Investigation of the Effect of PEG Detoxification on Diphtheria Vaccine.

Immunization has been considered a successful global health program that saves many persons' lives each year. The vaccines reduce the risk of getting the disease by building immunity in the body. Therefore, the constant availability of essential vaccines is an important factor in community health. One of the most important vaccines is the diphtheria vaccine, which is usually used as Multivalent diphtheria-tetanus-pertussis (DTP) combination vaccines. The production of this vaccine takes about 45 days, from the initial bacterial culture to the end of toxin production. However, the production of this vaccine can be optimized in case the production stages are carried out under normal conditions. In this study, a significant amount of impurities was removed after washing with phosphate buffer saline, and the toxin was then purified by Sephadex G-50. In this method, the toxin was concentrated to be stored in a smaller space (this removes the concerns for the provision of a suitable space). Another problem with the diphtheria vaccine is that it is reversible after detoxification of the toxin using formaldehyde. For this reason, it is suggested to use MPEG for detoxification, which will produce more stable covalent bonds between PEG and the first type of amine groups in the toxin chain. Tests were performed to evaluate factors, such as in vivo cytotoxicity, lack of edemas formation, the neutralizing activity of serum from guinea pigs immunized with the diphtheria toxoid inactivated with MPEG, and the immunogenic activity of the purified and modified toxin. Comparison of this PEG detoxification toxoid with the standard toxoid produced in Razi Vaccine and Serum Institution, Karaj, Iran, showed that washing with PBS and purification with Sephadex G-50 was an efficient method. The stability and reversibility of the toxoid approved by MPEG were acceptable. Therefore, the results of animal tests showed that the obtained product was stable and caused no wound or necrosis in the tested animals.

Proteome Analysis of Toxic Fractions of Iranian Cobra (Naja naja Oxiana) Snake Venom Using Two-Dimensional Electrophoresis and Mass Spectrometry.

Snake venoms are mostly composed of various proteins and peptides with toxicity and pharmacological effects depending on their geographical sources. Naja naja oxiana is one of the most medically important venomous snakes in Iran and Central Asia. The bite of this type of snake can cause severe pain and swelling, as well as neurotoxicity. Without medical treatment, symptoms quickly worsen and death can occur soon. A detailed understanding of venom components can provide new insight into the production of antivenom against toxic agents instead of crude venom. Specific antibodies against toxic fractions are of utmost importance in neutralizing crude venom. Therefore, the proteome profile of these fractions of Naja naja oxidana venom was analyzed using fractionation by gel filtration, two-dimensional electrophoresis, mass spectrometry, and data mining. Base on the results, in total, 32 spots were detected and categorized into three protein families, namely three-finger toxin (3FTx), phospholipase, and Cysteine-rich secretory proteins (CRISP). These proteins consist of more than 70% crude venom all with a molecular weight below 25 kDa. The 3FTx as a highly diverse constituent in the venom of Naja species was in large quantity in this district. Short-chain neurotoxins, including short neurotoxin, cytotoxin, and muscarinic toxin-like protein, were in abundance, respectively. In conclusion, the recognition of toxic fractions of Naja naja oxiana in this region could be of great help in the production of an effective antivenom against similar compositions. It can also help the medical care department to find out the clinical sign of cobra venom. To the best of our knowledge, this was the first study to report the proteomic of toxic fractions of Naja naja oxiana in Iran.