Immunology

1

• Immunology
• By
• Dr.Mohamed Barakat

2
(No Transcript)
3
RECOGNITION
Lymphocytes recognize and respond to particular
microbes and foreign molecules, i.e., they
display specificity
A foreign molecule that induces an immune
response is known as an antigen
4
Characteristics of Innate and Adaptive Immunity
Antigen independent
Antigen dependent
No time lag
A lag period
Not antigen specific
Antigen specific

• No Immunologic
• memory

Development of memory
5

• Immature dendritic cells internalize antigen,
  process it, mature, migrate to lymph node, and
  present processed Ag to T cells for adaptive
  immune response.
• Dendritic cells secrete cytokines that promote
  inflammation.

6
Simplified schematic of immune response system
proliferation differentiation
MHC Class I/peptides APCs
CD8 T-cell
CD8 cytolytic T-cells
MHC Class II/peptides APCs
proliferation
CD4 immune cell (delayed hypersensitivity)
CD4 T-cell (helper T-cells)
B-cell
Protein antigen
Plasma cell
proliferation differentiation
antibody production
LA-02
7
DC bridge innate and adaptive immunity

• DC recognize PAMPs through TLRs
• TLR7 and TLR8 play different roles in DC
  maturation

8

• Innate immunity is an immediate process via
  skin mucous membrane
• Antimicrobial peptides are molecules that
  circulating cells since oral mucosa is normally
  covered with mucin as a tissue barriers and
  saliva via protein histamine
• Major cells of innate immunity is phagocytes i.e
  neutrophils , basophilss , monocytes
• Macrophages are the natural killer (NK) along
  with dentritic cells which activate lymphocytes
• Lymphocytes act to initiate the adaptive immune
  response i.e T-lymphocytes B-lymphocytes
  leading to secretion of cytokines

9
Adaptive Immunity Two major mechanisms

• Cell-mediated immunity
• Humoral (antibody) immunity
• Soluble factors (cytokines) have a vital role in
  initiation and regulation of both immune responses

10
ATTACK MEMORY
The B and T cells that first recognize a given
foreign antigen are short lived, whereas immune
memory cells can have long lifetimes
Illustrated here for B cells, but the process for
T cells is similar
11
RECOGNITION of self molecules

• In a healthy immune system, as B and T cells
  mature they are destroyed by apoptosis if they
  attack self molecules

Healthy, mature B and T cells then have the
capacity to distinguish self from non-self
molecules
12
Central Role of Helper T Cells
13
Adaptive Immunity (Acquired Or Delayed)

• Adaptive Immunity is further classified into
• Cell mediated immunity (T cell )
• B) Humoral immunity (B cell )

14
Adaptive Immunity Two major mechanisms

• Cell-mediated immunity
• Humoral (antibody) immunity
• Soluble factors (cytokines) have a vital role in
  initiation and regulation of both immune responses

15
(No Transcript)
16
(No Transcript)
17

• Relationship Between Cell-Mediated and Humoral
  Immunity
• 1. Antibody Production
• T-Dependent Antigens
• Antibody production requires assistance from T
  helper cells.
• A macrophage cells ingest antigen and presents it
  to TH cell.
• TH cell stimulates B cells specific for antigen
  to become plasma cells.
• Antigens are mainly proteins on viruses,
  bacteria, foreign red blood cells, and
  hapten-carrier molecules.

18
A) Cell mediated Immunity

• Bone marrow produce T-cell precursor which
  migrate to Smyth , spleen lymph nodes which
  constitute 70 80 of lymphocytes
• Lymphocytes are normally circulating in
  peripheral blood stream
• When activated , lymphocytes produce cytokines
• T-cells develop into T-cell helper (Th-1 Th2)

19

• Th-1 secrete interferon interleukin
• Bothe interferon and interleukin leads to
  activation of macrophages which interns lead to /
  or eliminate intra cellular organisms
• Th-2 acts to eliminate extra cellular organisms
  via attraction of eiosnophils which act to send
  signal to B-cells to differentiate into plasma
  cells which produce antibodies circulate in the
  blood

20

• SO
• When Bacterial Or viral Antigen present in
  the tissue it leads to activation and
  production of lymphocytes which acts to produce
  lyses and destruction of infected host cell .
• SO
• Cell mediated immunity means movement of
  leukocytes between blood and tissue after being
  activated at the tissue

21
Simplified scheme of immune response system
proliferation differentiation
MHC Class I/peptides APCs
CD8 T-cell
CD8 cytolytic T-cells
MHC Class II/peptides APCs
proliferation
CD4 immune cell (delayed hypersensitivity)
CD4 T-cell (helper T-cells)
B-cell
Protein antigen
Plasma cell
proliferation differentiation
antibody production
LA-02
22
B) Humoral Immunity

• B-cells migrate to thymus , spleen and lymph
  nodes and tonsils when receiving a co
  stimulating signal from T-helper via its
  receptors immunoglobulin receptors to
  differentiate into I'm
• IgM producing plasma cells and / also B-cell
  undergone to class switching into IgM , IgA ,
  IgE and IgD ( which are macro molecules having 5
  antibody monomers in response to foreign
  antibody activation of complement
• Which leads to immune complex antibody
  antigen reaction

23
Primary and secondary Response

• After first response of antigen antibody
  reaction T-cell and B-cells , via adaptive
  immunity start making a memory against antigen
  (cells) by producing a primary antibodies against
  that particular antigen primary response
• When such antigen attacks again , this will
  leads to secondary response
  showing a high titers of already circulating
  antibody.
• All processes work to activate each other ,
  since complement system acts to regulate , and
  minimize tissue damage from inflammation

24

• Complement is a protein with multiple phagocytic
  and lysis effects which activate the process
  of phagocytosis
• Again , neutrophils which constitute 70 of
  leukocytes ,WBCS with a short life span , are
  usually activated by bacteria and cytokines so
  they migrate via receptors to reach the site of
  inflammation
• Bone marrow always acts to release huge numbers
  of such neutrophils due to infection .

