TY - JOUR
T1 - Features and protective efficacy of human monoclonal antibodies targeting Mycobacterium tuberculosis arabinomannan
AU - Liu, Yanyan
AU - Chen, Tingting
AU - Zhu, Yongqi
AU - Furey, Aisha
AU - Lowary, Todd L.
AU - Chan, John
AU - Bournazos, Stylianos
AU - Ravetch, Jeffrey V.
AU - Achkar, Jacqueline M.
N1 - Publisher Copyright:
© 2023 American Society for Clinical Investigation. All rights reserved.
PY - 2023
Y1 - 2023
N2 - A better understanding of the epitopes most relevant for antibody-mediated protection against tuberculosis (TB) remains a major knowledge gap. We have shown that human polyclonal IgG to the Mycobacterium tuberculosis (Mtb) surface glycan arabinomannan (AM) and related lipoarabinomannan (LAM) is protective against TB. To investigate the impact of AM epitope recognition and Fc-gamma receptor (FcgR)-binding on antibody functions against Mtb, we isolated a high-affinity human monoclonal antibody (mAb; P1AM25) to AM and show its binding to oligosaccharide (OS) motifs we previously found to be associated with in vitro functions of human polyclonal anti-AM IgG. Human IgG1 P1AM25, but not two other high-affinity human IgG1 anti-AM mAbs reactive with different AM OS motifs, enhanced Mtb phagocytosis by macrophages and reduced intracellular growth in an FcgR-dependent manner. P1AM25 in murine IgG2a, but neither murine IgG1 nor a non-FcgR-binding IgG, given intraperitoneally prior to and after aerosolized Mtb infection was protective in C57BL/6 mice. Moreover, we demonstrate the protective efficacy of human IgG1 P1AM25 in passive transfer with Mtb-infected FcgR-humanized mice. These data enhance our knowledge of the important interplay between both antibody epitope specificity and Fc effector functions in the defense against Mtb and could inform development strategies of vaccines against TB.
AB - A better understanding of the epitopes most relevant for antibody-mediated protection against tuberculosis (TB) remains a major knowledge gap. We have shown that human polyclonal IgG to the Mycobacterium tuberculosis (Mtb) surface glycan arabinomannan (AM) and related lipoarabinomannan (LAM) is protective against TB. To investigate the impact of AM epitope recognition and Fc-gamma receptor (FcgR)-binding on antibody functions against Mtb, we isolated a high-affinity human monoclonal antibody (mAb; P1AM25) to AM and show its binding to oligosaccharide (OS) motifs we previously found to be associated with in vitro functions of human polyclonal anti-AM IgG. Human IgG1 P1AM25, but not two other high-affinity human IgG1 anti-AM mAbs reactive with different AM OS motifs, enhanced Mtb phagocytosis by macrophages and reduced intracellular growth in an FcgR-dependent manner. P1AM25 in murine IgG2a, but neither murine IgG1 nor a non-FcgR-binding IgG, given intraperitoneally prior to and after aerosolized Mtb infection was protective in C57BL/6 mice. Moreover, we demonstrate the protective efficacy of human IgG1 P1AM25 in passive transfer with Mtb-infected FcgR-humanized mice. These data enhance our knowledge of the important interplay between both antibody epitope specificity and Fc effector functions in the defense against Mtb and could inform development strategies of vaccines against TB.
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U2 - 10.1172/jci.insight.167960
DO - 10.1172/jci.insight.167960
M3 - Article
C2 - 37733444
AN - SCOPUS:85173177667
SN - 2379-3708
VL - 8
JO - JCI Insight
JF - JCI Insight
IS - 18
ER -