Antibodies, Do they always induce immune responses?

[Kylonicus]

I was wondering whether or not antibodies generally induce immune responses(Not neutralization, but causing the white blood cells to attack), because I have heard that it really isn't the antibodies attaching that causes the immune response, but similarities in the protein sequences on the surface of the cell, that determines whether an immune response occurs.

 

Am I making any sense?

 

Just wanted to know what y'all thought.

[hyebeh]

immune responses are generated when an infected cell displays viral or bacterial antigens on its cell surface via MHC class I molecules, activating cytotoxic T cells, or when antigens directly activate B cells.

 

Also, Helper T Cells can be activated by phagocytotic leukocytes which display the antigens of "eaten" pathogens via MHC class II molecules. Helper T cells then go on to trigger the cell mediated or humoral response by activing cytotoxic T cells or B cells respectively.

[Dak]

IgA antibodies dont elicit an immune responce, as they are desighned purely to stick bacteria together into a 'clump' which cannot cross the mucouse membrane.

 

Also, IgM antibodies, whilst capable of initiating phagocytosis of the attached cell by a macrophage, are mainly focused on catalysing the initial reactions of the compliment system (which doesnt involve WBCs)

 

and as heybeh said, killer-T-cells (AKA cytotoxic-T-cells) operate indipendantly of antibodies, as do natural killer cells.

[Kylonicus]

If this is the case, couldn't we just innoculate someone against the CD4 molecule / T4 receptor to cure HIV?

 

I mean, hypothetically, if it didn't induce an autoimmune response, then the it would block the entrance for the HIV, which would in turn make the cells immune to HIV.

 

That's why I wanted to know, thanks guys.

[Dak]

you mean like this?