25

• Natural killer ( NK ) constitute 10- 15 of
  peripheral blood circulating lymphocytes leads
  to cytolysis of tumor / virus infection
• by secreting cytokines which act to direct
  DCs to promote T B cell function

26
RECOGNITION
B cells produce antibodies, that are either
secreted out of the cells or remain embedded in
the B cell membranes, and that bind to antigens
27
Overview of the Immune Response
28
RECOGNITION
Multiple antibodies may recognize the same
antigen by different epitopes (small accessible
portions of the larger molecule)
29
RECOGNITION
B cells produce antibodies, that are either
secreted out of the cells or remain embedded in
the B cell membranes, and that bind to antigens
T cells have T-cell receptors, embedded in their
cell membranes, that bind to antigens
30
RECOGNITION of self molecules

• In a healthy immune system, as B and T cells
  mature they are destroyed by apoptosis if they
  attack self molecules

Healthy, mature B and T cells then have the
capacity to distinguish self from non-self
molecules
31
Immune Disorders

• Hypersensitivities
• Exaggerated immune response
• Results in tissue damage
• Autoimmune diseases
• Transplantation rejection
• Immune deficiency

32
General Principles regarding immunosuppression

• Primary responses are suppressed more easily than
  secondary responses (memory)
• Immunosuppressive agents have different effects
  on different immune reactions
• Suppression is more effective when therapy
  precedes exposure to the immunogen

33
(No Transcript)
34
(No Transcript)
35
Immune disorders

• immunity immune disorders - extreme importance
  (comparable to bacteriology at the early 20th
  cent.)
• new diseases, immunological etiology in "old"
  diseases, immunotherapy - considerable amount of
  medical information
• immune system - important for survival
• increased or decreased immunity - disease

36
Introduction

• humoral cellular immunity
• B-lymphocytes - plasma cells - Ig A, M, G, E, D
• lymph nodes - cortex - germinal centers
• T-lymphocytes (60-70 in peripheral blood)
• lymph nodes - paracortex
• subspecialization (helper, suppressor, killer,
  natural killer)

37
Introduction

• Macrophages
• Antigen-presenting cells - dendritic cells,
  Langerhans cells (skin)
• MHC system
• HLA complex antigens - ability to recognize own
  Ag from foreign ones
• importance in transplantation - rejection
  (destruction of the graft by host)

38
1. Immune mechanisms of tissue damage

• immune response (both humoral cellular)
• Ag (both exogenous endogenous)
• inappropriate - hypersensitive reaction
• allergy - 4 types

39
2. Autoimmune diseases

• immune system reacts against own Ag
• A. Organ specific
• Hashimoto's thyroiditis
• Graves-Basedow disease
• chronic atrophic gastritis - pernicious anemia
• DM type I.
• B. Systemic (multiorgan)
• affection of vessels and/or connective tissue,
  variable symptomatology
• systemic disorders of connective tissue
  (collagenosis)
• rheumatic fever

40
AUTOIMMUNITY

• Ability of immune system to differentiate between
  self and non-self antigens
• Immune system response against self antigens

41
AUTOIMMUNITY

• Autoimmunity appears normal part of immune system
• Healthy people have low concentration of
  autoantibodies in serum and tissue
• Auto-antibodies may form antigen-antibody complex
  removed by macrophages as part of tissue damage
  removal

42
Definitions

• Auto-antigens
• Self antigens
• Immunologic tolerance
• No immune response to a specific antigen

43
Autoimmune Diseases

• Autoimmune Diseases
• What is an autoimmune disease?

44
Autoimmune Diseases

• When the immune system attacks the body's own
  cells, it produces an autoimmune disease.

45
Autoimmune Diseases

• Some examples of autoimmune diseases include
• Type I diabetes attacks insulin-producing cells.
• Rheumatoid arthritis attacks connective tissues
  around joints.
• Myasthenia gravis attacks neuromuscular
  junctions.
• Multiple sclerosis (MS) destroys functions of
  brain and spinal cord neurons.

46
Immunological Problems Diseases

• There are several ways in which the immune
  system may fail
• When the pathogen is too violent
  (multiplies too fast, causes too much
  damage), or evades the immune system (e.g.,
  via mutation). Solution vaccination or
  medication.
• Immune deficiencies inherited or acquired.
• Improper response to foreign (non-pathogenic)
  antigens Hypersensitivity and Allergy.
• Improper response to self Autoimmune
  diseases.
• Rejection of transplanted tissues.
• Failure to detect cancers.
• Cancer of immune cells.

