[T lymphocyte subsets combined with inflammatory indicators for auxiliary diagnosis and prognosis evaluation of sepsis].

Objective: To explore the application value of T lymphocyte subsets combined with procalcitonin (PCT), C-reactive protein (CRP), neutrophil to lymphocyte ratio (NLR) and white blood cell count (WBC) in the auxiliary diagnosis and prognosis evaluation of sepsis. Methods: In a retrospective study, seventy-two patients with sepsis diagnosed and treated in Tianjin First Central Hospital from June 2018 to April 2021 were selected as the research objects, and included in the sepsis group were 46 males and 26 females, aged 68 (57.3, 80.3) years. In addition, 111 patients with local infection admitted to hospital during the same period were included in the local infection group, including 62 males and 49 females, aged 68 (51, 77) years. Sepsis patients were divided into survival group (43 cases) and death group (29 cases) according to the 28-day outcome. CD3+, CD4+, CD8+, CD4+/CD8+ ratio were detected by flow cytometry within 24 h after admission, PCT was detected by ELISA, CRP was detected by immunoturbidimetry, blood routine examination, blood lactic acid (Lac) and oxygen partial pressure (PO2) were detected by instrumental method. Multivariate Logistic regression analysis was used to evaluate the correlation between each indicator and sepsis, and receiver operating characteristic curve (ROC) was drawn to evaluate the diagnostic value of each indicator for sepsis. Multivariate Logistic regression analysis and Kaplan Meier survival analysis were used to evaluate the prognostic value of each index for patients with sepsis. Results: Peripheral blood CD3+, CD4+, CD8+, CD4+/CD8+ ratio and PLT in sepsis group were significantly lower than those in local infection group(Z=-8.184,P<0.001;Z=-7.210,P<0.001;Z=-5.936,P<0.001;Z=-2.700,P=0.007;Z=-6.381,P<0.001); PCT, CRP, NLR and Lac levels were significantly higher than those in local infection group(Z=-8.262,P<0.001;Z=-3.094,P=0.002;Z=-9.004,P<0.001;Z=-4.770,P<0.001). Multivariate Logistic regression model showed that PCT, NLR, CD3+, CD8+, CD4+/CD8+ were independent risk factors for sepsis. According to ROC curve analysis, AUC of sepsis patients diagnosed by each indicator were 0.862, 0.894, 0.858, 0.760 and 0.618, respectively. The cut-off values were 3.075 ng/ml, 10.715, 44.935×109/L, 27.463×109/L and 0.750, respectively. The NLR sensitivity was 80.6%, and the CD3+ specificity was 94.6%. The AUC of combined detection of PCT and NLR was 0.947, sensitivity was 87.5% and specificity was 91.9%. The combined detection AUC of PCT, NLR, CD3+, CD4+/CD8+ was 0.958, the sensitivity and specificity were 90.3% and 91.0% respectively(P<0.001). PCT and Lac in death group were significantly higher than those in survival group(Z=-2.302,P=0.021;Z=-3.095,P=0.002);Peripheral blood CD4+/CD8+ levels were significantly lower than those in survival group(Z=-3.691,P<0.001),Multivariate Logistic regression model showed that CD4+/CD8+ ratio was an independent risk factor for 28 d mortality in patients with sepsis (P<0.001). The ROC curve showed that the AUC was 0.758, and the Youden index reached the maximum when the cut-off value was 1.27, the sensitivity and specificity were 79.3% and 60.5%, respectively. Compared with patients with CD4+/CD8+ ≥1.27, 28-day mortality was significantly increased in patients with CD4+/CD8+<1.27 (P=0.032). Conclusion: The combined detection of PCT, NLR, CD3+ and CD4+/CD8+ can improve the auxiliary diagnostic efficiency of sepsis, and the ratio of CD4+/CD8+ in peripheral blood may have certain predictive value for the prognosis of sepsis.

