Why
Does H5N1 Kill?
Much
of our biochemistry involves a balance of pro and anti inflammatory
activities, Yin and Yang. When these acivities are imbalanced,
the result is illness. Based on the article below, it appears that
the lethality of H5N1 may be due to the human body's imbalanced
immunological response to the bird flu virus. The paper shows a
strong pro-inflammatory cytokine response (cytokines are protein
messengers that enable cells to communicate and respond to things)
to H5N1 infection may account for the high lethality of H5N1.
If so, cannabis (NOT SMOKED-it is an irratant and could make things
worse) could be the life saving answer to the possible future pandemic
due to its capacity to down-regulate these cytokines (specifically
TNF).
PITFALLS-
health is a dynamic balance of opposing forces (pro versus anti-
inflammatory). Too much of an imbalance in either direction could
be lethal. For example, TNF induced inflammation could kill by
triggering ARDS (adult respiratory distress syndrome) on the other
hand, an uncontrolled fulminate viral infection could also kill.
Looking at the data, I would suggest that the ratio of pro- to
anti- inflammatory cytokines (TNF+IFN/Il10) is the critical factor
rather than simply the level of pro's .
The
abstract immediately below provides the basis for my proposing
that cannabis could save millions of lives if H5N1 evolves the
capacity to spread by human to human contact. Below it are a few
abstracts that show cannabinoids turn down tumer necrosis factor
(TNF).
Respir
Res. 2005
Nov 11;6:135.
Proinflammatory
cytokine responses induced by influenza A (H5N1) viruses in primary
human alveolar and bronchial epithelial cells.
BACKGROUND:
Fatal human respiratory disease associated with influenza A subtype
H5N1 has been documented in Hong Kong, and more recently in Vietnam,
Thailand and Cambodia. We previously demonstrated that patients
with H5N1 disease had unusually high serum levels of IP-10 (interferon-gamma-inducible
protein-10). Furthermore, when compared with human influenza virus
subtype H1N1, the H5N1 viruses in 1997 (A/Hong Kong/483/97) (H5N1/97)
were more potent inducers of pro-inflammatory cytokines (e.g. tumor
necrosis factor-a) and chemokines (e.g. IP-10) from primary human
macrophages in vitro, which suggests that cytokines dysregulation
may play a role in pathogenesis of H5N1 disease. Since respiratory
epithelial cells are the primary target cell for replication of
influenza viruses, it is pertinent to investigate the cytokine
induction profile of H5N1 viruses in these cells. METHODS: We used
quantitative RT-PCR and ELISA to compare the profile of cytokine
and chemokine gene expression induced by H5N1 viruses A/HK/483/97
(H5N1/97), A/Vietnam/1194/04 and A/Vietnam/3046/04 (both H5N1/04)
with that of human H1N1 virus in human primary alveolar and bronchial
epithelial cells in vitro. RESULTS: We demonstrated that in comparison
to human H1N1 viruses, H5N1/97 and H5N1/04 viruses were more potent
inducers of IP-10, interferon beta, RANTES (regulated on activation,
normal T cell expressed and secreted) and interleukin 6 (IL-6)
in primary human alveolar and bronchial epithelial cells in vitro.
Recent H5N1 viruses from Vietnam (H5N1/04) appeared to be even
more potent at inducing IP-10 than H5N1/97 virus. CONCLUSION: The
H5N1/97 and H5N1/04 subtype influenza A viruses are more potent
inducers of proinflammatory cytokines and chemokines in primary
human respiratory epithelial cells than subtype H1N1 virus. We
suggest that this hyper-induction of cytokines may be relevant
to the pathogenesis of human H5N1 disease.
All
the papers below show that cannabis can reduce inflammation by
turning down TNF levels.
Int
Immunopharmacol. 2006
Apr;6(4):656-65. Epub 2005 Nov 7.
Unheated
Cannabis sativa extracts and its major compound THC-acid have
potential immuno-modulating properties not mediated by CB1 and
CB2 receptor coupled pathways.
There
is a great interest in the pharmacological properties of cannabinoid
like compounds that are not linked to the adverse effects of Delta(9)-tetrahydrocannabinol
(THC), e.g. psychoactive properties. The present paper describes
the potential immuno-modulating activity of unheated Cannabis sativa
extracts and its main non-psychoactive constituent Delta(9)-tetrahydrocanabinoid
acid (THCa). By heating Cannabis extracts, THCa was shown to be
converted into THC. Unheated Cannabis extract and THCa were able
to inhibit the tumor necrosis factor alpha (TNF-alpha) levels in
culture supernatants from U937 macrophages and peripheral blood
macrophages after stimulation with LPS in a dose-dependent manner.
