In today's world, Immunogen has become a topic of great importance and interest, both for experts and the general public. Since its emergence, Immunogen has captured the attention of people of all ages and nationalities, generating debates and discussions in various areas. Its impact has been so significant that it has managed to influence decision-making at a global level, as well as the development of different industries and sectors. In this article, we will analyze in depth the relevance of Immunogen, its implications and possible future scenarios, in order to offer a comprehensive vision of this topic that has marked a before and after in today's society.
An immunogen is any substance that generates B-cell (humoral/antibody) and/or T-cell (cellular) adaptive immune responses upon exposure to a host organism. Immunogens that generate antibodies are called antigens ("antibody-generating"). Immunogens that generate antibodies are directly bound by host antibodies and lead to the selective expansion of antigen-specific B-cells. Immunogens that generate T-cells are indirectly bound by host T-cells after processing and presentation by host antigen-presenting cells.
An immunogen can be defined as a complete antigen which is composed of the macromolecular carrier and epitopes (determinants) that can induce immune response.
An explicit example is a hapten. Haptens are low-molecular-weight compounds that may be bound by antibodies, but cannot elicit an immune response. Consequently, the haptens themselves are nonimmunogenic and they cannot evoke an immune response until they bind with a larger carrier immunogenic molecule. The hapten-carrier complex, unlike free hapten, can act as an immunogen and can induce an immune response.
Until 1959, the terms immunogen and antigen were not distinguished.
An adjuvant (from Latin adiuvare – to help) is any substance, distinct from antigen, which enhances immune response by various mechanisms: recruiting of professional antigen-presenting cells (APCs) to the site of antigen exposure; increasing the delivery of antigens by delayed/slow release (depot generation); immunomodulation by cytokine production (selection of Th1 or Th2 response); inducing T-cell response (prolonged exposure of peptide-MHC complexes and stimulation of expression of T-cell-activating co-stimulators on the APCs' surface) and targeting (e. g. carbohydrate adjuvants which target lectin receptors on APCs). Adjuvants have been used as additives to improve vaccine efficiency since the 1920s. Generally, administration of adjuvants is used both in experimental immunology and in clinical settings to ensure a high quality/quantity memory-enhanced antibody response, where antigens must be prepared and delivered in a fashion that maximizes production of a specific immune response. Among commonly used adjuvants are complete and incomplete Freund's adjuvant and solutions of aluminum hydroxide or aluminum phosphate.
a substance that produces an immune response
A substance capable of eliciting a immune response. All immunogens are antigens, but some antigen are not immunogens (e.g. haptens)