The basal level of influenza specific antibody-secreting cells in healthy subjects

Abstract

Background: In the absence of true efficacy markers, the serum haemagglutination inhibition titre has been correlated with protection against influenza infection. Serum antibody does not, however, play a direct role in protection against infection. Two important factors that may be involved in protection against influenza infection are the number of influenza specific activated B-cells and the specificity of the secreted antibodies in the epithelial mucosa of the respiratory tract. Methods: Nineteen patients scheduled for tonsillectomy were enrolled in this study. Tonsils, blood, saliva and a biopsy from the inferior turbinate in the nasal cavity were collected from the patients. None of the patients had been infected or vaccinated with influenza in the previous year. ELISPOT and ELISA assays were used to examine the basal level of antibody-secreting cell (ASC) levels and antibodies in the collected samples, respectively. Results: We found low numbers of influenza specific ASC in the blood and tonsils, but there were much higher numbers of specific ASC in the nasal tissue despite no recent influenza exposure or vaccination. Conclusion: We found antibody-secreting B-cells in the nasal mucosa tissue, which probably results in secretion of specific antibody at the surfaces and protection from influenza infection.