Immunopathology 1 Flashcards by Iseoluwa Ojo

The body must defend itself against infections, organisms and maintain its identity by means of nonspecific defense mechanisms ( _______ ) and
specific defense mechanisms ( _______ )

resistance

immunity

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The task of the immune system is the body’s ability to distinguish between
_______ substances (“___ ”) and _______ substances (“______”).

This system can be subdivided into two different families of cells,
the _____ and ______

autologous; self

exogenous; non-self

B and T lymphocytes.

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The B cells are responsible for _____ immunity.

humoral

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B cells

Their effector mechanism consists of the ______ they produce , which are supported by a ____________

antibodies

system of complements activated in a cascade.

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B cells

Their effectiveness is attributable to the ______ they generate and to ______ among them

cytokines

killer cells

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HYPERSENSITIVITY REACTIONS

Here the organism responds to _____ contact with _________ and to which it is ______

renewed

an antigen that it already knows

hypersensitive

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Effectors and description of the hypersensitivity reactions

Type 1
Type 2
Type 3
Type 4

Immediate ; IgE
Cytotoxic ; IgG and IgM
Immune; IgG and IgM
Delayed; Tcells

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AUTOIMMUNE DISEASES

In these disorders, the body _____________

Accordingly, autoreactive ______ or autoreactive ______ that attack autologous substrates are crucial elements in the pathogenesis of these disorders

violates the protection of its own identity and attacks itself.

antibodies; lymphocytes

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IMMUNODEFICIENCY DISEASES

These disorders are attributable to a _________ response to various antigen stimuli.

deficient immune

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In immunodeficiency diseases

Congenital B-cell defects are clinically conspicuous because of the ______________ that they involve.
In contrast, primary T-cell defects leave the patient unprotected against _____________

reduced resistance to bacterial infection

viruses and fungi.

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IMMUNODEFICIENCY DISEASES

Patients with a combined B cell and T-cell deficiency are __________

poor candidates for survival.

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Among the acquired immunodeficiency disorders, _______ due to ___________ of a plasma cell clone and ____ due to infection with the human immunodeficiency virus (HIV) warrant special mention.

gammopathy

neoplastic proliferation

AIDS

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Innate immunity

It is the initial response by the body to eliminate microbes and prevent infection occurring ______ after exposure to an antigen

immediately or within several hours

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Innate immune responses are as powerful as adaptive immune responses in combating infections

Innate immune responses are not as powerful as adaptive immune responses

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Innate immune responses improve with repeated exposure to a given infection

T/F

Innate immune responses do not improve with repeated exposure to a given infection

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Innate immunity

-is present after infection
-mounted in response to infection
- recognizes every possible antigen.

F. Before
F. Not
F. Doesn’t

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Innate immunity

Designed to recognize ___________ molecules shared by groups of related microbes that are essential for the survival of those organisms but are not ___________.

pathogen-associated molecular patterns (PAMPS),

found in mammalian cells

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PAMPs are not found on _________ alone but __________ hence, they are also called ________

pathogenic microbes

all microbes of the specific groups

microbe associated molecular patterns (MAMPs

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Pathogen associated molecular patterns (PAMPs)
They include

____ from the gram-negative cell wall

____ and _____ from the gram-positive cell wall

the sugar ______

bacterial ______

______ from fungal cell walls

LPS; peptidoglycan and lipotechoic acids

mannose

flagellin

glucans

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Pathogen associated molecular patterns (PAMPs)
They include

bacterial and viral _______________ motifs (found in many bacteria)

the amino acid _____found in bacterial proteins double-stranded and single-stranded RNA from viruses

unique molecules displayed on stressed, injured, infected, or transformed human cells may also stimulate _____, called ________________

unmethylated CpG DNA

N-formylmethionine

TLRs

danger associated molecular patterns.

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Innate immunity
Examples of innate immunity include

anatomical _____

______ removal

_______ antagonism

________ receptors

___________ defense chemicals

the ______ pathways

____,_____,______

barriers; mechanical; bacterial

pattern-recognition

antigen-nonspecific

complement

phagocytosis
inflammation
fever

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Innate immunity

The major cells involved in innate immunity include

phagocytic cells ( _____,_____ ,_____)

cells that release inflammatory mediators (_____,______,______)

______ cells

_______ cells

neutrophils, monocytes and macrophages

basophils, mast cells, and eosinophils

Natural killer

Mucosal epithelial ; Endothelial

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The best defined pattern recognition receptors are the _______

Toll-like receptors (TLRs).

