Sevilla Movilla, SilviaFuentes, PatriciaRodríguez García, YaizaArellano Sánchez, NohemiKrenn, Peter W.Isern de Val, M. SoledadMontero Herradón, SaraGarcia-Ceca Hernández, JavierBurdiel Herencia, ValeriaGardeta, Sofía R.Aguilera Montilla, NoemíBarrio Alonso, CeliaCrainiciuc, GeorgianaBouvard, DanielGarcía-Pardo, AngelesZapata González, AgustínHidalgo, AndrésFässler, ReinhardCarrasco, Yolanda R.Toribio, Maria L.Teixidó, Joaquín2023-06-222023-06-222022-05-020014-2980; Electronic: 1521-414110.1002/eji.202149560https://hdl.handle.net/20.500.14352/72021ICAP-1 regulates β1-integrin activation and cell adhesion. Here, we used ICAP-1-null mice to study ICAP-1 potential involvement during immune cell development and function. Integrin α4β1-dependent adhesion was comparable between ICAP-1-null and control thymocytes, but lack of ICAP-1 caused a defective single-positive (SP) CD8+ cell generation, thus, unveiling an ICAP-1 involvement in SP thymocyte development. ICAP-1 bears a nuclear localization signal and we found it displayed a strong nuclear distribution in thymocytes. Interestingly, there was a direct correlation between the lack of ICAP-1 and reduced levels in SP CD8+ thymocytes of Runx3, a transcription factor required for CD8+ thymocyte generation. In the spleen, ICAP-1 was found evenly distributed between cytoplasm and nuclear fractions, and ICAP-1–/– spleen T and B cells displayed upregulation of α4β1-mediated adhesion, indicating that ICAP-1 negatively controls their attachment. Furthermore, CD3+- and CD19+-selected spleen cells from ICAP-1-null mice showed reduced proliferation in response to T- and B-cell stimuli, respectively. Finally, loss of ICAP-1 caused a remarkable decrease in marginal zone B- cell frequencies and a moderate increase in follicular B cells. Together, these data unravel an ICAP-1 involvement in the generation of SP CD8+ thymocytes and in the control of marginal zone B-cell numbers.engAtribución 3.0 Españahttps://creativecommons.org/licenses/by/3.0/es/journal articlehttps://doi.org/10.1002/eji.202149560open access577.27611.438B- cell maturationCell adhesionICAP-1IntegrinsThymocyte developmentInmunologíaBiología celular (Biología)2412 Inmunología2407 Biología Celular