awardee Talk: Pursuit of Novel Factors that Regulate Ovarian Follicular Function

Abstract As follicles grow, theca cells (TC) and granulosa cells (GC) must proliferate with minimal differentiation while thecal vascularization increases so that follicles do not prematurely ovulate or luteinize before the oocyte is fully mature. In the early 2000s we used Affymetrix microarrays to discover several unique genes involved in ovarian follicular development. Thrombospondin and fibroblast growth factor (FGF) 2 receptor genes were stimulated by IGF1 in porcine GC. We compared GC gene expression in bovine cystic versus normal follicles and discovered several novel genes including Indian hedgehog protein (IHH), FGF9, brain ribonuclease (BRB), and G protein-coupled receptor 34 (GPR34), leading to identification of roles for these proteins in ovarian follicular development. During the past 10 years, follow-up TC microarray and mechanistic studies have identified FGF9 control of cell cycle proteins, tight junction proteins, and microRNA 221 (MIR221), and that the mitogenic and steroidogenic responses to the major trophic hormones of the ovary (including IGF1, LH and FSH) are altered by overexpression of MIR221 in GC. In addition, we discovered that: 1) FGF9 stimulates GC and TC mitosis while inhibiting steroidogenesis; 2) FGF9 induces E2 transcription factor (E2F)-1, E2F-8 and cyclin D1 (CCND1), and that both IGF1 and vascular endothelial growth factor-A (VEGFA) synergize with FGF9 to further induce E2F8 and CCND1 mRNA; 3) FGF9 induces the nuclear protein UHRF1; and 4) an E2F inhibitor blocks the stimulatory and inhibitory effects of FGF9 on GC proliferation and steroidogenesis, respectively, and down-regulates UHRF1 mRNA and up-regulates VEGFA mRNA. Thus, aberrant production of FGF9 and the factors it induces/inhibits may lead to vascular dysfunction and ovarian disorders such as ovarian cysts. With additional research, knowledge about these newly identified factors may be used to help the livestock industry improve reproductive efficiency via new treatments for estrous synchronization, superovulation and cystic ovaries.

SARS-CoV-2 Coronavirus Spike Protein-Induced Apoptosis, Inflammatory, and Oxidative Stress Responses in THP-1-Like-Macrophages: Potential Role of Angiotensin-Converting Enzyme Inhibitor (Perindopril).

A purified spike (S) glycoprotein of severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) coronavirus was used to study its effects on THP-1 macrophages, peripheral blood mononuclear cells (PBMCs), and HUVEC cells. The S protein mediates the entry of SARS-CoV-2 into cells through binding to the angiotensin-converting enzyme 2 (ACE2) receptors. We measured the viability, intracellular cytokine release, oxidative stress, proinflammatory markers, and THP-1-like macrophage polarization. We observed an increase in apoptosis, ROS generation, MCP-1, and intracellular calcium expression in the THP-1 macrophages. Stimulation with the S protein polarizes the THP-1 macrophages towards proinflammatory futures with an increase in the TNFα and MHC-II M1-like phenotype markers. Treating the cells with an ACE inhibitor, perindopril, at 100 µM reduced apoptosis, ROS, and MHC-II expression induced by S protein. We analyzed the sensitivity of the HUVEC cells after the exposure to a conditioned media (CM) of THP-1 macrophages stimulated with the S protein. The CM induced endothelial cell apoptosis and MCP-1 expression. Treatment with perindopril reduced these effects. However, the direct stimulation of the HUVEC cells with the S protein, slightly increased HIF1α and MCP-1 expression, which was significantly increased by the ACE inhibitor treatment. The S protein stimulation induced ROS generation and changed the mitogenic responses of the PBMCs through the upregulation of TNFα and interleukin (IL)-17 cytokine expression. These effects were reduced by the perindopril (100 µM) treatment. Proteomic analysis of the S protein stimulated THP-1 macrophages with or without perindopril (100 µM) exposed more than 400 differentially regulated proteins. Our results provide a mechanistic analysis suggesting that the blood and vascular components could be activated directly through S protein systemically present in the circulation and that the activation of the local renin angiotensin system may be partially involved in this process.GraphicalSuggested pathways that might be involved at least in part in S protein inducing activation of inflammatory markers (red narrow) and angiotensin-converting enzyme inhibitor (ACEi) modulation of this process (green narrow).

Molecular and pharmacological characterization of insulin icodec: a new basal insulin analog designed for once-weekly dosing

IntroductionInsulin icodec is a novel, long-acting insulin analog designed to cover basal insulin requirements with once-weekly subcutaneous administration. Here we describe the molecular engineering and the biological and pharmacological properties...

Mycobacterial lymphadenitis without granuloma formation in a patient with anti-interferon-gamma antibodies.

