1. IMMUNOSUPPRESSANT DRUGS AND GENE THERAPY Dr. Rishi Pal Assist
IMMUNOSUPPRESSANT DRUGS AND GENE THERAPY Dr. Rishi Pal Assist. Professor Department of Pharmacology

2. Immune system
Is designed to protect the host from harmful foreign molecules.
Allograft introduction can elicit a damaging immune response.
Immune system include two main arms
1) Cell –mediated immunity.
2) Humoral (antibody –mediated immunity).

4. Cytokines
Cytokines are soluble, antigen-nonspecific signaling proteins that bind to cell surface receptors on a variety of cells.
Cytokines include
Interleukins,
Interferons (IFNs),
Tumor Necrosis Factors (TNFs),
Transforming Growth Factors (TGFs)
Colony-stimulating factors (CSFs).

5. Cell-mediated Immunity
IL-2 stimulates the proliferation of antigen-primed (helper) T cells.
Cell-mediated Immunity
TH1 produce more IL-2, TNF-β and IFN-γ.
Activate
NK cells (kill tumor & virus-infected cells).
Cytotoxic T cells (kill tumor & virus-infected cells).
Macrophages (kill bacteria).

6. Cell-mediated Immunity

7. B cells proliferates & differentiates into memory B cells
Humoral Immunity
B-lymphocytes TH2 produces (interleukins) IL-4 & IL-5 which in turn causes:
 B cells proliferates & differentiates into
memory B cells
Antibody secreting plasma cells

8. Humoral Immunity

9. Mutual regulation of T helper lymphocytes
TH interferon-γ:
inhibits TH2 cell proliferation
TH IL-10:
inhibits TH1 cytokine production

10. IMMUNOSUPPRESSANT DRUGS
I. Inhibitors of cytokine (IL-2) production or action:
1) Calcineurin inhibitors
Cyclosporine
Tacrolimus (FK506)
2) Sirolimus (rapamycin).
II. Inhibitors of cytokine gene expression
Corticosteroids

11. IMMUNOSUPPRESSANT DRUGS CONT..
Cytotoxic drugs
Inhibitors of purine or pyrimidine synthesis
(Antimetabolites):
Azathioprine
Myclophenolate Mofetil
Leflunomide
Methotrexate
Alkylating agents
Cyclophosphamide

12. IMMUNOSUPPRESSANT DRUGS CONTD…
IV. Immunosuppressive antibodies
that block T cell surface molecules involved in signaling immunoglobulins
antilymphocyte globulins (ALG).
antithymocyte globulins (ATG).
Rho (D) immunoglobulin.
Basiliximab
Daclizumab
Muromonab-CD3
V. Interferon
VI. Thalidomide

13. Cyclosporine is a fungal polypeptide composed of 11 amino acids.
Chemistry
Cyclosporine is a fungal polypeptide composed of 11 amino acids.
Mechanism of action
Acts by blocking activation of T cells by inhibiting interleukin-2 production (IL-2).
Decreases proliferation and differentiation of T- cells.

14. CYCLOSPORINE CONTD..
Cyclosporine binds to cyclophilin (immunophilin) intracellular protein receptors .
Cyclosporine- immunophilin complex inhibits calcineurin, a phosphatase necessary for dephosphorylation of transcription factor (NFATc) required for interleukins synthesis (IL-2).
NFATc (Nuclear Factor of Activated Tcells).
Suppresses cell-mediated immunity.

16. Pharmacokinetics of cyclosporine:
Can be given orally or i.v. infusion
Orally (25 or 100 mg) soft gelatin capsules, microemulsion.
Orally, it is slowly and incompletely absorbed.
Peak levels is reached after 1– 4 hours, elimination half life 24 h.
Oral absorption is delayed by fatty meal (gelatin capsule formulation)
Microemulsion
( has higher bioavailability-is not affected by food).

17. 50 – 60% of cyclosporine accumulates in blood
(erythrocytes – lymphocytes).
Metabolized by CYT-P450 system (CYP3A4).
Excreted mainly through bile into faeces, about 6% is excreted in urine.

