MORPHOMETRIC AND ULTRASTRUCTURAL ANALYSES OF IN VIVO-ACTIVATED MURINELANGERHANS CELLS INDUCED BY ADMINISTRATION OF A STREPTOCOCCAL PREPARATION (OK-432)
H. Teramae et al., MORPHOMETRIC AND ULTRASTRUCTURAL ANALYSES OF IN VIVO-ACTIVATED MURINELANGERHANS CELLS INDUCED BY ADMINISTRATION OF A STREPTOCOCCAL PREPARATION (OK-432), Archives of dermatological research (Print), 290(10), 1998, pp. 533-539
Langerhans cells (LCs) are activated in the epidermis by external and
internal stimuli, such as antigens and cytokines, respectively. To rev
eal the morphologic and functional properties of in vivo-activated LCs
during inflammation, we injected the streptococcal preparation OK-432
intradermally into the earskin of mice and performed time-course anal
yses by immunofluorescence and electron microscopy, Cellular infiltrat
e appeared in the dermis at 6 h after OK-432 injection and had progres
sively extended to the dermoepidermal junction at 12 and 24 h, Immunos
taining for class II antigen revealed that LCs were enlarged and exten
ded long dendrites during inflammation. Acidic compartments such as ly
sosomes and multivesicular bodies also increased in number and Golgi a
pparatuses developed as demonstrated by electron microscopy and morpho
metric analysis. Birbeck granules, although not showing numerical chan
ges, were translocated from the Golgi area to the subplasmalemmal area
. After epicutaneous application of cationic ferritin, LCs often conta
ined endosomes as the result of engulfment by the cytoplasmic projecti
ons. The present results indicate that nonspecifically induced dermal
inflammation is capable of inducing activation of LCs in vivo, and tha
t in vivo-activated LCs have the capacity for active endocytosis and i
ntracellular digestion or processing.