Adjuvants are artificial agents, which are popularly known as immunological substances. Adjuvants have the skill to improve the immune response against a single or a group of antigens. Among the several types of adjuvants, the most commonly substances used in antibody production are Freund’s Complete and Freund’s Incomplete Adjuvants. They play a vital role in the production of vaccines that are capable of enhancing the immune response of the host. Freund’s Adjuvant is also largely used in the production of synthetic antibodies.
What exactly is What is Freund’s Adjuvant?
Freund’s adjuvant is a solution of a molecule or molecular organization or any alien particulate matter or pollen grain, known as an antigen. These antigens are capable of binding to a specific T-cell or antibody receptor. The adjuvant can be emulsified, which is a process of mixing two or more generally immiscible liquids, usually, mineral oil and water, owing to liquid-to-liquid stage separation. Freund’s adjuvant is used as an immunopotentiator, meaning it can boost the immune response. Freund’s Adjuvant is available in two types known as Freund’s Complete Adjuvant or Complete Freund’s Adjuvant, which are shortly referred to as FCA or CFA respectively. The second type is Incomplete Freund’s Adjuvant or Freund’s Incomplete Adjuvant, which are referred to as IFA or FIA respectively. Both types of adjuvants are largely used in antibody production.
Differences between Freund’s Complete and Freund’s Incomplete Adjuvant
Both Freund’s Complete and Freund’s Incomplete Adjuvants include an emulsion of mineral oil and water and are used in antibody production to enhance the immune response versus an antigen. Similarly, both of them are capable of stimulating the manufacture of T cells, chiefly T helper cells. They are also used in the production of injections in immunization. Despite these similarities, both types of Freund’s Adjuvants differ greatly in terms of their characteristics, formulations, uses, etc. Here are those differences between the two Freund’s Adjuvants.
Composition
Freund’s Complete Adjuvant is made up of inactivated and dehydrated mycobacteria, which will be usually M. tuberculosis. On the other hand, Freund’s Incomplete Adjuvant does not comprise the mycobacterial constituents, thus the water in the oil mixture. It means that Freund’s Complete Adjuvant is made up of a mixture of water and mineral oil comprising heat-destroyed Mycobacteria whereas the incomplete form is not composed of any additional Mycobacteria but only the water and mineral oil emulsion.
Uses
Freund’s Complete Adjuvant is usually utilized for initial injections, whereas Freund’s Incomplete Adjuvant is mostly used for subsequent inoculations. However, when the adjuvant is combined with spleen cells, it is capable of reversing diabetes while administering diabetes-prone NOD mice. It is capable of restoring insulin-manufacturing beta cells in the pancreas of NOD mice without spleen cells. Freund’s complete adjuvant is capable of preventing juvenile-onset diabetes in non-obese diabetic (NOD) mice.
Capability
Freund’s complete adjuvant is capable of stimulating cell-arbitrated immunity effectively. It shows the way to potentiate T helper cells that in turn, leads to antibody production, containing certain effector T cells and immunoglobulins. The use of this type of Freund’s adjuvant in humans is prohibited by regulatory authorities, owing to its toxicity. Currently, there are guidelines related to its use, even for animal study because of its throbbing reaction and likely for tissue damage. FCA vaccinations are supposed to be intraperitoneal or subcutaneous, as intradermal inoculations may create skin ulceration and necrosis. On the other hand, FCA intramuscular inoculations may lead to provisional or enduring muscle lesions, and intravenous shots may cause pulmonary lipid embolism.
Applications
When it comes to Freund’s Incomplete Adjuvant, it is one of the most regularly used adjuvants in research as well as in antibody production. This form of adjuvant is usually made from non-metabolizable oils. It plays a crucial role in producing water-in-oil blends of antigens. The major characteristic of Freund’s Incomplete Adjuvant is that it is capable of inducing a chiefly Th2-biased response through the structure of a depot at the inoculation site and the encouragement of antibody-creating plasma cells. It is a premium pre-clinical grade of Freund’s Adjuvant. However, unlike Freund’s complete adjuvant, which can be used in humans, Freund’s Incomplete Adjuvant is not appropriate for veterinary or human use, but only for research purposes.
Structure
Freund’s Complete Adjuvant is made up of a mixture of water and mineral oil comprising heat-destroyed Mycobacteria whereas the incomplete form is not composed of any additional Mycobacteria but only the water and mineral oil emulsion.
Effects
Freund’s Complete Adjuvant is capable of encouraging the manufacture of Th1 cells whereas the incomplete form plays a vital role in kindling the manufacture of Th2 cells.
Administration period
Freund’s Complete Adjuvant is managed at the premature stage of the immunization program to get instant effects. On the other hand, the incomplete type of adjuvant is administered at the later juncture of the vaccination program. This type of adjuvant is normally used for the following boosts after the first injection with the complete form of adjuvant.
Immunity response
Freund’s Complete Adjuvant is capable of providing immediate immunity response whereas Freund’s Incomplete Adjuvant takes some time. However, both forms of Freund’s Adjuvant are actively used in antibody production.
Drawbacks
Every substance on earth has its advantages and disadvantages, so the two types of Freund’s Adjuvant are no different. When considering the disadvantage of Freund’s Complete Adjuvant, it may show the way to the increase of infection in immune-compromised people because of long-standing exposure.
On the other hand, the main drawback of Freund’s Incomplete Adjuvant is that it creates complexity in formulation with the antigen during the preparation of vaccines.
Both Freund’s Complete and Freund’s Incomplete Adjuvant are largely used in antibody production. They are considered the best boosters, which are utilized to increase the immune response of a host. Both types of Freud’s adjuvants contain an emulsion of water and oil and they are the first adjuvants to introduce for research purposes. Although both complete and incomplete adjuvants have some similarities, they differ greatly in the absence and presence of the heat-destroyed Mycobacterium variety respectively. Freund’s Complete Adjuvant is full of the slaughtered mycobacterial component whereas the incomplete form of Freund’s Adjuvant does not hold the mycobacterial component. Both types of Freud’s adjuvants are still under research in order to evaluate the immune response. These investigations aim at developing vaccinations that are more effective to combat a variety of communicable diseases.