Characterizing IL-2, IL-12 and IL-15 Cytokine Levels Following

Double Umbilical Cord Blood (dUCB) transplant

Gretchen A. Hoff

Verneris Lab NIH T-35 Fellowship

Medical Student Summer Research Program in Infection and Immunity

IL-2 = boosts cytolytic activity IL-12 = activates cell, boosts cytotoxicity and production of IFN� and TNF IL-15 = proliferation, accumulation, and survival IL-18 = boosts cytotoxicity eBioscience

Natural Killer Cell Maturation

NK Cells & Transplant !  Goals of hematopoietic stem cell (HSC) transplant:

1.  Replace the patient’s immune system

2.  Induce a graft versus leukemia (GVL) response

!  NK cells ! first lymphocytes to recover. Important role in GVL

PRELIMINARY STUDIES "  dUCBT ! highest number and range of proliferating cells

"  Ki67 = NK cell proliferation

"  High NK cell proliferation ! decreased relapse, increased disease free survival.

Unpublished data. Verneris Lab: Rachel J. Bergerson, PhD

Significant difference in IL-15 at Day +7 and +28 between patients with high vs low NK cell proliferation

Conditioning therapy

Day 0: transplant

day

Day 7: serum

collection for cytokine

analysis

Day 28: serum and cell collection

for cytokine and NK cell proliferation (Ki67)

Analysis

GVHD prophylaxis started

: Cyclosporin (CSA)/Mycophenolate mofetil

(MMF) or Sirolimus/MMF. Continued through ~ day

100

Preliminary set Validation set

# of patients 50 52

HLA mismatch 40% >2 HLA mismatch 60% 0-2 HLA mismatch

28% >2 HLA mismatch 72% 0-2 HLA mismatch

Conditioning therapy

32% Myeloablative 68% Non-myeloablative

40% Myeloablative 60% Non-myeloablative

GVHD prophylaxis 97% CSA/MMF* 57% CSA/MMF 43% Sirolimus/MMF

*Remaining GVHD prophylaxis was elutriation. Sirolimus article: Eissens 2010

IL-15 Expression: High vs Low NK cell proliferation

Preliminary findings not validated here.

IL-12 & IL-2: Patients with high NK cell proliferation express higher IL-2 at Day 28

Cytokine expression: Day +7 vs Day +28

Discussion/Future Aims !  Preliminary findings not validated

!  Ki67 assay used in preliminary study had detection artifact ! inaccurate readings

!  Change in GVHD prophylaxis: CSA/MMF ! CSA/MMF and Sirolimus/MMF

!  IL-15: !  There are lower serum IL-15 levels at Day 28 compared to Day

7. This could indicate that NK cell function, activation, and proliferation varies significantly between these time points.

!  IL-2: !  Investigate proliferation of other cells lines to determine

relevance

!  Future analysis: Phosphorylation of STAT5 vs. survival data ! functional differences of NK cells

Acknowledgements !  Rachel J. Bergerson, PhD

!  Michael Verneris, MD

!  Daniel Mueller, MD

!  Annette Bethke

!  Verneris Lab: !  Ashley Yingst, MS !  Hongbo Wang, MD !  Robin Williams, MD !  Kristy Pilbeam, MD

!  Translational Therapy Lab

!  University of Minnesota’s Center for Immunology

!  NIH T-35 Fellowship Grant