47
Immune Deficiencies

• Inherited
• Cellular - when the defective gene is only
  in T cells
• Humoral - when the defective gene is only
  in B cells
• Combined - when the defect is in a gene
  common to all lymphocytes, e.g., RAGs
  (recombination activation genes).
• Acquired - due to
• Hemopoietic diseases
• Treatments chemotherapy, irradiation
• Infection AIDS - caused by the Human
  Immunodeficiency Virus (HIV) which attacks
  helper T cells. The virus gradually kills
  more T cells than the body can produce,
  the immune system fails, and the patient
  dies from infections that are normally not
  dangerous.

48
Immune Hypersensitivity

• Hypersensitivity is an improperly strong
  response.
• Immediate hypersensitivity
• Mediated by antibodies.
• Types
• allergy - up to anaphylactic shock.
• Induction of antibody-mediated cytotoxicity.
• Sickness due to accumulation of immune
  complexes.
• Delayed hypersensitivity
• Mediated by T cells.
• Hyper-activity of CTLs and macrophages.
• Contact sensitivity.

49
Autoimmune diseases

• Normally, the immune system does not attack
  the self.
• This is ensured by elimination of
  auto-reactive lymphocytes during their
  development (negative selection).
• However, there is a large group of diseases
  in which the immune system does attack
  self-cells autoimmune diseases.
• The attack can be either humoral (by
  auto-antibodies) or cellular (by auto-reactive
  T cells).
• The attack can be directed either against
  a very specific tissue, or to a large
  number of tissues (systemic autoimmune
  disease), depending on the self-antigen
  which is attacked.

50
Autoimmune diseases

• Specific
• Juvenile diabetes (attacks insulin-producing
  cells)
• Multiple sclerosis (attacks myelin coating of
  nerve axons)
• Myasthenia gravis (attacks nerve-muscle
  junction)
• Thyroiditis (attacks the thyroid)
• Systemic Immune complexes accumulate in many
  tissues and cause inflammation and damage.
• Systemic Lupus Erythematosus (anti-nuclear
  antibodies) harms kidneys, heart, brain,
  lungs, skin
• Rheumatoid Arthritis (anti-IgG antibodies)
  joints, hearts, lungs, nervous system
• Rheumatic fever cross-reaction between
  antibodies to streptococcus and auto-antibodies.

51
What could cause the immune system to
attack the self?

• Changes in self-antigens, that make them
  look like non-self to the immune system,
  due to
• Viral or bacterial infection
• Irradiation
• Medication
• Smoking
• Changes in the immune system
• Normal auto-antibodies exist mutations in B
  cells producing them may create pathogenic
  auto-antibodies.
• Problems with control of lymphocyte
  development and differentiation.

52
SYSTEMIC LUPUSERYTHEMATOSUS (SLE)

• Chronic systemic autoimmune disease
• Cause unknown
• Affects almost any organ(s)
• Characterized by chronic inflammation

53
SYSTEMIC LUPUSERYTHEMATOSUS (SLE)

• Auto-antibodies formed against variety of self
  antigens
• Anti-double stranded DNA,RNA and histones
• Antibodies against cell surface antigens on RBCs
  and/or platelets
• Tissue damage caused by Type III hypersensitivity
  reactions
• Immune circulating complexes formed against self
  deposit on tissues
• Vasculitis, synovitis, glomerulonephritis

54
Systemic lupus erythematosis is the most commonly
known autoimmune disorder. This characteristic
butterfly rash is made worse by exposure to
sunlight. Lupus is a potentially fatal
autoimmune disease that strikes 1 in 2,000
Americans and 10 times as many women as men.
55
Systemic lupus erythematosus (SLE)

• febrile inflammatory multisystemic disease -
  variable symptomatology
• females (FM 101), 2.-3. decade
• most often affected skin, kidneys, serosal
  membranes, joints, heart
• several types of Ab - namely antinuclear Ab
• formation of immuncomplexes
• histologically - predominantly necrotizing
  vasculitis
• LE cells (fagocytosis of hematoxylin bodies -
  destroyed nuclei of cells) - lab test

56
Symptomatology

• Skin - facial exantema (butterfly) - cheeksradix
  of the nose
• Pleurapericardium - serous and fibrinous
  exsudation - fibrosis
• Heart - pericarditis
• endocarditis Libman-Sacks (verrucous) -
  nonbacterial thrombotic endocarditis
• both sides of the valve
• Kidneys - various forms of Glnf
• Joints - swelling, inflammation
• Spleen - thickening of the capsule (serositis)
• concentric perivascular fibrosis (onion-like)

57
Typical clinical presentation

• young female, butterfly-shaped exantema of the
  face
• febrile, joint pain, pleuritic pain, photophobia
• ANCA
• !!!CAVE!!! frequently atypical symptomatology
• clinical course
• progressive - death
• recurrences and remissions - years or decades
• treatment steroids, immunosupression

58
Rheumatoid Arthritis

• Systemic autoimmune disease
• Genetic factors (HLA-DR1, HLA-DR4)
• Autoreactive B-cells synthesize auto antibody
• against Fc portion of IgG
• Rheumatoid factor (RF)
• Chronic inflammation of synovial joints
• Proliferation of synovial lining cells
• Erosion of articular cartilage and adjacent bone

59
Rheumatoid arthritis (RA) affects peripheral
joints and may cause destruction of both
cartilage and bone. The disease affects mainly
individuals carrying the DR4 variant of MHC
genes. This fact can lead to better prognoses
and in aiding efforts to change immune reactions
that involve the DR4 variant while leaving other
reactions intact.
60
Rheumatoid arthritis (RA)

