Cytokines are secreted in sepsis and Systemic Inflammatory Response syndrome (SIRS) by -
Neutrophils
Adrenal
Platelets
Collecting duct
Cytokine release in Sepsis 

The mechanism by which endotoxin causes activation of inflammatory cells and release of cytokines has already been explained earlier.
It is by TL -4 and CD-14 mediated.
Signals from TLR-4 can directly activate vascular endotheliun and leukocytes to release cytokine mediators.
The major cells that secrete cytokines in sepsis area


Monocyte/Macrophages       
Neutrophils                    
Endothelial cells


Cytokine mediators involved are:-


TNF - (The most important cytokine in sepsis)               
IL-1                    
IL-6       
IL-8               
NO.