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Principal Investigator: Robert L. Ferris
Organization: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
Fiscal Year: 2024
Award: $250,000
Funding agency: National Cancer Institute
Optimization of a modified immunotherapeutic LANA antigen for use in treating persons with HIV/AIDS
and refractory KSHV-related cancers (Immuno/Microenvironment).
ABSTRACT
This PA-20-272 administrative supplement to the UPMC Hillman Cancer Center Support Grant (P30CA047904)
is directly responsive to the Immunotherapy and Tumor Microenvironment in HIV/AIDS Cancer Patients at
NCI-Designated Cancer Centers Administrative Supplement Announcement for P30 Cancer Centers Support
Grants (CCSG). It focuses on research to 1) discover and characterize an immunotherapeutic target (KSHV
LANA), 2) by developing a new immunotherapeutic approach (protein engineering to enhance LANA peptide
presentation), that 3) improves our understanding of the immunosuppressive environment of KSHV tumors. It
is 100% aligned with NIH HIV/AIDS Research Priorities as a new and important approach to treat persistent or
recurrent AIDS-related Kaposi sarcoma (KS) in patients who have undergone immune reconstitution through
antiretroviral therapy. This proposal also addresses targeting KS in the aging KSHV+ HIV/AIDS population who
do not currently have KS but can be expected to be at high-risk for developing KS with aging.
The purpose of this study is to optimize LANA as an immunotherapeutic by changing the immunologically “cold”
LANA protein into an immunologically “hot” CD8+ cytotoxic lymphocytic (CTL) antigen. Our preclinical mouse
study, using an ovalbumin T cell peptide reporter, reveals that the LANA central repeat domain 1 (CR1)
specifically inhibits LANA proteolytic processing and MHC I peptide presentation to evade cell-mediated
immunity. By deleting the CR1 domain and expressing LANADCR1 in murine MC38 cancer cells, we provoke a
robust CTL response with specific recognition and cell killing by OT-1 CD8+ cells. When wild-type LANA-
expressing MC38 cells are injected into syngeneic, immune-competent C57BL/6 mice, mice develop
monotonically-growing tumors that require termination, consistent with LANA-induced CTL immune escape. In
contrast, mice injected with MC38 cells expressing LANADCR1 show brief tumor formation and then tumor
regression, consistent with an effective anti-tumor CTL response. Both LANA- and LANADCR1-expressing cells
generate indistinguishable tumors when injected into Rag1-/- mice demonstrating that this differential response
is due to immune surveillance.
During this proposal period, we will further optimize the LANADCR1 as an immunotherapeutic antigen by
fragmenting the corresponding ORF73 gene, performing codon-optimization and removing additional repetitive
peptide regions and the nuclear localization signal that may contribute to reduced CTL responsiveness. We will
immunize mice with the optimized antigen and, after an appropriate boosting schedule, challenge the mice with
wild-type LANA only-expressing MC38 cells to determine whether optimized antigen can prevent tumor formation
through LANA epitope recognition. Successful conclusion of this study will set the stage for moving this vaccine
candidate into mRNA nanoparticle or virus-vector antigen presenting vaccines for animal studies as a preliminary
step to Phase I trials.
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Terms: <AIDS><AIDS population><AIDS with Kaposi's sarcoma><AIDS-Related Kaposi's Sarcoma><AIDS/HIV><Acquired Immune Deficiency><Acquired Immune Deficiency Syndrome><Acquired Immunodeficiency Syndrome><Address><Administrative Supplement><Aging><Animals><Antigen Presentation><Antigenic Determinants><Antigens><Autoimmune Deficiency Syndrome-Related Kaposi Sarcoma><Binding Determinants><C57BL/6 Mouse><CCSG><CD8><CD8 Cell><CD8 T cells><CD8 lymphocyte><CD8+ T cell><CD8+ T-Lymphocyte><CD8-Positive Lymphocytes><CD8-Positive T-Lymphocytes><CD8B><CD8B1><CD8B1 gene><Cancer Center Support Grant><Cancer Patient><Cancers><Cell Body><Cell Mediated Immunology><Cell-Mediated Immunity><Cells><Cellular Immunity><Codon><Codon Nucleotides><Environment><Epidemic Kaposi's Sarcoma><Epitopes><Genes><HHV-8><HHV8><HIV/AIDS><Human Herpesvirus 8><Immune><Immune Evasion><Immune Surveillance><Immune mediated therapy><Immune response><Immune system><Immunes><Immunize><Immunochemical Immunologic><Immunocompetent><Immunologic><Immunologic Surveillance><Immunologic Surveillances><Immunological><Immunological Surveillance><Immunological Surveillances><Immunological response><Immunologically><Immunologically Directed Therapy><Immunologics><Immunosurveillance><Immunotherapeutic agent><Immunotherapy><KSHV><Kaposi Sarcoma><Kaposi Sarcoma-Associated Herpes Virus><Kaposi Sarcoma-Associated Herpesvirus><Kaposi sarcoma associated virus><Kaposi sarcoma herpes virus><Kaposi's Sarcoma><Kaposi's Sarcoma Epidemic Type><Kaposi's sarcoma (KS)-associated herpesvirus><LD Antigens><LYT3><Laboratories><Lymphatic cell><Lymphocyte><Lymphocyte antigen><Lymphocytic><MC-38><MC38><Malignant Cell><Malignant Neoplasms><Malignant Tumor><Messenger RNA><Mice><Mice Mammals><Multiple Hemorrhagic Sarcoma><Murine><Mus><NCI-Designated Cancer Center><NIH><NLS Peptide><National Institutes of Health><Nuclear Localization Signal><Nuclear Localization Signal Peptide><Ovalbumin><Pathway interactions><Patients><Peptides><Persons><Protein Engineering><Proteins><Proteolytic Clipping><Proteolytic Processing><Rag1><Rag1 Mouse><Recurrence><Recurrent><Refractory><Reporter><Research><Research Priority><Schedule><T-Cells><T-Lymphocyte><T8 Cells><T8 Lymphocytes><Therapeutic><United States National Institutes of Health><Vaccines><Virus><Virus-HHV8><antiretroviral therapy><antiretroviral treatment><cancer cell><cancer microenvironment><cell killing><cytotoxic><genetic protein engineering><high risk><host response><immune competent><immune drugs><immune evasive><immune reconstitution><immune system response><immune therapeutic approach><immune therapeutic interventions><immune therapeutic regimens><immune therapeutic strategy><immune therapy><immune-based therapeutics><immune-based therapies><immune-based treatments><immuno therapy><immunogen><immunologic therapeutics><immunoresponse><immunotherapeutics><immunotherapy agent><improved><kaposi's sarcoma herpesvirus><kaposi's sarcoma-associated human herpesvirus><lymph cell><lymphocyte differentiation antigen><mRNA><malignancy><nano particle><nano-sized particle><nanoparticle><nanosized particle><neoplasm/cancer><pathway><peptide I><phase 1 trial><phase I trial><pre-clinical><preclinical><prevent><preventing><protein design><response><therapeutic vaccine><thymus derived lymphocyte><treatment vaccines><tumor><tumor microenvironment><vaccine candidate><vaccine for the treatment><vaccine for treatment><vector>