Research Proposal: Implications for Immunotherapy of Acute Radiation Syndromes. Part 2. Dmitri Popov Full-text available · Research Proposal · Feb 2017 File name: Implications for Immunotherapy of ARS. Part 2.

1. Implications for Immunotherapy
of Acute Radiation Syndromes.
Part 2.
Dmitri Popov, MD (Russia), Ph.D. Radiobiology.
Advanced Medical Technology and Systems Inc. Richmond Hill, Canada.

2. Immunotherapy of Acute Radiation
Syndromes.
• Research Proposal: Implications for Immunotherapy of Acute
Radiation Syndromes. Part 2.
• Dmitri Popov
• Full-text available · Research Proposal · Feb 2017
• File name: Implications for Immunotherapy of ARS2.pptx
DOI: 10.13140/RG.2.2.15634.66249

3. Radiation and cell structure damages.
• Ionizing radiation and autoimmunity. Induction of autoimmune disease in
mice by high dose fractionated total lymphoid irradiation and its
prevention by inoculating normal T cells.
• N Sakaguchi, K Miyai and S Sakaguchi
• J Immunol March 1, 1994, 152 (5) 2586-2595;
• “ irradiation of both the thymus and the peripheral lymphoid
organs/tissues was required for efficient induction of autoimmune disease
by TLI. TLI eliminated the majority of mature thymocytes and the
peripheral T cells for 1 mo, and inoculation of spleen cell, thymocyte, or
bone marrow cell suspensions (prepared from syngeneic nonirradiated
mice) within 2 wk after TLI effectively prevented the autoimmune
development. Depletion of T cells from the inocula abrogated the
preventive activity.”

4. Radiation and cell structure damage.
• Ionizing radiation and autoimmunity. Induction of autoimmune disease in
mice by high dose fractionated total lymphoid irradiation and its
prevention by inoculating normal T cells.
• N Sakaguchi, K Miyai and S Sakaguchi
• J Immunol March 1, 1994, 152 (5) 2586-2595;
• “CD4+ T cells mediated the autoimmune prevention but CD8+ T cells did
not. CD4+ T cells also appeared to mediate the TLI-induced autoimmune
disease because CD4+ T cells from disease-bearing TLI mice adoptively
transferred the autoimmune disease to syngeneic naive mice. Taken
together, these results indicate that high dose, fractionated ionizing
radiation on the lymphoid organs/tissues can cause autoimmune disease
by affecting the T cell immune system, rather than the target self-Ags,
presumably by altering T cell-dependent control of self-reactive T cells.”

5. Radiation and autoimmune reactions.
• “Autoimmune disease occurs when a specific adaptive immune
response is mounted against self antigens. The normal consequence
of an adaptive immune response against a foreign antigen is the
clearance of the antigen from the body.
Radiation damaged cell,virus-infected cells, for example, are
destroyed by cytotoxic T cells, whereas soluble antigens( which could
be a product of apoptosis or necrosis of irradiated cells) are cleared
by formation of immune complexes of antibody and antigen, which
are taken up by cells of the mononuclear phagocytic system such as
macrophages”

6. Immunobiology: The immune system in Health and Disease. Janeway C. et al. New Yourk. 2001.

7. Autoimmune reactions.
• Autoimmune reactions could be induced against normal self antigens,
or against self antigens which is damaged or modified after
irradiation, chemical modification, chemical reactions, modified by
viruses or bacteria, damaged by free radicals.
• Radiation disrupt immunological tolerance. Normally immune system
distinguish body normal proteins and proteins damaged by viruses,
bacteria or chemicals.
• Several processes make immunological recognition for self antigens
difficult. For example, radiation damage DNA and induce genes
mutation.

8. Protein damage by radiation.
• Trends Biochem Sci. 2005 Apr;30(4):213-9.
• When X-rays modify the protein structure: radiation damage at
work.
• Carugo O1, Djinović Carugo K.
• Proceeding of the National Academy of Science of the United States
of America.
• Specific chemical and structural damage to proteins produced by
synchrotron radiation.
• Martin Weik*†, et al

9. Genetic mutation after irradiation
• Radiation induce genetic mutations of DNA that code for the MHC
membrane proteins may lead to autoimmune reactions.
• Irradiated cells displayed damaged proteins which are resembled
normal proteins on the major histocompatibility complex on outer
surface of cell membrane.
• When the pathologic irradiated antigens induce immunological
response with antibody production, T helper cell activation and
activation of cytotoxic T cells.

