Using Multiplex Testing to Unravel Responses to Acute and Chronic Viral Infections

The immune response to viral infections is essential for efficient clearance of acute infection, yet in chronic viral infections this response can lead to inflammation and immunopathology. Understanding the global immune response requires measurement of multiple parameters simultaneously, since the arms of the immune system are interconnected and do not operate in isolation. One of the limitations in assessing immune responses is availability of immune cells, which require specialized collection and cryopreservation, and access to sufficient volume of plasma or serum to assess multiple soluble analytes. Cytokines and chemokines make attractive targets for immune profiling given their role in intercellular signaling and their presence in the peripheral circulation. One solution that has been widely adopted in the last decade is multiplex testing, which allows a much more comprehensive assessment of protein expression than previously achievable.

The most valuable samples to test in understanding human disease are clinical samples obtained from study subjects with acute or chronic infections. However, one of the key limiting factors in testing animal or human clinical samples is that cytokine levels tend to be near the limit of detection in serum or plasma. This webinar will discuss how to build multiplex panels to maximize efficiency in testing human or animal samples in terms of cost and sample volume limitations. After construction of a candidate panel, validation is necessary and we will review a method to validate assay performance before testing valuable clinical specimens. Other potential limitations of clinical sample testing is the possibility of long-term storage or multiple freeze-thaw cycles of samples prior to testing, and the effect of these variables will be discussed. During testing, QC is necessary to control for assay performance and to monitor for batch testing effects, plate-to-plate variation, and lot-to-lot variation. Methods to monitor and control for these factors will be discussed.

Once testing is operational and validated, the power of multiplex testing allows insight into a variety of disease states. This presentation will focus on cytokine network evolution in acute viral infections, as well as how chronic inflammation associates with immune pathology in chronic viral infections. These data will serve as a template for how multiplex testing can be applied to the study of a variety of animal models and human diseases using ex vivo samples.

Speaker

Philip J. Norris, M.D., VP Research and Scientific Programs, Vitalant

Philip Norris, MD, is the VP of Research and Scientific Programs at Blood Systems Inc, and Director of Laboratory Sciences-SF for Blood Systems Research Institute (BSRI), a UCSF-affiliated research institute. He is also an Adjunct Professor of Laboratory Medicine and Clinical Professor of Medicine at the University of California, San Francisco. Dr. Norris earned his BA and BS degrees from the University of California, Berkeley, his MD degree from the College of Physician & Surgeons at Columbia University, and completed his residency in internal medicine at Duke University Medical Center and fellowship in infectious diseases at the Massachusetts General Hospital. Dr. Norris has received numerous academic awards and was the recipient of a Doris Duke Charitable Foundation Clinical Scientist Development Award in 2000. 

The Norris lab research interests focus on how the human immune system responds to viral infections and transfusion. Early efforts centered on defining how HIV-specific CD4+ T cells might contribute to control of viral infection. A second area of interest has been defining the earliest events of viral infections through study of subjects with HIV, West Nile virus, and hepatitis viruses. More recent projects include understanding how blood transfusion affects the immune system and modulates immune responses in transfusion recipients. 

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