Overview of Immunology and Serology Concepts

Immunology

Study of organisms' defense against infections.

Serology

Study of blood serum and immune responses.

Immunochemistry

Chemical processes in immune responses.

Immunobiology

Biological aspects of immune system functions.

Immunogenetics

Genetic basis of immune responses.

Immunopathology

Study of diseases related to immune dysfunction.

Immunohematology

Study of blood-related immune responses.

Lymphocytes

White blood cells including T and B cells.

T cells

Lymphocytes that mediate cellular immunity.

B cells

Lymphocytes that produce antibodies.

Antigen presenting cells

Cells that display antigens to T cells.

Dendritic cells

APCs that activate T cells.

Macrophages

Phagocytic cells in immune response.

Follicular dendritic cells

Display antigens to B cells.

Anatomical Barriers

Physical barriers preventing pathogen entry.

Mechanical Factors

Physical processes like skin and mucus.

Chemical Factors

Substances like lysozymes and fatty acids.

Biological Factors

Living cells contributing to immune defense.

Innate Immunity

Non-specific first line of defense.

Adaptive Immunity

Specific immune response to pathogens.

Complement system

Group of proteins enhancing immune response.

Type I Interferons

Cytokines augmenting NK cell activity.

Coagulation system

Blood clotting factors aiding immune defense.

TNF

Mediates inflammatory response to infections.

TNF α (cachectin)

Cytotoxic to tumor cells directly.

TNF β (lymphotoxin)

Involved in killing and endothelial activation.

Beta-lysin

Protein from platelets that lyses Gram positive bacteria.

Lactoferrin

Binds iron, limiting bacterial growth.

Transferrin

Iron-binding protein, restricts bacterial access to iron.

Lysozyme

Enzyme that breaks down bacterial cell walls.

Interferons

Proteins that limit viral replication in cells.

Interleukin-1 (IL-1)

Regulates immune responses and inflammatory reactions.

Interleukin-2 (IL-2)

Activates cytotoxic T cells.

Interleukin-3 (IL-3)

Induces hematopoiesis.

Interleukin-4 (IL-4)

Stimulates B cell activation and growth.

Interleukin-5 (IL-5)

Promotes eosinophil growth and activation.

Interleukin-6 (IL-6)

Involved in B-cell differentiation and inflammation.

Interleukin-7 (IL-7)

Growth factor for early lymphoid cells.

Interleukin-8 (IL-8)

Activates neutrophils, promotes chemotaxis and phagocytosis.

Interleukin-9 (IL-9)

Supports growth of helper T-cells.

Interleukin-10 (IL-10)

Inhibits antigen presentation and Th2 cell activity.

Interleukin-11 (IL-11)

Stimulates megakaryocytopoiesis and inhibits epithelial proliferation.

Interleukin-24 (IL-24)

Involved in tumor suppression and wound healing.

Interleukin-27 (IL-27)

Regulates B and T lymphocyte activity.

Interleukin-28 (IL-28)

Role in immune defense against viruses.

Acute phase reactants (APR)

Serum proteins that change during inflammation.

Interleukin-12

Stimulates Th1 responses against intracellular pathogens.

Th1 Cellular Immune Response

Defensive mechanism against intracellular infections.

Interleukin-15

Promotes proliferation of NK cells.

Interleukin-17

Proinflammatory cytokine from activated memory T cells.

Interleukin-19

Regulates immune responses, synergistic with IL-2.

Interleukin-20

Regulates keratinocyte proliferation and differentiation.

TGF-β

Suppresses autoimmune responses and Th1 activity.

Macrophages

Phagocytose and kill microorganisms intracellularly.

Resident Macrophages

Main defense in non-specific immune system.

Transient Macrophages

Temporary macrophages responding to infection.

Neutrophils

Phagocytose and kill invading organisms intracellularly.

Myeloperoxidase (MPO)

Antimicrobial enzyme in neutrophil granules.

Lactoferrin

Iron-binding glycoprotein inhibiting microbial growth.

Azurophilic Granules

Contain antimicrobial products like defensins.

Natural Killer (NK) Cells

Non-specifically kill virus-infected and tumor cells.

Lymphokine Activated Killer (LAK) Cells

Enhanced NK cells targeting infected or cancerous cells.

Eosinophils

Kill parasites and involved in allergic reactions.

Eosinophil Granules

Contain neurotoxins and proteins for parasite killing.

Dendritic Cells

APCs that present antigens to T helper cells.

Langerhans Cells

Skin-resident dendritic cells for immune surveillance.

Interdigitating Dendritic Cells

Found in thymus and secondary lymphoid tissues.

Basophils

Involved in immediate hypersensitivity and allergies.

Mast Cells

Tissue-based basophils releasing histamine.

Inflammation

Body's response to injury or infection.

Vascular response

Dilation of capillaries increases blood flow.

Capillary permeability

Increased permeability allows fluid and cells to enter.

White blood cells (WBCs)

Cells that migrate to injured tissue.

Neutrophils

First responders in inflammation, migrate quickly.

Natural Killer cells

Attack infected or cancerous cells.

Macrophages

Engulf pathogens and debris in tissue.

Pattern-recognition receptors (PRRs)

Detect pathogens and initiate immune response.

Mannose receptors

Recognize carbohydrates in bacterial cell walls.

Alpha-helical receptors

Bind lipids, chemokines, and peptides.

Toll-like receptors (TLRs)

Recognize specific microbial components.

Histamine

Chemical that causes vasodilation during inflammation.

Kinins

Mediators that promote vasodilation.

Prostaglandins

Intensify effects of kinins and histamine.

Leukotrienes

Promote phagocytic attachment to pathogens.

Preformed molecules

Existing mediators like serotonin and histamine.

Newly synthesized molecules

Mediators produced during inflammation, e.g., cytokines.

Neutrophil mobilization

Occurs within 30 to 60 minutes post-injury.

Monocyte migration

Starts 4 hours after injury, peaks at 16-48 hours.

Phagocytosis

Process of engulfing and digesting pathogens.

Chemotaxis

Movement of cells toward chemical signals.

Opsonization

Coating of pathogens to enhance phagocytosis.

Pathogen-associated molecular patterns (PAMPs)

Molecular signatures recognized by immune cells.

CSF

Colony Stimulating Factor, regulates blood cell production.

EPO

Erythropoietin, stimulates red blood cell formation.

G-CSF (Granulocyte Colony Stimulating Factor)

promotes granulocyte production.

M-CSF (Macrophage Colony Stimulating Factor)

enhances macrophage development.

GM-CSF

Granulocyte-Macrophage Colony Stimulating Factor, stimulates both cell types.

TGF (Transforming Growth Factor)

involved in cell growth regulation.

SCF

Stem Cell Factor, supports hematopoietic stem cell survival.

IFN

Interferon, antiviral cytokine produced by immune cells.