Introduction: Sepsis is a dysregulated host immune response due to an uncontrolled infection. It is a leading cause of mortality in adult intensive care units globally. When the host immune response induced against a local infection fails to contain it locally, it progresses to sepsis, severe sepsis, septic shock and death.
Method: Literature survey was performed on the roles of different innate and adaptive immune cells in the development and progression of sepsis. Additionally, the effects of septic changes on reprogramming of different immune cells were also summarized to prepare the manuscript.
Findings: Scientific evidences to date suggest that the loss of balance between inflammatory and anti-inflammatory responses results in reprogramming of immune cell activities that lead to irreversible tissue damaging events and multi-organ failure during sepsis. Many surface receptors expressed on immune cells at various stages of sepsis have been suggested as biomarkers for sepsis diagnosis. Various immunomodulatory therapeutics, which could improve the functions of immune cells during sepsis, were shown to restore immunological homeostasis and improve survival in animal models of sepsis.
Conclusion: In-depth and comprehensive knowledge on the immune cell activities and their correlation with severity of sepsis will help clinicians and scientists to design effective immunomodulatory therapeutics for treating sepsis.
Keywords: Host response; Immune cells; Immune dysfunction; Infection; Sepsis; Systemic inflammation.