Flow Cytometry Characterization of Cerebrospinal Fluid Monocytes in Patients With Postoperative Cognitive Dysfunction: A Pilot Study.

My research team focuses on 3 areas:

1) We are interested in the mechanisms of postoperative neurocognitive disorders such as delirium, and the relationship between these disorders and Alzheimer's Disease and Related Dementias (ADRD). Towards these ends, we use a combination of methods including pre and postoperative CSF and blood sampling, functional neuroimaging, EEG recordings, rigorous biochemical assays, and cognitive testing and delirium screening. In the long run, this work has the potential to help us improve long term neurocognitive outcomes for the more than 20 million Americans over age 60 who undergo anesthesia and surgery each year.

2) We are interested in the idea that altered anesthetic-induced brain EEG waveforms can serve as indicators of specific types of preclinical/prodromal neurodegenerative disease pathology, specific cognitive domain deficits, and postoperative delirium risk. We are studying this topic in the ALADDIN study, a 250 patient prospective cohort study in older surgical patients at Duke. Many people have viewed anesthesia and surgery as a "stress test" for the aging brain; we hope that this work will help us learn how to develop a real-time EEG readout of this "perioperative stress test" for the aging brain, just as ECG analysis can provide a real-time readout of cardiac treadmill stress tests. 

3) We are interested in how the APOE4 allele damages brain circuitry throughout the adult lifespan, and how this contributes to increased risk of late onset Alzheimer's disease as well as worse outcomes following other acute brain disorders such as stroke and traumatic brain injury (TBI). In particular, we are investigating the hypothesis that the APOE4 allele leads to increased CNS complement activation throughout adult life, which then contributes to increased synaptic phagocytosis and long term neurocognitive decline. We are also studying whether acutely modulating APOE signaling in older surgical patients with the APOE mimetic peptide CN-105 is sufficient to block postoperative CSF neuroinflammation and complement activation. 

Our work is transdisciplinary, and thus our team includes individuals with diverse scientific and clinical backgrounds, ranging from neuropsychology and neuroimaging to proteomics, flow cytometry and behavioral neuroscience in animal models. What unites us is the desire to better understand mechanisms of age-dependent brain dysfunction, both in the perioperative setting and in APOE4 carriers. 

As a physician and researcher, my career has been driven by a passion for linking the basic and clinical sciences with the primary goal of understanding the disease pathogenesis. Through my training in epidemiology, basic science immunology, and clinical medicine, I have acquired a breadth of experience, knowledge, collaborators, and an adaptability which has culminated in a research focus on the reconstitution of immune responses and systemic inflammation in immunocompromised patients and vulnerable populations. My research focuses on T cell immunology utilizing a variety of platforms including polychromatic flow cytometry, cytokine multiplexing, and novel single cell assays. My initial research centered on the immune reconstitution syndrome (IRIS), with a focus on the mycobacterial precipitants of the disease, its epidemiology, and research efforts into elucidating the pathogenesis of the syndrome. Recently, I have translated my interest in co-infection immunology in the immunocompromised transplant population. With a career long interest in contrasting compartmental and peripheral immune responses, I have partnered with engineers in the Duke Pratt School of Engineering in order to develop novel single cell immune assays in order to comprehensively profile the immune response on limited specimens.

Computational immunology (stochastic and spatial models and simulations, T cell signaling, immune regulation)
Statistical methodology for immunological laboratory techniques (flow cytometry, CFSE analysis, receptor-ligand binding and signaling kinetics)
Informatics of the immune system (reference and application ontologies, meta-programming, text mining and machine learning)

Dr. Browndyke is an Associate Professor of Behavioral Health & Neurosciences in the Department of Psychiatry & Behavioral Sciences.  He has a secondary appointment as Assistant Professor of Cardiovascular & Thoracic Surgery.

Dr. Browndyke's research interests involve the use of advanced neurocognitive and neuroimaging techniques for perioperative contributions to delirium and later dementia risk, monitoring of late-life neuropathological disease progression, and intervention/treatment outcomes.  His research also involves novel telehealth methods for remote neurocognitive evaluation and implementation of non-invasive neuromodulatory techniques to assist in postoperative recovery and dementia risk reduction.

Dr. Browndyke's clinical expertise is focused upon geriatric neuropsychology with an emphasis in the assessment, diagnosis, and treatment of dementia and related disorders in adults and US veteran patient populations.

