In contrast, the cluster 2 considered as low immune responders included CPDs displaying no or low T cell immune response (T cell against one SARS-CoV-2 protein) and low or no neutralizing antibody (Figures 3A,B). Open in a separate window ARF3 Figure 3 Correlation between T cell reactions and neutralizing antibody titers. protein such as spike glycoprotein (80.0%), nucleocapsid (NCAP) (70.4%) and membrane protein (VME1) Pemetrexed (Alimta) (74.8%) were detected in CPD by eIFN- and TNF- ELISpot assays. Among CPD responders, most exhibited poly-specific T cell reactions (75%) defined by the ability to mount reactions against at least two SARS-CoV-2 antigens. We found a positive correlation between the magnitude and the poly-specificity of anti-SARS-CoV-2 T cell reactions in CPD. Notably, both the magnitude and poly-specificity of SARS-CoV-2 T cell reactions were highly correlated with neutralizing antibody titer in CPD. The present study highlights the poly-specificity and strength of SARS-CoV-2 specific T cell reactions predicts neutralizing antibody titer following COVID-19. These observations display the interest to combine T cell assays and antibody titer for the selection of CPD and to a second option lengthen to assess COVID-19 vaccine effectiveness in at-risk individuals. 0.05 (* 0.05, ** 0.01, *** 0.001, **** 0.0001). Variables were indicated as median and interquartile range (IQR) or mean (standard deviation) and evaluated with the MannCWhitney test. Rate of recurrence (percentage) was offered for the description of categorical variables. Proportions were compared using the Chi2 test (or Fisher Pemetrexed (Alimta) precise test, if appropriate). Results Convalescent Plasma Donor Cohort CPD’s demographic and medical characteristics are detailed in Table 1. SARS-CoV-2 illness was confirmed by PCR test after nasopharyngeal swab (= 86) or positive serology (= 111). CPD eligible for plasma donation were enrolled at least 32 days (10C60) after resolution of COVID-19. Pemetrexed (Alimta) None of them were hospitalized because of the disease. The median age was 37 years (20C65), and 71 (61.7%) were male. Blood group were respectively O (41.7%) A (36.5%), B (12.2%) and Abdominal (9.6%). Table 1 Characteristics of SARS-CoV-2 convalescent plasma donors. = 115)?Ladies44 (38.3%)?Males71 (61,7%)AgeCmedian (yr) and range (= 115)37 [20C65]? 30 years38 (33.0%)?30C50 years46 (40.0%)? 50 years31 (27.0%)ABO blood group (= 115)?O48 (41.7%)?A42 (36.5%)?B14 (12.2%)?Abdominal11 (9.6%)Time between COVID-19infection and samples (days) (= 56)32 [10C60]? 30 days33 (58.9%)? 30 days23 (41.1%)COVID-19 assay?Positive PCR (= 86)58 (67.4%)?Positive serology (= 111)83 (74.8%) Open in a separate windowpane Poly-Specificity of T Cell Reactions Against SARS-CoV-2 Proteins Is Correlated to the Magnitude of Anti-SARS-CoV-2 T Cell Pemetrexed (Alimta) Reactions To analyze COVID-19 related specific T cell reactions, IFN- or TNF- ELISpot assays were performed to measure effector T cells recognizing viral spike glycoprotein, NCAP and VME1 derived peptides. Anti-SARS-CoV-2 T cell reactions in CPD were distributed into three groups of low (10C20 places), intermediate (21C300 places), and high responders ( 300 places) (Number 1A). The median numbers of IFN-+ specific T cells were 354.5 SFC/3×106 cells [IQR: 203.8C631.3] against spike glycoprotein, 233.0 SFC/3 x 106 cells [IQR: Pemetrexed (Alimta) 101.5C419.0] against NCAP and 323.0 SFC/3 x 106 cells [IQR: 178.3C496.0] against VME1 (Number 1A). As demonstrated in Number 1B, the frequencies of CPD with T cell reactions directed against the SARS-CoV-2 proteins of interest were quite similar. Indeed, 80.0, 70.4, and 74.8% of CPD experienced T cell responses against spike glycoprotein, NCAP and VME1 respectively (= 0.2443). Related frequencies and distribution of SARS-CoV-2 specific T cell reactions were made by using TNF- ELISpot assay (Supplementary Numbers 1A,B). Related results were also showed when focusing on the sub-group with COVID-19 PCR positivity assay (Supplementary Statistics 1C,D, 2A,B). We seen in most CPD that anti-SARS-CoV-2 particular T cells concurrently created TNF- and IFN- (Supplementary Statistics 1E,F). Open up in another screen Body 1 magnitude and Poly-specificity of T cell replies against SARS-CoV-2 derived protein. (A) Magnitude of positive IFN-+ SARS-CoV-2 particular T cell replies in CPD. (B) Frequencies.