Chemokines as well as cytokines constitute two immune modulating agents that are involved in mediating and modulating of the immune system’s responses. immune system. Different types of cytokine superfamilies are recognized: chemokines INFs, INFs, CSFs, TGFs and TNFs. They differ only by the function they perform within the body. Chemokines cause a gradient of concentration that directs other leukocytes to the location of the infection. The primary distinction between chemokines and cytokines is that cytokines are tiny proteins that are released by cells within the body that affect other cells. Chemokines are a part of the superfamily of cytokines and possess Chemotactic properties.
What are Cytokines?
Cytokines are a group of substances released by immune system’s cells that affect other cells. Interferon, interleukin, and growth factors are all cytokines. Cytokines could be glycoproteins, polypeptides, or proteins and function as signalling molecules, facilitating and controlling the immune system and inflammation and the process of hematopoiesis. Different kinds of cells within the body are involved in the production of cytokines. The designation of cytokines is dependent on the function performed within the body cells of secretion or targets of action. Cytokines show a remarkable affinity for their receptors. Therefore, cytokines are kept at concentrations that are picomolar.
A specific cytokine could play a role in autocrine paracrine or the endocrine process. Autocrine activity refers to that cytokines are bound receptors in cells, which secrete a specific cytokine. Paracrine function is an interaction of the cytokine the receptors on cells, that are located close to the cells that secrete it. Endocrine activity refers to the movement of cytokines across blood to a particular area of the body in which they are released. The superfamily of cytokines includes chemokines interleukins (ILs) and interferons (INFs) and colony-stimulating factors (CSFs) and transformation growth factors (TGFs) and tumor necrosis factor (TNFs). Although each type of cytokine is identical in structure however, they are different in their roles. Type 1 cytokines play a role in the enhancement of the cellular immune response, while type 2 cytokines play a role in the immune response. Type 1 cytokines include IFN-g and TNFa. Type 2 cytokines include the IL-4, IL-10, and IL-13 and TGF-b.
What are Chemokines?
Chemokines are the chemokines of chemoattract. Chemotactic cytokines have the capability of initiating directed chemotaxis of adjacent cells that are responsive. Tissues infected with infection are stimulated through pro-inflammatory cytokines that release Chemotactic of cytokines. The pro-inflammatory cytokines include IL-1 and TNFs. An influx of chemokines produced, which sends leukocytes towards the tissue infected. Leukocytes migrate from the endothelial cell into the basement membranes of affected tissue. Chemokines also play a role in controlling cells , such as controlling lymphocytes to lymph nodes in the course of immune surveillance. These kinds of chemokines are known as homeostatic chemical Chemokines. Certain chemokines play a role in the development of angiogenesis. Others chemokines contribute to the process of metastasis and growth of tumors.
Four chemokines groups are identified based on the initial two cytosine residues of the chain of polypeptides. CC Chemokines are composed of two cytosine residues adjacent to the amino terminal. CXC chemokines are composed of two cytosine atoms at the N-terminus. They are separated by an amino acid. C chemokines are composed of one cytosine at the N-terminus, and another downstream cytosine. CX3C Chemokines comprise three amino acids sandwiched between two cysteine residues.
What are the Similarities Between Cytokines and Chemokines?
- Both are biomolecules made up of proteins.
- Both are released when there is inflammation.
- Both are able to be used as indicators of inflammation in particular clinical situations.
- Both of them bind to receptors, forming a receptor protein (cytokine or chemical) complex.
- Both are able to trigger a chain of reactions.
Differences between Cytokines and Chemokines – Cytokines vs Chemokines
| Characteristics | Cytokines | Chemokines |
| Definition | The smallest proteins made by immune cells, which are crucial in the process of cell-to-cell signaling. | Particular Cytokines that are specifically designed to Chemotaxis in cells. |
| Description | A wide range of chemical messengers used to induce immunity. | They are Chemotactic Cytokines. |
| Size | ~5-20 kDa | ~ 8-10 kDa |
| Classification | Cytokines are interleukins, chemokines, interferon, lymphokines, as well as the tumor necrosis factors. | Chemokines are classified into four major subfamilies: CXC (CXC), CC, CX3C and XC. |
| Immunity is a component of the immune system. | It is involved in both humoral and cell-mediated immunity. It is involved in both cell-mediated and humoral. | It is involved in only directing immune system cells to an area of interest. |
| Functions | Signaling molecules help control and regulate the immune system, inflammation and hematopoiesis.They also play a crucial role in the control of the cell, consequently, tissue growth and development, migration, and differentiation. | Facilitate the movement of white blood cells to damaged or infected tissues i.e. help cells move towards the desired location.They play a role in immunological reactions as well as in the homeostasis of our immune system. |
| Importance | Plays a role as a regulator (acts as messengers) within the system of immune defense. The process of healing following resolution of the infection is controlled by Cytokines. | It is important to ensure that the infection doesn’t get to other areas of the body at the source or location of detection. |
| Examples | IL-1,6,12, IFN-a, TNFa, IFN-g etc. | monocyte chemical attractant protein-1 (MCP-1 also known as CCL2) CCL1, CCL15 and CCL21 The CXCR1-7 protein, XCL1, CXCR1 and many others. |
