Immune response component images

Explore the 18 different cells and molecules of the immune system as shown in the Immune System magazine and poster (and download a PowerPoint version at the bottom of the page)

1. Mast cell

Mast cell — Involved in allergic responses, releasing histamine and other inflammatory molecules. Mast cells sit within skin and mucosal tissues.
CC BY Bret Syfert, ‘Big Picture’

2. Basophil

Basophil — Involved in allergic and inflammatory responses. Basophils release histamine like mast cells, but unlike mast cells they circulate in the blood.
CC BY Bret Syfert, ‘Big Picture’

3. Natural killer (NK) cell

Natural killer (NK) cell — These kill pathogen-infected cells and cancer cells. They release chemicals called cytokines, which alert and attract other immune cells.
CC BY Bret Syfert, ‘Big Picture’

4. Complement

Complement — A set of around 30 proteins in the blood plasma that can be activated by the presence of microbes or antibody–antigen complexes. Complement can destroy pathogens and activate phagocytic cells.
CC BY Bret Syfert, ‘Big Picture’

5. Neutrophil

Neutrophil — Fast-acting phagocytes that flock to the site of inflammation.
CC BY Bret Syfert, ‘Big Picture’

6. Macrophage

Macrophage — Antigen-presenting cells that destroy foreign substances by phagocytosis (engulfing them) and activating other immune cells.
CC BY Bret Syfert, ‘Big Picture’

7. Dendritic cell

Dendritic cell — Phagocytic antigen-presenting cells with an important role in alerting T cells to new pathogens.
CC BY Bret Syfert, ‘Big Picture’

8. Eosinophil

Eosinophil — Phagocytes that also produce enzymes to counteract the inflammatory molecules released by mast cells.
CC BY Bret Syfert, ‘Big Picture’

9. Antigens

Antigens — Antigens are non-self markers, often proteins, that alert the immune system’s cells to the presence of potential danger. These antigens may pose no threat on their own – they are just components, such as molecules in bacterial membranes, that raise a flag to immune cells.
CC BY Bret Syfert, ‘Big Picture’

10. B cell

B cell — Named after the bone marrow, where immature B cells are produced. Types include plasma B cells and memory B cells. A type of lymphocyte.
CC BY Bret Syfert, ‘Big Picture’

11. Plasma B cell

Plasma B cell — B cells that have been activated to produce antibodies (immunoglobulins). Each B cell makes only one type of antibody.
CC BY Bret Syfert, ‘Big Picture’

12. Antibodies

Antibodies — Also known as immunoglobulins (Ig). These are Y-shaped globular proteins, whose secondary structure is based mostly on beta-pleated sheets. They are produced by plasma B cells to fight against antigens. Types include IgA, IgD, IgE, IgG and IgM.
CC BY Bret Syfert, ‘Big Picture’

13. Memory B cell

Memory B cell — Long-lived B cells that remember past infections by recognising antigens to provide a secondary immune response.
CC BY Bret Syfert, ‘Big Picture’

14. T cell

T cell — Named after the thymus, the organ where T cells mature. T cells have a protein called the T cell receptor on their surface. Types include helper T cells, cytotoxic T cells and regulatory T cells. A type of lymphocyte.
CC BY Bret Syfert, ‘Big Picture’

15. Helper T cell

Helper T cell — T cells that recognise antigens presented by antigen-presenting cells and stimulate T, B and other immune cells. Also known as CD4⁺ cells, because of a protein that they express on their cell surface. These are the cells depleted by infection with HIV (human immunodeficiency virus). A type of lymphocyte.
CC BY Bret Syfert, ‘Big Picture’

16. Cytotoxic T cell

Cytotoxic T cell — T cells that kill infected cells and cancer cells by releasing toxic chemicals. Also known as CD8⁺ cells, because of a protein that they express on their cell surface, and as killer T cells. A type of lymphocyte.
CC BY Bret Syfert, ‘Big Picture’

17. Memory T cell

Memory T cell — Long-lived T cells that ‘remember’ past infections to provide a secondary immune response. A type of lymphocyte.
CC BY Bret Syfert, ‘Big Picture’

18. Perforins

Perforins — Proteins that cause cells to lyse (burst) by making pores form in the plasma membrane of the cell. Found in the granules of cytotoxic T cells.
CC BY Bret Syfert, ‘Big Picture’

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Further reading

Poster on the immune response

Downloadable resources

Immune response component images – from poster [PPTX 3MB]
Immune response components – all images download pack [ZIP 3MB]

About this resource

This resource was first published in ‘Immune System’ in January 2015.

Topics:: Cell biology, Immunology
Issue:: Immune System
Education levels:: 14–16, 16–19, Continuing professional development