Olga Afanasiev, MD, PhD joined the Stanford Dermatology Residency Program in 2016 to pursue a career in general dermatology, complex medical dermatology and procedural dermatology. Dr. Afanasiev graduated with honors from University of California, Berkeley, where she studied Molecular and Cell Biology and Psychology. She then completed the Medical Scientist Training Program to receive her MD/PhD degrees from University of Washington in Seattle. Dr. Afanasiev’s PhD thesis was conducted in Dr. Paul Nghiem’s lab, where she characterized the immune responses to the virus-driven Merkel cell cancer that led to novel and promising immunotherapies for patients. Her current clinical and research interests include cutaneous oncology (melanoma, high risk non-melanoma skin cancers, Merkel cell carcinoma), clinical trials of novel therapies, and development of digital health platforms to expand access to and efficacy of dermatology care.
- Skin Cancer
Honors & Awards
Alpha Omega Alpha Honor Medical Society, AOA (2014)
Kirschstein National Research Service Award for Individual Predoctoral MD/PhD Fellows, National Institute of Health (NIH) (2010)
Achievement Rewards for College Scientists, ARCS (2009)
Alexander Grinstein Endowed Fellowship, University of Washington (2009)
Boards, Advisory Committees, Professional Organizations
Member, California Society of Dermatology & Dermatologic Surgery (2016 - Present)
Member, American Society for Dermatologic Surgery (2016 - Present)
Member, California Society of Dermatology & Dermatologic Surgery (CalDerm) (2016 - Present)
Member, San Francisco Dermatological Society (2016 - Present)
Member, Alpha Omega Alpha Honor Medical Society (2014 - Present)
MD, University of Washington School of Medicine (2015)
PhD, University of Washington School of Medicine, Cancer Immunology / Pathology (2013)
BA, University of California, Berkeley, Molecular and Cell Biology; Psychology (2007)
TNF-inhibitor associated psoriatic alopecia: Diagnostic utility of sebaceous lobule atrophy.
Journal of cutaneous pathology
The increasingly successful and widespread use of Tumor Necrosis Factor inhibitors (TNFi) to treat autoimmune and inflammatory conditions has also been accompanied by adverse reactions, both systemic and cutaneous. Psoriasiform cutaneous rashes are well described. Recently, TNF inhibitor associated psoriatic alopecia (TiAPA) is being more frequently reported. The purpose of this study is to describe the features of TiAPA, including marked atrophy of sebaceous lobules as a histologic clue to diagnosis, helping to distinguish it from other types of alopecia. Clinical and histopathological features of 3 patients who developed scalp alopecia while on TNFi treatment were examined. Clinical follow up was conducted after discontinuation of TNFi. A review of the previous literature on the subject was also conducted. Atrophy of sebaceous lobules is a potentially reversible, characteristic and conspicuous feature of TiAPA that can be distinguished from idiopathic psoriatic alopecia by clinical history of drug exposure and sometimes by histologic presence of a mixed inflammatory response including plasma cells and eosinophils.
View details for DOI 10.1111/cup.12932
View details for PubMedID 28332233
Downregulation of MHC-I Expression Is Prevalent but Reversible in Merkel Cell Carcinoma
CANCER IMMUNOLOGY RESEARCH
2014; 2 (11): 1071-1079
Merkel cell carcinoma (MCC) is an aggressive, polyomavirus-associated skin cancer. Robust cellular immune responses are associated with excellent outcomes in patients with MCC, but these responses are typically absent. We determined the prevalence and reversibility of major histocompatibility complex class I (MHC-I) downregulation in MCC, a potentially reversible immune-evasion mechanism. Cell-surface MHC-I expression was assessed on five MCC cell lines using flow cytometry as well as immunohistochemistry on tissue microarrays representing 114 patients. Three additional patients were included who had received intralesional IFN treatment and had evaluable specimens before and after treatment. mRNA expression analysis of antigen presentation pathway genes from 35 MCC tumors was used to examine the mechanisms of downregulation. Of note, 84% of MCCs (total n = 114) showed reduced MHC-I expression as compared with surrounding tissues, and 51% had poor or undetectable MHC-I expression. Expression of MHC-I was lower in polyomavirus-positive MCCs than in polyomavirus-negative MCCs (P < 0.01). The MHC-I downregulation mechanism was multifactorial and did not depend solely on HLA gene expression. Treatment of MCC cell lines with ionizing radiation, etoposide, or IFN resulted in MHC-I upregulation, with IFNs strongly upregulating MHC-I expression in vitro, and in 3 of 3 patients treated with intralesional IFNs. MCC tumors may be amenable to immunotherapy, but downregulation of MHC-I is frequently present in these tumors, particularly those that are positive for polyomavirus. This downregulation is reversible with any of several clinically available treatments that may thus promote the effectiveness of immune-stimulating therapies for MCC.