• symetric chronic inflammation of the joints
• non-purulent productive synovitis - pannus
  (granulation tissue)
• destruction of cartilage - progressive impairment
  of function
• rather frequent females 0,5-4, males 0,1-1,3
  (FM3-51)
• usually young adults

61

• pathogenesis - both humoral and cellular immunity
• increased Ig in serum
• "rheumatoid factor"
• clinically
• symetric inflammation of small joints (hands and
  feet), later also ankle, wrist, elbow, shoulder,
  jaws
• only rarely hips
• deformation and loss of function of joints
• sometimes formation of subcutaneous nodules (2-3
  cm in diam.) - rheumatoid nodules

62
Special forms of RA

• Juvenile RA (Stils disease) - age 1-3 y.
• RA fever, hepatosplenomegaly, lymphadenopathy
• Felty's disease
• RA splenomegaly leukopenia

63
Systemic sclerosis (SS)

• interstitial tissue of various organs -
  inflammation and fibrosis
• in 95 skin (scleroderma)
• sometimes visceral lesions (GI tract, lungs,
  kidneys, heart, muscles) most important
• FM31
• any age (childhood - old age), mainly 3.-5.
  decade, rare
• histologically
• sclerosis of collagen (loss of filamentous
  structure, homogenization, hyalinization, no
  nuclei)

64

• skin - fingers - progression proximally
• first edema, than sclerosis of collagen, atrophy
  of epidermis, loss of skin adnexa
• skin is dry, with smooth surface, shiny, thin -
  ulceration
• loss of elasticity, rigidity
• spontaneous amputations, mask face

65

• GI tract
• namely esophagus - atrophy and fibrosis of the
  wall - problems with swallowing
• Locomotory apparatus
• loss of mobility, rigidity
• Lungs
• interstitial fibrosis
• Heart
• interstitial fibrosis of myocardium
• Vessels
• Raynaud's phenomenon - polyarteritis nodosa

66
Polymyositis (dermatomyositis)

• symetrical muscle weakness, pain, swelling,
  atrophy
• 2 peaks of incidence - 5-15 y., 50-60 y.
• frequently combination with other systemic
  diseases - overlap syndromes, vasculitis
• mixed connective tissue disease

67
Polymyositis (dermatomyositis)

• Histologically
• inflammation (lymphocytes, plasma cells,
  histiocytes)
• atrophy, necrosis, disappearance of muscle
  fibres, replacement by fibrous tissue and fat
• usually starts proximally (shoulder, pelvis) -
  distal progression
• in 10-20 combination with malignant tumors - ca
  lungs, GIT (males) or ca breast, ovary (females)

68
Sjögren's syndrome

• dry eyes (keratoconjuctivitis sicca) - corneal
  lesions
• dry mouth (xerostomia)
• caused by loss of salivary and lacrimal glands -
  immunologicaly induced inflammation
• only salivary glands - benign lymphoepithelial
  lesion (myoepithelial sialoadenitis) - see
  Mikulicz's sy
• salivary glands lacrimal glands - sicca
  syndrome
• combination with other autoimmune disorders (RA -
  60) - Sjögren's sy - 1933
• involvement of glands of other systems (nose,
  pharynx, vagina)

69

• histologically
• lymphoid infiltrates, atrophy - loss of
  parenchyma
• mostly females, over 40 y.
• Dx. based on histology (excision of minor
  salivary gland)
• Mikulicz's syndrome
• bilateral swelling of lacrimal glands, parotis
  and submandibular glands
• various etiology (leukemia, lymphoma, syphilis,
  TBC) cases with unknown etiology - Mikulicz's
  disease

70
Polyarteritis (periarteritis) nodosa

• necrotizing inflammation of the wall of middle
  sized and small arteries - necrotizing vasculitis
• deposition of immuncomplexes (similar to Arthus's
  phenomenon)
• often segmentally (uninvolved skipped areas) -
  thrombosis - infarctions
• variable clinical presentation - most frequently
  kidneys, heart, liver, GIT (perforation!), lungs
  rarely!

71
Polyarteritis (periarteritis) nodosa

• histologically
• fibrinoid necrosis (eosinophillic), infiltration
  by neutrophillic leucocytes, microaneurysms -
  rupture or thrombosis - infarction
• healing by scar (fibrous tissue)
• MF21 (!predominance of males!)
• Dx. based on histology - diagnostic excision

72
Wegener's granulomatosis

• rare
• acute necrotizing arteritis (similar to
  polyarteritis nod.) - kidneys, respiratory tract
  (lungs), spleen
• acute granulomatous inflammation, necrotizing -
  namely respiratory tract (nose, paranasal
  sinuses, larynx, trachea, bronchi, lungs)
• necrotizing progressive Glnf. - in the past
  fatal, today cytostatics

73
3. Immunodeficiency diseases

• A. Primary immunodeficiency states
• B. Secondary immunodeficiency states

74
A. Primary immunodeficiency states

• experiments of nature, extremely rare
• X-linked agammaglobulinemia (Bruton's disease)
• inability of pre-B cells to diff. into mature
  B-cells
• decrease in circulating B-cells, no germinal
  centers in LN, rudimentary Peyer's patches
• recurrent bacterial infections (H. influ., Str.
  pneumon., Staph. aur.)
• Isolated deficiency of IgA
• most frequent (1700)
• recurrent sinopulmonary infections, diarrhea

