Hybridomas to Specific Streptococcal Antigen Induce Tissue Pathology in Vivo; Autoimmune Mechanisms for Post-Streptococcal Sequelae

Abstract

A gross examination of organs from approximately 100 mice which were producing ascites fluids toward a series of streptococcal reactive monoclonal hybridomas showed, in some animals, what appeared to be autommune-like findings. A pattern of major lung pathology was associated with specific clones. These specific hybridomas led to the development of an experimental autoimmune animal model mimicking a Goodasture's syndrome. Tissue injury was induced in mice, on a dose dependent basis, by the injection of monoclonal antibody generated against streptococcal cell membrane (SCM) antigens. A more severe onset of the pathology, also on a dose dependent bases, was induced by placement of the anti-SCM mAb secreting hybridoma cells into the peritoneal cavity of the host. Severity of observed lesions was dependent upon the number of cells injected (10⁵, 5×10⁵, 10⁶ or 10⁷), as well as the animals' sex. Severe and total hemorrhagic lungs were seen in animals challenged with 1×10⁶ hybridoma cells when sacrificed on the tenth day. In all cases the lesions were greater in the female litter mate than the male. Gross and histologic observations were confirmed by lung/body weight ratios. Pulmonary hemorrhage ranged from slight, when mAb was injected at a low dose of 24 μg/g, to severe when 96 μg/g was injected. Reported findings were based on the review of approximately 300 mice. Immunochemical evaluations and ELISAs confirmed the ability of these anti-SCM mAb to react with glomerular basement membrane (GBM) antigens as well as lung basement membrane (LBM). Mitogenic experiments indicated that the parent immunogen (SCM) used to generate immunocytes was non-stimulatory to lymphocytes.

Key Words:

• Hybridomas
• autoantibody
• post-streptococcal
• Goodpasture's syndrome
• basement membranes
• lung hemorrhage