Basic mechanisms of human immune system response against the viral infections have been discussed here in short.

1. ROLE OF INFLAMMATORY RESPONSES IN
VIRAL INFECTIONS & ITS POSSIBLE TARGETS
ADVANCED PHARMACOLOGY II
[MPT 2081]
NAME – SHUVAM SAR
ROLL NUMBER – 19320219008
MOBILE NUMBER - +918478098881
EMAIL ID – itzshuvam@gmail.com

2. Abstract – Whenever virus invades the human body, the host cells and surrounding tissue cells
get activated to induce inflammatory response which is part of the innate immune responses, in
the aim of eradicating the viral progenies and kill the infected cells. Several mediators, involved
in this defensive reaction, include – cytokines, chemokines, macrophages, MIP-1α and others.
These are functional using different receptors found on the surface of infected cells and local
cells.
Keywords – Host cell, inflammatory response, innate immune response, viral progenies, MIP-
1α
Report – Following viral infection at the earliest stage, cytokines are produced after activation
of innate immune defense and released at the infection site, consequently initiates inflammatory
response as defense mechanism of body.
1. One of the earliest cytokines, TNF-α (Tumor Necrosis Factor- α), synthesized by
activated monocytes & macrophages, changes nearby capillaries so that circulating
leukocytes can reach the site of infection. TNF-α may also bind to receptors on infected
cells and induce antiviral response. Seconds after, a series of signals is initiated, leading
to cell death, to prevent the spread of infection. TNF- α is largely responsible for
inflammatory response.
2. The inflammatory response to viral infections is principally composed of mononuclear
cells. Inflammatory infiltrates consist of T lymphocytes of the helper/delayed-type
hypersensitivity (Lyt-1) and cytotoxic/suppressor (Lyt-2) phenotypes, B lymphocytes at
various stages of differentiation, natural killer (NK) cells, and monocyte/macrophages.
Mononuclear phagocytes are attracted to the infected area by cytokines.
3. Neutrophils are among the earliest types of phagocytic cells that enter a site of infection,
and are important markers of the inflammatory response. The infected cells, dendritic
cells and macrophages altogether produce cytokines which modify the response to
infection and also modulate the adaptive responses.
4. One of the critical components of inflammatory response is ‘inflammasome’, which
possesses very large cytoplasmic structure with pattern receptors and signaling initiators,
e.g. MDA 5 (melanoma differentiation-associated protein 5) & RIG-1 (retinoic acid-
inducible gene I). Recent findings state that inflammasome is critical in innate immune

3. response to influenza virus infection, and in moderating lung pathology in influenza
pneumonia.
5. Macrophage inflammatory protein-1α (MIP-1α), a chemokine, having pro-inflammatory
and stem cell inhibitory activities in vitro, has been found to be an important mediator of
virus-induced inflammation in vivo.
6. Lung airway epithelial cells and mucosal immune cells are the primary cells for
respiratory viruses. Following infection, these cells generate some mediators like- type I
interferon (IFN), proinflammatory cytokines, and chemokines which determine the
development of inflammation and disease.
Conclusion - Cytokines function locally by binding receptors on other cells. IFN produced by
infected cells attach receptors on neighboring cells. Those cells then produce hundreds of cellular
proteins which have antiviral activities. Still other mediators and their functions are being studied
to establish.