High affinity anti-TIM-3 and anti-KIR monoclonal antibodies cloned from healthy human individuals

PLoS One. 2017 Jul 19;12(7):e0181464. doi: 10.1371/journal.pone.0181464. eCollection 2017.

Abstract

We report here the cloning of native high affinity anti-TIM-3 and anti-KIR IgG monoclonal antibodies (mAbs) from peripheral blood mononuclear cells (PBMC) of healthy human donors. The cells that express these mAbs are rare, present at a frequency of less than one per 105 memory B-cells. Using our proprietary multiplexed screening and cloning technology CellSpot™ we assessed the presence of memory B-cells reactive to foreign and endogenous disease-associated antigens within the same individual. When comparing the frequencies of antigen-specific memory B-cells analyzed in over 20 screening campaigns, we found a strong correlation of the presence of anti-TIM-3 memory B-cells with memory B-cells expressing mAbs against three disease-associated antigens: (i) bacterial DNABII proteins that are a marker for Gram negative and Gram positive bacterial infections, (ii) hemagglutinin (HA) of influenza virus and (iii) the extracellular domain of anaplastic lymphoma kinase (ALK). One of the native anti-KIR mAbs has similar characteristics as lirilumab, an anti-KIR mAb derived from immunization of humanized transgenic mice that is in ongoing clinical trials. It is interesting to speculate that these native anti-TIM-3 and anti-KIR antibodies may function as natural regulatory antibodies, analogous to the pharmacological use in cancer treatment of engineered antibodies against the same targets. Further characterization studies are needed to define the mechanisms through which these native antibodies may function in healthy and disease conditions.

MeSH terms

  • Antibodies, Monoclonal / immunology*
  • Antibody Specificity
  • Hepatitis A Virus Cellular Receptor 2 / immunology*
  • Humans
  • Leukocytes, Mononuclear / immunology*
  • Receptors, KIR / immunology*

Substances

  • Antibodies, Monoclonal
  • HAVCR2 protein, human
  • Hepatitis A Virus Cellular Receptor 2
  • Receptors, KIR

Grants and funding

This research was funded by Trellis Bioscience, LLC. The funder provided support in the form of salaries for authors [SR, AE, ET, LK, MG], but did not have any additional role in the study design, data collection and analysis or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.