CRISPR-Feb10(s) (1) - Copy Flashcards
(29 cards)
What are Porcine endogenous retroviruses (PERVs)?
A type of retrovirus associated with pigs that can cause immune responses in humans
PERVs are of interest due to their potential impact on xenotransplantation.
What was the purpose of editing 20 genes in the second pig?
To encode cell surface proteins that cause a human immune response
This editing aims to reduce the likelihood of immune rejection during xenotransplantation.
What is the significance of PDCD1 KO in T-cells?
It prevents cancer cells from disabling T cells by removing the protein that identifies them as immune cells.
What CRISPR edits will be given to T cells of 18 patients with cancer?
- Remove PDCD1 gene
- Remove TCRa and TCRb
- Introduce synthetic cancer-specific TCR via lentivirus
These edits enhance T cell binding to cancer cells.
What were the results of the February 2020 trial with 3 patients?
No adverse effects were observed after 9 months.
What is the treatment approach for beta-thalassemia and sickle cell disease (SCD)?
Autologous hematopoietic stem cell transplant.
What were the outcomes of the June 2021 trial involving 15 beta thalassemia and 7 SCD patients?
All 15 beta thalassemia patients became transfusion independent and all 7 SCD patients had zero vaso-occlusive crises.
When did the initial trial for beta-thalassemia and SCD start?
2019.
What is CASGEVY and when was it FDA approved?
A treatment for beta-thalassemia, FDA approved in December 2023 for $2.1 million.
What does CRISPRi do?
Binds but does not cut: interferes with RNA polymerase or transcription factor binding.
CRISPR interference (CRISPRi) is a technique that uses a modified CRISPR system to inhibit gene expression.
What has increased success in mammalian cells related to CRISPR?
Fusion and/or recruitment of activation domains.
This refers to enhancements made to CRISPR systems to improve their effectiveness in mammalian cell environments.
What is CRISPRa?
Recruits general transcription factors and RNA polymerase.
CRISPR activation (CRISPRa) is a method to enhance gene expression using the CRISPR framework.
Which human acetyltransferase is linked to transcriptional activation in CRISPR adaptations?
p300.
p300 is a co-activator that plays a significant role in regulating transcription by enhancing the acetylation of histones.
What is linked to transcriptional inactivation in CRISPR adaptations?
HDAC3.
Histone deacetylase 3 (HDAC3) is involved in the removal of acetyl groups from histones, leading to transcriptional repression.
What role does DNMT3a play in CRISPR adaptations?
DNA methylase.
DNMT3a is an enzyme involved in adding methyl groups to DNA, which can affect gene expression and is linked to transcriptional repression.
What is the purpose of inducible CRISPR?
For genome editing or with dCas9 for gene repression/activation.
Inducible CRISPR systems allow for controlled editing or regulation of gene expression in response to specific stimuli.
List some disorders treated in mice using CRISPR.
- Tyrosinemia
- DMD
- Huntington’s
- Hemophilia
- Retinitis pigmentosa
- Sickle cell anemia
- Beta thalassemia
These disorders represent a range of genetic conditions that have been targeted for treatment in preclinical models using CRISPR technology.
What is the frequency of ‘GG’ in the reference human genome?
5.21%
This frequency indicates how often the dinucleotide ‘GG’ occurs in the genome.
How many NGG PAM sites are expected in the human genome based on the frequency of ‘GG’?
161,284,793
This is calculated based on the frequency of ‘GG’ and the total length of the human genome.
Roughly how many bases are there between each ‘GG’ dinucleotide in the human genome?
42 bases
This estimate relates to the average spacing of the ‘GG’ dinucleotide in the genome.
True or False: CRISPRi binds and cuts DNA.
False
CRISPRi binds but does not cut, interfering instead with transcription.
What is the function of CRISPRi?
Interferes with RNA polymerase or transcription factor binding
This mechanism inhibits gene expression by preventing the transcription process.
Fill in the blank: CRISPRi binds but does not _______.
cut
This highlights the key difference between CRISPRi and other CRISPR applications.
What is the function of the CRISPR system in bacteria?
The CRISPR system functions as an adaptive immune system in bacteria to protect against invading viruses and plasmids.
It allows bacteria to remember past infections and respond more effectively to future attacks.
