Ramón Castellanos Martínez, MsC

Cortactin and its hematopoietic homolog, HS1, are actin-binding proteins that regulate several cellular functions. In T cells, HS1 is recruited to the immunological synapse where it is essential for F-actin stabilization, Ca++ influx, NFAT- and NF-κB-mediated signaling and chemotaxis. On the other hand, cortactin has long been considered absent in T cells. Recent studies have shown that cortactin is expressed in T cells and is recruited to the immunological synapse between Jurkat and Nalm-6 cells. However, the physiological relevance of its presence here remains elusive. 

On the other hand, cortactin has been found highly expressed in different models of T-cell acute lymphoblastic leukemia (T-ALL). T-cell acute lymphoblastic leukemia has been historically considered as an aggressive disease among lymphoblastic leukemias in children. Previous work from our team showed that cortactin is overexpressed in B-cell acute lymphoblastic leukemia, and its presence associated with extramedullar infiltration and failure of steroid treatment. However, it is still unclear whether higher expression of cortactin is related to the aggressiveness observed during T-ALL. The main objective of my work is to elucidate the physiological relevance of cortactin for the activation of healthy CD4+ T cells and its contribution in the pathophysiology of T-cell acute lymphoblastic leukemia.

• Travel Award (Mexican Society of Immunology 2018, 200$)
• Travel Award (American Society for Investigative Pathology 2019, 750$)
• Research fellowship in the laboratory of Dr. Oxana Dobrovinskaya, University Center for Biomedical Research, University of Colima (March 2019).
• SLB Video Abstract Merit Finalist (Society for Leukocyte Biology 2020, 250$)
• PISA 2020 International Trainee Scholar Award (American Society for Investigative Pathology 2020, 100$) 
• Research Fellowship in the laboratory of Dr. Volker Spindler, Institute of Anatomy, University of Basel (January to July 2021).
• Participant in the Pronaii “Childhood Leukemia” supported by CONACyT.

• Castellanos-Martínez R, Schnoor M. Participación de cortactina en la transmigración de la leucemia linfoblástica aguda de tipo T. X Foro      Estudiantil. SMI, Mexico city. Mexico (2018). Poster presentation.
• Castellanos-Martínez R, Vadillo E, Nava P, Schnoor M. TLR stimulation in leukemic T cells and endothelial cells induces the expression of molecules needed to accomplish transendothelial migration. XII Congress of the Latin American Association of Immunology-ALAI/XXIII Congress of the Mexican Society of Immunology-SMI. Cancún, QR. Mexico (2018). Poster presentation.
• Castellanos-Martínez R, Vadillo E, Schnoor M. The actin-binding protein cortactin controls transendothelial migration and organ infiltration of acute lymphoblastic leukemia T cells. Experimental Biology. Orlando, FL. USA (2019). Oral and poster presentation.
• Castellanos-Martínez R, Valle-Reyes SJ, Schnoor M. Emerging Roles for the Actin-Binding Protein Cortactin in the Activation of T Cells. PISA. 2020. ePoster video.
• Castellanos-Martínez R, Valle-Reyes SJ, Schnoor M. Emerging Roles for the Actin-Binding Protein Cortactin in the Activation of T Cells. SLB. 2020. Video presentation.