Objective:To evaluate the immune-specific response after the full SARS-CoV-2 vaccination of multiple sclerosis (MS) patients treated with different Disease Modifying drugs by the detection of both serological- and T-cell responses.Methods:Health care workers (HCWs) and MS patients, having completed the two-dose schedule of an mRNA-based vaccine against SARS-CoV-2 in the last 2-4 weeks, were enrolled from two parallel prospective studies conducted in Rome, Italy, at the National Institute for Infectious diseases Spallanzani–IRCSS and San Camillo Forlanini Hospital. Serological response was evaluated by quantifying the Region-Binding-Domain (RBD) and neutralizing-antibodies. Cell-mediated response was analyzed by a whole-blood test quantifying interferon (IFN)-γ response to spike peptides. Cells responding to spike stimulation were identified by FACS analysis.Results:We prospectively enrolled 186 vaccinated individuals: 78 HCWs and 108 MS patients. Twenty-eight MS patients were treated with IFN-β, 35 with fingolimod, 20 with cladribine, and 25 with ocrelizumab. A lower anti-RBD-antibody response rate was found in patients treated with ocrelizumab (40%, p<0.0001) and fingolimod (85.7%, p=0.0023) compared to HCWs and patients treated with cladribine or IFN-β. Anti-RBD-antibody median titer was lower in patients treated with ocrelizumab (p<0.0001), fingolimod (p<0.0001) and cladribine (p=0.010) compared to HCWs and IFN-β-treated patients. Importantly, serum neutralizing activity was present in all the HCWs tested and only in a minority of the fingolimod-treated patients (16.6%). T-cell-specific response was detected in the majority of MS patients (62%), albeit with significantly lower IFN-γ levels compared to HCWs. The lowest frequency of T-cell response was found in fingolimod-treated patients (14.3%). T-cell-specific response correlated with lymphocyte count and anti-RBD antibody titer (rho=0.554, p<0.0001 and rho=0.255, p=0.0078 respectively). Finally, IFN-γ T-cell response was mediated by both CD4+ and CD8+ T cells.Conclusion:mRNA vaccines induce both humoral and cell-mediated specific immune responses against spike peptides in all HCWs and in the majority of MS patients. These results carry relevant implications for managing vaccinations suggesting to promote vaccination in all treated MS patients.Classification of Evidence:This study provides Class III data that COVID mRNA vaccination induces both humoral and cell-mediated specific immune responses against viral spike proteins in a majority of MS patients.

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Objectives To examine whether specific T-cell-responses to SARS-CoV-2 peptides can be detected in COVID-19 using a whole-blood experimental setting, which may be further explored as potential diagnostic tool. Methods We evaluated IFN-γ levels after stimulating whole-blood with spike and remainder-antigens peptides megapools (MP) derived from SARS-CoV-2 sequences; IL-1β, IL-1RA, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12p70, IL-13, IL-15, IL-17A, eotaxin, basic FGF, G-CSF, GM-CSF, IFN-γ, IP-10, MCP-1, MIP-1α, MIP-1β, PDGF, RANTES, TNF-α, VEGF were also evaluated. Results IFN-γ-response to spike and remainder-antigens MPs was significantly increased in 35 COVID-19-patients compared to 29 “NO COVID-19”-individuals (medians spike-MP: 0.26 vs 0, p=0.0002; medians remainder-antigens-MP: 0.07 vs 0.02; p=0.02). This response was detected independently of patients’ clinical parameters. IFN-γ-response to SARS-CoV-2-unrelated antigens CMV and SEB was similar in COVID-19 compared to NO-COVID-19-invididuals (median CMV: 3.46 versus 5.28, p=0.16; median SEB: 12.68 versus 15.05; p=0.1). In response to spike-MPs in COVID-19- compared to “NO COVID-19”-individuals, we found significant higher median of IL-2 (50.08 vs 0, p=0.0018), IFN-γ (90.16 vs 0, p=0.01), IL-4 (0.52 vs 0, p=0.03), IL-13 (0.84 vs 0, p=0.007) and MCP-1 (4602 vs 359.2, p=0.05). Conclusions Immune response to SARS-CoV-2 peptides in a whole-blood assay is associated to COVID-19 and it is characterized by both Th1 and Th2 profile. This experimental approach may be useful for developing new T-cell based diagnostic tests for disease and vaccine settings.

