One of the major causes of sickness, death, and economic loss in the cattle industry is Mannheimia haemolytica, which causes bovine pasteurellosis, or shipping fever. Noninvasive delivery of a vaccine using transgenic plants expressing immunogens would reduce labor costs and trauma to livestock. An early step toward developing an edible vaccine is to determine whether an injected version of an antigen (usually a derivative of the pathogen) is capable of stimulating the development of antibodies in a test organism. The following table assesses the ability of a transgenic portion of a toxin (Lkt) of M. haemolytica to stimulate development of specific antibodies in rabbits.

What general conclusion can you draw from the data?

Verified step by step guidance

1. Step 1: Begin by analyzing the table provided in the problem. The table compares antibody production in rabbits after injection with different forms of the immunogen (Lkt50) and a mock injection. Note the '+' and '-' symbols indicating the presence or absence of antibody production.
2. Step 2: Understand the significance of Lkt50. It is a smaller derivative of the toxin Lkt from Mannheimia haemolytica, modified to lack hydrophobic regions, and is capable of neutralizing at least 50% of the toxicity of Lkt. This modification makes it a candidate for testing as an immunogen.
3. Step 3: Compare the results of the injections. Both the saline extract and column extract of Lkt50 stimulate antibody production (indicated by '+'), while the mock injection does not (indicated by '-'). This suggests that the Lkt50 derivative is immunogenic and capable of eliciting an immune response.
4. Step 4: Consider the implications of the data. The ability of Lkt50 to stimulate antibody production in rabbits supports its potential as a component of an edible vaccine. This is an important step in developing a noninvasive vaccine delivery system using transgenic plants.
5. Step 5: Formulate the general conclusion. The data indicates that the transgenic portion of the toxin (Lkt50) is effective in stimulating the development of specific antibodies in rabbits, which is a promising result for vaccine development against bovine pasteurellosis.

Key Concepts

Antibody Production

Antibody production is a crucial aspect of the immune response, where the body generates specific proteins (antibodies) to identify and neutralize pathogens. In the context of vaccines, the goal is to stimulate this response through the introduction of antigens, which are components of the pathogen. The effectiveness of an antigen in eliciting an antibody response can be assessed by measuring the levels of antibodies in the serum after immunization.

Transgenic Plants

Transgenic plants are genetically modified organisms that have had foreign genes inserted into their genome. This technology allows for the expression of specific proteins, such as immunogens from pathogens, in plant tissues. The use of transgenic plants for vaccine production offers a non-invasive method to deliver vaccines, potentially reducing costs and improving animal welfare by eliminating the need for injections.

Immunogenicity

Immunogenicity refers to the ability of a substance, such as an antigen, to provoke an immune response. In vaccine development, it is essential to determine whether a particular antigen can stimulate the production of antibodies. The data presented in the question indicates that the Lkt50 extracts are capable of inducing antibody production, suggesting their potential as effective immunogens in vaccine formulations against Mannheimia haemolytica.