*Review* **The Regulatory Role of T Cell Responses in Cardiac Remodeling Following Myocardial Infarction**

### **Tabito Kino 1, Mohsin Khan 2 and Sadia Mohsin 1,\***


Received: 6 June 2020; Accepted: 13 July 2020; Published: 16 July 2020

**Abstract:** Ischemic injury to the heart causes cardiomyocyte and supportive tissue death that result in adverse remodeling and formation of scar tissue at the site of injury. The dying cardiac tissue secretes a variety of cytokines and chemokines that trigger an inflammatory response and elicit the recruitment and activation of cardiac immune cells to the injury site. Cell-based therapies for cardiac repair have enhanced cardiac function in the injured myocardium, but the mechanisms remain debatable. In this review, we will focus on the interactions between the adoptively transferred stem cells and the post-ischemic environment, including the active components of the immune/inflammatory response that can mediate cardiac outcome after ischemic injury. In particular, we highlight how the adaptive immune cell response can mediate tissue repair following cardiac injury. Several cell-based studies have reported an increase in pro-reparative T cell subsets after stem cell transplantation. Paracrine factors secreted by stem cells polarize T cell subsets partially by exogenous ubiquitination, which can induce di fferentiation of T cell subset to promote tissue repair after myocardial infarction (MI). However, the mechanism behind the polarization of di fferent subset after stem cell transplantation remains poorly understood. In this review, we will summarize the current status of immune cells within the heart post-MI with an emphasis on T cell mediated reparative response after ischemic injury.

**Keywords:** regulatory T cells; ubiquitin; mesenchymal stem cell; cortical bone derived stem cell; myocardial infarction
