Intracellular antibody immunity and its applications

Mechanism of action of IC 100, a humanized IgG4 monoclonal antibody targeting apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC)

“…Antibodies are taken up by cells by binding to receptors like the neonatal fragment crystallizable region (Fc) receptor, and the polymeric Ig receptor in endosomal compartments. 24 These receptors play a role in recycling, transport through the cell, transcytosis, and redistribution of antibodies back into serum. 24 To determine if IC 100 internalization was mediated by the Fc region of the antibody, we generated Fab fragments of IC 100 and labeled them with Alexa Fluor-488.…”

“… 24 These receptors play a role in recycling, transport through the cell, transcytosis, and redistribution of antibodies back into serum. 24 To determine if IC 100 internalization was mediated by the Fc region of the antibody, we generated Fab fragments of IC 100 and labeled them with Alexa Fluor-488. The labeled Fab fragments were first evaluated by ELISA to establish if the binding affinity was altered during the enzymatic digestion processes.…”

Anti-neuronal antibodies against brainstem antigens are associated with COVID-19

“… 39 Moreover, the three neuronal antigens DAB1, AIFM1, and SURF1 are intracellular proteins and the main mechanism of AB internalisation mediating intracellular immunity shows higher affinity for IgG. 40 These data suggest that in critically ill COVID patients immature B-cells recognise the three predicted auto antigens with subsequent class-switch and affinity maturation resulting in potentially pathogenic high affinity IgG. The latter may then affect the three neuronal antigens DAB1, AIFM1, and SURF1 and associated brainstem and cognitive functions.…”