2. Interferons: An Overview with Attention to Cancer
Surveillance
Discovered in 1957, interferon (IFN) earned its name with the
recognition that cells challenged by attenuated influenza A virus
created a substance that “interfered with” a subsequent infection by a
live virus [14]. IFN is now understood to represent a very large
family of immune-modulating proteins, divided into three types,
designated as type I, II, and III based upon the receptors each IFN
interacts with. Type I IFN includes both IFN-α and IFN-β, and this type
is the most diverse, being further divided into seventeen subtypes.
IFN-α alone has thirteen subtypes currently identified, and each of
those is further divided into multiple categories [15]. Type I IFNs
play a powerful role in the immune response to multiple stressors. In
fact, they have enjoyed clinical therapeutic value as a treatment option
for a variety of diseases and conditions, including viral infections,
solid tumors, myeloproliferative disorders, hematopoietic neoplasms and
autoimmune diseases such as multiple sclerosis [16].
As a group, IFNs play exceedingly complicated and pleiotropic roles that
are coordinated and regulated through the activity of the family of IFN
regulatory factors, or IRFs [17]. IRF9 is most directly involved in
anti-viral as well as anti-tumor immunity and genetic regulation
[18-20].
Closely related to this are plasmacytoid dendritic cells (pDCs), a rare
type of immune cell that circulate in the blood but migrate to
peripheral lymphoid organs during a viral infection. They respond to a
viral infection by sharply upregulating production of type I IFNs. The
IFN-α released in the lymph nodes induces B cells to differentiate into
plasmablasts. Subsequently, interleukin-6 (Il-6) induces plasmablasts to
evolve into antibody-secreting plasma cells [21]. Thus, IFNs play a
critical role in both controlling viral proliferation and inducing
antibody production. Central to both antiviral and anticancer immunity,
IFN-α is produced by macrophages and lymphocytes when either is
challenged with viral or bacterial infection or encounters tumor cells
[22]. Its role as a potent antiviral therapy has been recognized in
the treatment of hepatitis C complications [23], Cytomegalovirus
infection [24], chronic active ebola virus infection [25],
inflammatory bowel disease associated with herpes virus infection
[26], and others.
Impaired type I IFN signaling is linked to many disease risks, most
notably cancer, as type I IFN signaling suppresses proliferation of both
viruses and cancer cells by arresting the cell cycle, in part through
upregulation of p53, a tumor suppressor gene, and various
cyclin-dependent kinase inhibitors [27,28]. IFN-α also induces major
histocompatibility (MHC) class 1 antigen presentation by tumor cells,
causing them to be more readily recognized by the cancer surveillance
system [29,30]. The range of anticancer effects initiated by IFN-α
production is astounding and occurs through both direct and indirect
mechanisms. Direct effects include cell cycle arrest, induction of cell
differentiation, initiation of apoptosis, activation of natural killer
and CD8+ T cells, and others [31].
The indirect anticancer effects are predominantly carried out through
gene transcription activation of the Janus kinase signal transducer and
activator of transcription (JAK/STAT) pathway. IFN-α binding on the cell
surface initiates JAK, a tyrosine kinase, to phosphorylate STAT1 and
STAT2 [32]. Once phosphorylated, these STATs form a complex with
IRF9, one of a family of IRFs that play a wide range of roles in
oncogene regulation and other cell functions [33]. It is this
complex, named IFN-stimulated gene factor 3 (ISGF3), that translocates
to the cell nucleus to enhance the expression of at least 150 genes
[31]. IRF9 has been suggested to be the primary member of the IRF
family of proteins responsible for activation of the IFN-α
antiproliferative effects, and that appears to be through its binding to
the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)
receptor 1 and 2 (TRAIL-R1/2) [34]. IRF7 is another crucial member
of the IRF family of proteins involved early in the response to a viral
infection. It is normally expressed in low amounts but is strongly
induced by ISGF3. IRF7 also undergoes serine phosphorylation and nuclear
translocation to further activate the immune response. IRF7 has a very
short half-life, so its gene-induction process is transient, perhaps to
avoid overexpression of IFNs [35].
Once TRAIL is bound by IRF9, it is then able to act as a ligand for
Death Receptor 4 (DR4) or DR5, initiating a cascade of events involving
production of caspase 8 and caspase 3, and ultimately triggering
apoptosis [36]. Dysregulation of this pathway, through suppression
of either IFN-α or IRF9 and the resulting failure to bind TRAIL-R, has
been associated with several hematologic malignancies [37], and has
been shown to increase the metastatic potential in animal models of
melanoma, colorectal cancer, and lymphoma [38].
IFN-α both initiates and orchestrates a wide range of cancer suppressing
roles. Dunn et al. (2005) showed that IFN-α plays an active role in
cancer immunoediting, its locus of action being hematopoietic cells that
are “programmed” via IFN-α binding for tumor surveillance [39]. It
is via the exceedingly complex interactions between type I IFNs and IRF7
and IRF9 in particular that a great deal of antiproliferative effects
are carried out. This is evidenced by the large number of studies
showing increased tumor growth and/or metastases associated with a wide
number of cancer types.
