A newly discovered function of palatine tonsils in immune defence: the expression of defensins

The palatine tonsils have an undoubted role in the immune defence system. After antigen contact an effective adaptive immune response by B- and T-cell lymphocytes will be released. In addition the palatine tonsils seem to exert influence to the defence by the innate immune system. Therefore, we studied the ability of palatine tonsils to express different alpha and beta defensins and to find out any distinctions in chronic inflamed tonsils. Total RNA of 49 specimens of hyperplastic tonsils and chronic tonsillitis with pathological provided evidence of Actinomyces israelii was isolated using TRIzol protocol, reverse transcribed and the HNP-1, HNP-4, HBD-1 and HBD-2 gene expression densitometric determined, standardised in relation to glycerinaldehyd-3-phosphatdehydrogenase gene expression, after a semiquantitative polymerase chain reaction was performed. mRNA of HNP-1, HNP-4, HBD-1 and HBD-2 was detected in tissue samples, but their amount differed within the two defensin families and tissue of origins. HBD-1 was detected in all 49 tissues of hyperplastic tonsils and chronic tonsillitis. Only in chronic inflamed tonsils the amount of HBD-2 mRNA expression was significant increased. In these specimens also mean relative expression rate of all defensins was observed to be manifestly increased. Palatine tonsils express mRNA for different alpha and beta defensins and this expression suggest a newly supposed function in immune defence: the participation in the innate, non-adaptive immune system. Thus, palatine tonsils have a potentially influence in the growth and control of the physiological mouth bacteria by their bactericidal activity.