Rickettsia Vaccine Candidate pVAX1-OmpB24 Stimulates TCD4+INF-γ+ and TCD8+INF-γ+ Lymphocytes in Autologous Co-Culture of Human Cells

• Published in: Vaccines (Basel) Vol. 11; no. 1; p. 173
• Main Authors: Dzul-Rosado, Karla, Donis-Maturano, Luis, Arias-León, Juan, Machado-Contreras, Jesús, Valencia-Pacheco, Guillermo, Panti-Balam, Candi, Balam-Romero, Javier, Ku-González, Angela, Peniche-Lara, Gaspar, Mosqueda, Juan, Zazueta, Oscar E., Lugo-Caballero, Cesar, Puerto-Manzano, Fernando
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 13.01.2023; MDPI
• Subjects: activated lymphocytes; Animal models; Antigens; CD40 antigen; CD8 antigen; CD80 antigen; Cell culture; Fever; Flow cytometry; Histocompatibility antigen HLA; Infectious diseases; Lymphocytes; Lymphocytes B; Lymphocytes T; Macrophages; Monocytes; PD-1 protein; pVAX1-OmpB24; Rickettsia; Rickettsia rickettsii; Rickettsiosis; Subpopulations; Vaccination; Vaccines; γ-Interferon; United States > US; Mexico; pVAX1-OmpB24; Rickettsia rickettsii; activated lymphocytes
• ISSN: 2076-393X; 2076-393X
• DOI: 10.3390/vaccines11010173

Background: In recent years, promising vaccination strategies against rickettsiosis have been described in experimental animal models and human cells. OmpB is considered an immunodominant antigen that is recognized by T and B cells. The aim of this study was to identify TCD4+INF-γ+ and TCD8+INF-γ+ lymphocytes in an autologous system with macrophages transfected with the vaccine candidate pVAX1-OmpB24. Lymphocytes and monocytes from 14 patients with Rickettsia were isolated from whole blood. Monocytes were differentiated into macrophages and transfected with the plasmid pVAX1-OmpB24 pVax1. Isolated lymphocytes were cultured with transfected macrophages. IFN-γ-producing TCD4+ and TCD8+ lymphocyte subpopulations were identified by flow cytometry, as was the percentage of macrophages expressing CD40+, CD80+, HLA-I and HLA-II. Also, we analyzed the exhausted condition of the T lymphocyte subpopulation by PD1 expression. Macrophages transfected with pVAX1-OmpB24 stimulated TCD4+INF-γ+ cells in healthy subjects and patients infected with R. typhi. Macrophages stimulated TCD8+INF-γ+ cells in healthy subjects and patients infected with R. rickettsii and R. felis. Cells from healthy donors stimulated with OmpB-24 showed a higher percentage of TCD4+PD1+. Cells from patients infected with R. rickettsii had a higher percentage of TCD8+PD-1+, and for those infected with R. typhi the larger number of cells corresponded to TCD4+PD1+. Human macrophages transfected with pVAX1-OmpB24 activated TCD4+IFN-γ+ and CD8+IFN-γ+ in patients infected with different Rickettsia species. However, PD1 expression played an important role in the inhibition of T lymphocytes with R. felis.