The role of glutathione in cell defense

1. The Role of Glutathione in Cell Defense, with
References to Clinical Deficiencies and Treatment
Thomas A. Kwyer, M.D.

2. Glutathione Precursors: Amino Acids
 L-Glutamate
 L-Cysteine
the rate-limiting substrate
cystine (cysteine=cysteine) is an ideal form of cysteine
for glutathione synthesis
 Glycine

3. Glutathione: L-glutamylcysteinylglycine
 DNA synthesis and repair
 Protein synthesis
 Prostaglandin synthesis
 Amino acid transport
 Metabolism of toxins and carcinogens
 Immune system enhancement
 Prevention of oxidative cell damage
 Enzyme activation
Lomaestro, B. Ann Pharmacother, 1995 Dec;(12):1263 -73.

4. Immunonutrition in the Critically Ill: a Systematic
Review of Clinical Outcomes (12 studies with
1,557 subjects, 1,482 of whom were analyzed)
 “Objective: To perform a meta-analysis addressing whether
enteral nutrition with immune-enhancing feeds benefit critically
ill patients after trauma, sepsis, or major surgery.”
 “Main outcome measures were mortality, infection,ventilator
days, intensive care unit stay, hospital stay, diarrhea days,
calorie intake and nitrogen intake.”
Beale, R., Crit. Care Med. 1999, Dec.;27(12):2799-805.

5. Immunonutrition in the Critically Ill: a Systematic
Review of Clinical Outcomes (Summary)
 BENEFITS:
Infection: a significant reduction in the relative risk of
acquiring infection.
Ventilator Days: a significant reduction overall.
Hospital Length of Stay: the reduction in hospital
LOS was significant.
 SAFETY:
No increase in side effects of feeding was reported in
patients receiving immunonutrition.

6. Effect of Immune Enhancement on Length of
Therapeutic Intervention in Severe Abdominal
Trauma
0
5
10
15
20
Immune
Enhancing
Isocaloric
Diet
Control
(unfed)
Therapeutic
Antibiotic Days
Ventilator Days
ICU Days

7. Effect of Immune Enhancement on Total
Hospitalization Cost in Severe Abdominal Trauma
$0
$20,000
$40,000
$60,000
$80,000
$100,000
$120,000
$140,000
$160,000 Immune
Enhancing
Isocaloric
Diet
Control
(unfed)
Total Hospital
Charges

8. Effect of Immune Enhancement on Total Hospital
Days in Severe Abdominal Trauma
0
5
10
15
20
25
30
35
40
Immune
Enhancing
Isocaloric
Diet
Control
(unfed)
Total Hospital
Days

9. Pathogenesis of Glutathione Deficiency: Cytokine
Selection (Slide 1)
 “Glutathione Levels in Antigen-presenting Cells Modulate Th1
Versus Th2 Response Patterns.” (Title of Article)
“...the Th1 pattern is characterized by interleukin 12 (IL-
12) and interferon γ (IFN-γ) production and the up-
regulation cell-mediated, e.g.,delayed hypersensitvity,
(DTH) responses.”
“The Th2 response pattern is characterized by IL-4 and
IL-10 production and up-regulation of a variety of antibody
responses.”
 Peterson, J., Proc. Natl. Acad. Sci. U S A 1998, Mar.
17;95(6): 3071-3076.

10. Pathogenesis of Glutathione Deficiency: Cytokine
Selection (Slide 2)
 “Antigen-presenting cells (APC) -- macrophages, dendritic
cells, and B cells -- are central to the development of either
Th1 or Th2 immunity because antigen presentation and
recognition are required to initiate responses.”
 “...GSH depletion inhibits Th1-associated cytokine
production and/or favors Th2-associated responses.”
Peterson, J., Proc. Natl. Acad. Sci. U S A 1998, Mar.
17;95(6): 3071-3076.

11. “Defective Antigen Processing Correlates with a
Low Level of Intracellular Glutathione”
 “Therefore, low intracellular glutathione levels in antigen-
presenting cells correlate with defective processing of antigen
with disulfide bonds, indicating that this thiol may be a critical
factor in regulating productive antigen processing.”
Short, S., Eur. J. Immunol. 1996, Dec;26(12):3015-3020.
 Most antigens are proteins with disulfide bonds. GSH reduces
disulfide bonds. Low GSH prevents disulfide bond reduction.
 1. RSSR’ + GSH  RSH + GSSR’
 2. GSSR’ + GSH  GSSG + R’SH

12. “Lymphocyte Proliferation in Glutathione-depleted
Lymphocytes: Direct Relationship Between
Glutathione Availability and the Proliferative
Response”
 “Lymphocyte proliferation in response to mitogenic lectins is
directly dependent upon glutathione (GSH) availability.”
 “...the restoration of lymphocyte proliferation by exogenous
GSH is more closely linked to effects on intracellular rather
than extracellular GSH.”
 “These studies confirm the importance of intracellular GSH in
lymphocyte proliferation.”
Hamilos, D., Immunopharmacology, 1989, 18;223-235.

