Innate immune response to viral and bacterial infections are different. One similarity is that pathogen derived antigens are presented to the innate immune system to induce adaptive immune response. 1- 1- Viruses hijack a cells production factories to create their own components, describe a mechanism by which the cell uses a cytokine to decrease the viral production in the tissue. 2- 2- Describe how antigen presentation differs in viral vs bacterial infections. Hint: phagocytosis, APC, infected cell, histo 3- 3- How are viral infected cells killed

(1)Cytokins are signalling molecules which are freed by the infected viral cells that brings about the nearby cells to increase their antiviral defences.

(2)Since viruses are intra-cellular pathogens, the antigen noticed there is by the process of the endogenous pathway, n this pathway the virus proteins are reduced into fragment peptide and there present with MHC classl molecules to the CD8 T cells.

(3) Once virus enters into a cell, it takes on the host replicative machinery to producing its proteins. Some of theses viral proteins are degraded into peptide fragments which are present along with class1 MHC molecules which therefore are recognized by the CD8 T cells.

Explanation:

Solution

(1) The production of interferons refers to a process in which a cell uses a cytokine to reduce the production of viral in a tissue which is a part of a group large of proteins called cytokines,

Cytokins are signalling molecules which are freed by the infected viral cells that brings about the nearby cells to increase their antiviral defences. They are called so because of their ability to intervene with viral proliferation.

(2)Because viruses are intracellular pathogens, the antigen present is by means of the endogenous pathway.

In this pathway the virus proteins are reduced into fragment peptide and there along with MHC classl molecules to the CD8 T cells.

However, Bacteria are centralized by the cells into endocytic vesicles which combine with the lysosomes causes antigenic peptides. These peptides are available along with MHC ClassII molecules to the CD4 T cells

(3) Just as the virus enters into a cell, it takes on the host replicative machinery to manufactures its proteins. Some of theses viral proteins are reduced into peptide fragments which are there along with class1 MHC molecules which therefore are recognised by the CD8 T cells. This guides to the differentiation and activation of CD8 T cells to CD8+ T cells which produce apoptosis of the virus infected cells by the release of cytotoxic granules containing perforins,granzymes, and cytokines such as interferons and TNF