What makes altruism enhance immune function?

According to Dr. Candace B. Pert "Having loving relationships is how we evolved. The people who didn't have the mechanisms for this died out millions of years ago, but we have them, and it puts us in the right frame of bodymind for healing and survival to occur. E. O. Wilson, the famous biologist, actually talked about how there had to be a biological basis for altruism, or it wouldn't continue to exist. The people who have survived today are the people who have these things. If you deny this and go against the natural way our bodyminds are wired, you may get away with it for a little while. We do have the power to subvert what is going on in our bodies, to be in our heads, and not be loving or connected, but it has a cost. Eventually, our natural chemicals, our molecules of emotion, become suppressed and don't go where they should go, and I think that is what truly leads to diseased states.”