Rhinoviruses stimulate chemotaxis of peripheral lymphocytes from healthy and asthmatic subjects

Abstract
Respiratory viral infections caused mostly by rhinoviruses (RV) contribute to exacerbation of asthma. It was demonstrated that these viruses reach and penetrate also lower airways. At early stage of infection, infiltration of bronchial submucosa accompanied by peripheral lymphopenia and neutrophilia was found. The crucial importance for the course of RV-induced disease is the presence of RV antigens-specific T lymphocytes which are the first to undergo activation.
The study was performed on cells from 7 healthy subjects and 6 patients with stable, chronic asthma. The influence of live Human Rhinovirus Serotype 16 (HRV 16) (range of the titer 4x10²–10⁴ TCID₅₀/ml) on chemotaxis of lymphocytes and neutrophils was evaluated. Chemotaxis in response to nonspecific chemoattracttant fMLP was determined in parallel experiments.
It was found that HRV-16, at the titer 6x10³ TCID₅₀/ml, significantly increased chemotaxis of lymphocytes of healthy subjects (p<0.02) and asthmatics (p<0.001) whereas fMLP increased chemotaxis of lymphocytes of the patients only (p<0.001). Migration of neutrophils in fMLP gradient was significantly increased in both groups. RV had no influence on chemotaxis of neutrophils.
These results indicate the presence in circulation antigen-specific lymphocytes recognizing HRV-16 antigens. These lymphocytes may infiltrate airways most early after infection leading, in consequence, to peripheral lymphopenia.