T lymphocyte subsets combined with inflammatory indicators for auxiliary diagnosis and prognosis evaluation of sepsis / 中华预防医学杂志

Objective: To explore the application value of T lymphocyte subsets combined with procalcitonin (PCT), C-reactive protein (CRP), neutrophil to lymphocyte ratio (NLR) and white blood cell count (WBC) in the auxiliary diagnosis and prognosis evaluation of sepsis. Methods: In a retrospective study, seventy-two patients with sepsis diagnosed and treated in Tianjin First Central Hospital from June 2018 to April 2021 were selected as the research objects, and included in the sepsis group were 46 males and 26 females, aged 68 (57.3, 80.3) years. In addition, 111 patients with local infection admitted to hospital during the same period were included in the local infection group, including 62 males and 49 females, aged 68 (51, 77) years. Sepsis patients were divided into survival group (43 cases) and death group (29 cases) according to the 28-day outcome. CD3+, CD4+, CD8+, CD4+/CD8+ ratio were detected by flow cytometry within 24 h after admission, PCT was detected by ELISA, CRP was detected by immunoturbidimetry, blood routine examination, blood lactic acid (Lac) and oxygen partial pressure (PO2) were detected by instrumental method. Multivariate Logistic regression analysis was used to evaluate the correlation between each indicator and sepsis, and receiver operating characteristic curve (ROC) was drawn to evaluate the diagnostic value of each indicator for sepsis. Multivariate Logistic regression analysis and Kaplan Meier survival analysis were used to evaluate the prognostic value of each index for patients with sepsis. Results: Peripheral blood CD3+, CD4+, CD8+, CD4+/CD8+ ratio and PLT in sepsis group were significantly lower than those in local infection group(Z=-8.184,P<0.001;Z=-7.210,P<0.001;Z=-5.936,P<0.001;Z=-2.700,P=0.007;Z=-6.381,P<0.001); PCT, CRP, NLR and Lac levels were significantly higher than those in local infection group(Z=-8.262,P<0.001;Z=-3.094,P=0.002;Z=-9.004,P<0.001;Z=-4.770,P<0.001). Multivariate Logistic regression model showed that PCT, NLR, CD3+, CD8+, CD4+/CD8+ were independent risk factors for sepsis. According to ROC curve analysis, AUC of sepsis patients diagnosed by each indicator were 0.862, 0.894, 0.858, 0.760 and 0.618, respectively. The cut-off values were 3.075 ng/ml, 10.715, 44.935×109/L, 27.463×109/L and 0.750, respectively. The NLR sensitivity was 80.6%, and the CD3+ specificity was 94.6%. The AUC of combined detection of PCT and NLR was 0.947, sensitivity was 87.5% and specificity was 91.9%. The combined detection AUC of PCT, NLR, CD3+, CD4+/CD8+ was 0.958, the sensitivity and specificity were 90.3% and 91.0% respectively(P<0.001). PCT and Lac in death group were significantly higher than those in survival group(Z=-2.302,P=0.021;Z=-3.095,P=0.002);Peripheral blood CD4+/CD8+ levels were significantly lower than those in survival group(Z=-3.691,P<0.001),Multivariate Logistic regression model showed that CD4+/CD8+ ratio was an independent risk factor for 28 d mortality in patients with sepsis (P<0.001). The ROC curve showed that the AUC was 0.758, and the Youden index reached the maximum when the cut-off value was 1.27, the sensitivity and specificity were 79.3% and 60.5%, respectively. Compared with patients with CD4+/CD8+ ≥1.27, 28-day mortality was significantly increased in patients with CD4+/CD8+<1.27 (P=0.032). Conclusion: The combined detection of PCT, NLR, CD3+ and CD4+/CD8+ can improve the auxiliary diagnostic efficiency of sepsis, and the ratio of CD4+/CD8+ in peripheral blood may have certain predictive value for the prognosis of sepsis.

HIV-1-Specific CD11c+ CD8+ T Cells Display Low PD-1 Expression and Strong Anti-HIV-1 Activity.