B-cells not only produce immunoglobulins and present antigens to T-cells, but also additional key roles in the immune system. Current knowledge on the role of B-cells in infections caused by intracellular bacteria is fragmentary and contradictory. We therefore analysed the phenotypical and functional properties of B-cells during infection and disease caused by Mycobacterium tuberculosis (Mtb), the bacillus causing tuberculosis (TB), and included individuals with latent TB infection (LTBI), active TB, individuals treated successfully for TB, and healthy controls. Patients with active or treated TB disease had an increased proportion of antibodies reactive with mycobacteria. Patients with active TB had reduced circulating B-cell frequencies, whereas only minor increases in B-cells were detected in the lungs of individuals deceased from TB. Both active TB patients and individuals with LTBI had increased relative fractions of B-cells with an atypical phenotype. Importantly, these B-cells displayed impaired proliferation, immunoglobulin- and cytokine- production. These defects disappeared upon successful treatment. Moreover, T-cell activity was strongest in individuals successfully treated for TB, compared to active TB patients and LTBI subjects, and was dependent on the presence of functionally competent B-cells as shown by cellular depletion experiments. Thus, our results reveal that general B-cell function is impaired during active TB and LTBI, and that this B-cell dysfunction compromises cellular host immunity during Mtb infection. These new insights may provide novel strategies for correcting Mtb infection-induced immune dysfunction towards restored protective immunity.

Interferon-c release assays based on region of difference 1 antigens have improved diagnosis of latent tuberculosis infection (LTBI). However, these tests cannot discriminate between recently acquired infection (higher risk of progression to active tuberculosis) and remote LTBI. The objective of the present study was to evaluate the T-cell interferon-c responses to Mycobacterium tuberculosis DosR-regulon-encoded antigens (latency antigens) compared with QuantiFERON TB-Gold In-Tube (QFT-GIT) in subjects at different stages of tuberculosis.A total of 16 individuals with remote LTBI and 23 with recent infection were studied; 15 controls unexposed to M. tuberculosis and 50 patients with active tuberculosis and 45 with cured tuberculosis were also analysed.The results indicated that subjects with remote LTBI showed significantly higher whole-blood interferon-c responses to M. tuberculosis latency antigen Rv2628 than did individuals with recent infection, active tuberculosis and controls (p,0.003), whereas no significant differences between these groups were found for other latency antigens tested (Rv2626c, Rv2627c, Rv2031c and Rv2032). The proportion of responders to Rv2628 was five-fold higher among QFT-GIT-positiveindividuals with remote infection than among those with recently acquired infection.These data suggest that responses to M. tuberculosis latency antigen Rv2628 may associate with immune-mediated protection against tuberculosis. In contact-tracing investigations, these preliminary data may differentiate recent (positive QFT-GIT results without responses to Rv2628) from remote infection (positive to both tests).