Current research interests include:
1. The relationship between white matter patency, functional connectivity (fMRI) and neurocognitive function following cardiac surgery.
2. The relationship between global and regional cortical beta-amyloid deposition and postoperative cognitive decline.
3. The effect of lidocaine infusion upon neurocognitive function following cardiac surgery.
4. The association between genotype and outcome after cardiac surgery.
5. Atrial fibrillation following cardiopulmonary bypass.

The Weinhold Laboratory is currently focused on utilizing a comprehensive repertoire of highly standardized and formerly validated assay platforms to profile the human immune system in order to identify immunologic signatures that predict disease outcomes. These ongoing studies span a broad range of highly relevant clinical arenas, including: 1) cancer (non-small cell lung cancer, head and neck cancer, glioblastoma neoforme, ovarian cancer, and prostate cancer), 2) autoimmune diseases (rheumatoid arthritis, systemic lupus erythematosis, multiple sclerosis, and myasthenia gravis), 3) pulmonary disease (idiopathic pulmonary fibrosis), 4) solid organ transplantation (lung, kidney, liver, and heart), and 5) inflammatory disorders.

Two of the areas that have been especially active over the past few years include the comprehensive immunologic profiling of cancer patients receiving so-called ‘immune checkpoint blockade’ therapies and the search for immune signatures in lung transplant recipients that track with resistance to CMV infection. The laboratory conducted immune monitoring studies associated with a Phase I trial of Ipilimumab (anti-CTLA-4) in a neoadjuvant setting for the treatment of non-small cell lung cancer (NSCLC). For this trial we extensively utilized several high parameter flow cytometry (PFC) platforms to follow activation, maturation, exhaustion, and proliferation patterns within CD4+ and CD8+ subsets of T-cells. We are also utilizing an intracellular cytokine staining (ICS) platform in efforts to detect anti-tumor associated antigen (TAA) responses by CD4+ and CD8+ T cells from peripheral blood mononuclear cells as well as lymphocytes infiltrating the patients’ tumor. These assays are designed to measure antigen-driven intracellular production of IFN-γ, TNF-α, and IL-2, as well as the degranulation marker CD107a. This strategy enables us to not only document individual cytokine responses, but to also assess (through Boolean gating) changes in relative polyfunctionality of the responses. We have also performed similar immune monitoring of a Phase II trial evaluating nivolumab (anti-PD-1) alone vs. combined nivolumamb + ipilimumab vs. avastin (bevacizamab) alone in patients with glioblastomas. In both studies, we are seeking to identify pharmacodynamics markers and immune correlates predictive of clinical responses. In completed studies of a cohort of lung transplant recipients, we identified specific polyfunctional signatures in CD4+ and CD8+ subsets against CMV pp65 and IE-1 antigens that tracked with resistance to CMV infection (manuscript in preparation). These findings now serve as the basis for a Phase I clinical trial to compare conventional 6-month chemoprophylaxis in lung transplant recipients versus a regimen dictated by the presence or absence of the predictive signatures. This trial is the principal component of a recently awarded Clinical Trials in Organ Transplantation or CTOT award made from the NIH to Duke (Scott Palmer, PI). Ongoing studies will test the hypothesis that these signatures that have been validated in lung transplant recipients will also predict resistance to CMV infection in the context of other solid organ transplants such as kidney, liver, and heart.Future studies will also attempt to identify predictive signatures for resistance to BK polyomavirus, the cause of graft threatening nephritis in kidney transplant recipients and cystitis in bone marrow transplant recipients.  

Recent publications

Zidar, D.A., Mudd, J.C., Juchnowski, S., Lopes, J.P., Sparks, S., Park, S.S., Ishikawa, M., Osborne, R., Washam, J.B., Chan, C., Funderburg, N.T., Owoyele, A., Alaiti, M.A., Mayuga, M., Orringer, C., Costa, M.A., Simon, D.I., Tatsuoka, C., Califf, R.M., Newby, L.K., Lederman, M.M., and Weinhold, K.J.  Altered maturation status and possible immune exhaustion of CD8 T lymphocytes in the peripheral blood of patients presenting with acute coronary syndromes. Arterioscler., Thromb., and Vasc. Biol. 36(2): 389-397, Feb. 2016 PMID: 26663396

Yi, J.S., Ready, N., Healy, P., Dumbauld, C., Berry, M., Shoemaker, D., Clarke, J., Crawford, J., Tong, B.C., Harpole, D., D’Amico, T.A., McSherry, F., Dunphy, F., McCall, S.J., Christensen, J.D., Wang, X, and Weinhold, K.J. Immune activation in early stage non-small cell lung cancer patients receiving neoadjuvant chemotherapy plus ipilimumab. Clin. Cancer Res. 23(24):7474-7482, 2017. PMCID: PMC5732888.

