title: On the role of the inhibitory receptor LAG-3 in acute and chronic LCMV infection.
abstract: Chronic viral infections are often characterized by CD8 T-cell responses with poor cytokine secretion potential and limited expansion of the CD8 T-cell pool, collectively referred to as CD8 T-cell exhaustion. Exhaustion of lymphocytic choriomeningitis virus (LCMV)-specific CD8 T cells was shown to be partially regulated by the inhibitory receptor programmed death 1 (PD-1). Here, we demonstrate that exhausted LCMV-specific CD8 T cells also express the negative regulatory receptor lymphocyte activation gene 3 (LAG-3) which is mainly expressed on cells co-expressing the negative regulatory receptors PD-1 and Tim-3. Expression levels of LAG-3 on anti-viral CD8 T cells remain stable over short-term in vitro stimulations in presence of antigenic peptide. Nevertheless, in vitro and in vivo blockade of LAG-3 did not rescue cytokine production by virus-specific CD8 T cells and did not alter the virus titer in various organs. Likewise, chronic LCMV infection of LAG-3-/- mice led to a comparable degree of T-cell exhaustion as observed in C57BL/6 controls and to similar virus titers. Further, LAG-3 did not influence T-cell activation or cell division during chronic LCMV infection. These data suggest that even though LAG-3 is continuously up-regulated on LCMV-specific exhausted CD8 T cells, it alone does not significantly contribute to T-cell exhaustion.
authors.affiliation: Institute of Microbiology, Department of Biology, Wolfgang-Pauli-Strasse 10, HCI G401, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Richter
authors.forename: Paola
authors.initials: P
authors.lastname: Agnellini
authors.forename: Annette
authors.initials: A
authors.lastname: Oxenius
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D000954:Antigens, Surface / Q000276:immunology / Q000378:metabolism; D051017:Apoptosis Regulatory Proteins / Q000276:immunology / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D049109:Cell Proliferation; D002478:Cells, Cultured; D000072597:Hepatitis A Virus Cellular Receptor 2; D008213:Lymphocyte Activation / Q000235:genetics; D008216:Lymphocytic Choriomeningitis / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology* / Q000472:pathogenicity; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D061026:Programmed Cell Death 1 Receptor; D011991:Receptors, Virus / Q000378:metabolism; D019562:Viral Load / Q000235:genetics; D014774:Virulence; D000093322:Lymphocyte Activation Gene 3 Protein
chemical_list: D015703:Antigens, CD; D000954:Antigens, Surface; D051017:Apoptosis Regulatory Proteins; C442241:Havcr2 protein, mouse; D000072597:Hepatitis A Virus Cellular Receptor 2; C491383:Pdcd1 protein, mouse; D061026:Programmed Cell Death 1 Receptor; D011991:Receptors, Virus; D000093322:Lymphocyte Activation Gene 3 Protein