Immune-aging is linked to clinical malignancy, racial ancestry, and vaccine responses in myeloma

Myeloma and its precursor, monoclonal gammopathy (MGUS), are more common in individuals with Black ancestry and are associated with immune dysfunction. 1T cells in patients with multiple myeloma (MM) express inhibitory immune checkpoints and were previously implicated to be exhausted, extrapolating from models of chronic viral infection. 2However, functional validation in single-cell transcriptomic/immunophenotypic studies is limited, and the clinical success of T-cell engagers in MM argues against global T-cell exhaustion. 3,4 understand the functional properties of immune cells in patients with plasma cell disorders, we combined functional assays with immune profiling in biospecimens from MGUS, newly diagnosed MM (NDMM), and age-matched healthy controls (patient characteristics in supplemental Table 1; see "Methods" in the supplemental Appendix).The capacity of T cells from blood/marrow to produce cytokines (interferon gamma [IFN-], tumor necrosis factor [TNF-], interleukin-2 [IL-2], granulocytemacrophage colony-stimulating factor [GM-CSF], and IL-17) was analyzed by mass cytometry after stimulation by anti-CD3/CD2/CD28 antibodies.CD4 and CD8 + T cells from patients with NDMM/ MGUS in both blood and bone marrow retained the capacity to produce all tested cytokines (Figure 1A-B; supplemental Figure 1).T cells in MM marrow exhibited higher production of several inflammatory cytokines (GM-CSF, IL-17, and TNF- for CD4; and IL-2, TNF-, and IL-17 for CD8) than MGUS counterparts (Figure 1A-B).Flow cytometry self-organizing map analysis of CD4 T cells identified 3 metaclusters (MCs) enriched in MM marrow: MC2 with CD57 + memory T cells; and 2 cytokineproducing MCs, MC10, which expressed GM-CSF, and MC8 with a polyfunctional phenotype, secreting IL-2, IFN-, IL-17, and TNF-, which also expressed markers such as programmed cell death protein-1, lymphocyte activation gene-3, and T cell immunoreceptor with Ig and ITIM domains, previously linked to T-cell exhaustion (Figure 1C-D).Similar analysis of CD8 T cells identified 3 MCs as enriched in MM marrow, of which MC4 and MC6 had a terminal effector memory RA+ phenotype, whereas MC5 exhibited a polyfunctional phenotype, including IL-17 (Figure 1E-F).Most of the TNF-and IFN--producing CD8 T cells in MM marrow had a terminal effector phenotype, and KLRG1 + differentiated T cells maintained the capacity for cytokine production (supplemental Figure 2).Both circulating and bone marrow T cells from patients with MGUS/MM also exhibited the capacity for T-cell proliferation in culture, again supporting the lack of global T-cell exhaustion (Figure 1G-H).Together, these data demonstrate that T cells in the MM marrow are enriched for phenotypes of advanced differentiation and exhibit distinct functional phenotypes, such as GM-CSF 5 and IL-17 producers, 6 previously implicated in tissue inflammation or bone disease.Because the functional studies discussed above did not support the global T-cell exhaustion often implicated in cancer, we hypothesized that immunophenotypic changes, such as an increase in terminal