Exhaustion of HIV-1-specific CD8+ T cells prevents optimal control of HIV-1 infection. Identifying unconventional CD8+ T cell subsets to effectively control HIV-1 replication is vital. In this study, the role of CD11c+ CD8+ T cells during HIV-1 infection was evaluated. The frequencies of CD11c+ CD8+ T cells significantly increased and were negatively correlated with viral load in HIV-1-infected treatment-naïve patients. HIV-1-specific cells were enriched more in CD11c+ CD8+ T cells than in CD11c- CD8+ T cells, which could be induced by HIV-1-derived overlapping peptides, marking an HIV-1-specific CD8+ T cell population. This subset expressed higher levels of activating markers (CD38 and HLA-DR), cytotoxic markers (granzyme B, perforin, and CD107a), and cytokines (IL-2 and TNF-α), with lower levels of PD-1 compared to the CD11c- CD8+ T cell subset. In vitro analysis verified that CD11c+ CD8+ T cells displayed a stronger HIV-1-specific killing capacity than the CD11c- counterparts. These findings indicate that CD11c+ CD8+ T cells have potent immunotherapeutic efficacy in controlling HIV-1 infection.

CD11c+CD163+ Cells and Signal Transducer and Activator of Transcription 3 (STAT3) Expression Are Common in Melanoma Leptomeningeal Disease.

Leptomeningeal disease (LMD) in melanoma patients is associated with significant neurological sequela and has a dismal outcome, with survival measured typically in weeks. Despite the therapeutic benefit of targeted therapies and immunotherapies for Stage IV melanoma, patients with LMD do not typically benefit. A deeper understanding of the tumor microenvironment (TME) of LMD may provide more appropriate therapeutic selection. A retrospective analysis of subjects who underwent surgical resection with LMD (n=8) were profiled with seven color multiplex staining to evaluate the expression of the global immune suppressive hub - the signal transducer and activator of transcription 3 (STAT3) and for the presence of CD3+ T cells, CD68+ monocyte-derived cells, CD163+ immune suppressive macrophages, and CD11c+ cells [potential dendritic cells (DCs)] in association with the melanoma tumor marker S100B and DAPI for cellular nuclear identification. High-resolution cellular imaging and quantification was conducted using the Akoya Vectra Polaris. CD11c+ cells predominate in the TME (10% of total cells), along with immunosuppressive macrophages (2%). Another potential subset of DCs co-expressing CD11c+ and the CD163+ immunosuppressive marker is frequently present (8/8 of specimens, 8%). Occasional CD3+ T cells are identified, especially in the stroma of the tumor (p=0.039). pSTAT3 nuclear expression is heterogeneous in the various immune cell populations. Occasional immune cluster interactions can be seen in the stroma and on the edge. In conclusion, the TME of LMD is largely devoid of CD3+ T cells but is enriched in immune suppression and innate immunity.

Age- and sex-dependent alterations in the peripheral immune system in the 3xTg-AD mouse model of Alzheimer's disease: Increased proportion of CD3+CD4-CD8- double-negative T cells in the blood.

It is well documented that sporadic Alzheimer's disease (AD) is a multifactorial disease and considered to be a result of several pathological events, both in the periphery and in the brain. The role of the peripheral immune system in the etiology and/or progression of the disease is not fully understood yet, and the results in humans are contradictory so far. Several animal models of AD have been generated and thoroughly characterized to elucidate disease mechanisms and evaluate numerous therapeutic strategies in preclinical studies. In the present study, we carried out a longitudinal evaluation of blood lymphocytes from male and female 3xTg-AD mice to document important immunological abnormalities in the periphery. We documented the age-dependent decrease in the percentage of CD3+ and CD4+ lymphocytes and an increase in the percentage CD3+CD4-CD8- (DN T) cells in the blood of 3xTg-AD mice compared with non-transgenic animals. Severe splenomegaly was observed in 3xTg-AD mice in contrast to wild-type animals. Importantly, all these abnormalities in the peripheral immune system appeared earlier and were more pronounced in males compared with females of the same age, which may account for the shorter lifespan of male mice. We suggest that future research should include the measurement of CD3+ and DN T cells as a potential immunological marker of disease progression in AD patients.

Analysis of multispectral imaging with the AstroPath platform informs efficacy of PD-1 blockade.

