Model 12 immune

immunology

the study of the physiological defenses by which (the host) recognizes self fron nonself

pathogens

microbes that could potentially causes a diseas

explain what are the three layer of immune response

first layer physical skin, pH

second layer-innate immune responser: repid, nonspecific, no memory

• macrophages

• neutrophils

• natural killer (NK) cells

• dendritic cells

• ( uses 1. phagocytes 2.Natural killer (NK) cells 3. antimicrobial proteins 4. inflammation 5.fever)

third layer- adaptive immune responser: slow, specific, has memory

• B lymphocytes

• plasma cells

• T lymphocytes

• cytotoxic T cells

• Helper T cells

• antibody- mediated responses

Is a virus a cellular life form?

No virus need a host cell to replicate inside

what is the main defense against viruses that have infected host cells?

cytotoxic T lymphocytes

what is primary lymphoid tissue? and secondary lymphoid tissue?

immune cells develop and mature in primary lymphoid tissue

• red bone marrow

• thymus

where they work to intercept pathagens to keep them from entering the general circulation

• spleen

• lymp nodes

• Gut- associated lymphoid tissue (GALT)

In innate immune response give explamble of the phagocytic cells?

• macropages

• neutrophils

• dendritic cells

They express Pattern Recognition Receptors (PRRs) on their cell membranes

PRR specifically bind to Pathogen-Associated Molecular Patterns (PAMPs)

what unique features does pathogen-association molecular pattern (PAMPs) has so that RRP can recognized

PAMPs are conserved molecular structure (molecular motifs)

lipopolysaccharides (LPS) component of cell wall of many bacteria

• modecular motifs

• lipopolysaccharides

what does natural killer cells do?

recognize Major Histocompatibility Class I (MHCI)

NKCs release granzymes and perforin that induce apoptosis

release cytokines that activate other parts of the immune system

Cytokine: a family of peptide messengers released by one that affect the growth and activity of another cells; cytokines are made on demand, unlike peptide hormones, which are made in advance and stored in vesicles

antimicrobial proteins

complement : 30 proteins that are activated in a cascade, first inactive then they take the classical plathway when

C1 bind to antibody-antigen complex

then C3 protein is active which becomes C3a and C3b

C3a cause mast cell to release histamine(increase permeability of capillaries) - a inflmmation (local capillaries dilate and become more permeable to cells and fluid)

C3b functions as opsonin (tag) (antibody can function has opsonin too)

C3b function has activating C9

C9 is a polymerizes (along with other complement proteins) to form a membrane attack complex (MAC)

membrane attack complex (MAC) creates pores that make water go in to the bacteria and promote pathogen cell swells and lyses

• have also interferons

what is interferons

• interferons are proteins released by one virally infected host cell that prevent viral replication in neighboring host cell (interferons interfere with viral replication)

• interferons are a group of about 20 cytokines that are produced by host cells

• cytokines is a peptide signaling molecule that acts locally and is made on demand

• interferins are used as drug therapies, to treat multiple sclerosis

extravasation (also called diapedesis)

neutrophils and monocytes leave the capillaries and enter the tissue in a process called

antihistamines

use when ex: pollen appear

• antibodies are generated against the allergen and bind to the surface of mast cells

• degranulation( excess histamine) lead to vasodilation and excess inflamation

why would people use aspirin?

to block the production of prostagladin E2 a lipid signaling molecule which acts in the pre-optic nucleus of the hypothalamus to increase the temperature set point.

exogenous pyrogens as lipipilysaccharides lead to the synthesis of prostaglandin E2

what are the division of adaptive immune system?

• cell-mediated immunity

  • immune cells use contact with pathogens/abnormal cells and subsquent contact-dependent signaling processes to neutralize them

• Humoral immunity

  • antibody-mediated responses (plasma cells)

Antigens

a mocleucle such as peptide, protein, lipid, or carbohydrated that triggers an immune resposne (bacteria ex:)

explain what are B cell receptors (BCRs) and T cell receptors (TCRs)

B cell receptors

• expressed on surface of Bcells

• enconded by two genes that undergo rearrangement during development

• secreted B cell receptros are antibodies

• A single B cell receptor (BCR) consists of two identical heavy chains and two identical light chains linked by several disulfide bridges

T cell receptros (TCR)

• Expressed on surface of T cells

• Enconded by two genes that undergo rearrangment during development

• A single cell receptor (TCR) consist of one alha chain and one beta chain linked by a disulfide bridge

B cell

1. Antigen bind to B cell receptor

2. clonal expasion

3. some become memory B cells and other become plasma cells that release antibodies

What are antibody functions?

1. Antigen clumping

2. Inactivation of basterial toxins

3. Act as opsonins to tag antigens for phagocytosis

4. Trigger degranulation

5. Activate complement

6. Activate B lymphocytes

what are antigen-presenting cells (APCs)

• are a bridge between the innate and adaptive immune response

• Macrophages, dendrtic cell and Bcells

• antigen are displayed on the surface of the MHC class II

cyclosporine

blocks the expression of the gene that encondes interleukin 2 in Helper T cells

interleukin 2

make clone expasion in Helper T cells and promotes cell division of B cells that recognized that intigen so B cell become meory and plasma cells that release antibodies