Comparison of Influenza and SIV Specific CD8 T Cell Responses in Macaques

Abstract

Macaques are a potentially useful non-human primate model to compare memory T-cell immunity to acute virus pathogens such as influenza virus and effector T-cell responses to chronic viral pathogens such as SIV. However, immunological reagents to study influenza CD8+ T-cell responses in the macaque model are limited. We recently developed an influenza-SIV vaccination model of pigtail macaques (Macaca nemestrina) and used this to study both influenza-specific and SIV-specific CD8+ T-cells in 39 pigtail macaques expressing the common Mane-A*10+ (Mane-A01*084) MHC-I allele. To perform comparative studies between influenza and SIV responses a common influenza nucleoprotein-specific CD8+ T-cell response was mapped to a minimal epitope (termed RA9), MHC-restricted to Mane-A*10 and an MHC tetramer developed to study this response. Influenza-specific memory CD8+ T-cell response maintained a highly functional profile in terms of multitude of effector molecule expression (CD107a, IFN-γ, TNF-α, MIP-1β and IL-2) and showed high avidity even in the setting of SIV infection. In contrast, within weeks following active SIV infection, SIV-specific CD8+ effector T-cells expressed fewer cytokines/degranulation markers and had a lower avidity compared to influenza specific CD8+ T-cells. Further, the influenza specific memory CD8 T-cell response retained stable expression of the exhaustion marker programmed death-marker-1 (PD-1) and co-stimulatory molecule CD28 following infection with SIV. This contrasted with the effector SIV-specific CD8+ T-cells following SIV infection which expressed significantly higher amounts of PD-1 and lower amounts of CD28. Our results suggest that strategies to maintain a more functional CD8+ T-cell response, profile may assist in controlling HIV disease.

Cross-Reactive Influenza-Specific Antibody-Dependent Cellular Cytotoxicity Antibodies in the Absence of Neutralizing Antibodies

“…Because most human adults have Abs to one or more strains of influenza virus following natural infection, we used plasma from four pigtail influenza-naive macaques (M. nemestrina) as negative controls. We recently showed that 3-to 5-y-old pigtail macaques are seronegative to influenza but seroconvert following experimental infection with influenza (25). As expected, plasma from naive macaques did not contain Abs capable of binding the X-31 HA protein (median OD of 0.0885, significantly less than median OD 1.5745 of the human subjects, p = 0.005; Fig.…”

“…Three of the macaques studied were subsequently infected with PR8 [A/Puerto Rico/8/1934 (H1N1)], followed by X-31 [A/Aichi/2/1968 (H3N2)] influenza viruses 4 wk apart (10 8 PFU via the respiratory tract). All three macaques became infected with both influenza viruses, as assessed by recovery of influenza RNA from respiratory tract samples and seroconversion, as previously described (25).…”

Antibody-Dependent Cellular Cytotoxicity Is Associated with Control of Pandemic H1N1 Influenza Virus Infection of Macaques

“…Prior to any procedure, animals were anesthetized intramuscularly with ketamine or ketamine-medetomidine. Animals were inoculated with a total of 9 ϫ 10 6 PFU of virus via the trachea, tonsils, and conjunctivae as described previously (17,42,45). Virus titers in nasal and tracheal secretions and bronchoalveolar lavage (BAL) fluid were determined using standard plaque assays.…”

“…Although murine models have been valuable for dissecting NAb and T cell immunity, the ability of influenza virus to induce ADCC in mice remains relatively undefined. The macaque model of influenza virus infection has recently gained popularity, as most human strains of influenza virus readily infect macaques, a large number of nonhuman primate reagents are being established, and macaques show similar pathology and immune responses to influenza virus to those seen in humans (17,(40)(41)(42). Therefore, the use of the macaque influenza model allowed us to dissect the induction and protective capacity of influenza virus-specific ADCC.…”

Linking Pig-Tailed Macaque Major Histocompatibility Complex Class I Haplotypes and Cytotoxic T Lymphocyte Escape Mutations in Simian Immunodeficiency Virus Infection

“…To identify that CD8 T cells specific for particular Mamu-B017 epitopes could be recovered from Mane-B017 macaques and identified using Mamu-B*017:01 tetramers, frozen PBMCs were thawed and washed in RPMI (Life Technologies, USA) supplemented with 10% fetal calf serum (DKSH, Australia) and expanded as previously described (38). Briefly, PBMCs were split into stimulators and responders at a 1:2 ratio.…”