Next-generation tissue-based biomarkers for immunotherapy will likely include the simultaneous analysis of multiple cell types and their spatial interactions, as well as distinct expression patterns of immunoregulatory molecules. Here, we introduce a comprehensive platform for multispectral imaging and mapping of multiple parameters in tumor tissue sections with high-fidelity single-cell resolution. Image analysis and data handling components were drawn from the field of astronomy. Using this "AstroPath" whole-slide platform and only six markers, we identified key features in pretreatment melanoma specimens that predicted response to anti-programmed cell death-1 (PD-1)-based therapy, including CD163+PD-L1- myeloid cells and CD8+FoxP3+PD-1low/mid T cells. These features were combined to stratify long-term survival after anti-PD-1 blockade. This signature was validated in an independent cohort of patients with melanoma from a different institution.

How we treat advanced stage cutaneous T-cell lymphoma - mycosis fungoides and Sézary syndrome.

T-cell lymphomas (TCLs) constitute a rare subset of non-Hodgkin lymphomas, with mycosis fungoides/Sézary syndrome (MF/SS) being the most common subtype of cutaneous TCLs (CTCLs). Considered an incurable but treatable disease, MF/SS management presents several challenges including diagnostic delays, debilitating effect on patients' quality of life, need for several lines of therapies, multidisciplinary care and cumulative drug toxicities limiting duration of use. The present review intends to provide an overview of the recent advances in our understanding of the biology of CTCL and how these are being leveraged to provide additional treatment options for management of advanced and recurrent disease. In addition, the discussion of the different modalities of treatment is summarised to further outline the importance of multidisciplinary care and early referral to CTCL centres.

Discovery and characteristics of B cell-like T cells: A potential novel tumor immune marker?

BACKGROUND: CD3 and CD19 are the characteristic surface markers of mature T lymphocytes and B lymphocytes of human respectively. A special subset of immune cells that characteristically expressed the surface markers CD19+ of B lymphocytes and CD3+ of T lymphocytes simultaneously (CD19+CD3+ cells, hereinafter referred to as B-T cells) was found in the peripheral blood of human, yet it has not been reported in cancer research before. Our aims were to characterize the expression and possible value of B-T cells in cancer patients. METHODS: Flow cytometry was applied to analyse the CD19+CD3+ cells, and laser scanning confocal microscope was utilized to prove co-expressing CD19+ of B lymphocytes and CD3+ of T lymphocytes simultaneously on the surface of the cells. Then a total of 523 patients with malignant tumor were enrolled in this study, and 177 healthy donors were recruited as the control group. The levels of CD19+CD3+ cells in peripheral blood were measured by flow cytometry, and the differences between the two groups were compared. RESULTS: The healthy donors and cancer patients all had B-T cells in their peripheral blood, but the percentage of B-T cells was 0.16 % ± 0.11 % and 0.58 % ± 0.38 % respectively, showing statistically significant (P < 0.0001). There was no significant correlation between the percentage of B-T cells and lymphocyte subsets (P > 0.05). The percentages of B-T cells in different tumor species were different. The proportion of B-T cells was high in esophageal cancer, non-Hodgkin's lymphoma and lung cancer, but it was low in pancreatic cancer, ovarian cancer and kidney cancer. Meanwhile, there was significant difference between esophageal cancer and kidney cancer (P < 0.001). The distribution of B-T cells in pancreatic cancer and kidney cancer was more concentrated, yet more dispersed in other cancers. Although there was a trend of increase in clinical stage Ⅲ+Ⅳ and a trend of decrease in age above 60 years for breast cancer, gastric cancer and liver cancer, there was no significant difference in the percentage of B-T cells in age, gender, different clinical stages, tumor metastasis, lymph node metastasis, and splenomegaly (P > 0.05). CONCLUSION: The percentage of B-T cells in cancer patients was significantly higher than that of healthy donors. B-T cells maybe play a very complicated role in tumor, whether it could be a potential tumor immune marker or not and what are the specific phenotypes and functions of it to need be further verified.

Association between radiotherapy-induced alteration of programmed death ligand 1 and survival in patients with uterine cervical cancer undergoing preoperative radiotherapy.

