Expression of host defence peptides in the lip vermilion mucosa during early infancy

Expression of cutaneous immunity markers during infant skin maturation

BACKGROUND/OBJECTIVES

Infant skin undergoes a maturation process during the early years of life. Little is known about the skin's innate immunity. We investigated the dynamics of innate immunity markers collected from the surface of infant skin during the first 36 months of life.

METHODS

A total of 117 healthy infants aged 3-36 months participated in the study. We extracted human beta defensin-1 and interleukin 1 alpha and its receptor antagonist using transdermal analysis patches from the skin surface of the posterior lower leg area. The extracts were analyzed using a spot enzyme-linked immunosorbent assay.

RESULTS

Skin surface human beta defensin-1 levels were higher early in life and decreased with infant age. The ratio of interleukin 1 alpha receptor antagonist to interleukin 1 alpha did not change significantly with age but showed a distinct difference between sexes, with female infants having higher values than male infants.

CONCLUSION

As is the case with skin structure and functional properties, cutaneous innate immunity also appears to undergo a maturation period during infancy, with innate immunity slowly declining as adaptive immunity takes over. Sex differences in immune markers may explain sex-dependent susceptibilities to infection.

Influence of gender on epithelial host defence peptide gene expression under non-infected and infected conditions: A basic medical research study

Bacterial resistance against conventional antibiotics is increasing. This introduces challenges, for example, in the treatment of infected surgical wounds. Host defence peptides (HDP), which are endogenous peptide antibiotics, show broad-spectrum antimicrobial effectiveness. They protect the organism against pathological microorganisms. Synthetic HDP might supplement or even become alternatives to conventional antibiotics. Knowledge of their quantities under physiological and pathophysiological conditions is therefore required. The influence of gender on HDP expression is unknown. This study evaluates whether gender influences HDP expression in infected or healthy epithelium. Expression levels of HDP human beta-defensin (hBD)-1, -2 and -3 and psoriasin (S100A7) were analysed, by using real-time polymerase chain reaction, in samples of epithelium from infected surgical wounds (n = 20) and healthy epithelium (n = 14) from the neck in a basic medical research study (analytic observational design). The results demonstrated a significantly elevated expression of hBD-2, hBD-3 and psoriasin (P = 0.001 each) in infected epithelium compared with healthy epithelium. No difference in HDP expression levels was evident between samples from female and male patients, either within infected samples or within healthy epithelium samples. Thus, gender does not affect the cutaneous expression of the investigated HDP. This is fundamental knowledge for the study and potential use of HDP derivates as alternative antibiotic substances.

Labial Salivary Glands in Infants: Histochemical Analysis of Cytoskeletal and Antimicrobial Proteins

Human labial glands secrete mucous and serous substances for maintaining oral health. The normal microbial flora of the oral cavity is regulated by the acquired and innate immune systems. The localization and distribution of proteins of the innate immune system were investigated in serous acinar cells and the ductal system by the method of immunohistochemistry. Numerous antimicrobial proteins could be detected in the labial glands: β-defensin-1, -2, -3; lysozyme; lactoferrin; and cathelicidin. Cytoskeletal components such as actin, myosin II, cytokeratins 7 and 19, α- and β-tubulin were predominantly observed in apical cell regions and may be involved in secretory activities.

Radiotherapy for oral cancer decreases the cutaneous expression of host defence peptides

INTRODUCTION

Bacterial resistance against antibiotics has become an increasing challenge in the treatment of cutaneous infections. Consequences can be severe, especially in infected wounds following previous local radiotherapy. Certain endogenous peptide antibiotics, the host defence peptides (HDPs), exhibit broad-spectrum antimicrobial activity and promote wound healing. Their use as supplements to conventional antibiotics is a current topic of discussion; however, knowledge of their quantities in healthy and compromised tissue is a prerequisite for such discussion. To date, no data concerning HDP quantities in irradiated skin are available.

METHODS

Expression profiles of the genes encoding HDPs, namely human beta-defensin-1 (DEFB1, hBD-1), beta-defensin-2 (DEFB4A, hBD-2), beta-defensin-3 (DEFB103, hBD-3) and S100A7, were assessed in samples of non-irradiated and irradiated neck.

RESULTS

A reduction in the expression of all of the examined genes was observed in irradiated skin when compared with non-irradiated skin (statistically significant in the case of S100A7, P = 0.013). Immunohistochemistry revealed differences in HDP distribution with respect to the epithelial layers.

CONCLUSION

The study demonstrates a significant reduction in HDP gene expression in neck skin as a result of radiotherapy. These findings might represent a starting point for novel treatments of cutaneous infections in irradiated patients, such as topical supplementation of synthetic HDP.