BIOL 135: Diagnosis in Biomedical Science - Lectures 1-2

Flashcards for BIOL 135 Lectures 1-2 on Immune System Function

Lymphocytes

White blood cells including B lymphocytes, Tc (cytotoxic) lymphocytes, and TH (T helper) lymphocytes; they protect the body from infection.

B lymphocytes

Recognize and bind to free pathogens, leading to activation and production of plasma cells and memory cells.

Tc (cytotoxic) lymphocytes

Bind to presented antigens on the surface of infected self-cells and destroy these infected cells.

TH (T helper) lymphocytes

Bind to epitopes presented on antigen-presenting cells like macrophages and secrete cytokines to activate Tc and B cells; have CD4 on their surface.

Plasma cells

Derived from activated B cells, they secrete antibodies (immunoglobulins) with the same epitope recognition.

Memory cells

Derived from activated B cells, they remain in the blood and can mount a faster response to the appropriate antigen if it is encountered again.

Opsonisation

Coating of a pathogen by antibodies to stimulate faster phagocytosis.

Complement proteins

Activated by antibodies, resulting in the formation of a membrane attack complex that causes lysis of the bacterium.

Cytokines

Secreted by activated T Helper cells, they further activate Tc and B cells, crucial for the human acquired immune system.

HIV (Human Immunodeficiency Virus)

Virus that infects and destroys cells with CD4 on their surface (T helper cells), disrupting the acquired immune response.

GP120

Docking glycoprotein on the surface of HIV that attaches to the helper T cell CD4.

GP41

Transmembrane glycoprotein on the surface of HIV that binds to CXCR4/CCR5 co-receptors.

GP24

Capsid protein of HIV.

Reverse transcriptase

Enzyme used by HIV to make a DNA copy of its RNA genome for insertion into the host cell's genome.

AIDS (Acquired Immune Deficiency Syndrome)

The advanced stage of HIV infection, characterized by susceptibility to opportunistic infections.

Seroconversion

The production of antibodies to HIV, typically occurring 2-8 weeks after infection; commonly detected for HIV diagnosis.

ELISA (Enzyme-Linked Immunosorbent Assay)

A common method used for HIV infection diagnosis that detects the presence of HIV antibodies in a patient's serum.

Immunochromatography

A method used to detect seroconversion for HIV diagnosis via capillary action.

Latex particle agglutination

A method used to detect seroconversion where anti-HIV antibodies crosslink latex particles covered with HIV antigens, causing visual agglutination.

Window period

The period after HIV infection but before antibodies develop, resulting in a false negative HIV antibody ELISA; can be detected via RT-PCR.

RT-PCR (Reverse Transcription Polymerase Chain Reaction)

A modification of PCR used to detect HIV infection in the window period by making a DNA copy (cDNA) of the viral RNA and then amplifying the DNA.

Flow cytometry/FACS

Technique used to count T helper cells by mixing blood cells with a fluorescently labeled antibody specific to the CD4 glycoprotein on their surface.

Multiple myeloma

A condition caused by cancerous proliferation of plasma cells in the bone marrow, leading to bone fractures, hypercalcemia, and recurrent infections.

Paraprotein

Overproduced immunoglobulin band detected in the blood serum of a person with multiple myeloma, visualized by serum cellulose acetate electrophoresis.

Cellulose acetate electrophoresis

A technique used to detect paraprotein in multiple myeloma. Proteins with a negative charge migrate toward the anode.

Autoimmune diseases

Conditions where the body produces self-reactive lymphocytes (T or B cells) that are directed against the body's own cells.

Pernicious anaemia

An autoimmune condition caused by antibodies against gastric parietal cells or intrinsic factor, leading to vitamin B12 deficiency and impaired red blood cell production.

Intrinsic factor (IF)

A protein made in the stomach that enables vitamin B12 to be transported across the gut wall and into the blood.

Indirect immunofluorescence

A technique used to detect autoantibodies by adding test blood serum to a tissue sample, followed by a fluorescently-tagged anti-human antibody, and then observing under a fluorescence microscope.