The document discusses how infection can be detrimental for patients with mitochondrial disease due to the increased energy demands and potential immune dysfunction. It outlines how the immune system may be compromised in mitochondrial disease based on clinical observations of increased infections and poor vaccine responses in some patients. Animal studies show that mitochondrial dysfunction within immune cells can impair their function and response to infection.

1. Metabolism, Infection and Immunity in
Mitochondrial Disease
Peter J. McGuire MS, MD
Head, MINI Section
National Human Genome Research Institute
5 October 2018

2. No conflicts of interest to declare

3. Outline
• What is the immune system and why is it
important?
• Infection and mitochondrial disease
• Immune function in mitochondrial disease

4. Why is the immune system
important?
• Protects us against
Bacteria Viruses Fungi
CancerParasites Pollution

5. The immune system has
multiple lines of defense

6. The immune system is
composed of organs and
cells
Organs Cells

7. The immune system has many different type of cells
Bone graft
Multipotential
stem cell
Hematopoietic
stem cell
Platelets
Macrophage
Erythrocytes
Eosinophil
Neutrophil
Megakaryocyte
Mast cell
Basophil
T lymphocyte
Natural killer cell
Dendritic cell
B lymphocyte
Lymphoid progenitor cell
Myeloid
progenitor
cell
Monocyte
Marrow
Bone

8. How does the immune system
protect us?
• Body learns to defend
itself by:
– Natural infection
– Vaccination

9. vaccina on
Y
Y
YYY Y
Y
YY
infec on
Y Y Y Y Y
Y
Y
YYY Y
Y
YY
Y
Y
YYY Y
Y
YY
Y
Y
YYY Y
Y
YY
Y
Y
YYY Y
Y
YY
Y
Y
YYY Y
Y
YY“Immune memory”
Y
T-cells and B-cells
Protec ve an bodies
Key:
Weeks Years Days Years
Y Y Y
How does the immune system
protect us?

10. Why study the immune system immune
and mitochondrial disease (MD)?
• Because:
– Infection is bad for patients with
mitochondrial disease
• Our questions:
– What happens to patients with MD
during infection?
– Does having MD affect immune
function?

11. Infection is bad for patients with MD
• Point #1: Infection increases
energy requirements
– For every 1° C of fever,
metabolic rate can increase 10%
or more
– Problem: need more calories, but
you don’t feel like eating; ability
to generate energy

12. 13C-Pyruvate
13C-Pyruvate
Acetyl coA + 13CO2
TCA
PDH
13C-Lactate13C-Alanine
ALT LDH
Mitochondria
Figure 7: Poly I:C results in increased Lactate/Pyruvate and Alanine/Pyruvate.
Hyperpolarized 13C-pyruvate was injected by tail vein and alanine and lactate production
were measured by MR spectroscopy.
Tarasenko et al (submitted)
Infection is bad for patients with MD
• Point #2: Infection can lead to an increase in
tissue lactate production

13. Infection is bad for patients with MD
• Point #3: Immune reactions can damage
mitochondria
Tarasenko et al (submitted)
C
ontrol
Poly
I:C
0.0
0.5
1.0
1.5
ComplexI+III/CS
*

14. Infection is bad for patients with MD
• Point #3: Immune reactions can damage
mitochondria
Tarasenko et al (submitted)
Pair-fed
PR
8
0
5
10
15
20
SerummtDNA
(controlratio)
Pair-fed
PR
8
0.0
0.5
1.0
1.5
HepaticmtDNA
(controlratio)
*

15. Infection is bad for patients with MD
• Point #4: The immune response may be
part of the problem - cytokines
Cytokines produced as part of the immune response inhibit
mitochondrial metabolism in human liver cells.
Immune cells “text”
each other by cytokines
May be innocent
bystanders (e.g. liver)
cytokines C
ontrol
TN
Fα
0
50
100
150
200
OCR(pmoles/min)
*
C
ontrol
TN
Fα
0
50
100
150
200
OCR(pmoles/min)
*
Basal Maximal

16. Infection is bad for patients with MD
• Point #5: What do we see clinically with
infection?
0
50
100
Neurologicevents(%) SLE
Acidosis
Ataxia
Encephalopathy
43%
Edmonds et al. (2002)

17. The need for translational research in MD
Metabolic
decompensation
• In extremis (life-
threatening)
- Bioenergetic failure
- Lactic acidosis
- Organ failure (e.g. liver
failure)
- Encephalopathy
- Stroke
- Sequelae
• Extensive ICU care
• Viral infections
• Treatment is inadequate
Clinical question: How did we arrive at this point?
1) Are patients with MD immunodeficient?
2) What is the role of inflammation in MD pathophysiology?