75

• Thymic hypoplasia (DiGeorge's syndrome)
• congenital malformation of 3rd and 4th branchial
  pouches
• vulnerability to viral, fungal and protozoal
  infections
• Severe combined immunodeficiency
• X-linked or autosomal recessive

76
B. Secondary immunodeficiency states

• more common
• in malnutrition, infection, cancer, renal
  disease, malignancies
• patients treated by immunosupressive drugs
• AIDS

77
Acquired immunodeficiency syndrome (AIDS)

• viral etiology (HIV, RNA retrovirus)
• severe immunosupression - opportunistic
  infections, secondary tumors, neurologic symptoms
• first recognized 1981 - Los Angeles -
  pneumocystic pneumonia in 5 young homosexuals - 2
  died
• Pneumocystis carinii (interstitial pneumonia in
  premature infants)
• onset of epidemic
• 1998 - 33,4 million of infected (22,5 in
  sub-Saharian Africa)
• number of both infected and ill patients
  increases - USA, Africa (2/3 of all cases in the
  world), Southeast Asia (Thailand, India,
  Indonesia)

78
Transmission

• 1. sexual contact (lymphocytes in semen)
• 2. parenteral - blood derivates, drug abusers
  sharing needles
• 3. mother-to-infant - transplacental,
  intrapartum, breast-feeding
• HIV cannot be transmitted by casual personal
  contact !!!
• No transmission from patient to doctor (and vice
  versa) by casual contact !!!
• Prevention of injury - needle sticks, etc.
  operation or autopsy - special precautions

79
Epidemiology - 6 risk groups

• 1. homosexual males (60)
• 2. intravenous drug abusers (24)
• 3. hemophiliacs (1)
• 4. other blood recipients (2)
• 5. heterosexual partners of other high-risk
  groups members
• 6. children of parents from groups 1.-3.

80

• HIV-1 and HIV-2 - closely related
• long incubation period
• tropism for lymphocytes and nervous system
• immunosupression - CD4 T-cells (helpers)
• slowly progressive fatal outcome

81
Opportunistic infections in AIDS

• protozoal (pneumocystosis-lungs
  toxoplasmosis-lungs or CNS)
• fungal (candidiasis-GIT, respiratory tract
  cryptococcosis-CNS histoplasmosis-dissem.)
• bacterial (mycobacteriosis-frequently atypical
  nocardiosis-lungs, CNS)
• viral (CMV-lungs, GIT, kidneys, CNS HSV
  varicella-zoster slow viruses)

82
Neoplasms in AIDS

• Kaposi's sarcoma (sarcoma idiopathicum
  hemorrhagicum multiplex) - related to HSV
  infection
• non-Hodgkin's ML (Burkitt's or immunoblastic)
• primary ML of CNS
• invasive ca of uterine cervix

83

• "Typical" patient in the USA
• young male homosexual or drug abuser
• fever, weight loss, diarrhea, generalized
  lymphadenopathy, multiple opportunistic
  infections, neurologic disorders, secondary
  neoplasm(s)
• "Classical" clinical course
• after infection 4-7 W -gt seronegative period -gt
  seroconversion -gt long latency (2-5 Y) -gt
  lymphadenopathy -gt AIDS-related complex (ARC -
  fever, weight loss, diarrhea) -gt AIDS
• no vaccine, no drugs, only prevention
• AIDS - 100 mortality

84
IV. Amyloidosis

• amylum starch amyloid starchlike
• abnormal proteinaceous substance deposited
  between cells in many tissues and organs
• intercellular pink translucent material
• variety of clinical disorders

85

• A. not a single chemical entity
• two major and several minor biochemical forms
• several pathogenetically different mechanisms
• unique tertiary structure - ß-pleated sheet
  conformation
• responsible for staining properties and for
  resistance to enzymes

86

• Chemical nature of amyloid
• two types
• immunoglobulin light chains - AL (amyloid light
  chain) - in B-cell disorders
• nonimmunoglobulin protein - AA (amyloid
  associated) - in chronic inflammations
• Classification of amyloidosis
• systemic - kidneys, liver, spleen, adrenals,
  lymph nodes
• localized - various organs

87
Systemic amyloidosis

• 1. primary - immunocyte dyscrasias
• deposition of AL-A., produced by aberrant clones
  of B-cells - most frequent form
• A. in multiple myeloma
• monoclonal proliferation (neoplasm) of plasma
  cells - monoclonal gammopathy
• multiple osteolytic lesions of the bones
• in addition to monoclonal Ig - production of
  isolated kappa or lambda light chain (Bence-Jones
  protein)
• only 6-15 of patients with MM develop
  amyloidosis
• other cases of primary A. - e.g. light chain
  disease
• other B-cell related disorders

88

• 2. secondary amyloidosis
• reactive AA amyloid - protracted breakdown of
  cells, usually in chronic inflammatory disorders
• TBC, osteomyelitis, bronchiectasis
• RA, connective tissue disorders, ulcerative
  colitis, tumors (Hodgkin's ML)

