Contact Us
Technology

Immunology and Health

Immunity encompasses all the mechanisms available to the organism to maintain the integrity of its internal environment against external aggressions by pathogenic microorganisms and parasites. Understanding how it functions is fundamental to understanding how POLARIS works.

The Two Arms of Immunity

The immune system operates through two interconnected systems. Innate immunity is the first line of rapid, non-specific defence. Adaptive immunity is the second line, slower, highly specific, and capable of generating lasting memory against the pathogens it encounters.

First Line of Defence
Innate Immune System
Rapid, non-specific defence that does not require prior learning and does not generate immunological memory. It includes physical barriers, chemical signals and a range of cellular components that act immediately upon detecting a pathogen.
Neutrophils Macrophages NK Cells Dendritic Cells Mast Cells
Second Line of Defence
Adaptive Immune System
Slow, highly specific defence that requires recognition of a specific antigen and generates immunological memory. Mediated by B and T lymphocytes, it is the basis for vaccination and long-term disease resistance.
B Lymphocytes T Helper (CD4) Cytotoxic T (CD8) Th1 / Th2 Pathways

Cellular Components of Innate Immunity

The cellular arm of innate immunity includes a range of specialised white blood cells, each with a defined role in identifying and eliminating threats before the adaptive system is required.

  • Neutrophils: The most abundant leukocytes. They phagocytose microorganisms and destroy them with enzymatic compounds including lysozyme, defensins and lactoferrin.
  • Macrophages: Phagocytose antigens and bridge innate and adaptive immunity by activating CD4 and CD8 T cells for a targeted response.
  • Dendritic cells: Highly specialised antigen-presenting cells with Pattern Recognition Receptors (PRR and TLR). They phagocytose pathogens and present antigens to T lymphocytes, initiating the adaptive response.
  • Natural Killer (NK) cells: Originate in bone marrow and migrate to infection sites. They destroy cells infected by intracellular agents and tumour cells.
  • Eosinophils: Specialised leukocytes for defence against large parasites. They release chemical and enzymatic loads into the environment surrounding helminths.
  • Basophils: Circulating cells involved in inflammation as an alarm and defence mechanism against infection.
  • Mast cells: Tissue-resident cells with a similar function to basophils. Responsible for allergic reactions via release of histamine, heparin, serotonin and cytokines.
  • Non-cellular components: Skin and mucosal barriers, lysozymes, defensins, cathelicidins, and complement proteins that support the cellular response.

Pathogens carry chemical identity markers known as PAMPs (Pathogen Associated Molecular Patterns), recognised by TLRs (Toll-Like Receptors) on immune cells. These structural recognition systems are the basis for inactivated vaccine development and for immunomodulatory feed additives such as POLARIS.

Lymphocyte Subpopulations

Lymphocytes are the only immune cells capable of recognising specific antigenic determinants and generating memory. They are classified by the surface CD markers they express, which define their lineage and function. The main subpopulations of clinical and nutritional relevance are:

B Lymphocytes
CD19 / CD20
Drive humoral (antibody-mediated) adaptive immunity. Mature B cells are characterised by the expression of CD19 and CD20 markers. They produce immunoglobulins in response to specific antigens.
T Helper Cells
CD3+CD4+
After antigen exposure, they secrete cytokines that activate and expand macrophages and B lymphocytes. Their count is clinically significant as a marker of immune competence. A ratio of CD4/CD8 between 0.9 and 1.9 is considered normal in a healthy individual.
Cytotoxic T Cells
CD3+CD8+
Responsible for destroying cells infected by intracellular pathogens and tumour cells. They mediate cellular immunity and play a key role in antiviral defence, including the Th1 pathway activated by POLARIS.
Memory T Cells
CD127+CD3+
Precursors of long-term immune memory. Expansion of this subpopulation indicates a larger and more durable immunological memory pool. These cells are a key marker of the lasting immune competence demonstrated in POLARIS clinical trials.
NK Cells
CD56 / CD16
Morphologically similar to T and B lymphocytes, but characterised by CD56 and CD16 markers and the absence of CD3. They mediate cytotoxicity against tumour cells and virus-infected cells as part of innate defence.

Immunomodulatory Substances in Feed

Immune function in livestock can be supported through nutritional strategies that target the gut-immune interface. A range of compound categories have been studied for their effects on immune cell function, gut barrier integrity, and cytokine regulation.

Probiotics

Probiotics modulate host immunity through competition with pathogens at the gut mucosa, influencing macrophage and heterophil activity, and affecting cytokine expression downstream of TLR activation. Effects are strain, species, dose and timing dependent.

Prebiotics

Prebiotics modify gut microbial communities, promote intestinal morphology, and up-regulate innate immune factors including complement proteins and acute phase proteins. They modulate pro-inflammatory and anti-inflammatory cytokines involved in both cellular and humoral immunity.

Essential Oils and Nucleotides

Compounds such as carvacrol and cinnamaldehyde have demonstrated anti-inflammatory activity via suppression of intracellular signalling. Dietary nucleotides support NK cell and macrophage activation, IL-2 and IFN production, and resistance to bacterial and fungal infection, particularly in early life when endogenous synthesis is limited.

A new approach to immunomodulation
A new line of work in immunostimulation involves extracting and modifying structural fractions from Gram-negative bacteria that are recognised by TLRs. Through physical and chemical treatment, these fractions can increase IL-12 (Th1 cellular response) while attenuating pro-inflammatory cytokines (TNF, IFN-alpha and IFN-beta). Unlike vaccines, this results in a broad, non-antigen-specific enhancement of immune competence.

Postbiotics: How They Work

Bacterial lysates Cell wall fragments Enzymes Exopolysaccharides Lipopolysaccharides Short-chain fatty acids Vitamins and amino acids Cell-free supernatants

Postbiotics are the bioactive compounds and metabolites derived from microbial fermentation. Unlike probiotics, they contain no live microorganisms, giving them superior stability, batch consistency and safety profile.

Gut homeostasis is central to host health. Postbiotics act through three primary mechanisms. First, protection against pathogens via metabolites such as lactic acids, bacteriocins and short-chain fatty acids (acetate, propionate, butyrate) that lower gut pH and inhibit colonisation. Second, reinforcement of the gut barrier through tight junction support and reduction of epithelial permeability. Third, immune regulation through modulation of pattern recognition receptors and downstream cytokine expression.

Compared to probiotics, the stability and safety characteristics of postbiotics make them a practical and consistent approach to supporting gut and immune health in livestock nutrition.