No abstract

Tonsils are believed to play an important role during the development of the immune system. Although diseases of the tonsils like hypertrophy of the tonsil, acute tonsillitis, chronic tonsillitis or peritonsillar abscess are common, little is known about the underlying pathophysiology. Little is known about antimicrobial peptides produced by the tonsils. The human beta-Defensins 1-3 (hBD1-3) are naturally produced "antibiotics" with antimicrobial activity against different bacteria, fungi, and viruses. The objective of the study was to determine the concentrations for hBD1-3 in different states of diseases of the tonsilla palatina. After tonsillectomy and tissue fixation in formalin, total proteins were isolated from 38 samples (11 hypertrophy of the tonsil, 8 acute tonsillitis, 11 chronic tonsillitis, 8 peritonsillar abscesses). The protein concentration was determined and ELISA for hBD1-3 were performed. We also conducted immunofluorescence double stainings for the co-expression of streptococcus group A and hBD1-3. We could verify a significant difference for the mean hBD1 score of the acute tonsillitis in comparison to the hyperplastic tonsil, the chronic tonsillitis, and the peritonsillar abscess. There was no statistically significant difference in the hBD2 and hBD3 concentrations between the four groups. The immunofluorescence stainings showed that hBD1-3 and the streptococcus group A in the same place. We conclude that in the hyperplastic tonsilla palatina hBD1-3 play an important role. The mouth is constantly faced with a high bacterial load. During a tonsillitis, the hBD1 concentration is lower than in the non-acute infected tonsil because hBD1 is being consumed for fighting the bacterial infection. But, the existence of hBD1-3 in the tonsil cannot prevent the tonsillitis to become chronic.

Introduction Antimicrobial peptides (AMP)Generally speaking surfaces like the skin or the oral mucosa are protected by several factors including the adaptive and innate immune systems against invading bacteria and fungi. The antimicrobial mucosal shield of the human airways has been subject of several studies and is well investigated [1][2][3]. A growing number of different human antimicrobial peptides (AMP) have been described which are produced e. g. by surface epithelial cells or by neutrophil granulocytes. The AMPs have a broad, but not identical spectrum of antimicrobial activity against bacteria, virus or fungi. A synergistic and additive effect of different AMPs has been reported [4]. In addition to their antimicrobial charactics, AMPs play a major part in inflammation, immune activation, and wound healing [5][6][7]. Some of the well described AMPs are subject to this study and therefore will be further described. The human ß-Defensins (hBD)The family of human ß-Defensins (hBD) is named after their beta-sheet structure which is stabilised by intramolecular disulfide bonds. Human ß-Defensin 1 (hBD1) was first isolated from hemofiltrate [8] and is expressed in epithelial cells of the urinary, respiratory tract and in keratinocytes [9][10]. It has a strong antimicrobial effect on Gram-negative bacteria [11][12]. Human ß-Defensin 2 (hBD2) is an inducible (by Escherichia coli, Pseudomonas aeruginosa, Helicobacter pylori, Lipoprotienacid, Candida albicans, TumorNecrosis-Factor-α, Interleucine1-ß) peptide [13][14][15] with a strong antimicrobial effect on Escherichia coli, Pseudomonas aeruginosa and Candida albicans, and a relatively weak effect on Staphylococcus aureus [13]. The human ß-Defensin 3 (hBD3) can be induced by tumor necrosis factor α and contact with Pseudmonas aeruginosa or Staphalyococcus aureus e. g. in keratinocytes [16]. HBD3 has antimicrobial activity against Staphylococcus aureus, including Methicillin restistant Staphylococcus aureus (MRSA), Streptococcus pyogenes, Pseudomonas aeruginosa, Escherichia coli, Vancomycin-resistant Enterococcus faecium, Candida albicans and Haemophilus influenza [9; 12; 17]. Human LL-37 (LL-37)LL-37 is the 37-amino acid long C-terminus and the antimicrobial active component of the human Cathelicidin antimicrobial peptide 18 (hCAP-18). It is expressed in leukocytes (monocytes, neutrophiles, T-cells, B-cells), epithelial cells (skin, gastrointestinal and respiratory tract) and secreted into wound and airway surface fluid [18][19][20][21]. LL-37 alone and in combination with other AMPs is bactericidal against a broad spectrum of [21][22][23]. Apart from the antimicrobial activity LL-37 plays a role in angiogenesis, cancer development, neutralisation of bacterial lipopolysaccharide and is chemotactic for human monocytes, neutrophils and CD 4 T-lymphocytes [24-26.]. Human Secretory Leucoprotease Inhibitor (hSLPI)hSLPI is a 11.7-kDa heavy protein which is expressed in macrophages, neutrophils and epithelial cells [27-28.].The antimicrobial activity against Gram-negativ...