This inhibition persisted over a longer period of time, whereas
after prolonged exposure time THC and heated Cannabis extract tend
to induce the TNF-alpha level. Furthermore we demonstrated that
THCa and THC show distinct effects on phosphatidylcholine specific
phospholipase C (PC-PLC) activity. Unheated Cannabis extract and
THCa inhibit the PC-PLC activity in a dose-dependent manner, while
THC induced PC-PLC activity at high concentrations. These results
suggest that THCa and THC exert their immuno-modulating effects
via different metabolic pathways.
: Int
Immunopharmacol. 2002
Mar;2(4):537-43.
Effect
of the cannabinoid receptor ligand, WIN 55,212-2, on superoxide
anion and TNF-alpha production by human mononuclear cells.
INSERM
U456, IFR 97, Universite de Rennes 1, 2, France.
Cannabinoids
are known to downregulate immune response but the role for cannabinoid
receptors in cannabinoid-induced immunosuppression is still unclear.
To address this question, the interference of CB1 and CB2 receptor
antagonists with the inhibition of TNF-alpha production by synthetic
cannabinoid WIN 55,212-2 was studied using human peripheral blood
mononuclear cells (PBMC) in vitro. CB2 (SR 144528) but not CB1
(SR 141716A) receptor antagonist dose dependently interfered with
WIN 55,212-2-induced inhibition of TNF-alpha synthesis. Also, WIN
55,212-2 decreased fMLP-induced reactive oxygen species generation
in lipopolysaccharide (LPS)-primed PBMC. However, the high concentrations
of cannabinoid receptor ligands needed to achieve significant effects
suggest that the observed effects may be in part cannabinoid receptor
independent.
J
Neuroinflammation. 2005
Dec 12;2:29.
Stimulation
of cannabinoid receptor 2 (CB2) suppresses microglial activation.
ABSTRACT
: BACKGROUND : Activated microglial cells have been implicated
in a number of neurodegenerative disorders, including Alzheimer's
disease (AD), multiple sclerosis (MS), and HIV dementia. It is
well known that inflammatory mediators such as nitric oxide (NO),
cytokines, and chemokines play an important role in microglial
cell-associated neuron cell damage. Our previous studies have shown
that CD40 signaling is involved in pathological activation of microglial
cells. Many data reveal that cannabinoids mediate suppression of
inflammation in vitro and in vivo through stimulation of cannabinoid
receptor 2 (CB2). METHODS : In this study, we investigated the
effects of a cannabinoid agonist on CD40 expression and function
by cultured microglial cells activated by IFN-gamma using RT-PCR,
Western immunoblotting, flow cytometry, and anti-CB2 small interfering
RNA (siRNA) analyses. Furthermore, we examined if the stimulation
of CB2 could modulate the capacity of microglial cells to phagocytise
Abeta1-42 peptide using a phagocytosis assay. RESULTS : We found
that the selective stimulation of cannabinoid receptor CB2 by JWH-015
suppressed IFN-gamma-induced CD40 expression. In addition, this
CB2 agonist markedly inhibited IFN-gamma-induced phosphorylation
of JAK/STAT1. Further, this stimulation was also able to suppress
microglial TNF-alpha and nitric oxide production induced either
by IFN-gamma or Abeta peptide challenge in the presence of CD40
ligation. Finally, we showed that CB2 activation by JWH-015 markedly
attenuated CD40-mediated inhibition of microglial phagocytosis
of Abeta1-42 peptide. Taken together, these results provide mechanistic
insight into beneficial effects provided by cannabinoid receptor
CB2 modulation in neurodegenerative diseases, particularly AD.
J
Pharmacol. 2006
May 5; [Epub ahead of print]
Cannabinoid
signalling in TNF-alpha induced IL-8 release.
School
of Life Sciences, University of Hertfordshire, Faculty of Health
and Human Sciences, College Lane, Hatfield, Herts AL10 9AB, United
Kingdom.
The
molecular events mediating the immunomodulatory properties of cannabinoids
have remained largely unresolved. We have therefore investigated
the molecular mechanism(s) through which R-(+)-[2,3-dihydro-5-methyl-3-[(morpholinyl)methyl]
pyrrolo[1,2,3-de]-1,4-benzoxazinyl]-(1-napthanlenyl) methanone
(WIN55212-2) modulate production of interleukin-8 (IL-8) in HT-29
cells. Release of IL-8 induced by tumor necrosis factor-alpha (TNF-alpha)
was determined by enzyme-linked immunosorbent assay (ELISA). Changes
in expression of inhibitory kappa B (IkappaB) were monitored by
Western blotting and activation of nuclear factor-kappa B (NF-kappaB)
was determined in electrophoretic mobility shift assay (EMSAs).
