# CD28 Regulation of Alternative Splicing Changes in Human T cells

> **NIH NIH F31** · UNIVERSITY OF PENNSYLVANIA · 2020 · $45,520

## Abstract

Project Summary
 Alternative splicing consists of exons that are selectively included or excluded from the mature mRNA
transcript. In fact, most protein encoding genes, approximately 95%, contain an alternative exon. Previous
studies recognized that a subset of alternative spliced genes, 10-15%, undergo changes in isoform abundance
upon activation of primary human CD4+ T cells. A well-characterized example of signal-induced alternative
splicing changes includes a tyrosine phosphatase receptor, CD45, where the increased abundance of the
shorter RNA isoform is correlated with an increased activation threshold from future stimuli. Regulatory
mechanisms including the role of signaling pathways and RNA binding proteins influencing splicing changes
have been characterized by our lab and others. However, the field lacks general knowledge of the role and
mechanism of differential T cell stimuli to regulate global splicing changes.
 Previous studies investigated signal-induced alternative splicing changes with T cells activated in the
presence of anti-CD3 and anti-CD28 stimuli. CD3 is a component of the T cell receptor (TCR), which is
responsible for recognizing peptides presented by antigen presenting cells in the context of an infection. CD28
is a costimulatory receptor that enhances many signaling events downstream of the TCR. We ask if global
alternative splicing changes are differentially influenced by the presence of CD28 costimulation in primary
human CD4+ T cells. Therefore, I acquired primary CD4+ CD45RO- T cells from three human donors and
cultured the cells in the following conditions: media alone, anti-CD28 antibody, anti-CD3 antibody, or anti-
CD3/CD28 together. I harvested RNA for high-throughput sequencing analysis and discovered a subset of
alternative splicing events that are influenced by the presence CD28 costimulation compared to splicing events
regulated by CD3 stimulation alone. One of these splicing events includes a multi-exon skipping event within
Casapse-9 transcript that has not been characterized in CD4+ T cells. We hypothesize that the multi-exon
skipping event is regulating T cell survival upon stimulation. In our proposal, we plan to elucidate mechanisms
of splicing changes regulated by CD28 costimulation and the functional consequences of such events, such as
the multi-exon skipping event in Caspase-9 and impact on T cell survival. Overall, this work will be the stepping
stone into knowing how global alternative splicing events are regulated and the impact on cellular functions.

## Key facts

- **NIH application ID:** 10068466
- **Project number:** 1F31GM140978-01A1
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** Davia Blake
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $45,520
- **Award type:** 1
- **Project period:** 2021-01-01 → 2023-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10068466

## Citation

> US National Institutes of Health, RePORTER application 10068466, CD28 Regulation of Alternative Splicing Changes in Human T cells (1F31GM140978-01A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10068466. Licensed CC0.

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