View details for DOI 10.1158/2326-6066.CIR-14-0005
View details for Web of Science ID 000346134900006
View details for PubMedID 25116754
Regression of Metastatic Merkel Cell Carcinoma Following Transfer of Polyomavirus-Specific T Cells and Therapies Capable of Reinducing HLA Class-I
CANCER IMMUNOLOGY RESEARCH
2014; 2 (1): 27-36
Merkel cell carcinoma (MCC) is an aggressive skin cancer that typically requires the persistent expression of Merkel cell polyomavirus (MCPyV) oncoproteins that can serve as ideal immunotherapeutic targets. Several immune evasion mechanisms are active in MCC including down-regulation of HLA class-I expression on tumor cells and dysfunctional endogenous MCPyV-specific CD8 T cell responses. To overcome these obstacles, we combined local and systemic immune therapies in a 67-year-old man, who developed metastatic MCPyV-expressing MCC. Intralesional IFNβ-1b or targeted single-dose radiation was administered as a pre-conditioning strategy to reverse the down-regulation of HLA-I expression noted in his tumors and to facilitate the subsequent recognition of tumor cells by T cells. This was followed by the adoptive transfer of ex vivo expanded polyclonal, polyomavirus-specific T cells as a source of reactive antitumor immunity. The combined regimen was well-tolerated and led to persistent up-regulation of HLA-I expression in the tumor and a durable complete response in two of three metastatic lesions. Relative to historical controls, the patient experienced a prolonged period without development of additional distant metastases (535 days compared to historic median of 200 days, 95% confidence interval = 154-260 days). The transferred CD8(+) T cells preferentially accumulated in the tumor tissue, remained detectable and functional for >200 days, persisted with an effector phenotype, and exhibited evidence of recent in vivo activation and proliferation. The combination of local and systemic immune stimulatory therapies was well-tolerated and may be a promising approach to overcome immune evasion in virus-driven cancers.
View details for DOI 10.1158/2326-6066.CIR-13-0087
View details for Web of Science ID 000340030900005
View details for PubMedID 24432305
Merkel Polyomavirus-Specific T Cells Fluctuate with Merkel Cell Carcinoma Burden and Express Therapeutically Targetable PD-1 and Tim-3 Exhaustion Markers
CLINICAL CANCER RESEARCH
2013; 19 (19): 5351-5360
The persistent expression of Merkel cell polyomavirus (MCPyV) oncoproteins in Merkel cell carcinoma (MCC) provides a unique opportunity to characterize immune evasion mechanisms in human cancer. We isolated MCPyV-specific T cells and determined their frequency and functional status.Multiparameter flow cytometry panels and HLA/peptide tetramers were used to identify and characterize T cells from tumors (n = 7) and blood (n = 18) of patients with MCC and control subjects (n = 10). PD-1 ligand (PD-L1) and CD8 expression within tumors were determined using mRNA profiling (n = 35) and immunohistochemistry (n = 13).MCPyV-specific CD8 T cells were detected directly ex vivo from the blood samples of 7 out of 11 (64%) patients with MCPyV-positive tumors. In contrast, 0 of 10 control subjects had detectable levels of these cells in their blood (P < 0.01). MCPyV-specific T cells in serial blood specimens increased with MCC disease progression and decreased with effective therapy. MCPyV-specific CD8 T cells and MCC-infiltrating lymphocytes expressed higher levels of therapeutically targetable PD-1 and Tim-3 inhibitory receptors compared with T cells specific to other human viruses (P < 0.01). PD-L1 was present in 9 of 13 (69%) MCCs and its expression was correlated with CD8-lymphocyte infiltration.MCC-targeting T cells expand with tumor burden and express high levels of immune checkpoint receptors PD-1 and Tim-3. Reversal of these inhibitory pathways is therefore a promising therapeutic approach for this virus-driven cancer.
