Human-human hybrids secreting pneumococcal antibodies

Area of Science:

• Immunology
• Cell Biology
• Biotechnology

Background:

• Nonimmunoglobulin producing human myeloma cell lines limit research into antibody synthesis.
• Developing hybridomas capable of producing specific human antibodies is crucial for therapeutic and diagnostic applications.

Purpose of the Study:

• To construct a human myeloma cell line analog (LSM 2.7) capable of supporting immunoglobulin synthesis and secretion.
• To generate hybrid cells that produce specific human antibodies against pneumococcal capsular polysaccharides.
• To investigate the stability and potential reactivation of antibody secretion in hybridoma cells.

Main Methods:

• Fusion of the nonimmunoglobulin producing human myeloma cell line (LSM 2.7) with human peripheral blood and spleen mononuclear cells.
• Utilizing spleen cells from patients immunized with pneumococcal capsular polysaccharides.
• Employing HAT selection to isolate hybridoma cells.
• Monitoring immunoglobulin and specific antibody production in vitro.
• Assessing the stability and reactivation of antibody secretion.

Main Results:

• The LSM 2.7 cell line successfully supported the synthesis and secretion of human immunoglobulin upon fusion.
• Hybridomas derived from fusions with spleen cells of immunized patients consistently produced human immunoglobulin.
• Three out of ten independent fusions yielded hybrid cultures producing specific pneumococcal antibodies.
• Antibody secretion by hybrid cells ceased between 28 to 42 days post-fusion.
• Reactivation of specific antibody secretion was achieved by fusing a HAT-sensitive clone with peripheral blood mononuclear cells.

Conclusions:

• The constructed human myeloma analog (LSM 2.7) is a viable tool for generating human hybridomas that synthesize and secrete immunoglobulin.
• This system effectively produces specific human antibodies, particularly when using spleen cells from recently immunized individuals.
• The findings suggest that while antibody secretion is transient, it can be potentially reactivated, opening avenues for further research in hybridoma technology.