18. Immune function in MD
• Since infection can be very
serious...
– How well does the immune
system function in patients with
MD?

19. • mtDNA depletion syndrome
• Complex II+III and IV in muscle
• Recurrent infections, RIP 18 months with septicemia
• Hypogammaglobulinemia by 15 months
• Memory T-cells, CD8+ T-cells, NK cells
• T-cell response to Il-2

21. Immune function and MD
• What do we know? Not much,
but…
– Immune cells don’t like high levels
of toxins
– Mitochondrial RC deficiencies can
also be present in immune organs
and cells

22. Immune function and MD:
toxins (lactate)

23. • 15 year old male
• Complex III deficiency
• Multisystem disease
– Neurologic
– Musculoskeletal
– Endocrine
– Immunologic
• Multiple infections
• Hypogammaglobulinemia
• Loss of pneumococcal titers
• Research exome pending
Mitochondrial dysfunction in immune cells
It all started with a clinical case…
C
ontrols
Patient
0.0
0.5
1.0
1.5
ComplexIII/CS
(controlratio)
McGuire et al. (unpublished data)

24. Clinical features of MD
• Multisystem
• energy organs
• mtDNA and nDNA
inheritance
• Most common IEM
• Lactic acidosis
• Complications during/after
decompensation
(Edmonds et al, 2002)
• Pathophysiology: energy
deficiency, ROS
Immune system

25. Recurrent infection is common
in patients with MD
Tarasenko et al, Cell Metab, 2017

26. Immunodeficiency screen for MD patients
4+
O
M
/yr
2+
sinus
inf/yr
2+m
o
A
bx
2+
PN
A
/yrFTT/G
F
IV
A
bx
N
eed
IC
U
A
dm
it
R
ecovery
D
eep
A
bscess
FungalInf
2+Inf/Sepsis
FH
x
1o
IDPtH
x
ID
Im
m
uno
Eval
IVIGA
bx
PPx
0
20
40
60
80
100
%positive

27. Naïve
CD45RA+
CD45RO-
CD45RA-
CD45RO+
Memory
(protective)
Patients with MD may have poor immune memory

30. Vaccination Rate
92%
8%
Vaccination rates MMR
84%
16%
Vaccination rates VAR
YES
INCOMPLETE
Kruk et al (unpublished data)

31. MMR seropositivity
C
ontrol
MD
0
20
40
60
80
100
Measlesseropositivity%
Year Cases
2010 63
2011 220
2012 55
2013 187
2014 667
2015 188
2016 86
2017 118
2018 63
Measles cases per year
Kruk et al (unpublished data)

32. Varicella seropositivity
C
ontrol
MD
0
20
40
60
80
100
Varicellaseropositivity%
Kruk et al (unpublished data)

33. The immune phenotype
in patients with MD (NIH MINI Study)
Primary immunodeficiency
Allergic/Inflammatory diseases
Immune dysfunction
Stress-induced
immune dysfunction
Absent immune phenotype
Risk of decompensation

34. vaccina on
Y
Y
YYY Y
Y
YY
infec on
Y Y Y Y Y
Y
Y
YYY Y
Y
YY
Y
Y
YYY Y
Y
YY
Y
Y
YYY Y
Y
YY
Y
Y
YYY Y
Y
YY
Y
Y
YYY Y
Y
YY“Immune memory”
Y
T-cells and B-cells
Protec ve an bodies
Key:
Weeks Years Days Years
Y Y Y
How does the immune system
protect us?

35. Hypothesis: Bioenergetic deficiency in MD may extend
to immune cells leading to immunodeficiency.
Tarasenko et al, Cell Metab, 2017

36. How many patients are on IVIg?
How many patients have
problems with infection?

37. The mystery of IVIg
IVIg
•intravenous immune globulin
•aka “antibodies”
•produced from human plasma
•Immune mediated conditions
•Immunodeficiency
•Other effects? Benefits?
•Does the pathology of MD have
an immune component?

38. • 8 y/o male with MD
• Received PICC line 2
weeks prior for access
• Presented with fever and
hospitalized
0
2
4
6
8
10
6.5
7.0
7.5
8.0
Lactate(mmol/L)
Lactate
pH
pH
D
ay1
D
ay2
D
ay3
D
ay3
D
ay4
D
ay5
D
ay6
0
2
4
6
8
WBC(cellsx103/mm3)
WBC
Fever
Hypothesis: Bioenergetic deficiency in MD may extend
to immune cells leading to immunodeficiency.