For example, Bidwell et al. (2012) found that, among over 800 breast
cancer patients, those with high expression of IRF7-regulated genes had
significantly fewer bone metastases, and they propose assessment of
these IRF7-related gene signatures as a way to predict those at greatest
risk [40]. Use of microRNA to target IRF7 expression has also been
shown to enhance breast cancer cell proliferation and invasion in
vitro [41]. Zhao et al. (2017) found a similar role for IRF7 in
relation to bone metastases in a mouse model of prostate cancer
[42]. Regarding the anti-cancer mechanism behind IRF7 expression,
Solis et al. (2006) found that IRF7 induces transcription of multiple
genes and translation of their downstream protein products including
TRAIL, IL-15, ISG-56 and CD80, with the noted therapeutic implications
[43].
IRF9, too, has a central role to play in cancer surveillance and
prevention. Erb et al. (2013) demonstrated that IRF9 is the mediator
through which IL-6 augments the anti-proliferation effects of IFN-α
against prostate cancer cells [44]. Tian et al. (2018) found IRF9 to
be a key negative regulator of acute myeloid leukemia cell proliferation
and evasion of apoptosis [45]. It does so, at least in part, through
acetylation of the master regulatory protein p53.
Both IFN-α and IRF9 are also apparently necessary for the
cancer-preventative properties of a fully functional BRCA2 gene. In a
study presented as an abstract at the First AACR International
Conference on Frontiers in Basic Cancer Research, Mittal and Chaudhuri
(2009) describe a set of experiments which show for the first time that
BRCA2 expression leads to increased IFN-α production and augments the
signal transduction pathway resulting in the complexing of IRF9, STAT1
and STAT2 described previously [46]. Two years prior, Buckley et al.
(2007) had established that BRCA1 in combination with IFN-γ promotes
type I IFNs and subsequent production of IRF7, STAT1, and STAT2
[47]. Thus, the exceedingly important cancer regulatory genes BRCA1
and BRCA2 rely on IRF7 and IRF9, respectively, to carry out their
protective effects.
In a preprint, Mamoor (2020) used gene expression analysis to determine
that infection with either SARS-CoV-1 (in mice) or MERS-CoV (in
vitro ) leads to increased production of IRF7 and IRF9, and the author
speculates that “IRF7 and IRF9 may be important for SARS-CoV-2 immune
defense in humans.” [48] This speculation is somewhat confirmed by
Rasmussen et al. (2021), who reviewed the compelling evidence that
deficiencies of either IRF7 or IRF9 lead to significantly greater risk
of severe COVID-19 illness [49]. Importantly, they also note that
evidence suggests type I IFNs play a singularly important role in
protective immunity against COVID-19 illness, a role that is shared by
multiple cytokines in most other viral illnesses including influenza.
As will be discussed in more detail below, the SARS-CoV-2 spike protein
modifies host cell exosome production. Transfection of cells with the
spike gene and subsequent spike protein production results in those
cells generating exosomes containing microRNAs that suppress IRF9
production while activating a range of pro-inflammatory gene transcripts
[50]. Since these vaccines are specifically designed to induce high
and ongoing production of spike proteins, the implications are ominous.
As described above, inhibition of IRF9 will suppress TRAIL and all its
regulatory and downstream apoptosis-inducing effects. IRF9 suppression
via exosomal microRNA should also be expected to impair the
cancer-protective effects of BRCA2 gene activity, which depends on that
molecule for its activity as described above. BRCA2-associated cancers
include breast, fallopian tube, and ovarian cancer for women, prostate
and breast cancer for men, acute myeloid leukemia in children, and
others [51].
Vaccination has also been demonstrated to suppress both IRF7 and STAT2
[52]. This can be expected to interfere with the cancer-protective
effects of BRCA1 as described above. Cancers associated with impaired
BRCA1 activity include breast, uterine, and ovarian cancer in women;
prostate and breast cancer in men; and a modest increase in pancreatic
cancer for both men and women [53].
Reduced BRCA1 expression is linked to both cancer and neurodegeneration.
BRCA1 is a well-known breast cancer susceptibility gene. BRCA1 inhibits
breast cancer cell proliferation through activation of SIRT1 and
subsequent suppression of the androgen receptor [54]. In a study
conducted by Suberbielle et al. (2015), reduced levels of BRCA1 were
found in the brains of Alzheimer’s patients [55]. Furthermore,
experiments with knocking down neuronal BRCA1 in the dentate gyrus of
mice showed that DNA double-strand breaks were increased, along with
neuronal shrinkage and impairments in synaptic plasticity, learning and
memory.
Analysis detailed in a recent case study on a patient diagnosed with a
rare form of lymphoma called angioimmunoblastic T cell lymphoma provided
strong evidence for unexpected rapid progression of lymphomatous lesions
after administration of the BNT162b2 mRNA booster shot [56].
Comparisons of detailed metrics for hypermetabolic lesions conducted
immediately before and 21 days after the vaccine booster revealed a
five-fold increase after the vaccine, with the post-booster test
revealing a 2-fold higher activity level in the right armpit compared to
the left one. The vaccine had been injected on the right side. It is
worth pointing out in this regard that lymphoid malignancies have been
associated with suppression of TRAIL R1 [57].
Given the universally recognized importance of optimally functioning
BRCA1/2 for cancer prevention and given the central role of the TRAIL
signal transduction pathway for additional cancer surveillance, the
suppression of IRF7 and IRF9 through vaccination and subsequent spike
protein production is extremely concerning for long-term cancer control
in injected populations.