Immunologic Interactions Between Host Cells and Mycoplasmas: An Introduction

In addition to eliciting host immune responses, many mycoplasmas interact nonspecifically with host cells. Early reports revealed peculiar inhibitory and stimulatory effects of mycoplasmas on the immune response in vivo; several investigators have now clearly defined nonspecific stimulation of B and T lymphocytes and also a nonspecific immunosuppressive effect in experimental animals and humans. These interactions relate to attachment of mycoplasmas to host cell membranes and perhaps involve sharing of membrane components. The implications of these peculiar effects of mycoplasmas on host cells suggest that much of the disease seen in the infected host is due to a nonspecific, inflammatory response to the mitogenic properties of the organism. Since the organism becomes intimately involved with the host cell membrane, this could enable the organism to evade the immunologic surveillance system and thus achieve the prolonged surface colonization characteristic of many mycoplasmas.