Antigen resorption

The initial process of antigen resorption has thus been relatively well understood for almost a century however, the metabolic and/or immunological fate of large particles is a topic of more recent studies and the metabolic breakdown of Lycopodium spores and pollen of cultivated ryegrass only a few hours following resorption was first reported in 1974 [14], Figures 1-3 illustrate the degradation process of Lycopodium spores. 

The advent of oral/sublingual immunotherapy has redirected interest towards resorption of allergens from the oral mucosa. The resorption of small nonprotein molecules such as ethanol and nitro preparations from the oral mucosa is well known and the latter is arguably one of the most frequently used pharmacological interventions in clinical medicine. However, Passalacqua (fig. 6) was the first to demonstrate resorption of allergens from the oral and nasal mucosa. Parietaria antigen marked with radioactive iodine... 

Osteoclasts play a major role in bio-corrosion of orthopedic metal implants. Implant-derived metal ions enhance osteoclastic recruitment, maturation, survival and function. The metal ions also induce a peri-implant inflammation with accumulation of various immune cells. The metal ions form complexes with cellular proteins that become new antigens inducing allergenic reactions where T-lymphocytes play an essential role. Those immune cells produce various inflammatory cytokines that cause inflammation and pain. In addition, T-lymphocytes secrete RANK-L, an essential factor for osteoclast functions. Finally, the described mechanisms are probably responsible for a vicious cycle with enhanced peri-implant inflammation and pain, as well as enhanced osteoclastic bio-corrosion and peri-implant bone resorption culminating in implant loosening (Figure 3). 

---