Reap, E., Suryadevera, C., Batuch, K., Sanchez-Perez, L., Archer, G., Schmittling, R., Norberg, P., Herndon II, J., Healy, P., Congdon, K., Gedeon, P., Campbell, O., Swartz, A., Riccione, K., Yi, J., Hossain-Ibrahim, M., Saraswathula, A., Nair, S., Anastasie, A., Broome, T., Weinhold, K.J., Desjardins, A., Vlahoviv, G., Mclendon, R., Firedman, H., Bigner, D., Fecci, P., Mitchell, D., and Sampson, J. Dendritic cells enhance polyfunctionality of adoptively transferred T cells which target cytomegalovirus in glioblastoma. Cancer Research 78(1):256-264, 2018. PMCID: PMC5754236.

Woroniecka, K., Chongsathidkiet, P., Rhodin, K., Kemeny, H., Dechant, C., Elsamadicy, A.A., Koyama, S., Jackson, C., Farber, H.S., Elsamadicy, A.A., Cui, X., Koyama, S., Jackson, C., Hansen, L., Bigner, D.D., Giles, A., Healy, P., Dranoff, G., Weinhold, K.J., Dunn, G.P., and Fecci, P.E. T cell exhaustion signatures vary with tumor type and are severe in glioblastoma. Clin. Cancer Res. Sep 1;24(17)4175-4186, 2018. PMCID: PMC6081269.

Weinhold, K.J., Bukowski, J.F., Brennan, T.V., Noveck, R.J., Staats, J.S., Lin, L., Stempora, L., Hammond, C., Wouters, A., Mojcik, C.F., Cheng, J., Collinge, M., Jesson, M.I., Hazra, A., Biswas, P., Lan, S., Clark, J.D., and Hodge, J.A. Reversibility of peripheral blood leukocyte phenotypic and functional changes after exposure to and withdrawal from tofacitinib, a Janus kinase inhibitor, in healthy volunteers. Clin. Immunology 191:10-20, June 19, 2018. PMCID: PMC6036921.

Berger, M., Oyeyemi, D, Olurinde, M.O., Whitson, H.E., Weinhold, K.J., Woldorff, M.G., Lipsitz, L.A., Moretti, E., Giattino, C.M., Rpberts, K.C., Zhou, J., Bunning, T., Ferrandino, M., Scheri, R.P., Cooter, M., Chan, C., Cabeza, R., Browndyke, J.N., Murdoch, D.M., Devinney, M.J., Shaw, L.M., Cohen, H.J., Mathew, J.P., and the INTUIT Investigators. The INTUIT Study: Investigating neuroinflammation underlying postoperative cognitive dysfunction. J. American Geriatrics Society 67940;794-798, 2019. PMCID: PMC6688749.

Berger, M., Murdoch, D., Staats, J., Chan, C., Thomas J., Garrigues, G., Browndyke, J., Cooter, M., Quinones, Q., Matthew, J., and Weinhold, K.J. Flow cytometry characterization of cerebrospinal fluid monocytes in patients with postoperative cognitive dysfunction (POCD): A pilot study. Anesthesia & Analgesia May 3, 2019 doi: 10.1213/ANE. PMCID: PMC6800758.

Nyanhete, T.E., Frisbee, A., Bradley, T., Faison, W.J., Robins, E., Payne, T.,Freel, S.A., Sawant, S., Weinhold, K.J., Wiehe, K., Haynes, B.F., Ferrari, G., Li, Q-J., Moody, M.A., and Tomaras, G.D. HLA class II-restricted CD8+T cells in HIV-1 virus controllers. Nat. Sci. Rep. 9(1):10165, 2019; PMCID: PMC6629643.

Yi, J.S., Rosa-Bray, M., Staats, J., Zakroysky, P., Chan, C., Russo, M., Dumbauld, C., White, S., Gierman, T., Weinhold, K.J., and Guptill, J.T. Establishment of normative ranges of the healthy immune system with comprehensive polychromatic flow cytometry profiling. PLoS One 14(12):e0225512, Dec.11, 2019. PMCID: PMC6905525.

