In vitro activity of a monoclonal killer anti-idiotypic antibody and a synthetic killer peptide against oral isolates of Candida spp. differently susceptible to conventional antifungals.
OBJECTIVE
A monoclonal killer anti-idiotypic antibody (mAbK10) and a synthetic killer peptide, acting as internal images of a microbicidal, wide-spectrum yeast killer toxin (KT) have been recently shown to express candidacidal in vitro and an in vivo therapeutic activity against experimental mucosal and systemic candidosis models caused by a reference strain of Candida albicans (10S).


METHODS
The in vitro candidacidal activity of mAbK10 and synthetic killer peptide was compared using a colony forming unit assay against a large number of isolates of different Candida spp., obtained from oral saliva of adult diabetic (type 1 and 2) and nondiabetic subjects from Parma (Italy) and London (UK).


RESULTS
Both the KT-mimics exerted a strong dose-dependent candidacidal activity, probably mediated by the interaction with beta-glucan KT receptors on target yeast cells, against all the tested strains, regardless of their species and pattern of resistance to conventional antifungal agents.


CONCLUSIONS
These observations open new perspectives in the design and production of candidacidal compounds whose mechanism reflects that exerted in nature by killer yeasts.
Manfredi
M
M
Oral Medicine, Division of Infection and Immunity, Eastman Dental Institute, UCL, University of London, UK.
McCullough
M J
MJ
Conti
S
S
Polonelli
L
L
Vescovi
P
P
Al-Karaawi
Z M
ZM
Porter
S R
SR
D000328:Adult; D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000494:pharmacology*; D000908:Antibodies, Fungal / Q000494:pharmacology*; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D000935:Antifungal Agents / Q000494:pharmacology*; D002175:Candida / Q000187:drug effects* / Q000276:immunology; D015169:Colony Count, Microbial; D003920:Diabetes Mellitus / Q000276:immunology; D004305:Dose-Response Relationship, Drug; D015195:Drug Design; D006801:Humans; D055646:Killer Factors, Yeast; D008826:Microbial Sensitivity Tests; D009183:Mycotoxins / Q000494:pharmacology*; D015202:Protein Engineering; D051381:Rats; D011994:Recombinant Proteins / Q000494:pharmacology; D012463:Saliva / Q000382:microbiology
D000888:Antibodies, Anti-Idiotypic; D000908:Antibodies, Fungal; D000911:Antibodies, Monoclonal; D000935:Antifungal Agents; D055646:Killer Factors, Yeast; D009183:Mycotoxins; D011994:Recombinant Proteins; C087906:killer toxin, Pichia