Coexistence of the mouse mammary tumor virus (MMTV) major glycoprotein and natural antibodies to MMTV in sera of mammary tumor-bearing mice.

Sera of mammary tumor-bearing mice contain the major envelope glycoprotein (gp52) of mouse mammary tumor virus (MMTV) and autogenous antibodies to MMTV. Although antibodies to MMTV are readily demonstrable in sera of both tumor-free and tumorbearing animals, detection of the viral glycoprotein appears to be dependent on the presence of a palpable mammary tumor. MMTV gp52 was detected both as the free protein and in a high molecular weight complex as demonstrated by velocity sedimentation centrifugation. MMTV gp52 was also detected in both mammary tissue and lymph nodes of female C3H/HeN mice. The reproductive organs of the male C3H/HeN mice, such as the vas deferens and vesicular, coagulating, and prostate glands, contained gp52, while no MMTV gp52 could be demonstrated in the testes, epididymis, or preputial glands. This antigen was not found in any tissues of male or female BALB/c mice.