18. Therapeutic Uses of Cyclosporine
Organ transplantation (kidney, liver, heart) either alone or with other immunosuppressive agents (Corticosteroids).
Autoimmune disorders (low dose 7.5 mg/kg/d). e.g. endogenous uveitis, rheumatoid arthritis, active Crohn’s disease, psoriasis, psoriasis, nephrotic syndrome, severe corticosteroid-dependent asthma, early type I diabetes.
Graft-versus-host disease after stem cell transplants

19. Adverse Effects of cyclosporine (Dose-dependent)
Therapeutic monitoring is essential
Nephrotoxicity (increased by NSAIDs and aminoglycosides).
Liver dysfunction.
Hypertension, hyperkalemia.
(K-sparing diuretics should not be used).
Hyperglycemia.
Viral infections (Herpes - cytomegalovirus).

20. Adverse Effects of Cyclosporine (Dose-dependent) cont..
Lymphoma (Predispose recipients to cancer).
Hirsutism
Neurotoxicity (tremor).
Gum hyperplasia.
Anaphylaxis after I.V.

21. Cyclosporine Drug Interactions
Clearance of cyclosporine is enhanced by co-administration of CYT p450 inducers (Phenobarbitone, Phenytoin & Rifampin )  rejection of transplant.
Clearance of cyclosporine is decreased when it is co-administered with erythromycin or Ketoconazole, Grapefruit juice  cyclosporine toxicity.

22. TACROLIMUS (FK506) A fungal macrolide antibiotic.
Chemically not related to cyclosporine
Both drugs have similar mechanism of action.
The internal receptor for tacrolimus is immunophilin ( FK-binding protein, FK-BP).
Tacrolimus-FKBP complex inhibits calcineurin.

24. Kinetics of Tacrolimus
Given orally or i.v or topically (ointment).
Oral absorption is variable and incomplete, reduced by fat and carbohydrate meals.
Half-life after I.V. form is 9-12 hours.
Highly bound with serum proteins and concentrated in erythrocytes.
metabolized by P450 in liver.
Excreted mainly in bile and minimally in urine.

25. USES as cyclosporine Organ and stem cell transplantation
Prevention of rejection of liver and kidney transplants (with glucocorticoids).
Atopic dermatitis and psoriasis (topically).

26. NO hirsutism or gum hyperplasia Drug interactions as cyclosporine.
Toxic effects
Nephrotoxicity (more than CsA)
Neurotoxicity (more than CsA)
Hyperglycemia ( require insulin).
GIT disturbances
Hperkalemia
Hypertension
Anaphylaxis
NO hirsutism or gum hyperplasia
Drug interactions as cyclosporine.

27. What are the differences between CsA and TAC ?
TAC is more favorable than CsA due to:
TAC is 10 – 100 times more potent than CsA in inhibiting immune responses.
TAC has decreased episodes of rejection.
TAC is combined with lower doses of glucocorticoids.
But
TAC is more nephrotoxic and neurotoxic.

28. Sirolimus (Rapamycin)
SRL is macrolide antibiotic.
SRL is derived from fungus.
It binds to FKBP and the formed complex binds to mTOR (mammalian Target Of Rapamycin).
mTOR is serine-threonine kinase essential for cell cycle progression, DNA repairs, protein translation.

29. Sirolimus (Rapamycin) Contd..
SRL blocks the prog Sirolimus (Rapamycin) ression of activated T cells from G1 to S phase of cell cycle (Antiproliferative action).
It Does not block IL-2 production but blocks T cell response to cytokines.
Inhibits B-cell proliferation & immunoglobulin production.

31. Pharmacokinetics of Sirolimus
Given orally and topically, reduced by fat meal.
Extensively bound to plasma proteins
metabolized by CYP3A4 in liver.
Excreted in feces.
Pharmacodynamics
Immunosuppressive effects
Anti- proliferative action.
Equipotent to CsA.