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Cells of innate immunity

These cells express _______ receptors, cellular receptors that recognize ____.

pattern recognition

PAMPs

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Innate and adaptive immunity: complement activation In innate immunity, the complement system is activated by binding to microbes using the ________ pathways.

alternative and lectin

In adaptive immunity, it is activated by binding to antibodies using the ______ pathway.

classical

Cells of the adaptive immunity system ______ ______ ______ _________ ________

T lymphocytes B lymphocytes Macrophages Antigen presenting cells e.g. dendritic cells. NK cells

Neutrophils, basophils and eosinophils play a major role in defense systems and are directly involved in antigen handling. T/F

F They are not directly involved in that

T lymphocytes Account for ______% of circulating lymphocytes Found in the blood, T cell zones of peripheral lymphoid organs e.g. ______ of lymph nodes, ______ of the spleen

60-70 paracortical areas periarteriolar sheaths

T cells recognize cell bound antigens by means of ____________

an antigen-specific T-cell receptor (TCR)

T cell receptor The TCR is a disulfide-linked heterodimer of 2 polypeptide chains which may be ___ (___%) or ____

αβ; 95 γδ

T cell receptor αβ (95% of T cells)– recognizes antigens __________ γδ (a minority of T cells)- ______________

presented by MHC molecules on the surfaces of antigen-presenting cells does not require antigen presenting cells before they can bind antigens.

Exact function of γδ TCR is ???? but _________ where they are thought to _________.

not known they aggregate at epithelial surfaces be involved in immune surveillance

Knock out mice that cannot make γδ T cells are (slower or faster?) to heal injuries to their skin and are (more or less?) susceptible to skin cancers than normal mice.

Slower More

Function associated molecules: CD4 and CD 8 Expressed on 2 mutually exclusive subsets of αβ T cells CD4 is found on about ____% and CD 8 on about ____% of mature T cells CD 4 molecules bind to Class ___ MHC molecules CD8 molecules bind to Class __ MHC molecules

60 30 II I

T cell diversity and TCR gene rearrangements T cell diversity is generated by _________ All ____ cells have TCR genes from the germ line

TCR gene rearrangements somatic

Rearrangements of TCR genes occur only in _____

T cells.

Each T cell has a unique _______ and a unique ____ which is useful in differentiating _______ and _______ T cell proliferations

DNA rearrangement TCR monoclonal and polyclonal

End result of T cell activation is differentiation into ____ cells ( ____ or _____ cells) or ____ cells (T ___ cells)

T8; cytotoxic or suppressor T4; Helper

CD4 cells Are Activated by _______ and differentiate into _____ cells and _____ cells.

APC and IL-1 Helper T memory T

The _____ T cell acts as a master regulator, secreting cytokines and influencing the function of other cells of the immune system including T cells, B cells, macrophages and NK cells.

CD4

2 types of T Helper cells: T Helper 1 cells- secrete ____ and ____ T Helper 2 cells- secrete ____,____ ,_____ ,

IL-2 and IFN-γ, IL-4, IL-5 and IL-13

delayed hypersensitivity T helper 1 or T helper 2

Helper 1

macrophage activation T helper 1 or T helper 2

synthesis of opsonizing and complement-fixing antibodies. T helper 1 or T helper 2

synthesis of other classes of antibodies, notably IgE (mediated by ____,_____) and the activation of eosinophils (____). T helper 1 or T helper 2

IL, 4 and IL-13 IL-5 T helper 2

CD 8 cells Cytotoxic T cells Activated by ___________ or by ________ -Activated cytotoxic T cells disrupt the _____ of infected cells, ____ them.

contact with antigen presenting APC’s body cells infected with virus. cell membranes lysing

CD8 cells Suppressor T cells -Activated by _______ and ______ -it _________

contact with antigen and IL – 2. Terminate the actions of cytotoxic cells

B lymphocytes ____% of circulating peripheral lymphocyte population and in peripheral lymphoid tissues such as lymph nodes ( ______ ) and spleen ( _____ ), or ____ and extralymphatic organs such as the ____.

10-20 superficial cortex; white pulp; tonsils GIT

The end result of B cell activation is their differentiation into _____- secreting cells called ____ cells.

antibody plasma

Natural Killer (NK) cells Constitute ____% of circulating lymphocytes Are CD__ negative (T lymphocytes are CD__ positive)

10-15 3; 3

NK cells Express receptors for _____ (known as CD___) which enables them to _________ They also kill ____ infected and ____ cells

Fc of IgG; 16 lyse IgG coated cells virus; tumour

Nk cells They express _____ receptors for MHC I

inhibiting

Macrophages Belong to the class of APC T/F

Macrophages They take up ____, process it and present it to the ___ cells

antigens; T

Dendritic cells are APCs found in ______, interstitium of many organs and in the _____ ( ______ cells)

germinal follicles skin Langerhans

Major Histocompatibility molecules are antigens T/F

F Not antigens but antigen presenting cells

MHC These molecules are critical to ___ cell immunity as these cells recognize only membrane-bound antigens

MHC Encoded for by a cluster of genes on ____ arm of chromosome ___ called the major histocompatibility complex or the _________________ complex.

short 6 human leukocyte antigen (HLA)

Major Histocompatibility molecules The genes are contained within ___ HLA loci known as _______

4 A, B, C and D.

MHC genes and gene products are classified into ___ classes based on their chemical structure, tissue distribution and function-

Class I MHC - found in ___________ -encoded by __ closely linked loci – HLA- ______ it is a heterodimer consisting of ______ and ______ chain.

all nucleated cells and platelets 3; A, B and C, polymorphic α and non- polymorphic β

Viral infection of a cell is associated with altered HLA class ___ expression on cell surface which is recognized by ____ and ____

I CD8 and NK cells

Major Histocompatibility molecules •Class II MHC- coded for in a region called HLA- ___with __ sub-regions- HLA- ______ -it is a heterodimer with _____ α and β chains. -It is limited to ____.