PURPOSE: To evaluate radiotherapy-induced changes in the expression of programmed death ligand 1 (PD-L1), programmed death 1 (PD-1), and human leukocyte antigen class I (HLA-1) in patients with uterine cervical cancer, as well as infiltration of CD8+ and Forkhead box P3+ (FoxP3+) T lymphocytes into tumor tissue and the prognostic value of these parameters. MATERIALS AND METHODS: We performed immunohistochemical analysis of pre-radiotherapy biopsies and corresponding post-radiotherapy resected tissues in 104 uterine cervical cancer patients undergoing preoperative chemoradiotherapy or radiotherapy alone. We scored the expression of various proteins to distinguish positive from negative samples. RESULTS: PD-L1-expressing tumor cells (PD-L1 TC) increased significantly after chemoradiotherapy (p = 0.043). CD8+ T cell infiltration (p = 0.002) and FoxP3+ T cell infiltration (p = 0.003) decreased significantly after chemoradiotherapy. Expression of PD­1, PD-L1-expressing immune cells (PD-L1 IC), and HLA­1 did not change after chemoradiotherapy. In biopsy specimens obtained before chemoradiotherapy or radiotherapy, greater infiltration of CD8+ T cells (p = 0.001) and FoxP3+ T cells (p = 0.003) were significant predictors of better overall survival (OS). In surgical specimens obtained after chemoradiotherapy or radiotherapy, greater infiltration of PD-L1 TC was the only significant predictor of better OS (p < 0.001) and was related to a significantly lower probability of out-of-field recurrence (p = 0.005). CONCLUSION: Chemoradiotherapy induced an immunologic shift that increased PD-L1 TC. Chemoradiotherapy has immunological effects that can influence the results of treatment for uterine cervical cancer.

The Dual Roles of Human γδ T Cells: Anti-Tumor or Tumor-Promoting.

γδ T cells are the unique T cell subgroup with their T cell receptors composed of γ chain and δ chain. Unlike αß T cells, γδ T cells are non-MHC-restricted in recognizing tumor antigens, and therefore defined as innate immune cells. Activated γδ T cells can promote the anti-tumor function of adaptive immune cells. They are considered as a bridge between adaptive immunity and innate immunity. However, several other studies have shown that γδ T cells can also promote tumor progression by inhibiting anti-tumor response. Therefore, γδ T cells may have both anti-tumor and tumor-promoting effects. In order to clarify this contradiction, in this review, we summarized the functions of the main subsets of human γδ T cells in how they exhibit their respective anti-tumor or pro-tumor effects in cancer. Then, we reviewed recent γδ T cell-based anti-tumor immunotherapy. Finally, we summarized the existing problems and prospect of this immunotherapy.

Immunological Hallmarks for Clinical Response to BCG in Bladder Cancer.

Intravesical Bacillus Calmette-Guerin (BCG) is an effective immunotherapy for non-muscle invasive bladder cancer (NMIBC). However, recurrence and progression remain frequent warranting deeper insights into its mechanism. We herein comprehensively profiled blood and tissues obtained from NMIBC patients before, during and after BCG treatment using cytometry by time-of-flight (CyTOF) and RNA sequencing to identify the key immune subsets crucial for anti-tumor activity. We observed the temporal changes of peripheral immune subsets including NKT cells, central memory CD4+ T cells, CD8+ T cells and regulatory T cells (Treg) during the course of BCG. Gene expression analysis revealed enriched immune pathways involving in T cell activation and chemotaxis, as well as a more diversified T cell receptor repertoire in post-BCG tissues. Moreover, tissue multiplexed-immunofluorescence (mIF) showed baseline densities of non-Treg and CD8+PD-1+ T cells were predictive of response and better recurrence-free survival after BCG. Remarkably, post-BCG tissues from responders were found to be infiltrated with more active CD8+PD-1- T cells and non-Treg CD4+FOXP3- T cells; but increased exhausted CD8+PD-1+ T cells were found in non-responders. Taken together, we identified predictive biomarkers for response and uncovered the post-treatment expansion of exhausted PD-1+CD8+ T cells as key to BCG resistance, which could potentially be restored by combining with anti-PD-1 immunotherapy.

Staphylococcus aureus Isolated from Skin from Atopic-Dermatitis Patients Produces Staphylococcal Enterotoxin Y, Which Predominantly Induces T-Cell Receptor Vα-Specific Expansion of T Cells.

