The classical and lectin pathways of complement activation converge at the step of C3 activation. However, the initiating steps of each pathway use protein components and enzymatic mechanisms that share no similarity with each other.

Defects in C3 activation leads to impaired tagging of pathogens.

The C3 convertase of the alternative complement pathway amplifies the overall magnitude of complement activation regardless of which of the three pathways initiated the complement activation initially.  

Innate lymphoid cells (ILCs) are effector cells that generally reside in barrier tissues, such as the skin, the gut, and the lung. These cells closely resemble subsets of T lymphocytes, but lack a T cell antigen-receptor. Instead, these cells produce their effector molecules following stimulation by:

The alternative pathway of complement activation has an important role in innate immunity, due to its ability to greatly amplify the amount of C3b deposited onto the pathogen surface. This amplification occurs because:

Which complement component is common to both alternate and classical pathways?

Systemic TNF-α causes which of the following?

C5b6789 is the membrane attack complex when complement is activated

Multiple choice: Epithelial surfaces provide the first line of defense against infection by the use of several types of mechanisms. One of the chemical mechanisms used by epithelia is

A transplant patient began to show signs of rejection 8 days after receipt of a transplanted organ. What immune elements might be found in the rejected organ?