Our laboratory aims at understanding the unexpected roles of complement in the regulation of key basic processes of the cell in health and disease.
Complement is generally well appreciated as a serum-effective system and critical arm of innate immunity required for the detection and removal of invading pathogens. Recent work from Dr. Kemper's lab, however, has highlighted an equally profound impact of complement on adaptive immunity through direct regulation of CD4+ T cells: signals mediated by T cell-expressed anaphylatoxin receptor C3aR and the complement regulator CD46 (which binds the complement activation fragment C3b) are critical checkpoints in human T cell lineage commitment and control initiation and resolution of inflammatory Th1 responses. Further, they have discovered that activation of the key complement components C3 and C5 is not confined to the extracellular space but occurs intracellulary (the ‘Complosome’) and that intracellular C3 and C5 activation fundamentally dictates the magnitude of Th1-mediated inflammation. Consequently, lack of autocrine complement activation by T cells results in deficient Th1 responses and recurrent infections, while uncontrolled intracellular C3 and/or C5 activation contributes to hyperactive Th1 responses observed in autoimmunity (rheumatoid arthritis, CAPS) and can be normalised pharmacologically by inhibiting intracellular complement activity.
Likely the most exciting recent development in their work is the observation that intracellular C3 and C5 are critical for the homeostatic survival of T cells (through intracellular tonic C3aR activation) and for metabolic reprogramming during cell activation via CD46-driven induction of nutrient influx, mTORC1 assembly and glycolysis and oxidative phosphorylation, and C5-mediated increases in oxygen metabolism. Importantly, although intially discovered in T cells, these Complosome-regulated pathways seem to operate in a broad range of cells.
Thus, complement plays unexpectedly a fundamental role in basic processes of the cell and understanding these novel functions will deliver critical new knowledge about cell biology in health and disease.
The central goal of Dr. Kemper's research programme is therefore to define the functional roles and regulative mechanisms of intracellular/autocrine complement and assess their biological relevance with an eye on delivering druggable targets in these pathways to therapeutically intervene in (autoimmune) diseases. To achieve this overarching goal, Dr. Kemper's lab are currently focusing on three key questions:
1. What is the composition of the Complosome in different cells?
2. What are the functions of the Complosome?
3. How is the Complosome regulated?
They utilize immune/tissue cells from healthy donors, from patients with complement deficiencies, from patients with T cell-driven autoimmune disease and from patients with deviations in novel ‘complosome’-regulated pathways for gene and miRNA arrays, epigenetic landscape evaluation, and proteomic and metabolomic assessments. This unbiased approach driven by human genetics and robust experimental in vitro systems will be combined with appropriate small animal (mouse) in vivo models to define biological significance of proteins/pathways discovered and to develop preclinical animal models for future pharmacological targeting.
Dr. Claudia Kemper obtained her PhD from the Bernhard-Nocht-Institute for Tropical Medicine, University of Hamburg, Germany in 1998. She performed her postdoctoral fellowship in the laboratory of John Atkinson at Washington University School of Medicine in Saint Louis and became a faculty member of Washington University as an Instructor in Medicine and then Research Assistant Professor in 2004/2006. In 2008, Dr. Kemper joined the MRC Centre for Transplantation at King’s College London as a Senior Lecturer and was promoted to Reader in 2012 and full Professor in 2015. In 2017, she joined the Immunology Center at the NHLBI as a tenured Senior Investigator.
Dr. Kemper remains a Visiting Professor at King's College London as also serves as an Adjunct Professor for the University of Lübeck in Germany.
- Kolev M, West EE, Kunz N, Chauss D, Moseman EA, Rahman J, Freiwald T, Balmer ML, Lötscher J, Dimeloe S, Rosser EC, Wedderburn LR, Mayer-Barber KD, Bohrer A, Lavender P, Cope A, Wang L, Kaplan MJ, Moutsopoulos NM, McGavern D, Holland SM, Hess C, Kazemian M, Afzali B, Kemper C. Diapedesis-Induced Integrin Signaling via LFA-1 Facilitates Tissue Immunity by Inducing Intrinsic Complement C3 Expression in Immune Cells. Immunity. 2020;52(3):513-527.e8.
- Arbore G, West EE, Spolski R, Robertson AAB, Klos A, Rheinheimer C, Dutow P, Woodruff TM, Yu ZX, O'Neill LA, Coll RC, Sher A, Leonard WJ, Köhl J, Monk P, Cooper MA, Arno M, Afzali B, Lachmann HJ, Cope AP, Mayer-Barber KD, Kemper C. T helper 1 immunity requires complement-driven NLRP3 inflammasome activity in CD4⁺ T cells. Science. 2016;352(6292):aad1210.
- West EE, Merle NS, Kamiński MM, Palacios G, Kumar D, Wang L, Bibby JA, Overdahl K, Jarmusch AK, Freeley S, Lee DY, Thompson JW, Yu ZX, Taylor N, Sitbon M, Green DR, Bohrer A, Mayer-Barber KD, Afzali B, Kazemian M, Scholl-Buergi S, Karall D, Huemer M, Kemper C. Loss of CD4(+) T cell-intrinsic arginase 1 accelerates Th1 response kinetics and reduces lung pathology during influenza infection. Immunity. 2023.
- West EE, Kolev M, Kemper C. Complement and the Regulation of T Cell Responses. Annu Rev Immunol. 2018;36:309-338.
- Yan B, Freiwald T, Chauss D, Wang L, West E, Mirabelli C, Zhang CJ, Nichols EM, Malik N, Gregory R, Bantscheff M, Ghidelli-Disse S, Kolev M, Frum T, Spence JR, Sexton JZ, Alysandratos KD, Kotton DN, Pittaluga S, Bibby J, Niyonzima N, Olson MR, Kordasti S, Portilla D, Wobus CE, Laurence A, Lionakis MS, Kemper C, Afzali B, Kazemian M. SARS-CoV-2 drives JAK1/2-dependent local complement hyperactivation. Sci Immunol. 2021;6(58).
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Molecular Biology and Biochemistry
This page was last updated on Saturday, August 26, 2023