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 About Oral BiologyNew Home     December 3, 2016  

Bobek, Libuse M.A., Ph.D. Professor Emeritus, Department of Oral Biology

109 Foster Hall
Buffalo, NY 14214

Research Profile

1. Antimicrobial activity/mechanism of action of salivary proteins/peptides
2. Regulation of salivary gland-specific gene expression

Many proteins and glycoproteins found in human saliva have protective functions critical for oral health. Our research concentrates on the following two areas of salivary research:
1. Structure-function relationship of MUC7 mucin (modulator of microbial interactions and clearance from the oral cavityand) and mechanism of antimicrobial action of MUC7-derived peptides. We have discovered that a low molecular weight salivary mucin (MUC7)-derived peptides exhibit potent and a broad-spectrum antimicrobial activities in vitro. This includes antifungal activity against clinical important fungal strains (such as Candida albicans and Cryptococcus neoformans, and their azole-resistant and amphotericin B-resistant counterparts) and antibacterial activity (including Streptococcus mutans, bacteria causing tooth caries). The observed potencies of these peptides are comparable to that of the currently used antimicrobial agents. Due to undesirable toxicity and the rapid development of drug-resistant strains to conventional antimicrobials, increased interest has been developed in the discovery and use of naturally occurring (non-toxic) antimicrobial peptides. The long-range goal of our research is to develop the novel salivary-derived peptides into effective antimicrobial therapeutic agents (particularly for drug-resistant infections (primarily in immunocompromised patients, e.g. AIDS and organ transplant patients). These peptides could also be used as antibacterial and antifungal components of artificial saliva for the treatment of salivary dysfunctions, clinically manifested by increase in plaque formation, caries and periodontitis.

2. To determine the mechanisms that control the regulation of salivary gland-specific gene expression. In particular, we are interested in the regulation of expression of the low molecular weigh human salivary mucin gene, MUC7 (including developmental role(s) of MUC7 gene, physiological and pathophysiological regulators; signal transduction pathways). Examination of the human MUC7 expression in vivo by transgenic mice technology showed that one transgenic mice line expresses MUC7 at high level and in the same tissue and cell specific manner as humans. We will use these mice for studies directed towards understanding the intracellular signaling and gene regulation mechanisms mediating mucin overproduction in response to clinically important insults (such as air pollution, gram-positive and gram-negative bacteria, and tobacco smoke). We are also utilizing normal human tracheo-bronchial epithelial cells to investigate the MUC7 expression under normal and pathological conditions in vitro, and we plan to develop salivary cell lines for these studies. Lastly, we plan to determine any qualitative and quantitative differences in the MUC7 transcripts and/or glycoprotein in normal human salivary glands versus benign and malignant salivary tumors (alterations in expression maybe exploited for cancer diagnostic and prognostic assessments).