32. USES OF SIROLIMUS Solid organ allograft
Renal transplantation alone or combined with (CSA, tacrolimus, steroids, mycophenolate).
Heart allografts
In halting graft vascular disease.
Hematopoietic stem cell transplant recipients.
Topically with cyclosporine in uveoretinitis.
Synergistic action with CsA

33. Toxic effects Sirolimus
Hyperlipidaemia (cholesterol, triglycerides).
Thrombocytopenia
Leukopenia
Hepatotoxicity
Hypertension
GIT dysfunction

34. Inhibitors of cytokine gene expression
Corticosteroids
Prednisone
Prednisolone
Methylprednisolone
Dexamethasone
They have both anti-inflammatory action and immunosuppressant effects.

35. Mechanism of action
Bind to glucocorticoid receptors and the complex interacts with DNA to inhibit gene transcription of inflammatory genes.
Decrease production of inflammatory mediators as prostaglandins, leukotrienes, histamine, PAF, bradykinin.
Decrease production of cytokines IL-1, IL-2, interferon, TNF.
Stabilize lysosomal membranes.

36. Mechanism of action
Decrease generation of IgG, nitric oxide and histamine.
Inhibit antigen processing by macrophages.
Suppress T-cell helper function.
decrease T lymphocyte proliferation.

37. 1. Suppression of response to infection
Kinetics
Can be given orally or parenterally.
Dynamics
1. Suppression of response to infection
2. Anti-inflammatory and immunosuppressant.
3. Metabolic effects.

38. Indications
First line therapy for solid organ allografts & haematopoietic stem cell transplantation.
Autoimmune diseases as refractory rheumatoid arthritis, systemic lupus erythematosus (SLE), asthma.
Acute or chronic rejection of solid organ allografts.

39. Adverse Effects Adrenal suppression Osteoporosis Hypercholesterolemia
Hyperglycemia
Hypertension
Cataract
Infection

40. Cytotoxic drugs (Antimetabolites): Cyclophosphamide
Inhibitors of purine or pyrimidine synthesis
(Antimetabolites):
Azathioprine
Myclophenolate Mofetil
Leflunomide
Methotrexate
Alkylating agents
Cyclophosphamide

41. AZATHIOPRINE Derivative of mercaptopurine. Prodrug.
CHEMISTRY:
Derivative of mercaptopurine.
Prodrug.
Cleaved to 6-mercaptopurine then to 6-mercaptopurine nucleotide, thioinosinic acid (nucleotide analog).
Inhibits de novo synthesis of purines required for lymphocytes proliferation.
Prevents clonal expansion of both B and T lymphocytes.

43. Pharmacokinetics Drug Interactions: Orally or intravenously.
Widely distributed but does not cross BBB.
Metabolized in the liver to 6-mercaptopurine or to thiouric acid (inactive metabolite) by xanthine oxidase.
excreted primarily in urine.
Drug Interactions:
Co-administration of allopurinol with azathioprine may lead to toxicity due to inhibition of xanthine oxidase by allopurinol.

44. USES OF AZATHIOPRINE
Acute glomerulonephritis
Systemic lupus erythematosus
Rheumatoid arthritis
Crohn’ s disease.

45. Adverse Effects of Azathioprine
Bone marrow depression: leukopenia,
Thrombocytopenia.
Gastrointestinal toxicity.
Hepatotoxicity.
Increased risk of infections.

46. MYCOPHENOLATE MOFETIL
Is a semisynthetic derivative of mycophenolic acid from fungus source.
Prodrug; is hydrolyzed to mycophenolic acid.
Mechanism of action:
Inhibits de novo synthesis of purines.
mycophenolic acid is a potent inhibitor of inosine monophosphate dehydrogenase (IMP), crucial for purine synthesis deprivation of proliferating T- and B-cells of nucleic acids.

48. Pharmacokinetics: Given orally, i.v. or i.m.
rapidly and completely absorbed after oral administration.
It undergoes first-pass metabolism to give the active moiety, mycophenolic acid (MPA).
MPA is extensively bound to plasma protein.
metabolized in the liver by glucuronidation.
Excreted in urine as glucuronide conjugate
Dose : 2-3 g/d

49. CLINICAL USE OF MYCOPHENOLATE MOFETIL
Solid organ transplants for refractory rejection.
Steroid-refractory hematopoietic stem cell transplant patients.
Combined with prednisone as alternative to CSA or tacrolimus.
Rheumatoid arthritis, & dermatologic disorders.