10. Radiation damage.
• Radiation damage to biological systems is determined by the type of
radiation, the total dosage of exposure, the dose rate, and the region
of the body exposed. Three modes of cell death—necrosis, apoptosis,
and autophagy—as well as accelerated senescence have been
demonstrated to occur in vitro and in vivo in response to radiation in
cancer cells as well as in normal cells.
• Mechanisms of Radiation Toxicity in Transformed and Non-
Transformed Cells Ronald-Allan M. Panganiban, Andrew L. Snow and
Regina M. Day * Department of Pharmacology, Uniformed Services
University of the Health Sciences, Bethesda, MD 20814-4799, USA; E-
Mails: ronald-allan.panganiban@usuhs.edu (R.-A.M.P.);
andrew.snow@usuhs.edu (A.L.S.)

11. Radiation damage.
• Ionizing radiation (IR) generates both direct and indirect damage to
biological molecules. In high linear energy transfer (LET) radiation,
such as neutrons and alpha particles, most of the cellular damage
results from the direct ionization of cellular macromolecules including
DNA, RNA, lipids, and proteins.
• Mechanisms of Radiation Toxicity in Transformed and Non-
Transformed Cells Ronald-Allan M. Panganiban, Andrew L. Snow and
Regina M. Day * Department of Pharmacology, Uniformed Services
University of the Health Sciences, Bethesda, MD 20814-4799, USA; E-
Mails: ronald-allan.panganiban@usuhs.edu (R.-A.M.P.);
andrew.snow@usuhs.edu (A.L.S.)

12. Radiation damage.
• In contrast, low LET radiation, such as X-rays and gamma rays, indirect
damage to biological macromolecules occurs following the generation
of reactive oxygen species (ROS). ROS, especially superoxide and
hydroxide radicals from the radiolysis of intracellular H2O, can have
many effects, including the oxidation of biological macromolecules
and activation of intracellular signaling pathways.
• Mechanisms of Radiation Toxicity in Transformed and Non-
Transformed Cells Ronald-Allan M. Panganiban, Andrew L. Snow and
Regina M. Day * Department of Pharmacology, Uniformed Services
University of the Health Sciences, Bethesda, MD 20814-4799, USA; E-
Mails: ronald-allan.panganiban@usuhs.edu (R.-A.M.P.);
andrew.snow@usuhs.edu (A.L.S.)

13. Radiation damage.

14. Radiation induced autoimmune processes.
• Antibodies to self-antigens, proteins which is not normal, but
damaged by radiation, presented by MHC complex.
Auto-antigens modified by radiation induce activation of plasma cells
and elaboration antibodies to radiation modified self-antigens.

15. Radiation and Antigen Presenting Cells.
• Antigen-presenting cells (APCs) are a heterogeneous group of
immune cells that mediate the cellular immune response by
processing and presenting antigens for recognition by certain
lymphocytes such as T cells.
• Classical APCs include dendritic cells, macrophages, Langerhans cells
and B cells.

16. MCH class 1.
• “MHC class I molecules are one of two primary classes of major
histocompatibility complex (MHC) molecules (the other being MHC
class II) and are found on the cell surface of all nucleated cells in the
bodies of jawed vertebrates. They also occur on platelets, but not
on red blood cells. Their function is to display peptide fragments of
non-self proteins from within the cell to cytotoxic T cells; this will
trigger an immediate response from the immune system against a
particular non-self antigen displayed with the help of an MHC class I
protein. Because MHC class I molecules present peptides derived
from cytosolic proteins, the pathway of MHC class I presentation is
often called cytosolic or endogenous pathway”

17. MCH class 1 and Radiation.
• J Exp Med. 2006 May 15; 203(5): 1259–1271.
• doi: 10.1084/jem.20052494. Radiation modulates the peptide
repertoire, enhances MHC class I expression, and induces successful
antitumor immunotherapy. Eric A. Reits, et al.
• The effect of irradiation on antigen presentation by MHC class I
molecules was studied. Cell surface expression of MHC class I
molecules was increased for many days in a radiation dose-
dependent manner as a consequence of three responses.

