34. Humoral Immunity Flashcards by Ibby Khan

where are B CELLS typically found

BLOOD
LYMPH NODES
SPLEEN

How well did you know this?

Not at all

Perfectly

how are B CELLS ANTIBODIES INITIALLY

have ANTIBODIES on their CELL SURFACE,
acting as RECEPTORS for ANTIGENS

How well did you know this?

Not at all

Perfectly

what happens when an ANTIGEN BINDS to the ANTIBODIES on B CELL SURFACE

ACTIVATES
PROLIFERATION
drives B cell into a PLASMA CELL - SECRETORY CELL that SECRETES ANTIBODIES into bloodstream

How well did you know this?

Not at all

Perfectly

what do some PLASMA B CELLS become after

MEMORY B CELLS

How well did you know this?

Not at all

Perfectly

what is the major component of humoral immunity

antiodies

How well did you know this?

Not at all

Perfectly

what are the 5 CLASSES of ANTIBODIES

IgA, IgD, IgE, IgG, IgM

(all have same basic structure but some variation)

Ig = Immunoglobulin

How well did you know this?

Not at all

Perfectly

what type of molecule are ANTIBODIES

GLYCOPROTEINS
(GLYCOSYLATED)

How well did you know this?

Not at all

Perfectly

where are ANTIBODIES found

in SERUM and TISSUE FLUID

How well did you know this?

Not at all

Perfectly

Basic STRUCTURE of ANTIODIES - composed of:

2 IDENTICAL LIGHT CHAINS
2 IDENTICAL HEAVY CHAINS

2 IDENTICLE ANTIGEN BINDING SITES

VARIABLE region
CONSTANT region

How well did you know this?

Not at all

Perfectly

Basic STRUCTURE of ANTIODIES - what is it held together by

COVALENT & NON-COVALENT BONDS

2 HEAVY chains held together by DISULPHIDE BONDS

How well did you know this?

Not at all

Perfectly

Basic STRUCTURE of ANTIODIES-
HINGE REGION allows for

FLEXIBILITY
(for binding)

How well did you know this?

Not at all

Perfectly

which antibody is the PREDOMINANT ANTIBODY in the PRIMARY immune response

IgM

How well did you know this?

Not at all

Perfectly

which antibody is the PREDOMINANT ANTIBODY in the SECONDARY immune response

IgG

How well did you know this?

Not at all

Perfectly

IgM has a …. structure

PENTAMERIC STRUCTURE

5 basic antibody chains held together by a J CHAIN

How well did you know this?

Not at all

Perfectly

what does LARGE SIZE (pentameric) of IgM mean for it

LIMITED TRANSFER to tissues

mainly in SERUM
makes up around 10% of TOTAL SERUM IMMUNOGLOBULIN (significant)

How well did you know this?

Not at all

Perfectly

what is IgM good for (3)

COMPLEMENT FIXING
NEUTRALISING
OPSONISING antigens

How well did you know this?

Not at all

Perfectly

IgG is the PREDOMINANT antibody of which immune response

SECONDARY

How well did you know this?

Not at all

Perfectly

STRUCTURE of IgG

MONOMER (basic Y shape)
with 4 SUBCLASSES: IgG1, IgG2, IgG3, IgG4
(vary in hinge regions)

How well did you know this?

Not at all

Perfectly

what is the MAIN antibody found in SERUM and TISSUE FLUID

IgG

How well did you know this?

Not at all

Perfectly

IgG makes up how much of total SERUM IMMUNOGLOBULIN

75%

How well did you know this?

Not at all

Perfectly

IgG binds to Fc RECEPTORS on…(3)

LYMPHOCYTES
MONOCYTES
PHAGOCYTES

How well did you know this?

Not at all

Perfectly

ROLES of IgG

OPSONISATION
NEUTRALISATION
PHAGOCYTOSIS

How well did you know this?

Not at all

Perfectly

IgA is the PREDOMINANT antibody found in…

SECRETIONS

How well did you know this?