50. ADVERSE EFFECTS MYCOPHENOLATE MOFETIL
GIT toxicity: Nausea, Vomiting, diarrhea, abdominal pain.
Leukopenia, neutropenia.
Lymphoma
Contraindicated during pregnancy

51. LEFLUNOMIDE
A prodrug
Active metabolite undergoes enterohepatic circulation.
Has long duration of action.
Can be given orally
Antimetabolite immunosuppressant.
Pyrimidine synthesis inhibitor
Approved only for rheumatoid arthritis

52. LEFLUNOMIDE
Adverse effects
Elevation of liver enzymes
Renal impairment
Teratogenicity
Cardiovascular effects (tachycardia).

53. Methotrexate Folic acid antagonist Orally, parenterally (I.V., I.M).
Excreted in urine.
Inhibits dihydrofolate reductase required for folic acid activation (tetrahydrofolic)
Inhibition of DNA, RNA &protein synthesis
Interferes with T-cell replication.
Rheumatoid arthritis & psoriasis and Crohn disease
Graft versus host disease

54. Adverse effects Methotrexate
Nausea-vomiting-diarrhea
Alopecia
Bone marrow depression
Pulmonary fibrosis
Renal & hepatic disorders

56. Cyclophosphamide Alkylating agent to DNA.
Prodrug, activated into phosphamide.
Is given orally& intravenously
Destroy proliferating lymphoid cells.
Anticancer & immunosuppressant
Effective in autoimmune diseases e.g rheumatoid arthritis & systemic lupus erythrematosus.
Autoimmune hemolytic anemia

57. Side Effects of Cyclophosphamide
Alopecia
Hemorraghic cystitis.
Bone marrow suppression
GIT disorders (Nausea -vomiting-diarrhea)
Sterility (testicular atrophy & amenorrhea)
Cardiac toxicity

58. block T-cell surface molecules involved in signaling immunoglobulins
Antibodies
block T-cell surface molecules involved in signaling immunoglobulins
Antilymphocyte globulins (ALG).
Antithymocyte globulins (ATG).
Rho (D) immunoglobulin.
Basiliximab
Daclizumab
Infliximab

59. Antibodies contd…
Preparation
1. By immunization of either horses or rabbits with human lymphoid cells producing mixtures of polyclonal antibodies directed against a number of lymphocyte antigens (variable, less specific).

60. Antibodies preparation contd…
2. Hybridoma technology
produce antigen-specific, monoclonal antibody (homogenous, specific).
produced by fusing mouse antibody-producing cells with immortal, malignant plasma cells.
Hybrid cells are selected, cloned and selectivity of the clone can be determined.

61. Recombinant DNA Technology
Recombinant DNA technology can be used to replace part of the mouse gene sequence with human genetic material (less antigenicity-longer half life).
Antibodies from mouse contain Muro in their names.
Humanized antibodies contain ZU or XI in their names.

62. Antilymphocyte globulins (ALG) &Antithymocyte globulins (ATG)
Polyclonal antibodies obtained from plasma or serum of horses hyper-immunized with human lymphocytes.
Binds to the surface of circulating T-lymphocytes, which are phagocytosed in the liver and spleen giving lymphopenia and impaired T-cell responses & cellular immunity.

63. Antilymphocyte globulins (ALG) &Antithymocyte globulins (ATG) contd…
Kinetics
Given i.m. or slowly infused intravenously.
Half life extends from 3-9 days.
Uses
Combined with cyclosporine for bone marrow transplantation.
To treat acute allograft rejection.
Steroid-resistant rejection.

64. Adverse Effects Antigenicity. Leukopenia, thrombocytopenia.
Risk of viral infection.
Anaphylactic and serum sickness reactions (Fever, Chills, Flu-like syndrome).

65. Muromonab-CD3 Is a murine monoclonal antibody
Prepared by hybridoma technology
Directed against glycoprotein CD3 antigen of human T-cells.
Given I.V.
Metabolized and excreted in the bile.

