Viewing a single comment thread. View all comments

CrateDane t1_j48lc5y wrote

Reply to comment by Minute_Farmer in Is there physical differences between blood types? by terrip_t1

> > > > > The reason it's important to know this is because your body recognizes your cells by recognizing the cell surface antigens on your cells.

Well, mostly they don't recognize your own cells, they recognize anything foreign.

There are a few exceptions like NK cells recognizing MHC I from your own cells. But that's not involved here.

1

DisneyDee67 t1_j4at7tm wrote

That is absolutely wrong. The immune system HAS to recognize self in order to attack the non-self. It does so mostly through two self-identification molecules (Human leukocyte antigens [HLA], and the major histocompatibility complex [MHC]). When the immune system doesn’t recognize the body’s own cells you get autoimmune diseases.

1

CrateDane t1_j4atysl wrote

We're also talking about humoral immunity, which relies on antibodies. There is no self recognition involved there. As for cell-mediated immunity, it's true that the self MHC is part of what's required for recognition, but MHC alone is not sufficient - you need the foreign antigen loaded into the self MHC for recognition.

As for MHC and HLA, they are not two different molecules. MHCs are HLAs.

4