Adjuvant effect of Bacillus firmus on the expression of cytokines and toll-like receptors in mouse nasopharynx-associated lymphoid tissue (NALT) after intranasal immunization with inactivated influenza virus type A

Due to the persisting threat of development of new highly pathogenic influenza A subtypes a mucosal vaccination which would induce a potent and cross-protective reaction is desirable We succeeded in mucosal immunization of mice with an inactivated influenza A virus by using delipidated Bacillus firm us (DBF) as adjuvant The mechanism of adjuvant effect was followed in NALT by comparing the response after intranasal immunization by inactivated influenza virus type A (HI NI) alone adjuvant alone (DBF) or by a mixture of virus + DBF Expression of selected gene groups was tested via qPCR at 7 different time-points cytokmes (IL-2 IFN-gamma 1L-4 IL-6 and IL-10) type I interferons (IFN-alpha 4 IFN-alpha 11 IFN-alpha 12 and IFN-beta) toll-like receptors (TLR2 TLR3 TLR7 and TLR9) iNOS and CCR7 Intranasally administered DBF and the mixture of virus + DBF induced an elevated expression of IFN-gamma IL-6 and IL-10 cytokines type I interferons iNOS and pDC markers in NALT Multimarker qPCR data was analyzed by relative quantification and by principal component analysis DBF has been shown to be a very efficient adjuvant for the stimulation of innate immunity after IN immunization DBF accelerated increased and prolonged the antiviral response (C) 2010 Elsevier B V All rights reserved