89
Localized amyloidosis

• heterogenous group
• nodular deposits - lungs, larynx, skin, urinary
  bladder, tongue - infiltration of B-cells -
  probably well differentiated plasmacytoma
• special forms
• AE - endocrine tumors (medullary ca of thyroid)
• AS - senile amyloid (brain, heart)

90
Involvement of organs

• Kidneys
• most common, most serious
• glomeruli, vessels, peritubular stroma
• nephrotic syndrome
• Spleen
• two types - follicular (sago) and diffuse
  (lardaceous) spleen
• Liver
• weight up to 9kg!
• space of Disse - atrophy of hepatocytes
• Heart
• AS-amyloid - left atrium (ANF granules)
• AA - in systemic involvement - firm, wax-like

91
Clinical symptomatology

• incidental finding at autopsy
• severe clinical symptoms - renal malfunctions,
  hepatosplenomegaly, heart involvement
• Dx. needle biopsy of lesion in systemic -
  biopsy of rectal or oral mucosa

92
(No Transcript)
93
(No Transcript)
94

• you can delete all the next slides down to the
  bottom SAFLY
• NO worry .delete safely down

95
THERAPEUTIC CONCEPTS

• Immune system defends and participates in
  autoimmunity/hypersensitivity/transplant
  rejection
• Cure/prevention is achieved based on recognition
  of foreign antigens
• Immune response against self antigens causes
  autoimmunity/hypersensitivity

96
Immunopharmacologic agents fall into 2 categories

• Those that suppress the immune system
• Suppression overcomes rejection of organ/tissue
  transplantation and reduces effects of autoimmune
  diseases
• Those that stimulate the immune system
• Stimulation enhances activity of immune system
  against infectious agents and neoplastic cells

97
General Principles regarding immunosuppression

• Primary responses are suppressed more easily than
  secondary responses (memory)
• Immunosuppressive agents have different effects
  on different immune reactions
• Suppression is more effective when therapy
  precedes exposure to the immunogen

98
Immunosuppressive Agents

• CYCLOSPORINE
• TACROLIMUS
• SIROLIMUS
• CORTICOSTEROIDS
• CYCLOPHOSPHAMIDE
• AZATHIOPRINE
• MYCOPHENOLATE MOFETIL
• METHOTREXATE
• ANTIBODIES

• T-cell blockers
• Glucocorticoids
• Cytotoxic drugs
• Antibody reagents

99
T-cell blockers Cyclosporine, Tacrolimus, and
Sirolimus

• cyclosporine and tacrolimus act on helper
  T-cells inhibit T-cell receptor-activated
  induction of IL-2
• cyclosporine may also inhibit IgE-stimulated mast
  cell degranulation and stimulate TGF-? expression
• sirolimus inhibits T-cell activation and
  proliferation and IL-2 induction

100
CsA and FK506 mechanism of action
Complex with binding protein (CpN, FKBP) inhibits
calcineurin (CaN) CaN is required for
de-phosphorylation and nuclear translocation of
NFAT (nuclear factor of activated T cells) CaN
inhibition, blocks NFAT resulting in inhibition
of IL-2 gene
101
Absorption and metabolism of cyclosporine,
tacrolimus

• Oral bioavailability low and variable (20 -50
  cyclosporine 6 - 56 tacrolimus)
• new cyclosporine microemulsion gives more
  consistent absorption
• Almost all excreted in bile after liver
  metabolism by CYP3A enzymes
• bioavailability subject to drug interactions that
  can increase or decrease blood levels

102
Uses of calcineurin inhibitors (T-cell blockers)

• Cyclosporine commonly used with prednisone and
  other immunosuppressants to prevent allograft
  rejections in renal, hepatic and cardiac
  transplants, and in treatment of RA and psoriasis
• use is delayed posttransplantation due to
  neurotoxicity concerns
• Tacrolimus is approved for prevention of
  solid-organ allograft rejection, and eczema
  (topical)
• treatment begins prior to surgery, and is
  maintained well afterwards

103
Toxic effects of Cyclosporine and Tacrolimus

• Nephrotoxicity (CgtT)
• Neurotoxicity (TgtC)
• GI problems (T)
• Hypertension (CgtgtT)
• Hyperkalemia (T)
• Hyperglycemia and onset of diabetes
• especially with glucocorticoids (TgtC)
• Increased incidence of infections and secondary
  tumors
• least of immunosuppressants

104
Sirolimus and Everolimus new T-cell blockers
with different activity
Pre-drug sirolimus binds FKBP, but the complex
inhibits mTOR kinase mTOR activates p70S6K mTOR
inhibition prevents activity of p34cdc2 which
complexes with cyclin E, thus preventing
elimination of p27Kip which is a negative
regulator of cdks and eIF-4F Results in
inhibition of cell cycle proogression at G1 to S
phase
105
Sirolimus and Everolimus new T-cell blockers

• similar poor bioavailability as cyclosporine and
  tacrolimus, much longer half-life 62 h vs. 18
  and 12 h
• same metabolism (CYP3A) and potential drug
  interactions
• used for prophylaxis of organ transplant
  rejection in combination with a calcineurin
  inhibitor and glucocorticoids
• toxicities include
• hyperlipidemia, lymphocoele, anemia, leukopenia,
  thrombocytopenia, fever, GI effects, hyper- or
  hypokalemia

