Orthopoxvirus-Specific T-Cell Responses in Convalescent Mpox Patients

Abstract

Orthopoxvirus-specific T-cell responses were analyzed in 10 patients who had recovered from Mpox including 7 people with human immunodeficiency virus (PWH). Eight participants had detectable virus-specific T-cell responses, including a PWH who was not on antiretroviral therapy and a PWH on immunosuppressive therapy. These 2 participants had robust polyfunctional CD4+ T-cell responses to peptides from the 121L vaccinia virus (VACV) protein. T-cells from 4 of 5 HLA-A2-positive participants targeted at least 1 previously described HLA-A2-restricted VACV epitope, including an epitope targeted in 2 participants. These results advance our understanding of immunity in convalescent Mpox patients.

Keywords: Mpox; PWH; T-cells; orthopoxvirus.

Figure 1.

T-cell recognition of orthopoxvirus peptides. T-cell responses to the orthopoxvirus peptide pool (A), and the vaccinia virus 121L subunit 2 peptide pool (B) are shown. Each column represents responses for an individual HD or convalescent MP. Each dot represents an individual replicate. People with HIV are shown in red, and HIV-seronegative patients are shown in blue. MP1, MP2, MP3, MP7, and MP9 were treated with tecovirimat. The dashed line represents the cutoff for a positive response. C, Pie charts showing the proportion of polyfunctional cytokine expression for MP4 and MP9 CD4⁺ T cells. Pie arcs show the proportion making each cytokine as annotated. Abbreviations: HD, healthy donor; HIV, human immunodeficiency virus; IFN-γ, interferon-γ; IL-2, interleukin 2; MP, mpox patient; SFU, spot-forming unit; TNF, tumor necrosis factor.