Pattern recognition in the immune system

Specific peptide recognition Antibody epitopes T-cell receptors recognizing peptides presented on MHC-molecules

Other types of recognition MHC subclasses and levels – NK cells Lipid antigens – NK T cells Sugars, glycoproteins and nucleic acids – complement, B cells, T cells, dendritic cells, macrophages etc. Unknown receptor/ligand interactions and signalling pathways

NK cells and KIR Major class of stimulatory and inhibitory receptors: Killer-Immunoglobulin-like receptors (KIRs)

Different KIRs recognize different MHC I

KIR-MHC combinations and disease

Recognition of glycolipids MHC-like molecules (CD1d) on antigen presenting cells present glycolipids to NK T cells with an invariant T cell receptor Which ligands are recognized (self/foreign?)

Recognition of ”pathogenicity” Direct recognition of pathogens – ”danger signals” (viral, bacterial, fungal, parasitic)  Innate immune system alerts the adaptive immune system in parallel with antigen- presentation (3. signal = cytokines)

Pattern recognition receptors must recognize structures vital to the pathogen! Pathogen-associated molecular patterns

Complexity in receptor cooperation poorly understood i.e. TLRs, C-type lectins, complement  Need for immunological bioinformatics!