106
Glucocorticoid uses in Immunosuppression

• Used with other immunosuppressants to prevent
  transplant rejection and GVHD (synergistic
  effect/lower toxicity).
• natural glucocorticoids not used due to
  mineralocorticoid activity
• prednisone and prednisolone are used orally at
  high - moderate doses Very high doses of
  methylprednisolone used i.v. during acute organ
  rejection
• Used before and after antithymocyte Abs to
  inhibit allergic reactions

107
Glucocorticoid-sensitive sites of immune
responding
proliferation differentiation
X
MHC Class I/peptides APCs
CD8 T-cell
CD8 cytolytic T-cells
X
GC
GC
IL-2
MHC Class II/peptides APCs
proliferation
X
CD4 immune cell (delayed hypersensitivity)
CD4 T-cell (helper T-cells)
X
IL-1
IL-1, -4,-5,-6
B-cell
Protein antigen
Plasma cell
proliferation differentiation
antibody production
108
Glucocorticoid effects and toxicity

• Reduced immune cell content in lymph nodes,
  spleen and blood
• lymphopenia, monocytopenia, eosinopenia, but
  neutrophilia
• Interference with antigen presentation,T-cell and
  macrophage functions

• Major side effects are common due to high doses
  necessary for suppression
• Cushings syndrome
• glucose intolerance
• infections
• bone dissolution
• muscle wasting

109
Cytotoxic Agents as immunosuppressants

• Antineoplastic drugs will also prevent clonal
  expansion of T- and B-cells
• mycophenolate mofetil (CellCept)
• becomes MPA inhibits IMP dehydrogenase
• cyclophosphamide (DNA alkylating agent)
• methotrexate (inhibits dihydrofolate reductase)
• azathioprine (prodrug of nucleotide
  anti-metabolite)

110
Mechanism of action of mycophenolate mofetil

• Because the salvage pathway of purine synthesis
  is less active than the de novo pathway,
  lymphocytes depend on PRPP conversion to IMP and
  in turn GMP for DNA synthesis

111
Uses of cytotoxic agents

• Azathioprine with cyclosporine and/or prednisone
  for organ transplant rejection and severe RA
• Mycophenolate mofetil with cyclosporine and
  prednisone for renal transplants
• Cyclophosphamide for BMT
• Methotrexate GVHD prophylaxis

112
Immunosuppressant antibody reagents

• Antithymocyte antibodies (to antigens on surface
  of T cells)
• 3 types available
• all derived from non-human sources
• Rh(D) immune globulin
• Anti-TNF-a antibody

113
Antithymocyte antibodies

• Lymphocyte/thymocyte immune globulins (Atgam,
  thymoglobulin)
• lytic to human T cells blocks T-cell responses
• Anti-CD3 monoclonal antibody (OKT3,
  muromonab-CD3)
• binds CD3, blocks antigen binding depletes
  T-cells
• Anti-Tac, Anti-CD25 (basiliximab, daclizumab)
  monoclonal antibodies (anti-CD25 are humanized)
• bind IL-2 receptors on activated T-cells causing
  their inactivation

114
Daclizumab

• Therapeutic humanized Mab to the ? subunit of
  IL-2 receptor on T cells
• Saturates receptors and prevents T cell
  activation
• Used to prevent rejection in organ
  transplantation, especially in kidney transplants
  
• Does not increase incidence of opportunistic
  infections
• Given in multiple doses, first 1 hour before
  transplant and 5 doses at two week intervals
  after the transplant
• Similar drug basiliximab

115
Rh(D) immune globulin

• Human IgG high titer against Rh(D) red cell
  antigen
• Blocks sensitization of Rh-negative mothers to D
  antigen of Rh(D)-positive (Du-positive) offspring
  (prevents production by mother of Abs that lyse
  babys RBCs, primarily at second pregnancy)
• Must administer to the mother within 72 h of
  exposure to fetal blood
• May be administered at 28 wks gestation

116
Ca Therapy Everolimus

• Derivative of Sirolimus
• Oral inhibitor of mTOR
• In cancer cells, everolimus inhibits mTOR, a
  protein that acts as a central regulator of tumor
  cell division, cell metabolism and blood vessel
  growth
• Phase III interim results showed significantly
  better progression-free survival in patients with
  advanced kidney cancer than placebo

117
Ca Therapy Rituximab
slg
CD19
CD20
CD22
DR

• CD20 is a B-cell specific protein
• Overexpressed in B-cell lymphoma (gt90 cells)
• Precursor B-cells do not express CD20
• Rituximab is genetically engineered chimeric
  murine/human monoclonal antibody that targets
  (binds) CD20
• Used in the treatment of B cell non-Hodgkin's
  lymphoma, B-cell leukemias, and some autoimmune
  disorders.