TNF-alpha induced release of IL-8 was inhibited by WIN55212-2 which
also blocked the degradation of IkappaB-alpha and activation of
NF-kappaB induced by TNF-alpha. These data provide strong evidence
that WIN55212-2 may modulate IL-8 release by negatively regulating
the signaling cascade leading to the activation of NF-kappaB. These
findings highlight a potential mechanism for the immunomodulatory
properties of cannabinoids and contribute towards acquiring a clear
understanding of the role of cannabinoids in inflammation
J
Clin Invest. 2003
Apr;111(8):1231-40.
Immunoregulation
of a viral model of multiple sclerosis using the synthetic cannabinoid
R+WIN55,212.
Department
of Microbiology-Immunology, Interdepartmental Immunobiology Center,
Northwestern University Medical School, 303 E. Chicago Avenue,
Chicago, IL 60611, USA.
Theiler
murine encephalomyelitis virus-induced demyelinating disease (TMEV-IDD)
is a mouse model of chronic-progressive multiple sclerosis (MS)
characterized by Th1-mediated CNS demyelination and spastic hindlimb
paralysis. Existing MS therapies reduce relapse rates in 30% of
relapsing-remitting MS patients, but are ineffective in chronic-progressive
disease, and their effects on disability progression are unclear.
Experimental studies demonstrate cannabinoids are useful for symptomatic
treatment of spasticity and tremor in chronic-relapsing experimental
autoimmune encephalomyelitis. Cannabinoids, however, have reported
immunosuppressive properties. We show that the cannabinoid receptor
agonist, R+WIN55,212, ameliorates progression of clinical disease
symptoms in mice with preexisting TMEV-IDD. Amelioration of clinical
disease is associated with downregulation of both virus and myelin
epitope-specific Th1 effector functions (delayed-type hypersensitivity
and IFN-gamma production) and the inhibition of CNS mRNA expression
coding for the proinflammatory cytokines, TNF-alpha, IL1-beta,
and IL-6. Clinical trials investigating the therapeutic potential
of cannabinoids for the symptomatic treatment of MS are ongoing,
and this study demonstrates that they may also have potent immunoregulatory
properties.
Crit
Care Med. 2003
Feb;31(2):536-42.
Imbalance
between matrix metalloproteinases (MMP-9 and MMP-2) and tissue
inhibitors of metalloproteinases (TIMP-1 and TIMP-2) in acute
respiratory distress syndrome patients.
INSERM
U456, Universite de Rennes, Service de Reanimation Chirurgicale,
CHU de Rennes, Hopital de Pontchaillou, France.
OBJECTIVE:
Matrix metalloproteinases (MMPs) are known to be involved in degradation
of extracellular matrix. We aimed to assess the role of MMPs and
their natural inhibitors (TIMPs) in the genesis and the evolution
of acute respiratory distress syndrome (ARDS). DESIGN: Prospective,
clinical study. SETTING: Intensive care unit of a university hospital.
PATIENTS: Twenty-one patients were assigned to three different
groups: Group 1 patients developed ARDS that rapidly resolved in <4
days; Group 2 patients developed ARDS lasting >8 days; Group
3 (control group) patients had clinical criteria for hospital-acquired
pneumonia without ARDS. INTERVENTION: Bronchoalveolar lavages were
performed on day 0 of the onset of ARDS and on days 4, 8, and 12
for unresolving ARDS. For group 3, the bronchoalveolar lavages
were performed on day 0 of the pneumonia. On these bronchoalveolar
lavage fluids, we measured the amount of MMP-9 and -2 and their
inhibitors TIMP-1 and -2. MEASUREMENTS AND MAIN RESULTS: The amount
of MMP-9 measured by enzyme-linked immunosorbent assay was significantly
lower in the bronchoalveolar lavages from patients with ARDS (group
1 and group 2) compared with the control group (p <.01) throughout
the study. The ratio MMP-9/TIMP-1 was also significantly smaller
and was less than one in the two ARDS groups (p <.05) compared
with the control group (group 3), where this ratio was greater
than one. In the second bronchoalveolar lavages, this ratio was
greater than one only in the ARDS group that rapidly resolved (group
1), whereas it stayed less than one when the ARDS was lasting (group
2). Concerning the quantity of MMP-2 and the ratio MMP-2/TIMP-2,
there was no statistical difference between the three groups throughout
the study. Using zymography, there was no significant difference
in the amounts of active and latent MMP-9 between the three groups.
Moreover, no significant difference in the quantity of latent and
active MMP-2 in the three groups was noted. CONCLUSION: These results
suggest that the MMP-9 level and MMP-9/TIMP-1 ratio play a role
in the pathogenesis of ARDS and, namely, the imbalance between
MMP-9 and TIMP-1 would participate in airway remodeling leading
to either short- or long-course ARDS. The ratio MMP-9/TIMP-1 could
be a predictive factor of the ARDS evolution.
J
Pharmacol Exp Ther. 2006
Mar;316(3):1219-28. Epub 2005 Dec 5.