39. • 8 y/o male with MD
• Received PICC line 2
weeks prior for access
• Presented with fever and
hospitalized
Hypothesis: Bioenergetic deficiency in MD may extend
to immune cells leading to immunodeficiency.
D
ay
1D
ay
2D
ay
3
500
600
700
800
900
1000
IgG(mg/dL)

40. Translational model: TCox10-/-
COX10
• Maturation of cytochrome C oxidase (CIV)
• Present in lymphocytes
• Deficiency: MD or Leigh phenotype
• KO in T-cells only
• Mice are generally healthy
X
CD4-Cre Cox10flox/flox
TCox10-/-
Tarasenko et al, Cell Metab, 2017

41. Compromised respiratory chain in TCox10-/- T-cells
W
TTC
ox10-/-
0
100
200
300
400
500
OCR(pmoles/min)
****
W
TTC
ox10-/-
0
500
1000
1500
2000
COX/CS
****
Tarasenko et al, Cell Metab, 2017

42. TCox10-/- peripheral lymphocyte counts
HEMAVET
0
2
4
6
8
10
6.5
7.0
7.5
8.0
Lactate(mmol/L)
Lactate
pH
pH
D
ay1
D
ay2
D
ay3
D
ay3
D
ay4
D
ay5
D
ay6
0
2
4
6
8
WBC(cellsx103/mm3)
WBC
Fever
W
T
TC
ox10
-/-
0
5
10
15
WBC(K/mL)
W
T
TC
ox10
-/-
0
5
10
15
WBC(K/mL)
W
T
TC
ox10
-/-
0
2
4
6
8
10
Lymphocytes(K/mL)
W
T
TC
ox10
-/-
0
2
4
6
8
10
Lymphocytes(K/mL)
*
W
T
TC
ox10
-/-
30
40
50
60
70
80
90
Lymphocytes%
W
T
TC
ox10
-/-
30
40
50
60
70
80
90
Lymphocytes%
***
Baseline
Infection
W
T
TC
ox10-/-
0
5
10
15
WBC(K/mL)
W
T
TC
ox10-/-
0
5
10
15
WBC(K/mL)
W
T
TC
ox10-/-
0
2
4
6
8
10
Lymphocytes(K/mL)
W
T
TC
ox10-/-
0
2
4
6
8
10
Lymphocytes(K/mL)
*
W
T
TC
ox10-/-
30
40
50
60
70
80
90
Lymphocytes%
W
T
TC
ox10-/-
30
40
50
60
70
80
90
Lymphocytes%
***
Baseline
Infection
Tarasenko et al, Cell Metab, 2017

43. vaccina on
Y
Y
YYY Y
Y
YY
infec on
Y Y Y Y Y
Y
Y
YYY Y
Y
YY
Y
Y
YYY Y
Y
YY
Y
Y
YYY Y
Y
YY
Y
Y
YYY Y
Y
YY
Y
Y
YYY Y
Y
YY“Immune memory”
Y
T-cells and B-cells
Protec ve an bodies
Key:
Weeks Years Days Years
Y Y Y
How does the immune system
protect us?

44. Vaccination response is impaired in TCox-/-
0 14 28 35
Days
1° 2°
Y
Y
Y
Y Y
Y
Y
Y
Y
Y
Y
YY
Y
*
W
TTC
ox10-/-
B
lank
0.0
0.5
1.0
1.5
2.0
IgG1(controlratio)
****
W
TTC
ox10-/-
B
lank
0.0
0.5
1.0
1.5
2.0
IgG1(controlratio)
****
2 weeks (1°) 5 weeks (2°)
• Clinical correlate: loss of vaccine titers
Tarasenko et al, Cell Metab, 2017

45. Influenza viral clearance is impaired in TCox10-/-
W
T
TC
ox10-/-
0
50
100
150
NPmRNA
(controlratio)
Tarasenko et al, Cell Metab, 2017

46. Summary
• The immune system is important for vaccination
and protection against infection
• Infection may be detrimental to patients with MD
• Subsets of patients with MD may have immune
dysfunction
– Toxicity
– Metabolic dysfunction

47. Longitudinal natural history study of
immunity in MD
The NIH MINI Study: Metabolism, Infection, and Immunity in
Inborn Errors of Metabolism (NCT01780168)
Goals:
• Identify immune susceptibilities
and risks in patients with MD
• Characterize organ systems
which may be susceptible to
dysfunction/damage during
infection in MD

48. America’s Research Hospital
Travel and lodging arranged and covered by NIH
Meals covered by NIH

49. Children’s Inn at NIH

50. MINI Study contact information
Principal Investigator
Peter J. McGuire MS, MD
Staff Clinician
Eliza Gordon-Lipkin MD, PhD
Study Coordinator
Shannon Kruk, BSN, RN
Telephone
301-451-9145
Website
http://www.genome.gov/mini
Email
ministudy@mail.nih.gov