THE BIOLOGICAL BASIS FOR THE NEUROTOXICITY OF

VACCINES

Lucija Tomljenovic, PhDNeural Dynamics Research Group

Faculty of MedicineUniversity of British Columbia

Question...WHY WOULD AN IMMUNE CHALLENGE

SUCH AS VACCINATION, AFFECT BRAIN DEVELOPMENT AND/OR

FUNCTION ?

o “Until recently, the brain was studied almost exclusively by neuroscientists and the immune system by immunologists, fuelling the notion that these systems represented two isolated entities.

o ....the crosstalk between these systems can no longer be ignored and a new interdisciplinary approach is necessary.”

o Many proteins first identified in the immune system are also expressed in the developing and adult nervous system. Unexpectedly, recent studies reveal that a number of these proteins, in addition to their immunological roles, are essential for the establishment, function, and modification of synaptic connections.

o “Recent studies demonstrate that immune molecules are present at the right place and time to modulate the development and function of the healthy and diseased central nervous system (CNS).

o “...functions for immune molecules during neural development suggest that they could also mediate pathological responses to chronic elevations of cytokines in neurodevelopmental disorders, including autism spectrum disorders and schizophrenia.”

o “Despite the dogma that peripheral immune responses could not affect CNS function under normal circumstances, substantial evidence over the past 10 years suggests that immune-CNS cross-talk may be the norm rather than the exception.”

In: Handbook of Neurochemistry and Molecular Neurobiology: A Lajtha, HO Besedovsky, A Galoyan (Eds), Springer, 2008.

o Because the communication between the immune system and the brain occurs at multiple levels, this communication is now defined as a “immune–neuroendocrine network.”

o The immune–neuroendocrine network plays a key role in:‒ immune regulation‒ brain function‒ maintenance of general homeostasis

(circadian rhythms, endocrine and metabolic functions)

Disruption of the immune-neuroendocrine network leads to a wide range of diseases:

− neurological − immuno-inflammatory− metabolic disorders

What kind of disorder is autism?

“Increased oxidative stress and immune dysregulation are present in autism spectrum disorders.”

“We recently demonstrated the presence of neuroglial and innate neuroimmune system activation in brain tissue and cerebrospinal fluid of patients with autism, findings that support the view that neuroimmune abnormalities occur in the brain of autistic patients and may contribute to the diversity of the autistic phenotypes.”

o The evidence that changes in brain activity occur during the immune response implies that signals released by immune cells mediate these effects.

o peripheral immune insults can directly stimulate the synthesis of pro-inflammatory cytokines (i.e., IL-1β, IL-6, TNF)-α within the brain → brain inflammation

o It is clearly established that products derived from the immune system, particularly cytokines, affect neuroendocrine functions.

− Laye et al. Mol Brain Res 1994; 27:157-162− Besedovsky & Rey, Handbook of Neurochemistry and Molecular

Neurobiology, in: A. Lajtha, H.O. Besedovsky, A. Galoyan (Eds.), Springer, 2008

IMMUNE STIMULATION, IMMUNE CYTOKINES AND THEIR EFFECTS ON BRAIN ACTIVITY

− Endocrine functions− Autonomic functions− Growth, differentiation and repair−Neurotransmitter & neuropeptide synthesis & release− Neuronal activity and plasticity− Learning & memory− Behavior− Sleep− Pain− Food intake− Thermoregulation

Cytokines

NEUROENDOCRINE EFFECTS OF IMMUNE CYTOKINES

+ Endocrine functions

+ Autonomic functions

+ Growth, differentiation and repair

+ Neurotransmitter & neuropeptide

synthesis & release

+ Neuronal activity and plasticity

NEUROENDOCRINE DEFFECTS IN AUTISM

+ Learning

& memory

+ Behavior

+ Sleep

+ Pain

- Food intake

- Thermoregulation

Is autism in part caused by a disruption of the immune-neuroendocrine network via elevation of pro-inflammatory mediators (cytokines)?

o We demonstrate an active neuroinflammatory process in the cerebral cortex, white matter, and cerebellum of autistic patients.

o Immunocytochemical studies showed marked activation of microglia and astroglia.

o Chemokines and cytokines MCP–1, IL-6 and TGF-1, derived from neuroglia, were the most prevalent cytokines in brain tissues.

o Cerebrospinal fluid showed a unique proinflammatory profile of cytokines, including a marked increase in MCP-1.

Which common peripheral immune insults other than infections can induce the synthesis of

pro-inflammatory cytokines in the brainand the activation of glial cells?