D; 3 DP, DQ, DR polymorphic APCs

Class II MHC They bind phagocytosed antigens and present them on their surface to be recognised by ______ cells

CD4 helper

Class III MHC- encode components of the ________

complement system.

Role of HLA in diseases Individuals who inherit HLA alleles associated with specific diseases have a lesser chance of developing the disease than normal subjects do. T/F

F greater

2 random individuals can have the same HLA molecules T/F

F HLA genes are highly polymorphic hence, any 2 individuals except identical twins will have different HLA molecules which will be seen as foreign (allogeneic).

Examples of diseases associated with HLA alleles include _______ and other ______ with HLA B-27, _______ def with HLA-___, _______ with HLA-__, autoimmune endocrinopathies with the DR locus.

ankylosing spondylitis arthropathies 21- hydroxylase; BW47 hereditary chromatosis ; A

ANTIGEN Definition: A substance which the body recognizes as “ _____ ” and that triggers a ________

foreign; specific immune response

Complete antigen: A substance that ___________ and that can specifically ____________

induces an immune response react with the product of that response (the antibody).

Incomplete antigen Aka ______

Hapten

Incomplete antigen : A low-molecular-weight substance (a short peptide or drug) that only acts as an antigen once it ___________

binds to macromolecules

Physiology: The human immune system consists of about _____ lymphocytes and weighs about ____ kg. It is composed of tissues belonging to the _______ and _______ systems.

1 x 1012; 1 lymphatic and reticuloendothelial

The immune organs include the following anatomic structures: _______ Immune Organs _______ Immune Organs

Central Peripheral

THYMUS Until the end of the ____ month of embryonic development, the thymus is purely ______ organ. After that time, immature lymph cells migrate from hemopoietic embryonic tissue into the thymus. There they are cared for by ____ cells ( _______ cells) and are programmed to distinguish between “self” and “non-self.” They then enter the bloodstream as “fighting lymphocytes” (T lymphocytes) and settle in the peripheral lymphatic organs

second; an epithelial nurse; interdigitating

Central Immune Organs BURSA OF FABRICIUS AND BONE MARROW The bursa of Fabricius occurs only in ____ and is located near the ____. _______ appears to have assumed the function of this organ in mammals and may therefore be regarded as its equivalent with respect to the ontogeny of the human immune system. Accordingly, the lymphocytes produced here are referred to as ____ lymphocytes.

birds; cloaca Bone marrow B

Peripheral Immune Organs LYMPH NODES The follicular cortical region with ______ and ______ and the medullary region with the sinus of the node contain _____ The paracortical region with its _____ follicles supplied by venules harbors ___ lymphocytes.

primary and secondary follicles B lymphocytes. tertiary; T

Peripheral Immune Organs SPLEEN Branches of the _____ artery, the _________ of the arteries of the _____ belong to the T-cell system, whereas the splenic _____ and part of the ____ pulp belong to the B-cell system.

trabecular periarterial lymph sheaths splenic pulp follicles; red

Peripheral Immune Organs MALT includes the following structures: — Lymphatic _____ ring with the _____,_____, and ______ tonsils; — Gut-associated lymphoid tissue (GALT), including the ____ in the duodenum, the ____ of the appendix, the _____ of the colon, and the ______ of the intestinal mucosa;

pharyngeal; pharyngeal, lingual, and palatine Peyer’s patches; follicles; solitary follicles immunocompetent cells

Peripheral Immune Organs MALT —_________ (BALT), including the lymphoid tissue in the ___________; — Exocrine glands (_______ and ______);

Bronchi-associated lymphoid tissue peribronchial fascial sheath salivary glands and pancreas

The MALT is characteristically located in the __________ containing bacteria (gastrointestinal and respiratory tracts) and is in contact with ________ and other antigen material.

walls of hollow organs pathogenic germs

Antigens from the intestinal tract are treated as follows: The follicle-associated intestinal epithelium contains ______ cells (M cells), which pass antigens from the intestinal lumen to _________. The absorbed antigen is received by _________ and _____ and treated in such a manner that ____________ They then enter the peripheral blood through the lymph system and ______ However, their ____ receptors enable them to find their way back to the _____ of their home vessels in the intestinal mucosa and in the other mucosa-associated lymphoid tissues.

membranous; intraepithelial lymphocytes macrophages and dendritic cells T cells and/or B cells in the adjacent lymph follicle are activated. search for these antigens. homing; endothelium

Antigen presentation to T cell by dendritic cells MHC to ______ CD__ to CD___

TCR 80/86 to 28

Antigen presentation to T4 cell by B cells MHC ___ to ____ CD___ to CD___

2; TCR 40: 40L

Heavy chain contributes to ________ regions. Light chain contributes to _______ regions.

Fc and Fab only to Fab

Classic pathway of complement activation is by IG___ or IG___

G M

C1 is a macromolecule T/F With proof

T Has q,r,s S is the recognition molecule