Vaccines Flashcards
what is the main goal of therapeutic cancer vaccines?
to harness the immune system’s specificity to recognise, amplify responses against, and destroy tumour cells
name 3 viruses associated with T cell antigens identified in cancer research
human papillomavirus (HPV), hepatitis B (HBV) and Epstein-Barr virus (EBV)
why did early therapeutic cancer vaccines show limited efficacy in advanced cancers?
advanced cancers have complex tumour microenvironments and immune evasion mechanisms that make them resistant to immune responses
what is the difference between prophylactic and therapeutic cancer vaccines?
prophylactic vaccines prevent cancer by targeting viruses that cause cancer, while therapeutic vaccines treat existing cancers by stimulating an immune response against tumour cells
give an example of a prophylactic cancer vaccine
the HPV vaccine helps prevent cervical cancer
name an FDA approved therapeutic cancer vaccine
provenge for metastatic prostate cancer
what are TAAs?
antigens that are overexpressed in tumours but can also be found at lower levels in normal tissues
what are neoantigens, and why are they significant in cancer vaccines?
neoantigens are unique to tumour cells due to mutations and are not found in normal tissues, making them ideal targets for personalised cancer vaccines
name two examples of tumour-specific antigens used in cancer vaccine research
HER2 and human telomerase reverse transcriptase (TERT)
what role do APCs play in cancer vaccines?
APCs such as dendritic cells, present tumour antigens to T cells, initiating an immune response
explain the difference between MHC class 1 and MHC class 2 in antigen presentation
MHC class 1 presents antigens to CD8+ T cells (cytotoxic) and MHC class 2 presents to CD4+ T helper cells
why are dendritic cells considered the most potent APCs?
they activate both naive and memory T cells, making them crucial for strong cytotoxic T cell response
what was the median survival increase in the D9901 trial for Sipeluecel-T (Provenge)?
median survival increase of 4.5 months compared to placebo
why was Provenge significant in cancer vaccine development?
it was the first therapeutic cancer vaccine to be FDA approved
what type of cancer is T-VEC used to treat and what is its mechanism?
T-VEC is used for metastatic melanoma and is an oncolytic virus that selectively infects and kills tumour cells
what is one major reason cancer vaccines are challenging to develop?
the immunosuppressive tumour microenvironment can inhibit effective immune responses
what % of people do NOT respond to checkpoint inhibition therapies?
50%
how do combination therapies improve the efficacy of cancer vaccines?
combining vaccines with checkpoint inhibitors or adjuvants can enhance immune activation and overcome tumour immune evasion
what are neoantigen-specific CTLs and why are they important?
they are T cells that target neoantigens making them effective at rejecting tumours
describe the role of high neoantigen load in clinical outcomes
a high neoantigen load correlates with stronger T cell responses and improved clinical outcomes
what is the purpose of mRNA in neoantigen vaccines?
mRNA is used to encode neoantigens, facilitating the generation of tumour-specific T cell responses
what is the purpose of adjuvants in cancer vaccines?
adjuvants enhance the immune response to the vaccine antigens
name an adjuvant that activates TLR4
monophosphoryl lipid A (MPL)
what is the role of TLR7 in mRNA vaccine delivery?
TLR7 activation promotes dendritic cell maturation and a potent T cell response
