OCA-B/Pou2af1 is sufficient to promote CD4⁺T cell memory and prospectively identifies memory precursors

Abstract

The molecular mechanisms leading to the establishment of durable immunological memory are inadequately understood, limiting the development of effective vaccines and durable anti-tumor immune therapies. Using a T cell-conditional knockout mouse model and a viral pathogen, we show that expression of the transcription cofactor OCA-B (Pou2af1/Bob.1/OBF-1) within T cells is necessary for proper CD4+ memory T cell formation. We also show that ectopic OCA-B expression is sufficient to drive T cells towards a memory fate, while having minimal effects on primary antiviral effector response. Bulk and single-cell gene expression profiling comparing cells transduced with OCA-B and empty vector at primary effector response identifies changes in gene expression consistent with later memory formation, including genes increased (Tbx21, Il7r, Gadd45b, Socs2) in specific subpopulations by ectopic OCA-B expression. Short-lived effector T cell compartments are expanded but show increased expression of Gadd45b and Socs2, while clusters of effector cells with memory potential show increased expression of Bcl2, Il7r, Tcf7 and Slamf6. We also describe an OCA-B-mCherry reporter mouse allele that selectively labels B and T lymphocytes, and shows high reporter expression in CD4+ TCM cells. We show that elevated OCA-B expression prospectively identifies cells with increased survival capability and memory recall potential. Cumulatively, the results demonstrate that OCA-B is necessary and sufficient to promote CD4 T cell memory in vivo.

OCA-B promotes autoimmune demyelination through control of stem-like CD4+T cells

“…We used a recently described an OCA-B reporter (OCA-B-mCherry) mouse which selectively labels OCA-B expressing B and T cells with mCherry 47 to evaluate OCA-B expression within CNS infiltrating T cells. Female C57BL/6 homozygous OCA-B-mCherry reporter mice were induced with MOG 35-55 EAE and assessed by flow cytometry at peak clinical disease.…”

“…Similarly, in EAE models, peripheral central memory-like CD4 + CD44 hi CD62L hi T cells confer increased disease severity upon transfer 14 . Oct1 and OCA-B both promote the generation and functionality of long-lived CD4 + memory T cells 23,47 . We recently reported the generation of an OCA-B-mCherry reporter mouse which effectively labels memory progenitor CD4 + T cells during acute infection 47 .…”

“…Oct1 and OCA-B both promote the generation and functionality of long-lived CD4 + memory T cells 23,47 . We recently reported the generation of an OCA-B-mCherry reporter mouse which effectively labels memory progenitor CD4 + T cells during acute infection 47 . Similarly, OCA-B hi CD4 + T cells preferentially confer EAE, and reporter cells taken from the CNS at peak EAE selectively express stem/memory markers.…”

“…11-12 week-old female C57BL/6 littermate animals were used for all experiments. For adoptive transfer experiments using the OCA-B-mCherry reporter allele 47 , 11 week-old females were used for chronic EAE and 9 week-old males were used as MOG 35-55 primed adoptive transfer donors. EAE was induced on day 0 by two 100 μL subcutaneous injections into both hind flanks of 0.5 μmol/mL MOG 35-55 peptide (University of Utah Peptide Core) emulsified in complete Freud’s adjuvant (CFA), comprised of incomplete Freund’s adjuvant (Cat# 77145;ThermoFisher) together with 4 mg/mL heat-killed M. tuberculosis (Cat# DF3114338; Fisher Scientific).…”

“…OCA-B-mCherry reporter allele animals 47 were primed for 14 days with MOG 35-55 in CFA as described above. After priming, spleen and lymph nodes were collected and CD4 + T cells were purified by magnetic negative selection (Miltenyi Bio kit and LS columns).…”