[Circulating populations of CD4+ CD25+ CD127- regulatory t lymphocytes in peripheral blood of allergic asthmatic children]

OBJECTIVE

To carry out a preliminary analysis on the Treg lymphocyte counts present in the peripheral blood of allergic asthmatic children from the city of Cartagena, Colombia, compared to healthy controls.

METHODS

We compared cytometry counts of ten asthmatic patients (age 7-16 years) and seven healthy controls (6-12 years), recruited in the city of Cartagena. Peripheral blood samples were stained using Cytek's 14-color cFluor Immunoprofiling kit (Cytek® cFluor® Immunoprofiling Kit 14 Color RUO kit), and analyzed on a Northern Lights™ spectral cytometer (Cytek® Biosciences, Fremont, CA, USA), to read 50.000 events per sample. The data obtained were analyzed in SpectroFlo® and FlowJo. The study was approved by the ethics committee of the University of Cartagena (SGR, Grant BPIN2020000100405).

RESULTS

The frequency of CD3+, CD4+, CD25+, CD127- Tregs was 11% of all CD4+ T cells, with a range of minimum 8,1% and maximum 17,7%. There was no significant difference in the proportion of Tregs between allergic asthmatic patients and healthy controls (P = 0,2).

CONCLUSIONS

With this preliminary sample size, no significant differences were found in the Treg lymphocyte population between allergic asthmatic patients and healthy controls. The 14-color multiplexed panel is a useful tool not only to count CD3+ and CD4+ populations, but also to obtain the percentage of regulatory T cells using cell surface markers.

Expression of CD4+CD25+CD127Low regulatory T cells and cytokines in peripheral blood of patients with primary liver carcinoma

Objective: To assess the clinical utility of the ratio of CD4+CD25+CD127^low regulatory T cells (Tregs) in subjects at high risk of HCC, investigate the relationship between the percentage of Tregs and the expression of transforming growth factor (TGF)-β1 and interleukin (IL)-10 in patients with hepatocellular carcinoma before and after treatment. Methods: Peripheral venous blood was collected from patients with liver cancer before and after treatment. The proportion of CD4+CD25+CD127^low Tregs was detected by flow cytometry. The levels of TGF-β1 and IL-10 in serum were detected by enzyme-linked immunosorbent assay, and were compared with healthy subjects as a control group. Results: The proportion of CD4+CD25+CD127^low to CD4+T lymphocytes in patients with hepatocellular carcinoma was significantly higher than that in healthy controls (P<0.01). The proportion of CD4+CD25+CD127^lowTregs, whose AUC of ROC curve was 0.917, could effectively separate the HCC patients from the healthy subjects with a diagnostic sensitivity of 90%, specificity of 80%. The proportion of CD4+CD25+CD127^low to CD4+T lymphocytes and the levels of TGF-β1 and IL-10 in patients with hepatocellular carcinoma after the operation and chemotherapy were significantly lower than those before treatment (P<0.05).The proportion of CD4+CD25+CD127^lowTregs was positively correlated with the concentrations of TGF-β1 and IL-10 before and after treatment of primary liver cancer (P<0.05). Conclusion: CD4+CD25+CD127^lowTregs may be a significant predictor of HCC biopsy outcome and play an inhibitory role on effector T cells by regulating cytokines.

Effect and analysis of ulinastatin combined with thymosin on cardiopulmonary function and delirium in sepsis patients

The aim of this study was to explore the clinical effect of ulinastatin combined with thymosin in patients with sepsis and its influence on cardiopulmonary function and delirium. Sixty-eight sepsis patients were enrolled as study subjects. The patients were randomly divided into a symptomatic treatment group (n=34) and a combined treatment group (n=34) on the basis of random number table. The two groups were first operated and then, the symptomatic treatment group was given symptomatic support treatment, whilst the combined treatment group was treated with ulinastatin and thymosin on the prerequisite of the symptomatic treatment group. After 7 days of treatment, the evaluation of the curative effect was performed, followed by the comparison of the cardiopulmonary function, immune level and safety between the two groups of patients. The cardiac index and oxygenation index of the combined treatment group were higher than those of the symptomatic treatment group 7 days after treatment (P<0.05). Whereas, the levels of plasma D-dimer and cTnI were lower than those of the symptomatic treatment group (P<0.05). In addition, CD3+, CD4⁺, CD4⁺/CD8+ levels of the combined treatment group were higher than those of the symptomatic treatment group 7 days after treatment (P<0.05). On the contrary, CD8+ levels of the combined treatment group were lower than those of the symptomatic treatment group 7 days after treatment. There was no significant (P>0.05) difference in drug safety between the two groups during treatment.

Serum Lipid Profile and Its Relationship with Host Immunity in Carcinomas of the Breast and Uterine Cervix

Carcinomas of the uterine cervix and breast, which have a different etiopathogenesis, are the most common malignancies among Indian women. Between these two cancers a comparative study was undertaken in which serum lipids were assessed along with host immunity. Thirty randomly selected cases each of breast and cervical carcinoma, and 20 matched healthy control women were studied by means of standard procedures. Significantly higher (P < 0.001) mean levels of triglycerides (x = 192.1 mg/dl, SD ± 113.5) and total cholesterol (x = 212.9 mg/dl, SD ± 49.78) were observed in breast cancer as compared to controls or cervical cancer patients. Patients with cervical cancer had low mean values of all lipid fractions. Women with the above malignancies also showed a significantly decreased CD3+ and CD4+ population (P < 0.001), while there was a significant increase in CD8+ cells (P < 0.005) compared to normal controls. Interestingly, a significant relationship (P < 0.05) was observed between CD8+cells and LDL-cholesterol among the cancer patients (r = 0.3652 and r = 0.4298 for carcinomas of breast and cervix, respectively).