While investigating the virulence traits of Staphylococcus aureus adhering to the skin of atopic-dermatitis (AD) patients, we identified a novel open reading frame (ORF) with structural similarity to a superantigen from genome sequence data of an isolate from AD skin. Concurrently, the same ORF was identified in a bovine isolate of S. aureus and designated SElY (H. K. Ono, Y. Sato'o, K. Narita, I. Naito, et al., Appl Environ Microbiol 81:7034-7040, 2015, https://doi.org/10.1128/AEM.01873-15). Recombinant SElYbov had superantigen activity in human peripheral blood mononuclear cells. It further demonstrated emetic activity in a primate animal model, and it was proposed that SElY be renamed SEY (H. K. Ono, S. Hirose, K. Narita, M. Sugiyama, et al., PLoS Pathog 15:e1007803, 2019, https://doi.org/10.1371/journal.ppat.1007803). Here, we investigated the prevalence of the sey gene in 270 human clinical isolates of various origins in Japan. Forty-two strains were positive for the sey gene, and the positive isolates were from patients with the skin diseases atopic dermatitis and impetigo/staphylococcal scalded skin syndrome (SSSS), with a detection rate of ∼17 to 22%. There were three variants of SEY (SEY1, SEY2, and SEY3), and isolates producing SEY variants formed three distinct clusters corresponding to clonal complexes (CCs) 121, 59, and 20, respectively. Most sey+ isolates produced SEY in broth culture. Unlike SEYbov, the three recombinant SEY variants exhibited stability against heat treatment. SEY predominantly activated human T cells with a particular T-cell receptor (TCR) Vα profile, a unique observation since most staphylococcal enterotoxins exert their superantigenic activities through activating T cells with specific TCR Vß profiles. SEY may act to induce localized inflammation via skin-resident T-cell activation, facilitating the pathogenesis of S. aureus infection in disrupted epithelial barriers.

CD161+ CD4+ T Cells Harbor Clonally Expanded Replication-Competent HIV-1 in Antiretroviral Therapy-Suppressed Individuals.

The presence of an extremely stable latent reservoir of HIV-1 is the major obstacle to eradication, despite effective antiretroviral therapy (ART). Recent studies have shown that clonal expansion of latently infected cells without viral reactivation is an important phenomenon that maintains the long-term stability of the reservoir, yet its underlying mechanism remains unclear. Here we report that a subset of CD4+ T cells, characterized by CD161 expression on the surface, is highly permissive for HIV-1 infection. These cells possess a significantly higher survival and proliferative capacity than their CD161-negative counterparts. More importantly, we found that these cells harbor HIV-1 DNA and replication-competent latent viruses at a significantly higher frequency. By using massive single-genome proviral sequencing from ART-suppressed individuals, we confirm that CD161+ CD4+ T cells contain remarkably more identical proviral sequences, indicating clonal expansion of the viral genome in these cells. Taking the results together, our study identifies infected CD161+ CD4+ T cells to be a critical force driving the clonal expansion of the HIV-1 latent reservoir, providing a novel mechanism for the long-term stability of HIV-1 latency.IMPORTANCE The latent reservoir continues to be the major obstacle to curing HIV-1 infection. The clonal expansion of latently infected cells adds another layer maintaining the long-term stability of the reservoir, but its mechanism remains unclear. Here, we report that CD161+ CD4+ T cells serve as an important compartment of the HIV-1 latent reservoir and contain a significant amount of clonally expanded proviruses. In our study, we describe a feasible strategy that may reduce the size of the latent reservoir to a certain extent by counterbalancing the repopulation and dissemination of latently infected cells.

Maintenance of Functional CD57+ Cytolytic CD4+ T Cells in HIV+ Elite Controllers.

Cytolytic CD4+ T cells play a prominent role in chronic viral infection. CD4+ CTLs clones specific for HIV-1 Nef and Gag are capable of killing HIV-1 infected CD4+ T cells and macrophages. Additionally, HIV-specific cytolytic CD4+ T cell responses in acute HIV infection are predictive of disease progression. CD57 expression on CD4s identifies cytolytic cells. These cells were dramatically increased in chronic HIV infection. CD57 expression correlated with cytolytic granules, granzyme B and perforin expression. They express lower CCR5 compared to CD57- cells, have less HIV total DNA, and were a minor component of the HIV reservoir. A small percentage of CD57+ CD4+ CTLs from EC were HIV-specific, could upregulate IFNγ with Gag peptide stimulation, express cytolytic granule markers and maintain TbethighEomes+ transcription factor phenotype. This was not observed in viraemic controllers. The maintenance of HIV-specific CD4 cytolytic function in Elite controllers together with CD8 CTLs may be important for the control of HIV viraemia and of potential relevance to cure strategies.

