Immunology: Interferon-gamma IFN-g

Interferon-gamma IFN-g
Name:
Institution:
Date:
Summary
Inteferons protect the body against viral infections, and the also affect many biological processes through the cytokine system. The production of interferon occurs through lymphocytes, and regulation of interferon gamma is through macrophages. Furthermore, the production of Inteferons occurs in reaction to infections.
Introduction
IFN gamma is produced upon infection of T cells together with the interaction of natural killer cells (NK) which can be mitogens, alloantigen or antigen induced. On the contrary, IFN beta synthesis and IFN beta can be found in any cell. Furthermore, it is the only interferon found under Type II interferon. Interferon are grouped under cytokines since there discovery in 1957, and have protective mechanisms against viral infections [1-2]. The secretion of type II interferon through T and NK killer cells gives immunity against intracellular pathogens on the host. On the contrary, type I interferon offers protection through targeting cells and binding to receptors. Consequently, the mutation of interferon receptors and the deficiency of IFN gamma have been found to increase susceptibility to microbial infections. This paper looks into the mode of action and mechanisms associated with interferon gamma.
Review of literature
The discovery of the IFNs proved pivotal in the medical field as they could hinder the process of viral replication. To begin with their classification depended on the type of secreting cell, but nowadays they fall under type I and type II depending on sequence homology and receptor specificity [3]. Type I consists of various subtypes includes the alpha and beta types in humans. In addition, the production of IFN- β may occur through macrophages and viral infections facilitates the production of these types of interferon. Type I INFs have similar structures and they also bind to the same receptors.
On the other hand, IFN gamma binds to different types of receptors since the structure is different from that of type I IFNs. To begin, with scientists thought that the production of IFN gamma occurred through lymphocytes, CD 4+ cells, CD8+ cells, but after numerous studies were conducted other cells including professional antigen presenting cells and B cells also have the same effect[4]. Of particular interest is the impact of professional antigen cells in the activation of cells, this is thought to be effective through the defense of host cells, while through the adaptive immune system the lymphocytes are the main basis of gamma interferon.
The bone marrow is responsible for the production of macrophages, which typically die in large numbers following production through a process known as apoptosis [5]. After their productions the macrophages may gain special function, differentiate or simply die. In some cases the presence if IFNG makes sure that the macrophages survives through a signaling effect. IFNs are also though to inhibit cellular propagation through increase in the levels of proteins. In addition, the ability of IFNG to able to offer both innate and adaptive immunity is a special function that is different from other types of [6]. The stimulation of both IL 12 and IL 18 lead to increase in interferon gamma [6-7] or production in T cells, natural killer cells and macrophages
The mechanism by which Interferon gamma activates macrophages is a process that facilitates immunity response through numerous pathways. In essence, interferon abrogates endotoxin tolerance through a feedback loop that minimizes the impact of inflammatory macrophage genes that have been in contact with endotoxin [8].The authors offer valuable research studies by focusing on the manner in which interferon and endotoxin tolerance is related. This area of research has received little attention, and it was found necessary to observe the effect of pretreatment with interferon. Consequently, the study, found out that it altered tolerance association inn TNF and IL6. The authors concluded that the process occurred through choratin induced remodeling inTLR4.
     
The receptor of interferon gamma consists of two binding chain, signals and related signaling mechanism. The two chains namely INFNGR1 and 2, in turn belong to the same cytokine receptor subgroup, that typically link together into extracellular domain [9]. Nonetheless, the expression of the INFGR 2 chain occurs depending on the activation or differentiation of cells. For instance the propagation of T cells with low level of INFGR 2 chain may continue after there is a slowdown in the growth of inhibitory effects on interferon gamma. On the contrary, the interaction of interferon gamma with CD 4+ cells may lead to the death of cells through apoptosis.
The TH1 cells produce Interferon gamma, IL1 and IL2 whereby the excretion of interferon gamma results in the regulation of either allergic responses or Th mediated immunity. In e...