233 Microbial Presentation at the Epithelial Linings: A Strategic Way to Promote the Generation of Immunity at Birth.

Abstract

Background: Epithelial linings in the human body are constantly populated by different microbes, an active process where innate immunity plays a pivotal role. We have previously reported that there is an upregulation of innate immunity in the skin of the healthy newborn infant. This event may be seen as a rash, known as Erythema Toxicum and is most probably a response to commensal skin colonization at birth. Now we postulated that the hair follicle immune system constitutes the physiologic room where microbes are presented to immune competent cells.

Design: Microbial cultures were collected from 70 healthy 1-day infants, skin punch-biopsies were analysed with transmission electron microscopy (TEM) and with immunohistochemistry by staining for Toll-like receptor (TLR) 2 and 4.

Results: We found that 84% of all of healthy 1-day old infants were colonized with coagulase-negative Staphylococci, remaining were positive for Staphylococcus aureus, Alfa-streptococcus, group B streptococcus and Enterococcus species.We also found that TLR 2 and TLR4 were expressed in the epidermis and in the epithelial layer of the hair follicle. In the lesions of Erythema Toxicum, TEM revealed microbe-like material into phagosomes of epithelial cells and into immune cell located in proximity to the hair follicles.

Conclusion: At birth, there is a penetration/presentation of commensal microbes at the epithelial linings. This exposure provides signals, possibly mediated by the TLRs, that alert the immune system and promotes a protective immune response.

Log in or create a free account to read this content

Gain free access to this article, as well as selected content from this journal and more on nature.com

Access through your institution

or

Sign in or create an account

Continue with Google

Continue with ORCiD