Wuchereria bancrofti infection is linked to systemic activation of CD4 and CD8 T cells.

BACKGROUND: Susceptibility to HIV has been linked to systemic CD4+ T cell activation in cohorts of seronegative individuals with high HIV-exposure risk. We recently described an increased risk of HIV transmission in individuals infected with Wuchereria bancrofti, the causative agent for lymphatic filariasis, in a prospective cohort study. However, the reason for this phenomenon needs further investigation. METHODOLOGY/PRINCIPAL FINDINGS: Two-hundred and thirty-five HIV negative adults were tested using Trop Bio ELISA for detection of W. bancrofti infection and Kato Katz urine filtration and stool based RT-PCR for detection of soil transmitted helminths and schistosomiasis. FACS analysis of the fresh peripheral whole blood was used to measure T cell activation markers (HLA-DR, CD38), differentiation markers (CD45, CD27), markers for regulatory T cells (FoxP3, CD25) and the HIV entry receptor CCR5. Frequencies of activated HLA-DRpos CD4 T cells were significantly increased in subjects with W. bancrofti infection (n = 33 median: 10.71%) compared to subjects without any helminth infection (n = 42, median 6.97%, p = 0.011) or those with other helminths (Schistosoma haematobium, S. mansoni, Trichuris trichiura, Ascaris lumbricoides, hookworm) (n = 151, median 7.38%, p = 0.009). Similarly, a significant increase in HLA-DRposCD38pos CD4 T cells and effector memory cells CD4 T cells (CD45ROposCD27neg) was observed in filarial infected participants. Multivariable analyses further confirmed a link between W. bancrofti infection and systemic activation of CD4 T cells independent of age, fever, gender or other helminth infections. CONCLUSIONS/SIGNIFICANCE: W. bancrofti infection is linked to systemic CD4 T cell activation, which may contribute to the increased susceptibility of W. bancrofti infected individuals to HIV infection.

LAP+ Cells Modulate Protection Induced by Oral Vaccination with Rhesus Rotavirus in a Neonatal Mouse Model.

Transforming growth factor ß (TGF-ß) has been shown to play a role in immunity against different pathogens in vitro and against parasites in vivo However, its role in viral infections in vivo is incompletely understood. Using a neonatal mouse model of heterologous rhesus rotavirus (RV) vaccination, we show that the vaccine induced rotavirus-specific CD4 T cells, the majority of which lacked expression of KLRG1 or CD127, and a few regulatory rotavirus-specific CD4 T cells that expressed surface latency-associated peptide (LAP)-TGF-ß. In these mice, inhibiting TGF-ß, with both a neutralizing antibody and an inhibitor of TGF-ß receptor signaling (activin receptor-like kinase 5 inhibitor [ALK5i]), did not change the development or intensity of the mild diarrhea induced by the vaccine, the rotavirus-specific T cell response, or protection against a subsequent challenge with a murine EC-rotavirus. However, mice treated with anti-LAP antibodies had improved protection after a homologous EC-rotavirus challenge, compared with control rhesus rotavirus-immunized mice. Thus, oral vaccination with a heterologous rotavirus stimulates regulatory RV-specific CD4 LAP-positive (LAP+) T cells, and depletion of LAP+ cells increases vaccine-induced protection.IMPORTANCE Despite the introduction of several live attenuated animal and human rotaviruses as efficient oral vaccines, rotaviruses continue to be the leading etiological agent for diarrhea mortality among children under 5 years of age worldwide. Improvement of these vaccines has been partially delayed because immunity to rotaviruses is incompletely understood. In the intestine (where rotavirus replicates), regulatory T cells that express latency-associated peptide (LAP) play a prominent role, which has been explored for many diseases but not specifically for infectious agents. In this paper, we show that neonatal mice given a live oral rotavirus vaccine develop rotavirus-specific LAP+ T cells and that depletion of these cells improves the efficiency of the vaccine. These findings may prove useful for the design of strategies to improve rotavirus vaccines.

