Sweating the small stuff: Glycoproteins in human sweat and their unexplored potential for microbial adhesion

Abstract

There is increasing evidence that secretory fluids such as tears, saliva and milk play an important role in protecting the human body from infection via a washing mechanism involving glycan-mediated adhesion of potential pathogens to secretory glycoproteins. Interaction of sweat with bacteria is well established as the cause of sweat-associated malodor. However, the role of sweat glycoproteins in microbial attachment has received little, if any, research interest in the past. In this review, we demonstrate how recent published studies involving high-throughput proteomic analysis have inadvertently, and fortuitously, exposed an abundance of glycoproteins in sweat, many of which have also been identified in other secretory fluids. We bring together research demonstrating microbial adhesion to these secretory glycoproteins in tears, saliva and milk and suggest a similar role of the sweat glycoproteins in mediating microbial attachment to sweat and/or skin. The contribution of glycan-mediated microbial adhesion to sweat glycoproteins, and the associated impact on sweat derived malodor and pathogenic skin infections are unchartered new research areas that we are beginning to explore.

Differential involvement of glycans in the binding of Staphylococcus epidermidis and Corynebacterium spp. to human sweat

“…confirmed the presence of many glycoproteins, consistent with the results of previous analyses (Park et al, 2011;Peterson et al, 2016;Raiszadeh et al, 2012). The most abundant glycoproteins were Prolactin-inducible protein, Apolipoprotein D, Clusterin, Zinc alpha-2-glycoprotein, Immunoglobulin A1, and Cathepsin (Supplementary Table 1 provides the proteomic profiles of four typical sweat samples).…”

“…Sweat, the secretory fluid that regularly bathes human skin, provides some protection for the skin via at least components such as antimicrobial peptides and salts (Park et al, 2011). Our recent review (Peterson et al, 2016) has revealed that sweat also contains secreted glycoproteins that seem likely to play a role in providing molecular decoys for microbial adhesion as discovered in other…”

Wearable electrochemical biosensors to measure biomarkers with complex blood-to-sweat partition such as proteins and hormones

“…The exocytic mechanism mobilizes the cytoplasmic vesicles to sites on the plasma membrane, where the vesicular content is released to the extracellular space. On the other hand, the apical part of cells, at the apocrine sweat glands, are pinched off, leading to the release of the cytoplasm and cell membrane joined to the secretory materials (e.g., glycoproteins) [ 35 ]. Thus, the protein's partition rate into the sweat will be slower than ions.…”

“…While more studies are necessary to determine the standard or basal levels of proteins in the sweat according to the activity level and the type of sweat gland that produces it, all the commented researches suggest that the ideal sweat sample should come from a unique type of sweat gland. The significant quantity of secreted sweat comes from eccrine glands [ 35 ], probably the best candidates to be tested.…”

Potassium Aluminium Sulphate (Alum) Inhibits Growth of Human Axillary Malodor-Producing Skin Flora in Vitro

“…Alum (molecular formula: KAl(SO 4 ) 2 .12H 2 O) is a colourless, odorless crystalline solid that turns white in air [8]. The medical uses of alum in mouth rinses, vaccines development, haemostasis and inhibition of V. cholerae growth in water have been described [9][10][11][12]. However, to date there is no study on the effect of alum salt against bacterial skin flora.…”