Specific immune response

1)B lymphocytes

• produced in bone marrow.

• Involved in humoral response.

• Form B memory cells

Humoral response

• response to antigens on cells.

PRIMARY:

• B cell engulfs antigens and forms APC.

• Antigen on Bcell locks with a T cell.

• Forms antibody producing plasma cells which is released into blood (antibodies)

SECONDARY:

• production of B memory cells.

B memory cells

B memory cells are important for immunological memory. Remember antigen specific pathogens so quicker response.

2)T lymphocytes

• mature in thymus gland.

• Involved in cell mediated response

• T memory cells.

T helper cells

bind to antigens on APC (antigen-presenting cells) stimulates interleukin production (type of cytokine)

• Stimulates B cells.

• Stimulates T cells

• Stimulates macrophages

T killer cells

produce perforins which produces holes in pathogen cell membrane, KILLING IT.

T memory cells

Immunological memory, allows quicker responses.

T suppressor cells

Suppresses immune responses when pathogen eliminated. Important to prevent body attacking self cells.

• leads to autoimmune conditions e.g lupus.

Cell mediated response

Response to altered cells: cancers.

• T cell (after engulfing antigens)

PRIMARY

• produces clones:

• T killer cells

• T helper cells

• T suppressor cells

• T memory cells

Antibodies function

• Form complexes with antigens and neutralise foreign substances, produced when lymphocytes fight specific pathogens.

• Agglutin: clump to stop harmful actions.

• Opsonins: act as binding site.

• antitoxins: neutralise toxins from antigens

Antibody structure

Y shaped glycoprotein on cell surface.

• Hinge for flexibility

• Held by disulphide bonds.

Primary and secondary immune response

Primary: first exposure to pathogen, takes long as B and T cells first time fighting.

Secondary: re-exposure to pathogen, memory cells make it quicker to fight pathogen.

autoimmune disease

immune system attacks cells as it recognises them as non self

environmental factors

• vaccinations produce primary immune response (memory cells)

• poor diet can weaken immune system (low vitamins)

• exposes to different pathogens determine immune response

genetic factors

• genes that code for antibodies are inherited from parents (lymphocytes)

• different alleles code for different versions of antibodies

• mutation produces new alleles for antigens

• autoimmune diseases e.g lupus