Mould-reactive T cells for the diagnosis of invasive mould infection-A prospective study.

Invasive mould infections (IMI) in immunocompromised patients are difficult to diagnose. Early and targeted treatment is paramount, but minimally invasive tests reliably identifying pathogens are lacking. We previously showed that monitoring pathogen-specific CD4+T cells in peripheral blood using upregulation of induced CD154 positive lymphocytes can be used to diagnose acute IMI. Here, we validate our findings in an independent patient cohort. We stimulated peripheral blood cells from at-risk patients with Aspergillus spp. and Mucorales lysates and quantitated mould-reactive CD4/CD69/CD154 positive lymphocytes via flow cytometry. Mould-reactive lymphocytes were quantitated in 115 at-risk patients. In 38 (33%) patients, the test was not evaluable, mainly due to low T cell counts or non-reactive positive control. Test results were evaluable in 77 (67%) patients. Of these, four patients (5%) had proven IMI and elevated mould-reactive T cell signals. Of 73 (95%) patients without proven IMI, 59 (81%) had mould-reactive T cell signals within normal range. Fourteen (19%) patients without confirmed IMI showed elevated T cell signals and 11 of those received antifungal treatment. The mould-reactive lymphocyte assay identified presence of IMI with a sensitivity of 100% and specificity of 81%. The mould-reactive lymphocyte assay correctly identified all patients with proven IMI. Assay applicability is limited by low T cell counts during bone marrow suppression. The assay has the potential to support diagnosis of invasive mould infection to facilitate tailored treatment even when biopsies are contraindicated or cultures remain negative.

γδ T-cell subsets in HIV controllers: potential role of Tγδ17 cells in the regulation of chronic immune activation.

OBJECTIVES: HIV controllers (HICs) are rare HIV-infected individuals able to maintain undetectable viremia in the absence of antiretroviral treatment. Although HIV-specific cytotoxic T cells have been well deciphered in HIC, γδ T lymphocytes remain largely uncharacterized. The aim of this study was to analyse phenotypic and functional characteristics of γδ T cells and their relationship with immune activation, which remains abnormally elevated and associated with comorbidities in HICs. METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated from 16 HICs, 16 patients with untreated chronic HIV infection (UT-CHI) and 20 healthy donors. Surface marker expression and cytokine production by γδ T cells were analysed by flow cytometry. RESULTS: Despite normal frequencies of total γδ T cells, the Vδ2/Vδ2 ratio was significantly reduced in HIC, albeit to a lesser extent than UT-CHI patients. Of note, nine HICs showed elevated Vδ2 γδ T cells, as patients with UT-CHI, which was associated with higher CD8 T-cell activation. Interleukin (IL)-17-production by γδ T cells (Tγδ17) was better preserved in HIC than in UT-CHI patients. Proportion of total γδ T cells positively correlated with CD8 T-cell activation and HIV-DNA, IP-10 and sCD14 levels. Conversely, Tγδ17 cells negatively correlated with CD8 T-cell activation and plasma sCD14 levels. Moreover, transforming growth factor (TGF)-ß producing Vδ2 T cells were as dramatically depleted in HIC as in UT-CHI patients. CONCLUSION: The relative preservation of IL-17-producing γδ T cells in HIC and their negative association with immune activation raise the hypothesis that Tγδ17 cells - potentially through prevention of microbial translocation - may participate in the control of chronic systemic immune activation.

LAP+ Treg is a better biomarker than total Treg in viral myocarditis.

Latency associated peptide (LAP) is a protein expressed on the membrane of some regulatory T cells (Treg). LAP+ Treg have a greater immunomodulatory effect than that of their negative counterparts. In this study, we presented the data on the proportion of LAP+ Treg out of CD4+ cells in mice with viral myocarditis, which we believed was more sensitive and specific than that of the ratio of total Treg in CD4+ cells. Comparing with the previously recognized total Treg, LAP+ Treg was a better biomarker on myocardial inflammation.