Mechanism of action of edible vaccines

nirupama's picture
Submitted by nirupama on Sat, 05/17/2008 - 10:31.
in

Let’s go back to what I discussed in “Concept behind edible vaccines”.

The gene which codes the active antigenic protein is isolated from the pathogen and is incorporated in a suitable “gene vehicle”. This gene vehicle is integrated into the genome of the plant and is allowed to express to produce the corresponding antigen. Then these plant parts are fed to animals and humans to run their course.

Plant parts are fed directly since the outer tough wall of plant cells acts to protect the antigens against attack by enzymes, gastric and intestinal secretions. This method is known as bio-encapsulation. The plant cell wall breaks in the intestines to release the antigens.

The antigens which are released are taken up by M cells in the intestinal lining that are present over the Peyer’s patches (in the ileum) and the gut associated lymphoid tissue(GALT). Peyer’s patches refer to the groups of lymphatic nodules also called aggregated lymphatic follicles.

The antigens are then passed onto macrophages and other APCs(antigen presenting cells) and local lymphocytes. This triggers formation of serum IgG,IgE and local IgA antibodies and memory cells. These immediately neutralize the infectious agent present in the body.

References:
Lal P, Ramachandran VG, Goyal R, Sharma R. Edible vaccines: Current status and future. Indian J Med Microbiol [serial online] 2007 [cited 2008 May 2];25:93-102.
Available from: http://www.ijmm.org/text.asp?2007/25/2/93/32713

Re:dose of plant parts

nirupama's picture
Submitted by nirupama on Sun, 06/15/2008 - 13:30.

ok i get it now
i think this link will explain it better http://www.molecularfarming.com/ediblevaccine.html
hope this helps!

dose???

guptashubhranshu's picture
Submitted by guptashubhranshu on Thu, 05/29/2008 - 18:42.

This system of oral administration of vaccines really does gurantee a promise...But how can we know the dose of plant parts to be fed???The antigens might not be present uniformly in that part of the plant to be fed....

thanks for your comment!

nirupama's picture
Submitted by nirupama on Sat, 05/31/2008 - 12:20.

hey subhranshu
i believe you had a similar doubt on my other blog entry
do check the reply to that
hope i have helped!

About dose of Plant parts....

guptashubhranshu's picture
Submitted by guptashubhranshu on Mon, 06/02/2008 - 07:12.

Hi nirupama....Actually, that question I had raised was different than this one. That question was about a pre-prepared vaccination dose through oral route. But this question is on how to decide the dose of whole plant parts. Is it like that we isolate the antigens from the plant part and then administer it or administer the raw plant part itself? If the latter, then on what basis the dose can be decided because deciding the dose of plant part is virtually a very difficult and unapproachable task ....If still u couldn't get the question, then feel free to ask me for clarification and do state the question you have.....Thanks.....