Antibody complementarity-determining regions (CDRs): a bridge between adaptive and innate immunity
Elena Gabrielli1, Eva Pericolini, Elio Cenci
1Microbiology Section, Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia, Italy.
Background:
It has been documented that, independently from the specificity of the native antibody (Ab) for a given antigen (Ag), complementarity determining regions (CDR)-related peptides may display differential antimicrobial, antiviral and antitumor activities.
Methodology/Principal Findings:
In this study we demonstrate that a synthetic peptide with sequence identical to V(H)CDR3 of a mouse monoclonal Ab (mAb) specific for difucosyl human blood group A is easily taken up by macrophages with subsequent stimulation of: i) proinflammatory cytokine production; ii) PI3K-Akt pathway and iii) TLR-4 expression. Significantly, V(H)CDR3 exerts therapeutic effect against systemic candidiasis without possessing direct candidacidal properties.
Conclusions/Significance:
These results open a new scenario about the possibility that, beyond the half life of immunoglobulins, Ab fragments may effectively influence the antiinfective cellular immune response in a way reminiscent of regulatory peptides of innate immunity.
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