66. Mechanism of action of Muromonab-CD3
The drug binds to CD3 proteins on T-lymphocytes (antigen recognition site) leading to transient activation and cytokine release followed by disruption of T-lymphocyte function, their depletion and decreased immune response.
Prednisolone, diphenhydramine are given to reduce cytokine release syndrome.

67. Uses Muromonab-CD3 Adverse effects
Used for treatment of acute renal allograft rejection & steroid-resistant acute allograft
To deplete T cells from bone marrow donor prior to transplantation.
Adverse effects
Anaphylactic reactions.
Fever
CNS effects (seizures)
Infection
Cytokine release syndrome (Flu-like illness to shock like reaction).

68. Rho (D) immune globulin
Rho (D) is a concentrated solution of human IgG1 containing higher titer of antibodies against Rho (D) antigen of red cells.
Given to Rh-negative mother within hours after delivery of Rh positive baby (2 ml, I.M.) to prevent hemolytic disease of the next Rh positive babies (erythroblastosis fetalis).
Adverse Effects
Local pain
Fever

69. Monoclonal antibodies Basiliximab and Daclizumab
Obtained by replacing murine amino acid sequences with human ones.
Basiliximab is a chimeric human-mouse IgG (25% murine, 75% human protein).
Daclizumab is a humanized IgG (90% human protein).
Have less antigenicity & longer half lives than murine antibodies

70. Mechanism of action Basiliximab and Daclizumab
IL-2 receptor antagonists
Are Anti-CD25
Bind to CD25 (α-subunit chain of IL-2 receptor on activated lymphocytes)
Block IL-2 stimulated T cells replication & T-cell response system
Basiliximab is more potent than Daclizumab.

71. Basiliximab and Daclizumab
Given I.V.
Half life Basiliximab (7 days )
Daclizumab (20 days)
are well tolerated - only GIT disorders
USES
Given with CsA and corticosteroids for Prophylaxis of acute rejection in renal transplantation.

72. Monoclonal antibodies
Infliximab
A chimeric human-mouse IgG
Directed against TNF-α
Is approved for ulcerative colitis, Crohn’s disease &rheumatoid arthritis
Omalizumab
A humanized monoclonal IgE
Directed against Fc receptor on mast &basophils
Is approved for asthma in steroid-refractory patient

73. INTERFERONS Three families: Type I IFNs ( IFN-α, β ):
Acid-stable proteins; act on same target cell receptor
Induced by viral infections
Leukocyte produces IFN-α
Fibroblasts & endothelial cells produce IFN-β
Type II IFN (IFN-γ):
Acid-labile; acts on separate target cell receptors
Produced by Activated T-lymphocytes.

74. IFN- γ : Immune Enhancing
Interferon Effects
IFN- γ : Immune Enhancing
Increased antigen presentations with macrophage, natural killer cell, cytotoxic T-lymphocyte activation
IFN- α, β :
effective in inhibiting cellular proliferation
(more effective than IFN- γ in this regard)

75. USES OF INTERFERON
Treatment of certain infections e.g. Hepatitis C (IFN- α ).
Autoimmune diseases e.g. Rheumatoid arthritis.
Certain forms of cancer e.g. melanoma, renal cell carcinoma.
Multiple sclerosis (IFN- β): reduced rate of exacerbation.
Fever, chills, myelosuppression.

76. THALIDOMIDE A sedative drug. Teratogenic (Class-X).
Can be given orally.
Has immunomodulatory actions
Inhibits TNF-α
Reduces phagocytosis by neutrophils
Increases IL-10 production

77. USES OF THALIDOMIDE Myeloma Rheumatoid arthritis
Graft versus host disease.
Leprosy reactions
Treatment of skin manifestations of lupus erythematosus

79. CLINICAL USES OF IMMUNOSUPPRESSIVE AGENTS
DISEASE
AGENT USED
Autoimmune Disease:
Acute glomerulonephritis
Autoimmune haemolytic anaemia.
Prednisone*, mercaptopurine.
Cyclophosphamide.
Prednisone*, cyclophosphamide, mercaptopurine, azathioprine, high dose -globulin.