A previously healthy 49-year-old Japanese woman presented with cervical lymph node swelling and tenderness. Lymph node biopsy revealed reactive lymphadenitis without granulomas. No malignant cells were found, and no acid-fast positive bacilli were identified by Ziehl–Neelsen staining. She was treated unsuccessfully with various antibiotics, and it was very challenging to reach a diagnosis. 18F-Fluorodeoxyglucose (18F-FDG) uptake in bones was evaluated using positron emission tomography-computed tomography (PET-CT), and disseminated mycobacterial infection was suspected. The interferon-gamma (IFN-γ) release assays QuantiFERON (QFT) and T-SPOT were used to diagnose tuberculosis infection. On testing, a difference in mitogen response was found between these assays. The response was low for QFT but adequate for T-SPOT, suggesting the presence of anti-IFN-γ antibodies. This difference depended on whether the patient’s plasma (including anti-IFN-γ antibodies) was used within the assay system. Mycobacterium abscessus was isolated from lymph node cultures, and plasma anti-IFN-γ antibodies were confirmed. The patient was diagnosed with disseminated M. abscessus infection with underlying adult-onset immunodeficiency caused by anti-IFN-γ antibodies. Granulomas are a pathological hallmark of mycobacterial infection, but may not fully form in immunodeficient patients. Clinicians should be aware of the possibility of mycobacterial infection without granuloma formation due to anti-IFN-γ antibodies.

Pneumonitis in patients with thymoma and Good's syndrome.

e20595 Background: The association between thymoma (T) and immunological dysregulations is well acknowledged. Good’s syndrome (GS), which occurs in approximately 6% to 11% of T patients, is characterized by hypogammaglobulinemia, few or absent B-cells (CD19+), CD4 T cells lymphopenia, abnormal CD4/CD8 T ratio and impaired T cell mitogenic response. Patients with GS have increased susceptibility to bacterial, opportunistic and viral infections related to both humoral and cell-mediated immunodeficiency. The recent Sars-Cov-2 pandemic drew attention to the clinical condition of fatal viral pneumonitis and cytokines storm. Here we reported our monocentric experience of pneumonitis in patients with T and GS before the Sars-Cov-2 pandemic. Methods: We conducted a retrospective analysis of T patients with associated GS referred to the Rare Tumours Reference Center of University Federico II of Naples over a 10-year period (from 2009 to 2019). All the patients with radiological and/or clinical pneumonitis diagnosis were evaluated for this report. Immunological features, histopathological diagnosis and clinical outcome were registered. Results: A total of 41 patients with T and GS were identified, including 17 patients with local disease (stage I-II according to Masaoka-Koga) and 24 with advanced disease (stage III-IV). The majority (56.3%) had B2 T diagnosis. Radiological and/or clinical pneumonitis diagnosis was assessed in 23 cases (56%). Viral pneumonitis was detected in 8 patients: 3 patients with H1N1 infection, 3 patients with CMV infection, 2 patients with EBV infection. Bacterial pneumonitis was diagnosed in 9 patients (3 patients with K. pneumoniae, 4 patients with S. aureus, 2 patients with H. influenza). Opportunistic pneumonitis was found in 2 patients with Aspergillosis infection. In 2 cases no pathogenic agent was identified. The immunophenotyping, assessed in 4 patients with viral pneumonitis, displayed very low/undetectable levels of B cells, with median % value of CD3+T cells and NKT of respectively 9.8% and 0.4% of the total leukocytes. The median % of Treg was 4.7%. CD4+/CD8+ ratio was variable, ranging from 1,2 to 0,6. Interestingly the number of B cells was extremely low, independent of CD4+/CD8+ ratio. Blood levels of cytokines, chemokines and growth factors revealed elevated IL-4, Eotaxin, CCL2 / MCP-1 and CCL5 / RANTES ad strong reduction of IL-10. PDGF-BB levels were also elevated. 15 patients required admission to intensive care Six patients died for fatal pneumonitis. Conclusions: The management of T patients with GS is extremely challenging. Clear diagnostic algorithms do not yet exist and immune-profiling and quantitative immunoglobulins should be considered a part of diagnostic search in these patients. The coexistence of cancer, infections and immunosuppression may trigger life-threatening conditions, such as fatal pneumonitis, which often require intensive care and multidisciplinary approach.

Edible Bird's Nest: The Functional Values of the Prized Animal-Based Bioproduct From Southeast Asia-A Review.

Edible Bird’s Nest (EBN) is the most prized health delicacy among the Chinese population in the world. Although some scientific characterization and its bioactivities have been studied and researched, no lights have been shed on its actual composition or mechanism. The aim of this review paper is to address the advances of EBN as a therapeutic animal bioproduct, challenges and future perspectives of research involving EBN. The methodology of this review primarily involved a thorough search from the literature undertaken on Web of Science (WoS) using the keyword “edible bird nest”. Other information were obtained from the field/market in Malaysia, one of the largest EBN-producing countries. This article collects and describes the publications related to EBN and its therapeutic with diverse functional values. EBN extracts display anti-aging effects, inhibition of influenza virus infection, alternative traditional medicine in athletes and cancer patients, corneal wound healing effects, stimulation of proliferation of human adipose-derived stem cells, potentiate of mitogenic response, epidermal growth factor-like activities, enhancement of bone strength and dermal thickness, eye care, neuroprotective and antioxidant effects. In-depth literature study based on scientific findings were carried out on EBN and its properties. More importantly, the future direction of EBN in research and development as health-promoting ingredients in food and the potential treatment of certain diseases have been outlined.