Non-Classical MHC I and the Role of HLA Proteins

The role of HLA proteins is to present 'peptide antigens' to the immune system, enabling recognition of non-self antigens and development of immune responses.

MHC-I proteins are expressed ubiquitously on all nucleated cells in the body for the presentation of intracellular self/non-self antigens.

Classical MHC-I proteins are split into HLA-A, HLA-B, and HLA-C subtypes.

<p>Non-classical MHC-I molecules are less polymorphic, expressed at lower levels, and have a more limited tissue distribution compared to classical MHC-I molecules.</p> Signup and view all the answers

<p>HLA-G belongs to the HLA nonclassical class I heavy chain paralogues.</p> Signup and view all the answers

<p>Seven different isoforms of HLA-G are encoded by the same primary mRNA through alternative splicing.</p> Signup and view all the answers

<p>HLA-G1, HLA-G2, HLA-G3, HLA-G4</p> Signup and view all the answers

<p>HLA-G5, HLA-G6, HLA-G7</p> Signup and view all the answers

<p>NK cells, T-cells, antigen presenting cells (APC)</p> Signup and view all the answers

<p>To avoid the lysis of semiallogeneic fetal tissue by maternal NK cells.</p> Signup and view all the answers

<p>From the rejection by the host’s immune system.</p> Signup and view all the answers

<p>It provides them with an immune escape mechanism, avoiding recognition and lysis by immune effectors such as NK cells and cytotoxic T lymphocytes.</p> Signup and view all the answers

<p>The presentation of self-peptides to NK cells, monitoring global HLA-I expression in the immune system.</p> Signup and view all the answers

<p>Presence of peptides.</p> Signup and view all the answers

<p>CD94NKG2A (inhibitory) and CD94-NKG2C (activating)</p> Signup and view all the answers

<p>Peptides derived from signal peptides of MHC class I molecules, namely HLA-A, B, C, G</p> Signup and view all the answers