13. Pathogenesis of Glutathione Deficiency in the
Immune Response: Summary
 Glutathione levels in antigen-presenting cells modulate
Th1 versus Th2 response patterns.
 Antigen presentation and recognition are required to
initiate immune responses.
 Key events that determine whether IFN-γ is produced
occur almost immediately.
 IFN-γ production predominates when GSH levels are high.
 GSH depletion may play a key role in exacerbating HIV
and other infectious diseases in which Th2 predominance
is an important aspect of the disease pathology.

14. Pathogenesis of Glutathione Deficiency and
Apoptosis: AIDS (Slide 1)
 “Glutathione Deficiency is Associated with Impaired
Survival in HIV Disease.” (Title of Article from Stanford)
 “The crucial connection revealed here between GSH
deficiency and survival in HIV disease was foreshadowed by
several studies.”
 Survival in all HIV+: GSB≥ 0.91 = 90%, GSB< 0.91 = 32%.
 Survival in CD4 < 200: GSB≥ 1.05 = 87%, GSB< 1.05 = 17%.
Herzenberg, L, Proc. Natl. Acad. Sci. U S A 1997, Mar.
4;94(5): 1967-1972.

15. Pathogenesis of Glutathione Deficiency and
Apoptosis: AIDS (Slide 2)
 “Type 1 and Type 2 Cytokines in HIV Infection -- a Possible
Role in Apoptosis and Disease Progression.” (Title of Article)
 “...a strong type 1/weak type 2 cytokine production profile
was observed in HIV-seropositive patients with delayed or
absent disease progression, whereas progression of HIV
infection was characterized by a weak type 1/strong type 2
cytokine production profile.”
Clerici, M., Ann. Med. 1997, Jun.;29(3):185-188.

16. Pathogenesis of Glutathione Deficiency and
Apoptosis: AIDS (Summary)
 Glutathione Deficiency is Associated with Impaired
Survival in HIV Disease.
 Survival in all HIV+: GSB≥ 0.91 = 90%, GSB< 0.91 = 32%.
 Survival in CD4< 200: GSB≥ 1.05 = 87%, GSB< 1.05 =
17%.
 Antiretroviral therapies will not successfully eradicate
HIV and HIV-seropositive patients will not be ultimately
cured unless therapies aimed at restoring the immune
system are associated with the antiretroviral drugs
currently employed.

17. Benefits of Glutathione Enhancement in Disease
or Stress: Pulmonary Disease
 “We describe a case of a patient who had obstructive lung
disease responsive to corticosteroids, and low whole blood
GSH levels.”
 “After 1 month of supplementation with a whey-based oral
supplement designed to provide GSH precursors, whole
blood GSH levels and pulmonary function increased
significantly and dramatically.”
Lands, L., J. Appl. Physio. 1999, Oct.;87(4):1381-5.

18. Benefits of Glutathione Enhancement in Disease
or Stress: Pulmonary Disease
 Relationship to Immunocal®
intake:
Time 6 on Immunocal® 1
month.
Time 7 off Immunocal®.
Time 8 back on
Immunocal®.
 Immunocal® significantly and
dramatically increased
pulmonary function.
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
Time
1
Time
2
Time
3
Time
4
Time
5
Time
6
Time
7
Time
8
FEV1
FVC

19. Method of Intracellular GSH Enhancement:
Undenatured Whey Protein Concentration
 Contains highly concentrated amounts of cystine (cysteine =
cysteine) because of a new Pasteurization technique which
preserves the disulfide bond between the two cysteines.
 The naturally occurring constituent heat labile proteins found
in “Mother’s Milk” that imparts immune enhancement.
 Dose: 10 - 40 grams per day for adults and ½ gram/Kg for
infants and young children up to 40 Kg.
 High dose to reverse cachexia: up to 120 grams has been
reported (anecdotal) to increase total body weight 15% in
two weeks in a near death AIDS patient with cachexia.