View details for DOI 10.1158/1078-0432.CCR-13-0035
View details for Web of Science ID 000325203700012
View details for PubMedID 23922299
Vascular E-Selectin Expression Correlates with CD8 Lymphocyte Infiltration and Improved Outcome in Merkel Cell Carcinoma
JOURNAL OF INVESTIGATIVE DERMATOLOGY
2013; 133 (8): 2065-2073
Merkel cell carcinoma (MCC) is an aggressive, polyomavirus-linked skin cancer. Although CD8 lymphocyte infiltration into the tumor is strongly correlated with improved survival, these cells are absent or sparse in most MCCs. We investigated whether specific mechanisms of T-cell migration may be commonly disrupted in MCC tumors with poor CD8 lymphocyte infiltration. Intratumoral vascular E-selectin, critical for T-cell entry into skin, was downregulated in the majority (52%) of MCCs (n=56), and its loss was associated with poor intratumoral CD8 lymphocyte infiltration (P<0.05; n=45). Importantly, survival was improved in MCC patients whose tumors had higher vascular E-selectin expression (P<0.05). Local nitric oxide (NO) production is one mechanism of E-selectin downregulation and it can be tracked by quantifying nitrotyrosine, a stable biomarker of NO-induced reactive nitrogen species (RNS). Indeed, increasing levels of nitrotyrosine within MCC tumors were associated with low E-selectin expression (P<0.05; n=45) and decreased CD8 lymphocyte infiltration (P<0.05, n=45). These data suggest that one mechanism of immune evasion in MCC may be restriction of T-cell entry into the tumor. Existing therapeutic agents that modulate E-selectin expression and/or RNS generation may restore T-cell entry and could potentially synergize with other immune-stimulating therapies.
View details for DOI 10.1038/jid.2013.36
View details for Web of Science ID 000321939300023
View details for PubMedID 23353989
Immunobiology of Merkel Cell Carcinoma: Implications for Immunotherapy of a Polyomavirus-Associated Cancer
CURRENT ONCOLOGY REPORTS
2011; 13 (6): 488-497
Merkel cell carcinoma (MCC) is an aggressive skin malignancy with a high mortality rate and an increasing incidence. The recent discovery of Merkel cell polyomavirus has revolutionized our understanding of MCC pathogenesis. Viral oncoproteins appear to play a critical role in tumor progression and are expressed in the majority of MCC tumors. Virus-specific humoral and cellular immune responses are detectable in MCC patients and are linked to the natural history of the disease. Despite persistent expression of immunogenic viral proteins, however, MCC tumors are able to evade the immune system. Understanding of the mechanisms of immune evasion employed by MCC tumors is rapidly increasing and offers opportunities for development of rational immune therapies to improve patient outcomes. Here we review recent discoveries in MCC with a special focus on the pathogenic role of Merkel cell polyomavirus and the immunobiology of this virus-associated disease.
View details for DOI 10.1007/s11912-011-0197-5
View details for Web of Science ID 000296881500009
View details for PubMedID 21953511
Identification and validation of a novel mature microRNA encoded by the Merkel cell polyomavirus in human Merkel cell carcinomas
JOURNAL OF CLINICAL VIROLOGY
2011; 52 (3): 272-275
Merkel cell polyomavirus (MCPyV) is present in approximately 80% of human Merkel cell carcinomas (MCCs). A previous in silico prediction suggested MCPyV encodes a microRNA (miRNA) that may regulate cellular and viral genes.To determine the presence and prevalence of a putative MCPyV-encoded miRNA in human MCC tumors.Over 30 million small RNAs from 7 cryopreserved MCC tumors and 1 perilesional sample were sequenced. 45 additional MCC tumors were examined for expression of an MCPyV-encoded mature miRNA by reverse transcription real-time PCR.An MCPyV-encoded mature miRNA, "MCV-miR-M1-5p", was detected by direct sequencing in 2 of 3 MCPyV-positive MCC tumors. Although a precursor miRNA, MCV-miR-M1, had been predicted in silico and studied in vitro by Seo et al., no MCPyV-encoded miRNAs have been directly detected in human tissues. Importantly, the mature sequence of MCV-miR-M1 found in vivo was identical in all 79 reads obtained but differed from the in silico predicted mature miRNA by a 2-nucleotide shift, resulting in a distinct seed region and a different set of predicted target genes. This mature miRNA was detected by real-time PCR in 50% of MCPyV-positive MCCs (n = 38) and in 0% of MCPyV-negative MCCs (n = 13).MCV-miR-M1-5p is expressed at low levels in 50% of MCPyV-positive MCCs. This virus-encoded miRNA is predicted to target genes that may play a role in promoting immune evasion and regulating viral DNA replication.