80. Organ transplant: Renal Heart
Cyclosporine, Azathioprine, Prednisone, ALG, Tacrolimus.
Liver
Cyclosporine, Prednisone, Azathioprine, Tacrolimus.
Bone marrow
Cyclosporine, Cyclophosphamide, Prednisone, Methotrexate, ALG, total body radiation.

81. Thymocytes cells that develop in the thymus and serve as T cell precursors.

82. Gene Therapy

83. Genes Are carried on a chromosome The basic unit of heredity
Encode how to make a protein
DNARNA proteins
Proteins carry out most of life’s function.
When altered causes dysfunction of a protein
When there is a mutation in the gene, then it will change the codon, which will change which amino acid is called for which will change the conformation of the protein which will change the function of the protein. Genetic disorders result from mutations in the genome.

84. Picture of a Chromosome

85. What is Gene Therapy
It is a technique for correcting defective genes that are responsible for disease development
There are four approaches:
A normal gene inserted to compensate for a nonfunctional gene.
An abnormal gene traded for a normal gene
An abnormal gene repaired through selective reverse mutation
Change the regulation of gene pairs
Is the most common approach
The abnormal gene would be swapped by homologous recombination
Would cause a return to normal function
Control expression of genes. Similar to epistasis, when one gene affects the expression of another gene.

86. The Beginning…
In the 1980s, Scientists began to look into gene therapy.
They would insert human genes into a bacteria cell.
Then the bacteria cell would transcribe and translate the information into a protein
Then they would introduce the protein into human cells

87. The First Case
The first gene therapy was performed on September 14th, 1990
Ashanti DeSilva was treated for SCID
Sever combined immunodeficiency
Doctors removed her white blood cells, inserted the missing gene into the WBC, and then put them back into her blood stream.
This strengthened her immune system
Only worked for a few months 

88. How It Works
A vector delivers the therapeutic gene into a patient’s target cell
The target cells become infected with the viral vector
The vector’s genetic material is inserted into the target cell
Functional proteins are created from the therapeutic gene causing the cell to return to a normal state
A vector is a carrier molecule, usually a virus
The target cells are usually in the liver or lung

89. Picture

90. Viruses Replicate by inserting their DNA into a host cell
Gene therapy can use this to insert genes that encode for a desired protein to create the desired trait.
Four different types

91. Retroviruses Created double stranded DNA copies from RNA genome
The retrovirus goes through reverse transcription using reverse transcriptase and RNA
the double stranded viral genome integrates into the human genome using integrase
integrase inserts the gene anywhere because it has no specific site
May cause insertional mutagenesis
One gene disrupts another gene’s code (disrupted cell division causes cancer from uncontrolled cell division)
Vectors used are derived from the human immunodeficiency virus (HIV) and are being evaluated for safety

92. Adenoviruses
Are double stranded DNA genome that cause respiratory, intestinal, and eye infections in humans
The inserted DNA is not incorporate into genome
Not replicated though
Has to be reinserted when more cells divide
Ex. Common cold

93. Adenovirus cont.

94. Adeno-associated Viruses
Adeno-associated Virus- small, single stranded DNA that insert genetic material at a specific point on chromosome 19
From parvovirus family- causes no known disease and doesn't trigger patient immune response.
Low information capacity
gene is always "on" so the protein is always being expressed, possibly even in instances when it isn't needed.
hemophilia treatments, for example, a gene-carrying vector could be injected into a muscle, prompting the muscle cells to produce Factor IX and thus prevent bleeding.
Study by Wilson and Kathy High (University of Pennsylvania), patients have not needed Factor IX injections for more than a year

95. Herpes Simplex Viruses
Double stranded DNA viruses that infect neurons
Ex. Herpes simplex virus type 1

96. Non-viral Options Direct introduction of therapeutic DNA
But only with certain tissue
Requires a lot of DNA
Creation of artificial lipid sphere with aqueous core, liposome
Carries therapeutic DNA through membrane
Chemically linking DNA to molecule that will bind to special cell receptors
DNA is engulfed by cell membrane
Less effective 
Trying to introduce a 47th chromosome
Exist alongside the 46 others
Could carry a lot of information
But how to get the big molecule through membranes?

