Immunological response of rodents to murine mycoplasmas

Mycoplasma arthritidis, M. pulmonis, M. neurolyticum, and M. felis strains administered on various immunization schedules induced complement-fixing and agglutinating antibodies in rats, mice, and guinea pigs. Metabolic inhibiting (MI) antibodies against M. felis were produced by guinea pigs, mice, and rats. M. neurolyticum did not induce MI antibody in mice but induced high titers in guinea pigs and rats. M. pulmonis failed to induce MI antibody titers in mice, induced low titers in rats, and induced high titers in guinea pigs. M. arthritidis induced no or very low titers in rats and low titers in mice, but induced high MI titers in guinea pigs. A positive correlation was demonstrated between ability of the mycoplasma to induce disease and lack of MI antibody formation by its natural host. It is suggested that the apparent inability of the various animals to produce MI antibodies against their natural mycoplasmal parasites may enable the mycoplasmas to become established in their hosts. The concept of biological mimicry is brought forward to explain these observations.