Affiliations: [a] Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran | [b] Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran | [c] Department of Immunology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran | [d] Monoclonal Antibody Research Center, Avicenna Research Institute, ACECR, Tehran, Iran
Correspondence:
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Corresponding author: Mehdi Yousefi, Department of Immunology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran. Tel.: +98 4133364665; Fax: +98 4133364665; E-mail:Yousefime@tbzmed.ac.ir
Abstract:
BACKGROUND: Tetanus neurotoxin (TeNT) is composed of a light (LC)
and heavy chain (HC) polypeptides, released by anaerobic bacterium
Clostridium tetani and can cause fatal life-threatening infectious disease. Toxin HC and LC
modules represents receptor binding and zinc metalloprotease activity,
respectively. The passive administration of animal-derived antibodies
against tetanus toxin has been considered as the mainstay therapy for years.
However, this treatment is associated with several adverse effects due to
the presence of anti-isotype antibodies. OBJECTIVE: In the present study, we have produced the fully human
single chain antibody fragments (HuScFv) from two human antibody phage
display libraries. MATERIAL AND METHODS: Twenty-four different HuscFvs were isolated from two
anti TeNT immune libraries. Our produced human ScFv (HuScFv) were converted
to IgG platform and analyzed regarding their specific reactivity to TeNT. RESULTS: All of the selected scFvs have the same VL but different
VH. Three HuscFvs from the first library (TTX15, 51, 75) and two HuscFvs
from the second library (TTX16, 20) were chosen to convert to IgG1 using
pOptiVEC and pcDNA3.3 systems. Production of IgG1 from transfected DG44 and
binding capacity of them to tetanus toxin and toxoid were measured by ELISA.
ELISA results showed no detectable production of TTX16 and TTX20 IgG1.
Although, TTX51 and TTX75 were converted and produced as IgG1, no
reactivity to tetanus toxin and toxoid was observed. However, TTX15 was
successfully produced as whole IgG1 platform with reactivity to both tetanus
toxin and toxoid. The latter would be an appropriate replacement for
conventional polyclonal antibodies if would meet the further
characterization including specificity determination, affinity measurement
and toxin neutralizing assays. CONCLUSION: Our results demonstrated production of functional IgG1
derived from TTX15 scFv and might be an appropriate replacement for
polyclonal Tetabulin but it needs further characterization.