Duplicating the pediatric vaccine schedule with alum adjuvants in mice

2) Behavioral testing (social interaction) at 4-6 months of age3) Sacrifice and collecting of brain tissue at 6 months of age4) Semi-quantitative RT-PCR5) Western blot for protein levels

Treatment Group

Mouse Age (days postnatal) Total Al injected

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 (ug/kg body weight)

High aluminum (US) 　 170 　 150 110 　 　 　 80 　 20 　 　 　 　 20 550

Low aluminum (SCA)

90 80 50 20 240

Control (saline) 　 X 　 X X 　 　 　 X 　 X 　 　 　 　 X 0

1) Aluminum injection schedule:

Gene expression changes in male mice brains

Protein level changes in male mice brains

Genes affected in male mouse brains

Gene Function

NFKBIB NF-kappa-B inhibitor, which inhibits NF-kappa-B by complexing with, and trapping it in the cytoplasm. NF-κB is the central regulator of inflammation. Constitutive NF-κB activation is essential for macrophage survival.

ACHE Neurotransmitter (Ach) degradative enzyme, acetylcholinesterase. Anti-depression/anxiety effect. Low AChE activity is associated with deficits in neurodevelopment, particularly in attention and memory.

CCL2/MCP-1

Chemokine secreted by a few cell types including macrophage. A cytokine involved in immunoregulatory and inflammatory processes.

IFNG Interferon gamma, a secreted product and potent activator of macrophages. A soluble cytokine with antiviral, immunoregulatory and anti-tumor properties.

TNF Tumor necrosis factor mainly secreted by macrophages. Multifunctional proinflammatory cytokine.

Gene expression changes in female mice brains

BEHAVIORAL TESTS: LIGHT-DARK BOX

High aluminum group exhibits significantly increased anxiety & reduced exploratory behavior. Females are more severely affected, showing deficits even at low concentration of aluminum.

Males in the high aluminum group are significantly more lethargic than those in the low aluminum group & control mice.

BEHAVIORAL TESTS: OPEN FIELD

Object Mouse0

50

100

150

200

250

CTRL femalesUS females

Sn

iffin

g t

ime (

sec)

***

Object Mouse0

20

40

60

80

100

120

140

CTRL malesUS males

Sn

iffin

g t

ime (

sec)

BEHAVIORAL TESTS: SOCIAL INTERACTIONS

REPEATED VACCINATIONS =

Stimulation of aberrant immune responses

Increased levels of inflammatory cytokines in the brain

IMPAIRED BRAIN DEVELOPMENT & FUNCTION

MOREOVER….

Repeated immunization with foreign antigen compounds causes systemic autoimmunity in mice otherwise not prone to spontaneous autoimmune diseases.

o CD4+ T cells from repeatedly-immunized mice acquire the ability to induce autoantibodies which results in autoimmune tissue injury similar to that seen in human autoimmune diseases.

o “SYSTEMIC AUTOIMMUNITY APPEARS TO BE THE INEVITABLE CONSEQUENCE OF OVER-STIMULATING THE HOST’S IMMUNE ‘SYSTEM’ BY REPEATED IMMUNIZATION WITH ANTIGEN.”

THE KEY PROBLEM IS NOT SINGLE VACCINESTHE KEY PROBLEM IS:

Other reasons why vaccines tend to adversely affect the central nervous system

o Vaccine-derived aluminum persists in the body long after injection (> 6 months)

o The alum adjuvant penetrates the blood-brain barrier carried by macrophage cells. Once in the brain, alum has the potential to trigger abnormal immuno-inflammatory reactions in the brain

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Penetration of the blood-brain barrier by aluminum can allow access of antibodies to the brain and cause unwanted autoimmune reactions

Testing the hypothesis:

Is there experimental evidence to indicate that antibodies induced by the HPV vaccine

cross-react with neural antigens?

Gardasil

Mouse serumMouse brain protein extract

Gardasil antigens (HPV-16, 18, 11, 6)

Anti-HPV antibody

Anti – HPV antibody binds to HPVBrain extract inhibits Anti – HPV antibody

binding to HPV

Mouse serum

Brain extract m/ml

% I

nh

ibit

ion

0

20

40

60

80

100

10 20 30 40 50

Gardasil + pertussis

Gardasil

Aluminum

Brain protein extract inhibits anti-HPV antibodies binding to HPV antigens

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BRAIN

BLOOD

BLOOD-BRAIN BARRIER

HPV-16L1 Anti-HPV-16L1

Alum

AutoimmunityNeuro-inflammation

Macrophage

SUMMARY:The neurotoxic risk of the HPV vaccine

o Neurotoxic action of the aluminum adjuvant+

o Immuno-inflammatory effect of the HPV-16L1 vaccine antigen

+o Neuro-autoimmune effect of the cross-reactive HPV

vaccine-induced anti-HPV-16L1 antibody

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