Activation of vitamin D in the gingival epithelium and its role in gingival inflammation and alveolar bone loss.

Background And Objective: Both chronic and aggressive periodontal disease are associated with vitamin D deficiency. The active form of vitamin D, 1,25(OH) D , induces the expression of the antimicrobial peptide LL-37 and innate immune mediators in cultured human gingival epithelial cells (GECs). The aim of this study was to further delineate the mechanism by which vitamin D enhances the innate defense against the development of periodontal disease (PD).

Potent in vitro and in vivo antifungal activity of a small molecule host defense peptide mimic through a membrane-active mechanism.

Lethal systemic fungal infections of Candida species are increasingly common, especially in immune compromised patients. By in vitro screening of small molecule mimics of naturally occurring host defense peptides (HDP), we have identified several active antifungal molecules, which also exhibited potent activity in two mouse models of oral candidiasis. Here we show that one such compound, C4, exhibits a mechanism of action that is similar to the parent HDP upon which it was designed.

Identification of unstimulated constitutive immunocytes, by enzyme histochemistry, in the coenenchyme of the octocoral Swiftia exserta.

Most animals rely on circulating hemocytes as cellular effectors of immunity. These cells traditionally have been characterized by morphology, function, and cellular contents. Morphological descriptions use granule differences and cell shapes; functional descriptions rely on phagocytic ability and oxygen transport; and cellular content descriptions include cytochemical features and key enzymes.

Natural Peptide antibiotics from tunicates: structures, functions and potential uses.

Because tunicates rely on innate immunity, their hemocytes are important contributors to host defense. Styela clava, a solitary ascidian, have eight hemocyte subtypes. Extracts of their total hemocyte population contained multiple small (2-4 kDa) antimicrobial peptides.

Plicatamide, an antimicrobial octapeptide from Styela plicata hemocytes.

Plicatamide (Phe-Phe-His-Leu-His-Phe-His-dc Delta DOPA), where dc Delta DOPA represents decarboxy-(E)-alpha,beta-dehydro-3,4-dihydroxyphenylalanine, is a potently antimicrobial octapeptide from the blood cells of the solitary tunicate, Styela plicata. Wild type and methicillin-resistant Staphylococcus aureus (MRSA) responded to plicatamide exposure with a massive potassium efflux that began within seconds. Soon thereafter, treated bacteria largely ceased consuming oxygen, and most became nonviable.

Immunolocalization of clavanins in Styela clava hemocytes.

Antimicrobial peptides play an important role in innate host defenses against infection. Clavanins are histidine-rich, amidated, 23-residue alpha-helical antimicrobial peptides that were isolated from a mixed population of Styela clava hemocytes. To learn which types of hemocytes contained clavanins, we raised a polyclonal antibody that recognized five different clavanins, and used it to localize these peptides by light and electron microscopy.