Not at all

Perfectly

what is the STRUCTURE of IgA

basic Y shape
but generally DIMER STRUCTURE
- joined by a J CHAIN

often associated with a SECRETORY COMPONENT

(in circulation it is a MONOMER)

How well did you know this?

Not at all

Perfectly

what is IgA DIMER often associated with

SECRETORY COMPONENT - produced by EPITHELIAL CELLS

IgA is important in what immunity

MUCOSAL IMMUNITY - found at MUCOUS MEMBRANES

where is IgA found

MUCOUS MEMBRANES in GUT, RESPIRATORY TRACT, SKIN sometimes circulation (as a monomer)

what is IgA good at (3)

NEUTRALISING BLOCKING pathogen ENTRY BLOCKING pathogen GROWTH

how is IgE STRUCTURE

MONOMER (basic Y shape)

how is IgE concentration in SERUM

LOWA

IgE is important in...

ALLERGY & response to PARASITES

what does IgE do in response to ALLEGREN (antigen)

binds to antigen & BINDS to FceRI on MAST CELLS - activates RELEASE of HISTAMINE & INFLAMMATORY MEDIATORS

when IgE binds to FceRI on MAST CELLS what is released (2)

HISTAMINE INFLAMMATORY MEDIATORS

how are IgD SERUM LEVELS

VERY LOW

how is IgD STRUCTURE and where is it FOUND

MONOMER at CELL SURFACE of B CELLS

IgD acts as...

an ANTIGEN RECEPTOR on surface of B-cells - antigen BINDS to it and triggers cell activation

which Immunoglobulin has a PENTAMERIC STRUCTURE

IgM

which Immunoglobulin is found as a DIMER

IgA (mucous membranes)

which Immunoglobulin has 4 SUBCLASSES

IgG (secondary response)

which Immunoglobulins are MONOMERS

IgG, IgE, IgD IgA in circulation

which Immunoglobulin is important in response to ALLERGY

IgE

which Immunoglobulin is important in MUCOSAL IMMUNITY (at mucous membranes of gut, respiratory tract, skin)

IgA

which Immunoglobulin acts as an ANTIGEN RECEPTOR

IgD

which Immunoglobulin is good at COMPLEMENT FIXING, NEUTRALISING, OPSONISING

IgM (primary response)

which Immunoglobulin binds to FceRI on MAST CELLS

IgE (response to allergy)

which Immunoglobulin responds to PARASITES

IgE

which Immunoglobulin is found at the CELL SURFACE of B CELLS

IgD (antigen receptor)

which Immunoglobulin binds to Fc RECEPTORS on LYMPHOCYTES, MONOCYTES, PARASITES

IgG (secondary response)

which Immunoglobulin is good at NEUTRALISING, BLOCKING ENTRY, BLOCKING GROWTH

IgA (at mucosal membranes - secretory)

which Immunoglobulin is good at OPSONISATION, NEUTRALISATION, PHAGOCYTOSIS

IgG

which Immunoglobulin makes up 10% of SERUM

IgM

which Immunoglobulin makes up 75% of SERUM

IgG

which IMMUNOGLOBULIN is found predominantly in SECRETIONS

IgA

which Immunoglobulin activates release of HISTAMINE and INFLAMMATORY MEDIATORS

IgE (response to allergy)

where is the primary location of IgM

CIRCULATION (& sometimes found on B-cells)

where is the primary location of IgG

CIRCULATION & MOST TISSUES

where is the primary location of IgA in its 2 forms

as a DIMER: MUCOUS MEMBRANES & SKIN as a MONOMER: CIRCULATION

where is the primary location of IgE (allergy)

GUT, AIRWAY, SKIN

where is the primary location of IgD

B-CELLS

how is SECONDARY RESPONSE compared to PRIMARY

FASTER SHORTER LAG EXTENDED PLATEU HIGHER ANTIBODY TITRE INCREASED AFFINITY of ANTIBODIES to ANTIGEN (AFFINITY MATURATION) Predominantly IgG (IgA or IgE) primary = IgM

how is AFFINITY of antibodies to antigens different in primary and secondary immune response

