PMID- 31589599 OWN - NLM STAT- MEDLINE DCOM- 20200203 LR - 20200602 IS - 1553-7358 (Electronic) IS - 1553-734X (Print) IS - 1553-734X (Linking) VI - 15 IP - 10 DP - 2019 Oct TI - A simulation of the random and directed motion of dendritic cells in chemokine fields. PG - e1007295 LID - 10.1371/journal.pcbi.1007295 [doi] LID - e1007295 AB - Dendritic cells (DCs) are the most effective professional antigen-presenting cell. They ferry antigen from the extremities to T cells and are essential for the initiation of an adaptive immune response. Despite interest in how DCs respond to chemical stimuli, there have been few attempts to model DC migration. In this paper, we simulate the motility of DCs by modeling the generation of forces by filopodia and a force balance on the cell. The direction of fliopodial extension is coupled to differential occupancy of cognate chemokine receptors across the cell. Our model simulates chemokinesis and chemotaxis in a variety of chemical and mechanical environments. Simulated DCs undergoing chemokinesis were measured to have a speed of 5.1 +/- 0.07 mum.min-1 and a persistence time of 3.2 +/- 0.46 min, consistent with experiment. Cells undergoing chemotaxis exhibited a stronger chemotactic response when exposed to lower average chemokine concentrations, also consistent with experiment. We predicted that when placed in two opposing gradients, cells will cluster in a line, which we call the "line of equistimulation;" this clustering has also been observed. We calculated the effect of varying gradient steepness on the line of equistimulation, with steeper gradients resulting in tighter clustering. Moreover, gradients are found to be most potent when cells are in a gradient of chemokine whose mean concentration is close to the binding of the Kd to the receptor, and least potent when the mean concentration is 0.1Kd. Comparing our simulations to experiment, we can give a quantitative measure of the strength of certain chemokines relative to others. Assigning the signal of CCL19 binding CCR7 a baseline strength of 1, we found CCL21 binding CCR7 had a strength of 0.28, and CXCL12 binding CXCR4 had a strength of 0.30. These differences emerge despite both chemokines having virtually the same Kd, suggesting a mechanism of signal amplification in DCs requiring further study. FAU - Parr, Avery AU - Parr A AUID- ORCID: 0000-0003-1036-8362 AD - Harriton High School, Rosemont, Pennsylvania, United States of America. AD - Department of Chemical and Biological Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America. FAU - Anderson, Nicholas R AU - Anderson NR AUID- ORCID: 0000-0001-6027-9101 AD - Department of Chemical and Biological Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America. FAU - Hammer, Daniel A AU - Hammer DA AUID- ORCID: 0000-0002-3522-3154 AD - Department of Chemical and Biological Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America. AD - Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America. LA - eng GR - R01 GM123019/GM/NIGMS NIH HHS/United States PT - Journal Article PT - Research Support, N.I.H., Extramural PT - Research Support, U.S. Gov't, Non-P.H.S. DEP - 20191007 PL - United States TA - PLoS Comput Biol JT - PLoS computational biology JID - 101238922 RN - 0 (Chemokines) SB - IM MH - Adaptive Immunity MH - Animals MH - Cell Movement MH - Chemokines/*physiology MH - Chemotaxis/physiology MH - Computer Simulation MH - Dendritic Cells/*physiology MH - Humans MH - Models, Theoretical MH - Motion MH - Signal Transduction/immunology PMC - PMC6797211 COIS- The authors have declared that no competing interests exist. EDAT- 2019/10/08 06:00 MHDA- 2020/02/06 06:00 PMCR- 2019/10/07 CRDT- 2019/10/08 06:00 PHST- 2019/01/31 00:00 [received] PHST- 2019/07/30 00:00 [accepted] PHST- 2019/10/17 00:00 [revised] PHST- 2019/10/08 06:00 [pubmed] PHST- 2020/02/06 06:00 [medline] PHST- 2019/10/08 06:00 [entrez] PHST- 2019/10/07 00:00 [pmc-release] AID - PCOMPBIOL-D-18-01787 [pii] AID - 10.1371/journal.pcbi.1007295 [doi] PST - epublish SO - PLoS Comput Biol. 2019 Oct 7;15(10):e1007295. doi: 10.1371/journal.pcbi.1007295. eCollection 2019 Oct.