18. MHC class 1.
• “Initially, enhanced degradation of existing proteins occurred which
resulted in an increased intracellular peptide pool. Subsequently,
enhanced translation due to activation of the mammalian target of
rapamycin pathway resulted in increased peptide production, antigen
presentation, as well as cytotoxic T lymphocyte recognition of
irradiated cells. In addition, novel proteins were made in response to
γ-irradiation, resulting in new peptides presented by MHC class I
molecules, which were recognized by cytotoxic T cells.”

19. MHC class 1.
• “The best-known effect of ionizing radiation is the induction of
double-stranded DNA breaks, which can result in mutations leading to
transformation and tumor formation if DNA repair fails.”
• “Cells respond to DNA damage by activating complex pathways to
arrest the cell cycle, allowing DNA repair, or inducing programmed
cell death”

20. Major Histocompatibility Complex class 1.
• “Microarray analysis of cells after ionizing radiation has revealed up-
regulation of nucleotide excision repair genes, cell cycle genes, and
genes involved in apoptosis . In addition, irradiation-induced radical
formation modifies proteins by radical-induced cross-linking,
breakage of disulphide bonds, and amino acid side-chain oxidation ,
which may result in protein unfolding and degradation.”
• “Absorption of radiation can occur directly within proteins but mostly
causes radiolysis of water, which constitutes up to 90% of the volume
of cells. The resulting short-living radicals can modify intracellular
proteins and DNA.”

21. Major Histocompatibility Complex Class 1.
• “It is unknown if γ-irradiation modifies the intracellular protein pool
in vivo and whether the resulting MHC class I peptide repertoire is
altered by this treatment. We show that γ-irradiation enhanced
peptide production and surface expression of MHC class I for many
days at higher doses.”
• “In addition, the MHC class I peptide repertoire now includes
radiation-specific peptides. The radiation-induced effects on MHC
class I antigen presentation may have important consequences
because combining radiotherapy with immunotherapy results in
superior antitumor responses.”

22. MCH class 2.
• “MHC class II molecules are a class of major histocompatibility
complex (MHC) molecules normally found only on antigen-presenting
cells such as dendritic cells, mononuclear phagocytes, some endothelial
cells, thymic epithelial cells, and B cells. These cells are important in
initiating immune responses.
• The antigens presented by class II peptides are derived from extracellular
proteins – degraded irradiated cells (not cytosolic as in MHC class I).
• Loading of a MHC class II molecule occurs by phagocytosis; extracellular
proteins are endocytosed, digested in lysosomes, and the
resulting epitopic peptide fragments are loaded onto MHC class II
molecules prior to their migration to the cell surface.
• In humans, the HLAs corresponding to MHC class II are HLA-DP, HLA-
DM, HLA-DOA, HLA-DOB, HLA-DQ, and HLA-DR.”

23. Major histocompatibility complex (MHC) class
II.
• “Major histocompatibility complex (MHC) class II molecules are cell-
surface glycoproteins that play a central role in the immune system by
presenting peptides to the antigen receptor of CD4+ T cells.1 Antigen
presentation is not only crucial for the regulation of protective
immune responses against invading pathogens, but is also necessary
for the maintenance of self-tolerance. Indeed, MHC class II expression
directs positive and negative selection processes that shape the
specificity of the T-cell-receptor repertoire of the CD4+ T-cell
population during its development in the thymus”

24. Antigen presenting cells and MCH.
• “An antigen-presenting cell (APC) or accessory cell is a cell that
displays antigen complexed with major histocompatibility
complexes (MHCs) on their surfaces; this process is known as antigen
presentation.
• T cells may recognize these complexes using their T cell
receptors (TCRs). These cells process antigens and present them to T-
cells.”

25. Radiation and antigen presenting cells.
• Dendritic cells(DCs),as professional antigen-presenting cells, are
members of the innate immune system and function as key players
during the induction phase of adaptive immune-responses. Uptake,
processing, and presentation of antigens direct the outcome toward
either tolerance or immunity.
• Those cell that express MHC class II molecules along with co-
stimulatory molecules and pattern recognition receptors are often
called professional antigen-presenting cells.

26. Radiation and antigen presenting cells.
• An antigen-presenting cell (APC) is a cell that displays radiation
antigens complexed with major histocompatibility complex (MHCs)
on their surfaces; this unique process is known as antigen
presentation.
• Antigen-presenting cells process antigens and present them to T-cells.