Kiera Clayton, PhD - Principal Investigator

After receiving her Honors BSc in Biochemistry at the University of Toronto, she completed her PhD in Immunology under the supervision of Dr. Mario Ostrowski, working on Tim-3 regulation of immune responses during HIV infection. In 2015, she joined Dr. Bruce Walker’s lab at the Ragon Institute of MGH, MIT and Harvard, where she showed that HIV-infected macrophages were resistant to killing by CTL and NK cells. In July of 2021, she moved to UMass Medical School’s Department of Pathology to start the lab, focused on macrophages as hide outs for pathogens and methods used by these cells to evade killer immune responses.


Paula Grasberger - Graduate Student

Paula is a PhD student in the Clayton lab. After receiving her BSc in Biology from Tufts University, she worked in the lab of Andy Tager at Massachusetts General Hospital studying idiopathic pulmonary fibrosis. Paula next transitioned to industry and worked in immuno-oncology and targeted oncology at KSQ Therapeutics, before making her way to UMass for her PhD. Her research in the Clayton Lab will focus on identifying and targeting mechanisms of HIV-infected cell resistance to killing by cytotoxic T lymphocytes and NK cells as part of the Martin Delany REACH Collaboratory.When she’s not in the lab, Paula enjoys skiing, climbing, kiteboarding, and competitive sailing. She also likes spending time with her two cats and doing crossword puzzles.


Michelle Pan - Undergraduate Intern

Michelle is an undergraduate student at Worcester Polytechnic Institute studying biology & biotechnology. She is interested in understanding and managing human health diseases and hopes to pursue her PhD following her graduation in 2023. Her research in the Clayton lab focuses on determining how infected macrophages evade natural killer cell antibody-dependent cellular cytotoxicity (ADCC) elimination. In her free time, she enjoys playing tennis, hiking, cooking and water-coloring.


Abby Sondrini - Research Associate

Abigail is a Research Associate in the Clayton lab. She recently graduated from UMass Amherst, where she received her BS in microbiology. In her undergraduate, she worked with soil microbes, studying bacterial genomics in Dr. Kristen DeAngelis’ Lab. Abigail is interested in pursuing graduate school and continuing her career in the field of research. Her research in the Clayton lab focuses on characterizing mechanisms through which HIV-infected macrophages evade CTL-mediated killing. Outside of the lab, you can find Abigail spending time with her family and her dog Mavis, exploring skincare, and reading dystopian novels.


Mika O'Shea - Research Associate

Mika is a Research Associate in the Clayton lab. After graduating from Occidental College with a BA in Cell & Molecular Biology, she received her MS in Infectious Disease and Global Health from Cummings School of Veterinary Medicine at Tufts University. Her research in the Clayton lab focuses on identifying natural granzyme inhibitors that may be differentially expressed in macrophages and CD4+ T cells, allowing HIV-infected macrophages to evade CTL-mediated killing. Outside of the lab, she enjoys weightlifting, playing the bass, and spending time with her one-eyed cat Tobi.

Contact: Mika.O'

Patrick Kao - Postdoctoral Fellow

Patrick completed his undergrad and master education in Taiwan before heading to Nanyang Technological University in Singapore to pursue PhD degree. His research background focuses on immunology, ranging from sterile inflammation to asthma, as well as infectious diseases. For his current project, I’ll be studying the resistance of Mtb-infected macrophages against NK cell-mediated killing. In my free time, I enjoy playing basketball and watching movies.


Join the Clayton Lab! - we are actively recruiting for all positions

Graduate Students - Those interested in graduate school can apply to the University of Massachusetts Graduate School of Biomedical Sciences ( We are currently accepting rotation students staring in the Fall of 2022 and Winter of 2023

Postdoctoral Fellow

We are looking for talented and motivated Postdocs! Available research projects include differentiation of microglia from different myeloid precursors, characterizing HIV infection in human microglia, characterization of NK cells that differentially respond to CD4+ T cells versus macrophages, assessing NK cell interactions with Ebola virus and cytomegalovirus-infected macrophages (collaboration with Boston University and Tim Kowalik at UMass, respectively), enhancement of antibody-dependent cellular cytotoxicity (ADCC) towards HIV-infected macrophages (a collaboration with the University of Miami) and others. Experimental methods related to these projects include HIV infections with primary immune cells, cellular co-culture assays, flow cytometry and FACS analysis, RNA-Seq, CRISPR editing of immune cells, deep sequencing of HIV variants, custom antibody production and purification, and molecular cloning of mutant viruses. The ideal candidate for this position would have a PhD and lab experience in immunology, virology, and biochemistry, and an interest in a career in industry or academia. In addition to laboratory activities, attendance at national/international conferences, contributions towards manuscript preparation and fellowship/grant writing is encouraged. A minimum time commitment of two years will be required. If interested, please send a cover letter and CV to Dr. Kiera Clayton at