SECONDARY- INCREASED AFFINITY AFFINITY MATURATION

how do ANTIBODIES help FIGHT INFECTION (2)

NEUTRALISATION - binding to toxin or virus, preventing it from binding to a receptor on host cell - IgG, IgA, IgM ENHANCING Fc RECEPTOR MEDIATED PHAGOCYTOSIS -OPSONISATION (coating eg bacteria) - IgG

which ANTIBODY CLASS ENHANCES Fc RECEPTOR MEDIATED PHAGOCYTOSIS (OPSONISATION)

IgG

other ROLES of ANTIBODIES (3)

- Antibody and antigen ACTIVATION of the COMPLEMENT PATHWAY (classical pathway) - IgE ACTIVATION of MAST CELLS (release histamine & inflammatory mediators). ANTI-PARASITE responses and role in ALLERGY. (can also bind to FcR on EOSINOPHILS) - TUMOUR CELL KILLING by NK cells and antibody (Fc receptors on NK recognise bound antibody)

which COMPLEMENT pathway ACTIVATION involves ANTIBODIES

CLASSICAL PATHWAY

which are the best ANTIBODIES at ACTIVATING COMPLEMENT

IgM, IgG1, IgG3

COMPLEMENT system results in the FORMATION of

MEMBRANE-ATTACK COMPLEX

ANTIBODIES can INDUCE

ALLERGY

ANTIBODIES are importing in inducing effective...

VACCINATION against pathogens

ANTIBODIES play a role in IMMUNOPATHOLOGY:

AUTOIMMUNE DISEASE

ANTIBODIES are important TOOLS for...

DIAGNOSIS

ANTIBODIES are also being used in...

THERAPEUTICS (treatment) modern but expensive drugs

what is HUMMORAL IMMUNODEFICIENCY

conditions where an individual is DEFICIENT IN or LACKS the ABILITY TO TO PRODUCE ANTIBODIES ranges from no antibody to reduced production of one class e.g. Selective IgA deficiency (SIgAD), reduced IgA levels, a genetic immunodeficiency, (type of hypogammaglobulinemia), affects around 1 in 600 people,

what is AUTOIMMUNITY

PRODUCTION of ANTIODY AGAINST SELF PROTEINS e.g. Myasthenia Gravis: muscular weakness associated with Abs to acetylcholine receptors.

what is ALLERGY

ANTIBODY PRODUCED AGAINST COMMON ENVIRONMENTAL PROTEINS (eg pollen) which would otherwise be harmless eg Hay fever, Asthma

ANTIBODIES in THERAPEUTICS are suitable for the TREATMENT of...

IMMUNE / INFLAMMATORY DISEASES or CANCER - mainly work by NEUTRALISING a molecule important in the disease process.

why do ANTIBODIES have potential to be GOOD DRUGS (4)

- HIGH SPECIFICITY - well CHARACTERISED STRUCTURE and BIOCHEMISTRY - seen as NORMAL body component - can be MADE AGAINST ANYTHING

ANTIBODIES given THERAPEUTICALLY are...

GENETICALLY ENGINEERED MONOCLONAL ANTIBODIES - antibodies in any one preparation are identical, binding the same part of the antigen

what is the PROBLEM with MONOCLONAL ANTIBODIES being generated in MICE

mouse antibodies are IMMUNOGENIC in humans - cause IMMUNE RESPONSE fully human antibodies are best but HARDER to generate

example of ANTIBODIES in THERAPEUTICS: for Respiratory Syncytial virus (RSV) (Common infection in young children, can cause serious respiratory disease, no vaccine)

PALIVIZUMAB - HUMANIZED antibodies (mostly human but still got some mouse sequence) provides PASSIVE IMMUNITY (not long-lasting protection) - NEUTRALISES the FUSION PROTEIN (viral particle)

34. Humoral Immunity Flashcards

(80 cards)