ObjectiveTo assess in rheumatoid arthritis (RA) patients, treated with different immunosuppressive therapies, the induction of SARS-CoV-2-specific immune response after vaccination in terms of anti-region-binding-domain (RBD)-antibody- and T-cell-specific responses against spike, and the vaccine safety in terms of clinical impact on disease activity.MethodsHealth care workers (HCWs) and RA patients, having completed the BNT162b2-mRNA vaccination in the last 2 weeks, were enrolled. Serological response was evaluated by quantifying anti-RBD antibodies, while the cell-mediated response was evaluated by a whole-blood test quantifying the interferon (IFN)-γ-response to spike peptides. FACS analysis was performed to identify the cells responding to spike stimulation. RA disease activity was evaluated by clinical examination through the DAS28crp, and local and/or systemic clinical adverse events were registered. In RA patients, the ongoing therapeutic regimen was modified during the vaccination period according to the American College of Rheumatology indications.ResultsWe prospectively enrolled 167 HCWs and 35 RA patients. Anti-RBD-antibodies were detected in almost all patients (34/35, 97%), although the titer was significantly reduced in patients under CTLA-4-inhibitors (median: 465 BAU/mL, IQR: 103-1189, p&lt;0.001) or IL-6-inhibitors (median: 492 BAU/mL, IQR: 161-1007, p&lt;0.001) compared to HCWs (median: 2351 BAU/mL, IQR: 1389-3748). T-cell-specific response scored positive in most of RA patients [24/35, (69%)] with significantly lower IFN-γ levels in patients under biological therapy such as IL-6-inhibitors (median: 33.2 pg/mL, IQR: 6.1-73.9, p&lt;0.001), CTLA-4-inhibitors (median: 10.9 pg/mL, IQR: 3.7-36.7, p&lt;0.001), and TNF-α-inhibitors (median: 89.6 pg/mL, IQR: 17.8-224, p=0.002) compared to HCWs (median: 343 pg/mL, IQR: 188-756). A significant correlation between the anti-RBD-antibody titer and spike-IFN-γ-specific T-cell response was found in RA patients (rho=0.432, p=0.009). IFN-γ T-cell response was mediated by CD4+ and CD8+ T cells. Finally, no significant increase in disease activity was found in RA patients following vaccination.ConclusionThis study showed for the first time that antibody-specific and whole-blood spike-specific T-cell responses induced by the COVID-19 mRNA-vaccine were present in the majority of RA patients, who underwent a strategy of temporary suspension of immunosuppressive treatment during vaccine administration. However, the magnitude of specific responses was dependent on the immunosuppressive therapy administered. In RA patients, BNT162b2 vaccine was safe and disease activity remained stable.

Tuberculosis (TB) is still the principal cause of death caused by a single infectious agent, and the balance between the bacillus and host defense mechanisms reflects the different manifestations of the pathology. The aim of this work was to study the role of myeloid-derived suppressor cells (MDSCs) during active pulmonary tuberculosis at the site of infection. We observed an expansion of MDSCs in the lung and blood of patients with active TB, which are correlated with an enhanced amount of nitric oxide in the plasma. We also found that these cells have the remarkable ability to suppress T-cell response, suggesting an important role in the modulation of the immune response against TB. Interestingly, a trend in the diminution of MDSCs was found after an efficacious anti-TB therapy, suggesting that these cells may be used as a potential biomarker for monitoring anti-TB therapy efficacy.

The QuantiFERON-TB Gold Plus (QFT-Plus) represents the new QuantiFERON-TB Gold In-tube (QFT-GIT) to identify latent tuberculosis infection (LTBI). The main differences is the addition of a new tube containing shorter peptides stimulating CD8 T-cells. Aim of this study is to evaluate the accuracy of QFT-Plus compared with QFT-GIT in a cross sectional study of individuals with or without tuberculosis (TB). We enrolled 179 participants: 19 healthy donors, 58 LTBI, 33 cured TB and 69 active TB. QFT-Plus and QFT-GIT were performed. The two tests showed a substantial agreement. Moreover we found a similar sensitivity in active TB and same specificity in healthy donors. A higher proportion of the LTBI subjects responded to both TB1 and TB2 compared to those with active TB (97% vs 81%). Moreover, a selective response to TB2 was associated with active TB (9%) and with a severe TB disease, suggesting that TB2 stimulation induces a CD8 T-cell response in absence of a CD4-response. In conclusion, QFT-Plus and QFT-GIT assays showed a substantial agreement and similar accuracy for active TB detection. Interestingly, a higher proportion of the LTBI subjects responded concomitantly to TB1 and TB2 compared to those with active TB, whereas a selective TB2 response associated with active TB.