View details for DOI 10.1016/j.jcv.2011.08.012
View details for Web of Science ID 000296556800024
View details for PubMedID 21907614
Merkel Cell Polyomavirus-Specific CD8(+) and CD4(+) T-cell Responses Identified in Merkel Cell Carcinomas and Blood
CLINICAL CANCER RESEARCH
2011; 17 (21): 6671-6680
Merkel cell polyomavirus (MCPyV) is prevalent in the general population, integrates into most Merkel cell carcinomas (MCC), and encodes oncoproteins required for MCC tumor growth. We sought to characterize T-cell responses directed against viral proteins that drive this cancer as a step toward immunotherapy.Intracellular cytokine cytometry, IFN-γ enzyme-linked immunospot (ELISPOT) assay, and a novel HLA-A*2402-restricted MCPyV tetramer were used to identify and characterize T-cell responses against MCPyV oncoproteins in tumors and blood of MCC patients and control subjects.We isolated virus-reactive CD8 or CD4 T cells from MCPyV-positive MCC tumors (2 of 6) but not from virus-negative tumors (0 of 4). MCPyV-specific T-cell responses were also detected in the blood of MCC patients (14 of 27) and control subjects (5 of 13). These T cells recognized a broad range of peptides derived from capsid proteins (2 epitopes) and oncoproteins (24 epitopes). HLA-A*2402-restricted MCPyV oncoprotein processing and presentation by mammalian cells led to CD8-mediated cytotoxicity. Virus-specific CD8 T cells were markedly enriched among tumor infiltrating lymphocytes as compared with blood, implying intact T-cell trafficking into the tumor. Although tetramer-positive CD8 T cells were detected in the blood of 2 of 5 HLA-matched MCC patients, these cells failed to produce IFN-γ when challenged ex vivo with peptide.Our findings suggest that MCC tumors often develop despite the presence of T cells specific for MCPyV T-Ag oncoproteins. The identified epitopes may be candidates for peptide-specific vaccines and tumor- or virus-specific adoptive immunotherapies to overcome immune evasion mechanisms in MCC patients.
View details for DOI 10.1158/1078-0432.CCR-11-1513
View details for Web of Science ID 000296624000011
View details for PubMedID 21908576
Endogenous Wnt/beta-Catenin Signaling Is Required for Cardiac Differentiation in Human Embryonic Stem Cells
2010; 5 (6)
Wnt/beta-catenin signaling is an important regulator of differentiation and morphogenesis that can also control stem cell fates. Our group has developed an efficient protocol to generate cardiomyocytes from human embryonic stem (ES) cells via induction with activin A and BMP4.We tested the hypothesis that Wnt/beta-catenin signals control both early mesoderm induction and later cardiac differentiation in this system. Addition of exogenous Wnt3a at the time of induction enhanced cardiac differentiation, while early inhibition of endogenous Wnt/beta-catenin signaling with Dkk1 inhibited cardiac differentiation, as indicated by quantitative RT-PCR analysis for beta-myosin heavy chain (beta-MHC), cardiac troponin T (cTnT), Nkx2.5, and flow cytometry analysis for sarcomeric myosin heavy chain (sMHC). Conversely, late antagonism of endogenously produced Wnts enhanced cardiogenesis, indicating a biphasic role for the pathway in human cardiac differentiation. Using quantitative RT-PCR, we show that canonical Wnt ligand expression is induced by activin A/BMP4 treatment, and the extent of early Wnt ligand expression can predict the subsequent efficiency of cardiogenesis. Measurement of Brachyury expression showed that addition of Wnt3a enhances mesoderm induction, whereas blockade of endogenously produced Wnts markedly inhibits mesoderm formation. Finally, we show that Wnt/beta-catenin signaling is required for Smad1 activation by BMP4.Our data indicate that induction of mesoderm and subsequent cardiac differentiation from human ES cells requires fine-tuned cross talk between activin A/BMP4 and Wnt/beta-catenin pathways. Controlling these pathways permits efficient generation of cardiomyocytes for basic studies or cardiac repair applications.
View details for DOI 10.1371/journal.pone.0011134
View details for Web of Science ID 000278775900023
View details for PubMedID 20559569
View details for PubMedCentralID PMC2886114