20. Cystine: the Preferred Substrate for Optimal
Glutathione Synthesis and Immune Enhancement
 Hepatic Nitrogen Metabolism: Cysteine from muscle catabolism
arrives in the liver in the form of cystine. Enteral feeding of cystine
takes advantage of this well-developed metabolic pathway that is
also utilized when digesting breast milk which has well
documented and indisputable immune enhancing properties.
 Antigen Presenting Cells: Prefer cystine for GSH synthesis which
is required to initiate the immune response then feed lymphocytes
cysteine as an immunoregulatory signal.
 Astrocytes: Prefer cystine for GSH synthesis and feed cysteine to
neurons to protect against neurodegenerative diseases.

21. Proton Donation is the Basis for Preservation of
the Amino Acid Pool (Positive Nitrogen Balance)
(Dröge, W, FASEB J., 1997 Nov.;11(13):1077-89)

22. Proton Donation: the Sulfur of Glutathione can
give up a Proton (H+
)
GSH + GSH  GSSG + 2H+

23. Pathogenesis of Cystine Deficiency: Wasting
Syndromes (Slide 1)
 “Role of Cysteine and Glutathione in HIV Infection and Other
Diseases Associated with Muscle Wasting and
Immunological Dysfunction.” (Title of Article)
 “Evidence suggests that 1) the cystine level is regulated
primarily by the normal postabsorptive skeletal muscle
protein catabolism, 2) the cystine level itself is a
physiological regulator of nitrogen balance and body cell
mass...”
Dröge, W., FASEB J. 1997, Nov;11(13):1077-89.

24. Pathogenesis of Cystine Deficiency: Wasting
Syndromes (Slide 2)
 AIDS, sepsis, major injury, trauma, cancer, chronic fatigue
syndrome, Crohn’s disease, ulcerative colitis, and athletic
over-training are associated with:
low cystine,
low glutamine,
elevated glutamate,
increased urea production, and
reduced natural killer (NK) cell activity.

25. Pathogenesis of Cystine Deficiency: Wasting
Syndromes (Slide 3)
 This diagram demonstrates the
relationship between cystine
and nitrogen balance to be as
follows:
 ↑ Cystine.
 ↑ Protons (H+
).
 ↓ Bicarbonate (HCO2
-
).
 ↓ Carbamoylphosphate.
 Ammonium ion (NH4+
) is
saved.
 This results in positive nitrogen
balance with maintenance or
increase in weight.

26. Pathogenesis of Cystine Deficiency: Wasting
Syndromes (Slide 4)
 This diagram demonstrates the
relationship between cystine and
nitrogen balance to be as follows:
 ↓ Cystine.
 ↓ Protons (H+
).
 ↑ Bicarbonate (HCO2
-
) .
 ↑ Carbamoylphosphate.
 Ammonium ion (NH4+
) is
saved.
 This results in negative nitrogen
balance with decrease in weight
and possible cachexia.

27. Glutathione Precursor Transport: Cystine is
Preferred form of Cysteine for GSH Synthesis
 Cystine (cysteine=cysteine) is the preferred form of
cysteine for macrophages and astrocytes.
“Macrophages consume cystine...”
Gmunder, H., Macrophages Regulate Intracellular
Glutathione Levels of Lymphocytes. Cell. Immunol.,
1990, Aug.; 129(1): 32-46.
“These results demonstrate that astroglial cells prefer
cystine...” Kranich, O., Glia, 1998, Jan.;22(1): 11-8.

28. Glutathione Depleting Agents
Smoking.
Alcohol.
Caffeine.
Acetaminophen.
Drugs.
Vigorous exercise.
x-, γ- and UV radiation
Xenobiotics.

29. Total Parenteral Nutrition: the Road to Enteral
Atrophy, Leaky Gut Syndrome and Pneumonitis
 Enterocyte nutrient transport is one way: from the gut to the
cell to the capillary.
 Enterocytes cannot transport nutrients from the blood
vessel.
 Enterocytes starve as the rest of the body is fed by way of
the vasculature.
 Enterocytes pull away from each other as a consequence of
gut atrophy.

30. Total Parenteral Nutrition: the Road to Enteral
Atrophy, Leaky Gut Syndrome and Pneumonitis
 Bacteria slip between the atrophying enterocytes.
 Bacteria enter lymph nodes and then gain access to
thoracic duct.
 The thoracic duct emtpies into the blood flowing toward the
right heart and into the pulmonary circulation.
 Atrophic gut cannot generate sufficient amounts of
secretory IgA.
 The lungs are also compromised and pneumonitis
frequently occurs due to constant seeding and lack of IgA.