Cholera Toxin Enhances Vaccine-Induced Protection against Mycobacterium Tuberculosis Challenge in Mice
This experiment is an animal experiment made in accordance with the basic guideline the UK Animal Act 1986. Methods use was by collecting mice of 6-8wks. BCG Pasteur vaccine administered. Others vaccines are MVA85A and cholera toxin. Intradermal agents administered are the anti-IL-1A blocking antibody and the isotype IgG2a. Animals were then challenge with Biaera AeroMP aerosol nebulizer at a targeted pressure and dose. Organ harvest and stimulation for immunogenicity was then done. The lungs and spleen are the organs harvested aseptically. The organs were then processed with different steps such as mincing and digestion with DNase/collagenases. The cells collected were then plated using a 96 well plate and Ag85A peptide pool while the Brefeldin and GolgiStop were added for 2 hours before the cells were then processed for 16 hours. It was after the cells were stimulated during the processing period that they were then later stained. The organs were also harvested for bacterial load quantification when the organs were removed from the challenged animals, tissues then homogenized and plating was then done. It was after this the organ preparation conducted and analysis of the sections done.
The results as shown in the experiment revealed that the vaccination of BCG and MVA85A tend to enhance the overall cytokine production in the lungs once the vaccination is by intranasal process. In case of intradermal vaccination cytokine production is not as compared to that of intradermal hence the improved protection seen to be associated with the vaccination is noticeable when the route of administration is via the intranasal route.
Cholera Toxin B-Subunit Gene Enhances Mucosal Immunoglobulin A, Th1-Type, and CD8+ Cytotoxic Responses When Coadministered Intradermally with a DNA Vaccine
The experiment involves the use of plasmid vector encoding the cholera toxin B subunit (pCtB) in form of p16L1 (a capsid gene). The control was done using a coadmiinistration of pCtB and p16L1 as a positive. Animals were used based on the research guideline of institute of Biomedical research. The female mice age 6-8 weeks were immunized intradermally on days 0 and 14 with p16L1, pCtB, PL1tB, commercial CtB or Commercial CT holoxin. Additional group of animals were also immunized with 100ul of sterile, contaminant-free of PBS as a negative control. An Adjuvant capacity study was made by injecting 100ug of p16L1 with pCtB at various dosages to a group. The Cervical secretions of the animals were collected, later cleared of cell debris and tissue fragments via centrifugation. Fecal pellets also collected and later weighed. The spleen cells were also extracted from the spleen collected from the animals. The antibodies were also determined with the use of ELISA.
Result of this experiment show that the mice that were immunize with DNA vaccine and plasmid showed a form of coadministration of pCtB which was found to enhance the production fecal and genital IgA antibodies. Some analysis was done to show that protein extracts were seen in plasmid based transfected cell. The results also show that pCtB induced a Th1-type response but not alter the production of any antibody. That coadministration with pCtB is that which shows a form of an increase in cell mediated immune response on CD8+--Cell Specific cytotoxic activity which was noted from the analysis. The deduction from the aspect of the adjuvant result is that the capacity of pCtB is comparable to that of CtB polypeptide and CtB protein in the ability to produce IgA antibodies
The main idea and benefits of the experiments
The results of the experiments reviewed are of great importance, especially towards understanding the boosting effects or protective effects of the vaccines injected into the mice. The idea relating to the first experiments showed benefits that could be derived when the CT is used as an adjuvant vaccine. It also shows the effects of such on the immunogenicity of the mice. In terms of the route of administration, that which is via the intranasal route poses more beneficial effect in terms of the effect compared to that via the intradermal route. This simply indicates that such vaccines can be further tested in humans to further understand the effects on the human lungs. Another benefit this could also give us is that which help to understand the pathology relating to lung or spleen especially in animal with the mycobacterium tuberculosis. The experiment could serve as a basis for further experiments, especially relating to discovery of of why intranasal route influences the result of the experiment.
The second experiment which involves the use of cholera toxin B-subunit gene shows several beneficial effects of having a DNA vaccine when compared to other old type of vaccine. The implication of this is that such vaccines targets the genetic component of the pathology which has a great effect, especially on the economic aspect of the developing the vaccine. In this research, there are several areas that needs further research studies for better understanding. The area of effect of using CtB and CT as adjuvant for a DNA based vaccine needs further research. The capacity of CtB plasmid in order to induce IgA is one important benefits of this study actually helps to reveal, however the main factor or mechanism of induction is yet to be fully described. The isotype switching capacity was a suggestion, hence need further research to confirm such feature.
Work cited
Griffiths et al. Cholera Toxin Enhances Vaccine-Induced Protection against Mycobacterium Tuberculosis Challenge in Mice. PLOS. 23 October, 2013. Web. 5 April, 2014
Sanchez et al. Cholera Toxin B-Subunit Gene Enhances Mucosal Immunoglobulin A, Th1-Type, and CD8+ Cytotoxic Responses When Coadministered Intradermally with a DNA Vaccine. Clinical and Vaccine immunology. July 2004. Web. 5 April, 2014.
