Antibody-Based Diagnostics and T Cell Immune Functions

A complete set of vocabulary flashcards covering antibody-based diagnostics, T cell types, MHC classes, and effector functions as described in the lecture notes.

Antibodies

Highly specific molecules capable of binding pathogens, host cells, or molecules for diagnostic and therapeutic purposes.

ELISA

Acronym for Enzyme-Linked Immunosorbent Assay, a technique using antibody-antigen specificity for detection.

Antigen Capture ELISA

A method where wells are coated with antibody specific for a pathogen to detect antigens in a patient sample.

Antibody Capture ELISA

A method where wells are coated with pathogen antigen to detect specific antibodies in patient serum.

Enzyme-conjugated secondary antibody

A molecule that binds to a captured antigen in ELISA to produce a visible color change.

Enzyme-conjugated anti-human antibody

A detection molecule used in antibody capture ELISA to bind to patient antibodies.

Rapid Diagnostic Tests (RDTs)

Diagnostic assays used in clinical or field settings for pathogens like Legionella or Streptococcus pneumoniae.

Sample well

The components of an RDT where the patient sample is initially placed.

Test line

The part of an RDT containing solid phase antibodies that capture pathogen antigens to produce a visible color change.

Control line

The part of an RDT containing anti-antibody to confirm assay validity and proper diffusion.

Colloidal gold-labeled antibodies

Molecules in RDTs that bind pathogen antigens and migrate across the test strip.

T cells

Critical components of adaptive immunity categorized as cytotoxic or helper cells.

Cytotoxic T cells (CTLs)

T cells equipped with the $CD8^+$ surface marker that kill infected cells by inducing apoptosis.

Helper T cells (Th)

T cells with the $CD4^+$ surface marker that coordinate immune responses via cytokines.

$$CD8^+$$

The surface marker found on cytotoxic T cells which allows interaction with MHC Class I.

$$CD4^+$$

The surface marker found on helper T cells which allows interaction with MHC Class II.

Thymus

The organ where T cells mature and undergo gene rearrangement to express unique T cell receptors.

T Cell Receptors (TCRs)

Unique receptors on T cells that recognize antigen peptides presented via MHC molecules.

Gene rearrangement

The process by which T cells generate highly specific and unique receptors during development.

Major Histocompatibility Complex (MHC)

Molecules that serve as platters to present pathogen-derived peptides to T cells.

MHC Class I

Molecules that present cytosolic intracellular peptides to $CD8^+$ cytotoxic T cells.

MHC Class II

Molecules that present extracellular endocytosed peptides to $CD4^+$ helper T cells.

Nucleated cells

Cells that express MHC Class I molecules, excluding red blood cards.

Specialized immune cells

Cells such as dendritic cells, macrophages, and B cells that express MHC Class II molecules.

Highly polymorphic

A characteristic of MHC genes that enables them to present a diverse array of different peptides.

Antigen-Presenting Cells (APCs)

Cells that present antigen peptides on MHC molecules to activate T cells.

Secondary lymphoid tissues

The location where T cell activation occurs after antigen presentation by APCs.

Dendritic cells

A type of specialized immune cell that acts as an antigen-presenting cell (APC) to activate T cells.

Apoptosis

The process of programmed cell death induced in target cells by cytotoxic T cells.

Cytotoxic enzymes

Substances released by cytotoxic T cells that trigger intrinsic apoptotic pathways in infected cells.

Th1 Subset

Helper T cells that activate macrophages to kill intracellular bacteria and secrete $IFN-\gamma$.

$$IFN-\gamma$$

A cytokine secreted by Th1 cells to stimulate macrophages and $CD8^+$ T cells.

$$IL-2$$

A cytokine secreted by Th1 cells to help coordinate the activation of macrophages and cytotoxic cells.

Th2 Subset

Helper T cells that assist B cells in proliferating and differentiating into antibody-secreting plasma cells.

$$IL-4$$

A cytokine secreted by Th2 cells that supports the immune response and B cell activity.

CD40L

A ligand expressed by Th2 cells that binds to CD40 on B cells to facilitate their differentiation.

CD40

A molecule on the surface of B cells that interacts with CD40L on helper T cells.

Th17 Subset

A subset of helper T cells that promotes inflammation and recruits neutrophils.

Follicular Helper T (Tfh)

T cells located in lymph node follicles that induce isotype switching in B cells.

Isotype switching

The process, also called class switching, where B cells transition from producing IgM to other antibodies like IgG or IgA.

Regulatory T cells (Tregs)

T cells that maintain immune homeostasis by suppressing immune responses to prevent autoimmunity.

Inhibitory cytokines

Molecules released by Tregs to dampen the activity of effector T cells after an infection.

Macrophages

Immune cells activated by Th1 cells to target persistent intracellular infections like tuberculosis.

Plasma cells

Differentiated B cells that secrete antibodies, a process coordinated by Th2 helper cells.

Neutrophils

Inflammatory cells recruited by the activity of the Th17 helper T cell subset.

Lymph node follicles

The specific anatomical locations where follicular helper T (Tfh) cells induce B cell antibody class switching.

Cytokine signaling

The mechanism through which helper T cells orchestrate broader immune responses.

Autoimmunity

Potential damage to the host which is prevented by the suppressive actions of regulatory T cells.

Adaptive immunity

The branch of the immune system to which T cells and antibodies belong, characterized by specificity and memory.

Ebola antigen

A substance used to coat ELISA plates when detecting host anti-Ebola antibodies in patient serum.