Salivary histatins in human deep posterior lingual glands (of von Ebner).
OBJECTIVE
Human saliva contains a family of low molecular weight histidine-rich proteins, named histatins, characterised by bactericidal and fungicidal activities in vitro against several microbial pathogens, such as Streptococcus mutans and Candida albicans. They represent a major component of an innate host non-immune defense system. In an earlier study we described the distribution of histatins in the glandular parenchyma of human major salivary glands, confirming that all human major salivary glands are involved in the secretion of histatins into saliva. In the present study we determined the expression and localisation of histatins in human posterior deep lingual glands (von Ebner's glands) by means of immunoelectron microscopy.


METHODS
Thin sections of normal human salivary glands, embedded in Epon resin, were incubated with rabbit polyclonal antibodies specific for human histatins and successively with a gold conjugated goat anti-rabbit IgG used as secondary antibody. Sections incubated with medium devoid of primary antibody or containing non-immune serum were used as controls.


RESULTS
The serous secreting cells represented the main source of histatins in the glandular parenchyma of von Ebner's glands. At the electron microscopic level, labeling was associated with rough endoplasmic reticulum, Golgi complex and secretory granules that represented the main cytoplasmic site of histatin localisation. However, variability in the intensity of labeling was observed among adjacent cells.


CONCLUSIONS
The present results show for the first time that human von Ebner's glands produce and represent a significant source of histatins, supporting the hypothesis of their important role in preventing microbial assaults on the tissues in the posterior region of the tongue and in the circumvallate papillae.
Piludu
Marco
M
Dipartimento di Citomorfologia, Università Degli Studi di Cagliari, Cagliari, Italy. mpiludu@unica.it <mpiludu@unica.it>
Lantini
Maria Serenella
MS
Cossu
Margherita
M
Piras
Monica
M
Oppenheim
Frank G
FG
Helmerhorst
Eva J
EJ
Siqueira
Walter
W
Hand
Arthur R
AR
D004721:Endoplasmic Reticulum / Q000737:chemistry; D005260:Female; D006056:Golgi Apparatus / Q000737:chemistry; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D016253:Microscopy, Immunoelectron / Q000379:methods; D008875:Middle Aged; D011506:Proteins / Q000032:analysis*; D012470:Salivary Glands, Minor / Q000737:chemistry*; D012471:Salivary Proteins and Peptides / Q000032:analysis*; D000099053:Histidine-Rich Glycoprotein
D011506:Proteins; D012471:Salivary Proteins and Peptides; D000099053:Histidine-Rich Glycoprotein