[MICRO20] Lec 6: Overview of Host Immune Response (Flashcards)

immūnis

Immune comes from the word "_____" which means exempted.

Immunology

A branch of biology that covers the study of immune systems in all organisms. It encompasses the study of development, anatomy, functions, and malfunctions of the immune system, all of which are fundamental to the understanding of human diseases.

Hematopoiesis

Process of formation and development of blood cells from hematopoietic stem cells.

Single stem cell or a pluripotent (aka multipotent stem cell).

It is the "original cell". It is capable of producing all leukocytes (white blood cells) as well as erythrocytes (red blood cells) and thrombocytes (platelets).

TRUE

TRUE OR FALSE

Myeloid is a word denoting a derivation of body structure from the bone marrow while lymphoid is a word which is used to refer to the lymph and lymphatic system. Myeloid can also refer to an illness referring to the origin of bone marrow structures while lymphoid is a term denoting illness from the lymphatic system.

TRUE

TRUE OR FALSE

Leukocytes (white blood cells) are of two main types-granulocytes or granular leukocytes (containing granules in their cytoplasm) and agranular leukocytes (lacking granules in their cytoplasm).

Natural Killer Cells

Large, non-phagocytic lymphocytes that are capable of killing abnormal host cells, so when they see something abnormal in our bodies, they kill it. These may be "functionally cytotoxic" because they kill cells that are infected with viruses or tumors

Perforin

A chemical used by NK cells that damages the target cell's membrane, resulting in its death.

Granzymes

These are serine proteases released by cytoplasmic granules within cytotoxic T cells and natural killer cells. They induce programmed cell death in the target cell, thus eliminating cells that have become cancerous or are infected with viruses or bacteria

B Lymphocytes (B cells)

They are important because they synthesize immunoglobulin molecules (aka antibodies) in response to attacks of foreign particles like tumors, viruses, bacteria, etc.

TRUE

TRUE OR FALSE

The etymological origins of in vivo and in vitro come from Latin; in vivo describes something "within a living organism" while in vitro describes something "in glass" such as a test tube or petri dish.

T Lymphocytes (T cells)

- If B cells are 'hairy', these cells are 'bald'.
- Cells of the lymphoid lineage that migrate to and differentiate in the thymus.
- Their function is to help B cells produce antibodies and immunoglobulins;

TRUE

TRUE OR FALSE

Monocytes are mononuclear cells that are in circulation in the blood. They are called macrophages once they become tissue residents.

Antigen-presenting cells (APCs)

Antigen-presenting cells (APCs) are a heterogeneous group of immune cells that mediate the cellular immune response by processing and presenting antigens for recognition by certain lymphocytes such as T cells.

Pseudopod or pseudopodium

This is a temporary arm-like projection of a eukaryotic cell membrane that emerges in the direction of movement. Filled with cytoplasm, these primarily consist of actin filaments and may also contain microtubules and intermediate filaments.

Dendritic cells

- They initiate and also efficiently activate your T cells.
- They transport antigens/foreign bodies to lymph nodes
- Since they transport, they are also responsible for antigen presentation.
- They dictate T cell development thus controlling the responses to antigens. They are manipulative.

Granular Leukocytes

These leukocytes have more than one nucleus, and have cytoplasmic granules containing elements that stain differently. These cells are the front-liners during the immune response. The granules are released in response to the presence of pathogens. For example, in the event of an allergy, the granules are
released.

Neutrophils

They comprise around 60% of the peripheral blood leukocytes. They are also known as polymorphonuclear or PMNs due to their varied number of nuclear segments. They also produce: Lactoferrin, lysozyme, Leukotrienes, prostaglandins, and Myeloperoxidase

Basophils

They contain cytoplasmic granules that are colored blue to black. Once they granulate, the cells release vasoactive amines and other molecules that are associated with an allergic reaction. E.g. histamines (causes smooth muscle contraction)

Eosinophils

They contain eosinophilic (orange to red, or even pinkish) granules, and comprise 0-5% of the peripheral blood leukocytes. They also actively participate in the innate and adaptive immunity
especially in parasitic infections. They secrete cytokines that help regulate T- and B-cells during adaptive immune response)

TLR9 Receptors

Part of the innate immunity commonly found on the cell surfaces. It "polices" the host cells: Once antigens infiltrate the body, these receptors monitor and reports them, alerting the immune response of the presence of these foreign bodies

Innate Immunity

Conferred by several cellular and subcellular components that a person acquires by birth. It is always present and available (even at a very short notice) to protect one from invasion by foreign invaders. They also provide the first line of defense against pathogens.

Stratum Corneum

It is the outermost epidermal layer of the skin. The cells of this layer provide a water-tight barrier, preventing dehydration. There are special cells (keratinocytes) on the skin that continuously divide and slough off.

TRUE

TRUE OR FALSE

Coughing is not a sign of illness, rather it is a sign that we are expelling something (immune response)

Microcidal

_____ means that something is able to inhibit or kill microbes that attempt to colonize our body.

Defensins

Produced by the skin as a response to microbial products

Paneth Cells

Specialized small intestine epithelial cells that contain lysozyme, possess phagocytic properties, and secrete cytoplasmic granules into the intestinal crypt lumen after the entry of bacteria.

TRUE

TRUE OR FALSE

Lysozyme in sweat breaks down peptidoglycan. Peptidoglycans are one of the structural components of bacteria.

Beta-defensins

These defensins are found in the respiratory tract and attracts microbes and makes them more susceptible to ingestion or phagocytosis

IgE

- Present in circulation at very low levels (>.0005% of total Ig)
- Easily destroyed by heat
- Initiate degranulation of basophils and mast cells upon binding to specific antigen

IgM

- Makes up 5% - 10% of all serum immunoglobulins
- Known as macroglobulin
- Also known as primary response antibody because it is the first to appear in the antigenic stimulation and the first to appear in a maturing infant

IgA

Predominant immunoglobulin in secretions; Binds antigens and prevents their adherence to mucous membranes to keep them from invading the body

IgG

- Predominant immunoglobulin in the adult
- longest half-life (23-25 days)
- Only immunoglobulin that crosses the placental barrier
- Widely used in production of monoclonal antibody for clinical purposes
- "delayed response"

Effector T cell

A kind of T cell that is induced to differentiate into a form capable of mounting a specific immune response. These are key players in immune responses to execute immune functions

Helper T cell

A kind of T cell that usually expresses the CD4 co-receptor. It is important in producing Inflammatory reactions.

Cytotoxic T cell

A kind of T cell that is unable to attack any target cell but just a precursor of cytotoxic lymphocytes, which have that ability

Memory T cell

A kind of T cell that remains in the body after initial infection and retains a memory of a pathogen. They are derived from normal T-cells that have learned how to overcome an invader by 'remembering' the strategy used to defeat previous infections.