Vaccine and Infectious Disease Organization -
International Vaccine Centre

Neonatal mucosal immunity

Project Team: Philip Griebel, Natasa Arsic, Paola Elizalde, Antonio Facciuolo, Angela Howell, Nilusha Malmuthuge

The immune system has two major induction and effector mechanisms, innate and adaptive immunity. Adaptive immunity includes both humoral (antibody) and cellular (activated T-cells) responses and is defined by exquisite antigen specificity driven by gene rearrangements. In contrast, innate immunity is either constitutively active or rapidly activated, works through nonrearranging receptors (e.g. Toll-like receptors), that recognize conserved microbial signature molecules (PAMPs), and is relatively non-specific. Activation of innate immunity may be particularly dangerous at mucosal surfaces if inflammation disrupts life-sustaining functions. Therefore, it is critical to understand the regulation of both innate and acquired mucosal immunity when investigating host-pathogen interactions and developing therapeutic strategies, such as vaccines, to enhance mucosal immune defences.

The primary objective of the neonatal mucosal immunity project is to use a variety of genomic and proteomic tools to characterize the role of specific mucosal cell populations and genes in regulating innate and adaptive mucosal immune responses during the critical neonatal period. Model systems being used to analyze innate and acquired immunity include using surgically isolated intestinal segments to selectively alter the gut microbiome or target enteric infection or vaccines to specific mucosal sites. The role of stress in regulating innate mucosal immune responses and the microbiome is also being investigated through the use of various psychological and physical stressors.