Healy, Z.R., Weinhold, K.J., and Murdoch D.M. Transcriptional profiling of CD8+ CMV-specific T cell functional subsets obtained using a method for isolating high-quality RNA from fixed and permeabilized cells. Frontiers in Immunology 11:1859, Sep. 2, 2020. PMCID: PMC7492549.

Zhang, T., Harrison, M.R., O’Donnell, P.H., Ajjai, A., Hahn, N.M., Appleman, L.J., Cetnar, J., Burke, J.M., Fleming, M., Miloswsky. M., Mortazavi, A., Shore, N., Sonapavde, G., Schmidt, E., Bitman, B., Munugalavadla, V., Izumi, P., Patel, P., Staats, J., Chan, C., Weinhold, K.J.*and George, D.J.,*senior co-authors. A randomized phase 2 trial of pembrolizumab versus pembrolizumab and acalabrutinib in patients with platinum-resistant metastatic urothelial cancer. Cancer Oct.15, 2020 126(20):4485-4497. PMCID: PMC7590121

Salama, A.K.S., Palta, M., Rushing, C.N., Selim, M.A., Linnet, K.N., Czito, B.G., Yoo, D.S., Hanks, B.A., Beasley, G.M., Mosca, P., Dumbauld, C., Steadman, K.N., Yi, J.S., Weinhold, K.J., Tyler, D.S., Lee, W.T., and Brizel, D.M. Ipilimumab and radiation in patients with high risk resected or regionally advanced melanoma. Clin. Cancer Res. 1 March, 2021 27(5):1287-1295. PMCID: PMC8759408.

Li, Y., Yi, J.S., Russo, M.., Rosa-Bray, M., Weinhold. K.J., and Guptill, J.T. Normative dataset for plasma cytokines in healthy human adults. Data Brief 2021 Feb. 9;35:106857. PMCID: PMC7900339

White, S., Quinn, J., Enzor, E., Staats, J., Mosier, S.M., Almarode, J., Denny, T.N., Weinhold, K., Ferrari, G., and Chan, C. FlowKit: A Python toolkit for integrated manual and automated cytometry analysis workflows. Frontiers in Immunology 12:768541,Nov. 5, 2021. PMCID: PMC8602902.

Sung, B-Y., Lin, Y-H., Shah, P.D., Bieler, J.G., Palmer, S., Weinhold, K.J., Chang, H-R., Huang, H., Avery, R.K., Schneck, J., and Chiu, Y-L. Wnt activation promotes memory T cell polyfunctionality via epigenetic regulator PRMT1. J. Clin. Invest. 132(2):e140508, January 18, 2022. PMCID: PMC8759796.

Lusk, J.B., Quinones, Q.J., Staats, J.S., Weinhold, K.J., Grossi, P.M., Laskowitz, D.T., and James, M.L. Coupling hematoma evacuation with immune profiling for analysis of neuroinflammation after primary intracerebral hemorrhage: a pilot study. World Neurosurg. 2022 May;161:162-168 PMCID:PMID:35217228.

Brown, Landon C., Halabi, S., Somarelli, J., Humeniuk, M., Wu, Y., Oyekunle, T., Howard, L., Huang, J., Anand, M., Davies, C., Patel, P., Staats, J., Weinhold, K.J., Harrison, M.R., Zhang, T., George, D.J., and Armstrong, A.J. A phase 2 trial of avelumab in men with aggressive-variant or neuroendocrine prostate cancer. Prostate Cancer and Prostatic Diseases 25(4):762-769, 2022. PMCID: PMC8933335.

Khatri, A., Todd, J.L., Kelly, F.L., Nagler, A., Ji, Z., Jain, V., Gregory, S..G., Weinhold, K.J., and Palmer, S.M. JAK-STAT activation in basal cells contributes to cytotoxic T-cell mediated basal cell death in human chronic lung allograft dusfunction. JCI Insight 8(6) March 22, 2023 PMCID:PMC pending.

Zaffiri, L., Messinger, M., Staats, J.S., Patel, P., Palmer, S.M., Weinhold, K.J., Snyder, L.D., and Luftig, M.A. Evaluation of host cellular responses to Epstein-Barr virus (EBV) in adult lung transplant recipients with EBV-associated diseases. J. Med. Virol. 95(4):e28724, 2023.