CD4+ T lymphocytes, or cells, are white blood cells that are involved in immune protection. These cells assist B cells in creating antibodies, allow macrophages to establish heightened antimicrobial activity, recruit neutrophils, eosinophils, and basophils towards inflammation and infection. CD4+ T cells also produce a group of cytokines, which respectively, trigger an abundance of immune responses.
T cell differentiation Originally, Mosmann et al., 1986 reported that CD4 T cells can be subdivided into those that produce interferon gamma (IFN-ϒ) and those that produce interleukin 4 (IL-4). Currently, CD4 T cells are recognized as a cell population with a variety of functions. Two subsets of CD4+ T cells that are recognized individually are …show more content…
Regulatory T cells are part of the adaptive immune response and are derived from the thymus. Treg cells are known as CD4+CD25+ T cells. They maintain immune cell homeostasis during inflammation and disease. NKT cells are part of the innate immune response, and are the first line of defense against tumors and viruses; they recognize infected cells by their down regulation of the major histocompatibility complex (MHC) class 1 molecules. NKT cells release cytokines and recruit other immune cells. (Pedroza-Pacheco et al., 2013)
Naïve T cell differentiation Naïve CD4+ T cells’ differentiation is not as straight forward; naïve T cells can differentiate into many CD4+ effector T helper (Th) cells. These T helper cells include Th1, Th2, and Th17. (Takeuchi et al., 2015) Mossoman et al., 1986 considered Th1 to be essential for intracellular microorganism immunity, and Th2 for extracellular pathogen immunity (Zhu et al., 2008). Th17’s roles were not yet discovered. Th1 is now known to be involved in cell-mediated immunity. T helper 1 (Th1) cells control intracellular pathogens, such as viruses and certain bacteria, by producing the cytokine IFN-ϒ. IFN-ϒ is called type II interferon; it’s a cytokine involved in regulating all phases …show more content…
It is briefly expressed on these molecules throughout the initial phase of T cell activation. CD8+ T cells are cytotoxic T cells; they recognize peptides represented on MHC Class I. MHC Class I is located on all nucleated cells. T cells with CRTAM (CRTAM+) mediate cell adhesion with its ligand, Cadm1. CD8+ T cells with CRTAM associate with CD8+ dendritic cells with Cadm1 in lymph nodes. This association is crucial for the aggregation of antigen-specific cytotoxic T cells (CTLs) and their consequent increase when draining lymph nodes (LNs) (Takeuchi et al., 2009). Mice without CRTAM and without Cadm1 had fewer CD4_ and CD8+ T cells in the intestinal mucosa compared to wild type (WT) mice. CRTAM and Cadm1 deficient mice also lacked CD4+CD8+ T cells in the intestinal epithelium. CD4+CD8+ T cells originate from CD4+ T cells that obtain a CD8 T cell lineage gene expression profile when arriving in the intestinal mucosa. (Mucida et al., 2013; Reis et al.,
T cell differentiation Originally, Mosmann et al., 1986 reported that CD4 T cells can be subdivided into those that produce interferon gamma (IFN-ϒ) and those that produce interleukin 4 (IL-4). Currently, CD4 T cells are recognized as a cell population with a variety of functions. Two subsets of CD4+ T cells that are recognized individually are …show more content…
Regulatory T cells are part of the adaptive immune response and are derived from the thymus. Treg cells are known as CD4+CD25+ T cells. They maintain immune cell homeostasis during inflammation and disease. NKT cells are part of the innate immune response, and are the first line of defense against tumors and viruses; they recognize infected cells by their down regulation of the major histocompatibility complex (MHC) class 1 molecules. NKT cells release cytokines and recruit other immune cells. (Pedroza-Pacheco et al., 2013)
Naïve T cell differentiation Naïve CD4+ T cells’ differentiation is not as straight forward; naïve T cells can differentiate into many CD4+ effector T helper (Th) cells. These T helper cells include Th1, Th2, and Th17. (Takeuchi et al., 2015) Mossoman et al., 1986 considered Th1 to be essential for intracellular microorganism immunity, and Th2 for extracellular pathogen immunity (Zhu et al., 2008). Th17’s roles were not yet discovered. Th1 is now known to be involved in cell-mediated immunity. T helper 1 (Th1) cells control intracellular pathogens, such as viruses and certain bacteria, by producing the cytokine IFN-ϒ. IFN-ϒ is called type II interferon; it’s a cytokine involved in regulating all phases …show more content…
It is briefly expressed on these molecules throughout the initial phase of T cell activation. CD8+ T cells are cytotoxic T cells; they recognize peptides represented on MHC Class I. MHC Class I is located on all nucleated cells. T cells with CRTAM (CRTAM+) mediate cell adhesion with its ligand, Cadm1. CD8+ T cells with CRTAM associate with CD8+ dendritic cells with Cadm1 in lymph nodes. This association is crucial for the aggregation of antigen-specific cytotoxic T cells (CTLs) and their consequent increase when draining lymph nodes (LNs) (Takeuchi et al., 2009). Mice without CRTAM and without Cadm1 had fewer CD4_ and CD8+ T cells in the intestinal mucosa compared to wild type (WT) mice. CRTAM and Cadm1 deficient mice also lacked CD4+CD8+ T cells in the intestinal epithelium. CD4+CD8+ T cells originate from CD4+ T cells that obtain a CD8 T cell lineage gene expression profile when arriving in the intestinal mucosa. (Mucida et al., 2013; Reis et al.,