B lymphocyte

• Rituximab
• Murine antigen binding domain
• Human ? constant region
• Human IgG1 constant region

118
Rituximab Mechanism of action
119
HERCEPTIN (trastuzumab)

• So far the only monoclonal antibody that seems to
  be effective against solid tumors.
• Treatment for breast cancer
• Usually administered alongside traditional
  chemotherapy drugs
• Targets the HER2 receptor, which is often
  overexspressed in breast cancer cells
• Possible effects include down-regulation of HER2,
  accelerated receptor degradation, disruption of
  receptor heterodimer formation, altered signal
  transduction, and induction of ADCC

120
Etanercept

• TNF? blocker
• Fusion protein linking human soluble TNF receptor
  to the Fc component of human IgG1
• Mimics the inhibitory effects of naturally
  occurring soluble TNF receptors
• Has longer half-life in the blood and therefore
  more profound and long-lasting effect than
  naturally occurring soluble TNF receptor
• TNFa inactivation is important in downregulating
  the inflammatory reactions associated with
  autoimmune diseases
• Approved for rheumatoid arthritis, juvenile
  idiopathic arthritis, psoriatic arthritis, plaque
  psoriasis, ankylosing spondylitis and Crohns
  disease.
• Serious safety concerns histoplasmosis and
  fungal infections

121
General Principles regarding immunostimulation

• Stimulating cellular and/or humoral immunity
  should benefit people with immune deficiencies
• Degree of stimulation relatively small

122
Types of Immunostimulants

• BCG
• Levamisole, IMiDs
• ILs, CSFs, TNFs, IFNs
• IL-2 (with or without LAKs)
• IFN-? enhances antigen presentation and NK
  activity, favors Th1 responses
• G-CSF

• Bacteria-derived products
• Synthetic drugs
• Cytokines
• Intravenous immune globulin (IVIG)
• Immunostimulatory MAbs

123
Bacterial-derived agents

• Bacille Calmette-Guerin (BCG) licensed for use in
  USA
• several other in use world-wide
• BCG is an attenuated live strain of Mycobacterium
  bovis
• acts in part by stimulating TNF-? release from
  macrophages
• approved for intravesical therapy of superficial
  bladder cancer
• Toxicities hypersensitivity, shock, chills,
  fever, immune complex disease

124
Synthetic immunostimulants

• Levamisole-HCl potentiates stimulation of
  lymphocytes, granulocytes and macrophages by
  various factors
• Approved for use with 5-flurouracil in resected
  patients with Dukes C colon cancer
• IMiDs (Revimid, Actimid), a group of oral drugs
  similar to thalidomide are immunostimulatory.
• Mechanism of action unknown. Enhance activation
  of T cells and NK and production of IL-2 and
  inhibit inflammatory cytokines (IL-1ß, IL-10)
• Also Inhibit myeloma cell growth and angiogenesis
  (in clinical trials for myeloma)

125
(No Transcript)
126
Cytokines - Interferons
Specifically IFN-alpha

• Slow growth of cancer cells and angiogenesis
• Cause cancer cells to produce more antigens
• Boost killing ability of natural killer cells
• Approved for use with some leukemias,
  non-Hodgkins lymphoma, renal cancer and melanoma
• Toxicity fever, headaches, fatigue, myalgias,
  cardiovascular and GI disturbances

127

INTERLEUKIN -2

• rhIL-2 (human recombinant IL-2 aldesleukin)
• approved for metastatic renal cancer and melanoma
• highly toxic
• capillary leak syndrome associated with edema,
  reduce organ perfusion and hypotension
• cardiac arrhythmias, myocardial infarction, GI
  bleeding, changes in mental status
• increase incidence of infections

• Binds to IL-2 receptor on T cells
• induces proliferation and differentiation of
  helper T-cells and cytotoxic T-cells
• elevates serum IL-1, TNF-?, and IFN-? levels

LA-03
128
(No Transcript)
129
Uses of Interferons (IFN)

• IFN-?-1b?
• approved for prevention of infections in chronic
  granulomatous disease
• IFN-a-2a/2b?(rhIFNa)
• approved for treatment of hairy cell leukemia,
  AIDS-related Kaposis sarcoma, human
  papillomavirus and hepatitis C infections
• pegylated-alfa-2b as monotherapy (1/wk) for
  HCV
• IFN-?-1a/1b (analogs of IFN-??
• may reduce number and severity of attacks in
  relapsing-remitting multiple sclerosis

130
Geanulocyte Colony-stimulating factor

• rhG-CSF induces development of neutrophils,
  eosinophils and macrophages
• used to accelerate myeloid recovery after
  autologous BMT in non-Hodgkins lymphoma,
  Hodgkins disease and acute lymphoblastic
  leukemia
• fluid accumulation most bothersome adverse effect
  of short-term GM-CSF
• used after chemotherapy to decrease infections in
  patients with non-myeloid malignancies
• bone pain primary adverse effect of short-term
  treatment
• splenomegaly and abnormal urate levels may occur

LA-03
131
Intravenous immune globulins(passive
immunization)

• IVIGs pooled plasma from donors
• contain IgG subclasses no IgM, variable IgA
• Used as replacement therapy in primary immune
  deficiency diseases
• All except Gammagard are contraindicated in IgA
  deficiency
• Antigen-specifc preparations also available
• hepatitis B, botulism, diptheria, tetanus, rabies

132
Immunostimulatory mAbs

• Lyse tumor cells and inhibit cell growth and
  pro-angiogenic mediators.
• Stimulate tumor-specific immune response
• Grouped by function as (i) interfering with
  inhibitory receptors (ii) agonist/ super-agonist
  ligands for co-stimulatory receptors (iii)
  enhance APC activation/ maturation and (iv)
  delete/inhibit immunosuppression (viz. Tregs).
• Problem Toxicity (commonly reversible
  autoimmunity and/or systemic inflammation)
• Synergistic combinations of immunostimulatory
  mAbs with cancer vaccines, adoptive T-cell
  therapy, radiotherapy and chemotherapy will
  probably have important roles in future clinical
  development.