Interesting, I hadn't heard about that theory of HIV transmission. Do you think that having appropriate IgA secretions in the female genital tract might decrease initial infections?
1) I think what is understood about the immune system is really, really over-exaggerated. One specific thing is that a lot of studies regarding antibodies may be messed up by the presence of natively unfolded proteins (which will react with any antibody raised towards beta-sheets and give inaccurate mass estimates on western blot). Every anti-body is promiscuous, it just matters how much.
2) Notice I have no quantification or numbers associated with these ideas. As far as I know, no one has ever spent the time to work this out into a real model that can make precise predictions. Accordingly, consider them wild speculations.
3) According to this sketch of an idea, anything that contributes to identifying and lysing non-self cells should reduce transmission in a given tissue.
