[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › Immunity and inflammation: basics for pharmacology # Immunity and inflammation: basics for pharmacology The innate and adaptive immune systems and the mediators of inflammation, as the background needed to understand anti-inflammatory and immune drugs. Updated Nov 2, 2026 Immune and anti-inflammatory drugs act on specific cells, receptors and cytokines. To understand what a TNF inhibitor, a calcineurin inhibitor or a vaccine does, it helps to know the main players: barriers and innate cells that act within minutes, lymphocytes that learn and remember, and the chemical signals that link them. ## Key points - Innate immunity is fast and not specific: barriers, complement, neutrophils, macrophages, natural killer cells and pattern-recognition receptors. - Adaptive immunity is slower, specific and has memory: B cells make antibodies, CD4 helper T cells coordinate, CD8 cytotoxic T cells kill infected or abnormal cells. - T cells recognise antigen only when it is presented on MHC (HLA) molecules by antigen-presenting cells, plus a second costimulatory signal. - Cytokines such as TNF, IL-1, IL-6, IL-17 and interferons carry the messages; many biologic drugs block one of them. - Inflammation brings redness, heat, swelling, pain and loss of function; when it does not switch off, it damages tissue. ## Innate immunity Skin and mucosa, stomach acid and normal flora are the first defence. Toll-like receptors and other sensors on macrophages and dendritic cells recognise common microbial patterns and trigger cytokine release. Neutrophils arrive first and engulf bacteria; complement coats microbes (opsonisation), attracts cells and can punch holes in membranes. Natural killer cells destroy cells that have lost their normal surface markers. ## Adaptive immunity - Antigen-presenting cells (dendritic cells above all) carry antigen to lymph nodes - CD4 helper T cells: Th1 (intracellular microbes), Th2 (parasites, allergy), Th17 (fungi, neutrophil recruitment), regulatory T cells (keep tolerance) - CD8 cytotoxic T cells: kill virus-infected and tumour cells - B cells and plasma cells: antibodies (IgM first, then IgG; IgA at mucosa; IgE in allergy) - Memory cells: faster, stronger responses on second exposure, the basis of vaccination ## Inflammatory mediators Pre-formed mediators (histamine) act in seconds; newly made lipids (prostaglandins, leukotrienes) in minutes; cytokines and chemokines over hours. TNF and IL-1 cause fever, activate endothelium and drive the liver to make acute-phase proteins such as C-reactive protein, with IL-6. Chronic inflammatory diseases such as rheumatoid arthritis, psoriasis and inflammatory bowel disease are kept going by a few dominant cytokines, which is why blocking one of them can work so well. ## From biology to drugs - Corticosteroids: switch off the transcription of many inflammatory genes at once - NSAIDs: block prostaglandin synthesis - Biologics: block a single cytokine (TNF, IL-6, IL-17, IL-23) or a cell (B cells) - Small molecules: block signalling inside the cell (calcineurin, JAK, mTOR) - Replacement: immunoglobulin for antibody deficiency, growth factors for low neutrophils ## Memory aid «Innate is instant, adaptive adapts»: innate defences act in minutes without memory; adaptive ones take days and remember. ## Test yourself Think of the answer, then tap the question to see it. ## Which T cell type recognises antigen on MHC class I, and what does it do? CD8 cytotoxic T cells; they kill cells that present foreign (for example viral) or abnormal peptides. ## Which three cytokines are targets of approved biologic drugs? Any three of: TNF, IL-1, IL-6, IL-17, IL-23, IL-12/23, IL-5, IL-4/13. ## Why does a second exposure to an antigen give a faster response? Memory B and T cells formed after the first exposure respond quickly and strongly; this is the basis of vaccination. ## What two signals does a naive T cell need to be activated? Antigen presented on MHC (signal 1) and a costimulatory signal such as CD28 binding CD80/86 (signal 2). [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/pharmacology/topics/immunity-and-inflammation-basics-for-pharmacology/) [More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology) ## Example drugs - [Prednisone](https://durgical.com/en/pharmacology/prednisone/) - [Adalimumab](https://durgical.com/en/pharmacology/adalimumab/) - [Anakinra](https://durgical.com/en/pharmacology/anakinra/) - [Tocilizumab](https://durgical.com/en/pharmacology/tocilizumab/) - [Normal human immunoglobulin (IVIG)](https://durgical.com/en/pharmacology/normal-human-immunoglobulin/) - [Filgrastim](https://durgical.com/en/pharmacology/filgrastim/) - [Interferon gamma](https://durgical.com/en/pharmacology/interferon-gamma/) ## Connections ## Related classes 7 - [Corticosteroids (glucocorticoids)](https://durgical.com/en/pharmacology/classes/corticosteroids/) - [Nonsteroidal anti-inflammatory drugs (NSAIDs)](https://durgical.com/en/pharmacology/classes/nonsteroidal-anti-inflammatory-drugs/) - [TNF inhibitors](https://durgical.com/en/pharmacology/classes/tnf-inhibitors/) - [Interleukin inhibitors](https://durgical.com/en/pharmacology/classes/interleukin-inhibitors/) - [Immunoglobulins and antitoxins](https://durgical.com/en/pharmacology/classes/immunoglobulins-and-antitoxins/) - [Myeloid colony-stimulating factors](https://durgical.com/en/pharmacology/classes/myeloid-colony-stimulating-factors/) - [Interferons](https://durgical.com/en/pharmacology/classes/interferons/) [← All of pharmacology](https://durgical.com/en/pharmacology/) Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given. Sources: [Immune response: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/000821.htm) (MedlinePlus (U.S. National Library of Medicine), 2026). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/pharmacology/topics/immunity-and-inflammation-basics-for-pharmacology/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/topics/immunity-and-inflammation-basics-for-pharmacology/