97. Current Status
FDA hasn’t approved any human gene therapy product for sale
Reasons:
In 1999, 18-year-old Jesse Gelsinger died from multiple organ failure 4 days after treatment for omithine transcarboxylase deficiency.
Death was triggered by severe immune response to adenovirus carrier
January 2003, halt to using retrovirus vectors in blood stem cells because children developed leukemia-like condition after successful treatment for X-linked severe combined immunodeficiency disease

98. Problems with Gene Therapy
Short Lived
Hard to rapidly integrate therapeutic DNA into genome and rapidly dividing nature of cells prevent gene therapy from long time
Would have to have multiple rounds of therapy
Immune Response
new things introduced leads to immune response
increased response when a repeat offender enters
Viral Vectors
patient could have toxic, immune, inflammatory response
also may cause disease once inside
Multigene Disorders
Heart disease, high blood pressure, Alzheimer’s, arthritis and diabetes are hard to treat because you need to introduce more than one gene
May induce a tumor if integrated in a tumor suppressor gene because insertional mutagenesis

99. Unsuccessful Gene therapies
Jesse Gelsinger, a gene therapy patient who lacked ornithine transcarbamylase activity, died in 1999.
Within hours after doctors shot the normal OTC gene attached to a therapeutic virus into his liver, Jesse developed a high fever. His immune system began raging out of control, his blood began clotting, ammonia levels climbed, his liver hemorrhaged and a flood of white blood cells shut down his lungs.
One problem with gene therapy is that one does not have control over where the gene will be inserted into the genome. The location of a gene in the genome is of importance for the degree of expression of the gene and for the regulation of the gene (the so-called "position effect"), and thus the gene regulatory aspects are always uncertain after gene therapy

100. Successful Gene Therapy for Severe Combine Immunodeficiency
Infants with severe combined immunodeficiency are unable to mount an adaptive immune response, because they have a profound deficiency of lymphocytes.
Severe combined immunodeficiency is inherited as an X-linked recessive disease, which for all practical purposes affects only boys. In the other half of the patients with severe combined immunodeficiency, the inheritance is autosomal recessive — and there are several abnormalities in the immune system when the defective gene is encoded on an autosome.

101. Severe Combine Immunodeficiency Continued
A previous attempt at gene therapy for immunodeficiency was successful in children with severe combined immunodeficiency due to a deficiency of adenosine deaminase. In these patients, peripheral T-cells were transduced with a vector bearing the gene for adenosine deaminase. The experiment was extremely labor intensive, because mature peripheral-blood T-cells were modified rather than stem cells, and the procedure therefore had to be repeated many times to achieve success.

102. Successful One Year Gene Therapy Trial For Parkinson's Disease
Neurologix a biotech company announced that they have successfully completed its landmark Phase-I trial of gene therapy for Parkinson's Disease.
This was a 12 patient study with four patients in each of three dose escalating cohorts. All procedures were performed under local anesthesia and all 12 patients were discharged from the hospital within 48 hours of the procedure, and followed for 12 months. Primary outcomes of the study design, safety and tolerability, were successfully met. There were no adverse events reported relating to the treatment.

103. Parkinson's Disease Cont.
The gene transfer procedure utilized the AAV (adeno-associated virus) vector, a virus that has been used safely in a variety of clinical gene therapy trials, and the vehicle that will be used in all of the company's first generation products, including epilepsy and Huntington's disease. In its Parkinson's disease trial, Neurologix used its gene transfer technology.

104. Recent Developments
Genes get into brain using liposomes coated in polymer call polyethylene glycol
potential for treating Parkinson’s disease
RNA interference or gene silencing to treat Huntington’s
siRNAs used to degrade RNA of particular sequence
abnormal protein wont be produced
Create tiny liposomes that can carry therapeutic DNA through pores of nuclear membrane
Sickle cell successfully treated in mice