CCL5 persists in RSV stocks following sucrose-gradient purification

Abstract

Respiratory syncytial virus (RSV) is associated with bronchiolitis in infancy and the later development of asthma. Research on RSV in vitro requires preparation of a purified RSV stock. The objective for this work was to develop best methods for RSV purification, while monitoring the samples for potential contaminating proinflammatory mediators. Using polyethylene glycol concentration, and sucrose‐gradient ultracentrifugation, we collected samples at each step of purification and measured the values of RSV titer, total protein (µg/mL), and proinflammatory cytokines (ELISA). We analyzed the efficacy of each step in the purification procedure. In so doing, we also determined that despite optimal purification methods, a well‐known chemokine in the field of allergic disease, CCL5 (RANTES), persisted within the virus preparations, whereas other cytokines did not. We suggest that researchers should be aware that CCL5 appears to co‐purify with RSV. Despite reasonable purification methods, a significant level of CCL5 (RANTES) persists in the virus preparation. This is relevant to the study of RSV‐induced allergic disease.

Binding of respiratory syncytial virus particles to platelets does not result in their degranulation in vitro

“…However, upon further inspection, these molecules turned out to originate from the virus stocks and were thus in fact not platelet-derived. Interestingly, others have previously also shown co-purification of host proteins with RSV, speculating that these were either virion-associated or carried within extracellular vesicles [28, 29]. These findings highlight the importance of including proper controls when working with cell-culture-derived materials such as virus stocks.…”