R(+)-methanandamide
and other cannabinoids induce the expression of cyclooxygenase-2
and matrix metalloproteinases in human nonpigmented ciliary epithelial
cells.
Department
of Experimental and Clinical Pharmacology and Toxicology, Friedrich
Alexander University Erlangen-Nurnberg, Fahrstrasse 17, D-91054
Erlangen, Germany.
Prostaglandins
(PGs) and matrix metalloproteinases (MMP) have been implicated
in lowering intraocular pressure (IOP) by facilitating aqueous
humor outflow. A possible role of cyclooxygenase-2 (COX-2) in this
process was emphasized by findings showing an impaired COX-2 expression
in the nonpigmented ciliary epithelium (NPE) of patients with primary
open-angle glaucoma. Using human NPE cells, the present study therefore
investigated the effect of the IOP-lowering cannabinoid R(+)-methanandamide
[R(+)-MA] on the expression of COX-2 and different MMPs and tissue
inhibitors of MMPs (TIMPs). R(+)-MA led to a concentration- and
time-dependent increase of COX-2 mRNA expression. R(+)-MA-induced
COX-2 expression was accompanied by time-dependent phosphorylations
of p38 mitogen-activated protein kinase (MAPK) and p42/44 MAPK
and was abrogated by inhibitors of both pathways. Moreover, R(+)-MA
increased the mRNA and protein expression of MMP-1, MMP-3, MMP-9,
and TIMP-1 but not that of MMP-2 and TIMP-2. Inhibition of COX-2
activity with NS-398 [N-[2-(cyclohexyloxy)-4-nitrophenyl]-methanesulfonamide]
was associated with a virtually complete suppression of R(+)-MA-induced
MMP-9 and TIMP-1 expression. Consistent with these data, MMP-9
and TIMP-1 expression was also induced by PGE2, a major COX-2 product.
Two other COX-2-inducing cannabinoids, anandamide and Delta9-tetrahydrocannabinol,
caused the same pattern of MMP and TIMP expression as R(+)-MA both
in the absence and presence of NS-398. Altogether, cannabinoids
induce the production of several outflow-facilitating mediators
in the human NPE. Our results further imply an involvement of COX-2-dependent
PGs in MMP-9 and TIMP-1 expression. In conclusion, stimulation
of intraocular COX-2 and MMP expression may represent a potential
mechanism contributing to the IOP-lowering action of different
cannabinoids.
Eur
J Pharmacol. 1997
Jul 9;330(2-3):231-40.
Influence
of fatty acid ethanolamides and delta9-tetrahydrocannabinol on
cytokine and arachidonate release by mononuclear cells.
Institute
of Marine Biology, Vladivostok, Russia.
The
effects of arachidonic acid ethanolamide (anandamide), palmitoylethanolamide
and delta9-tetrahydrocannabinol on the production of tumor necrosis
factor-alpha (TNF-alpha), interleukin-4, interleukin-6, interleukin-8,
interleukin-10, interferon-gamma, p55 and p75 TNF-alpha soluble
receptors by stimulated human peripheral blood mononuclear cells
as well as [3H]arachidonic acid release by non-stimulated and
N-formyl-Met-Leu-Phe (fMLP)-stimulated human monocytes were investigated.
Anandamide was shown to diminish interleukin-6 and interleukin-8
production at low nanomolar concentrations (3-30 nM) but inhibited
the production of TNF-alpha, interferon-gamma, interleukin-4
and p75 TNF-alpha soluble receptors at higher concentrations
(0.3-3 microM). Palmitoylethanolamide inhibited interleukin-4,
interleukin-6, interleukin-8 synthesis and the production of
p75 TNF-alpha soluble receptors at concentrations similar to
those of anandamide but failed to influence TNF-alpha and interferon-gamma
production. The effect of both compounds on interleukin-6 and
interleukin-8 production disappeared with an increase in the
concentration used. Neither anandamide nor palmitoylethanolamide
influenced interleukin-10 synthesis. delta9-Tetrahydrocannabinol
exerted a biphasic action on pro-inflammatory cytokine production.
TNF-alpha, interleukin-6 and interleukin-8 synthesis was maximally
inhibited by 3 nM delta9-tetrahydrocannabinol but stimulated
by 3 microM delta9-tetrahydrocannabinol, as was interleukin-8
and interferon-gamma synthesis. The level of interleukin-4, interleukin-10
and p75 TNF-alpha soluble receptors was diminished by 3 microM
delta9-tetrahydrocannabinol. [3H]Arachidonate release was stimulated
only by high delta9-tetrahydrocannabinol and anandamide concentrations
(30 microM). These results suggest that the inhibitory properties
of anandamide, palmitoylethanolamide and delta9-tetrahydrocannabinol
are determined by the activation of the peripheral-type cannabinoid
receptors, and that various endogenous fatty acid ethanolamides
may participate in the regulation of the immune response.