Prediction of extended high viremia among newly HIV-1-infected persons in sub-Saharan Africa

Objective

Prompt identification of newly HIV-infected persons, particularly those who are most at risk of extended high viremia (EHV), allows important clinical and transmission prevention benefits. We sought to determine whether EHV could be predicted during early HIV infection (EHI) from clinical, demographic, and laboratory indicators in a large HIV-1 incidence study in Africa.

Design

Adults acquiring HIV-1 infection were enrolled in an EHI study assessing acute retroviral syndrome (ARS) symptoms and viral dynamics.

Methods

Estimated date of infection (EDI) was based on a positive plasma viral load or p24 antigen test prior to seroconversion, or the mid-point between negative and positive serological tests. EHV was defined as mean untreated viral load ≥5 log₁₀ copies/ml 130–330 days post-EDI. We used logistic regression to develop risk score algorithms for predicting EHV based on sex, age, number of ARS symptoms, and CD4 and viral load at diagnosis.

Results

Models based on the full set of five predictors had excellent performance both in the full population (c-statistic = 0.80) and when confined to persons with each of three HIV-1 subtypes (c-statistic = 0.80–0.83 within subtypes A, C, and D). Reduced models containing only 2–4 predictors performed similarly. In a risk score algorithm based on the final full-population model, predictor scores were one for male sex and enrollment CD4<350 cells/mm³, and two for having enrollment viral load >4.9 log₁₀ copies/ml. With a risk score cut-point of two, this algorithm was 85% sensitive (95% CI: 76%-91%) and 61% specific (55%-68%) in predicting EHV.

Conclusions

Simple risk score algorithms can reliably identify persons with EHI in sub-Saharan Africa who are likely to sustain high viral loads if treatment is delayed. These algorithms may be useful for prioritizing intensified efforts around care linkage and retention, treatment initiation, adherence support, and partner services to optimize clinical and prevention outcomes.

Characterization of broadly neutralizing antibody responses to HIV-1 in a cohort of long term non-progressors

Background

Only a small fraction of HIV-1-infected patients develop broadly neutralizing antibodies (bNAbs), a process generally associated to chronic antigen stimulation. It has been described that rare aviremic HIV-1-infected patients can generate bNAbs but this issue remains controversial. To address this matter we have assessed bNAb responses in a large cohort of long-term non-progressors (LTNPs) with low or undetectable viremia.

Methods

Samples from the LTNP cohort of the Spanish AIDS Research Network (87 elite and 42 viremic controllers) and a control population of 176 viremic typical-progressors (TPs) were screened for bNAbs using Env-recombinant viruses. bNAb specificities were studied by ELISA using mutated gp120, neutralization assays with mutated viruses, and peptide competition. Epitope specificities were also elucidated from the serum pattern of neutralization against a panel of diverse HIV-1 isolates.

Results

Broadly neutralizing sera were found among 9.3% LTNPs, both elite (7%) and viremic controllers (14%). Within the broadly neutralizing sera, CD4 binding site antibodies were detected by ELISA in 4/12 LTNPs (33%), and 16/33 of TPs (48%). Anti-MPER antibodies were detected in 6/12 LTNPs (50%) and 14/33 TPs (42%) whereas glycan-dependent HIV-1 bNAbs were more frequent in LTNPs (11/12, 92%) as compared to TPs (12/33, 36%). A good concordance between standard serum mapping and neutralization-based mapping was observed.

Conclusion

LTNPs, both viremic and elite controllers, showed broad humoral immune responses against HIV-1, including activity against many major epitopes involved in bNAbs-mediated protection.

Occult hepatitis B virus infection in HIV positive patients at a tertiary healthcare unit in eastern India

Occult HBV infection (OBI), defined by the presence of HBV DNA in absence of hepatitis B surface antigen (HBsAg), is a significant concern in the HIV-infected population. Of 441 HIV+/HBsAg- patients analyzed, the overall prevalence of OBI was 6.3% (28/441). OBI was identified in 21 anti-HBc positives (17.8%), as well as among those who lacked any HBV-specific serological markers (2.2%). Comparison with HIV/HBV co-infection revealed that the levels of CD4, ALT, and HBV DNA were significantly lower during occult infection. Discrete differences were also observed with respect to quasispecies divergence. Additionally, subgenotype D1 was most frequent in occult infection, while D2 was widespread during chronic infection. The majority (~90%) of occult D1 sequences had the sQ129R mutation in the surface gene. This study highlights several distinct features of OBI in India and underscores the need for additional HBV DNA screening in HIV-positive individuals.

Decreased Frequencies of Peripheral Blood CD4+CD25+CD127-Foxp3+ in Patients with Graves' Disease and Graves' Orbitopathy: Enhancing Effect of Insulin Growth Factor-1 on Treg Cells

Graves' orbitopathy (GO) is characterized by orbital T cell infiltration. We evaluated the regulatory T (Treg) cell fractions induced with IGF-1 in Graves' disease (GD) with and without GO. Peripheral blood mononuclear cells (PBMCs) were obtained from 13 patients with GD without eye manifestations; 10 patients with active GO; and 12 patients with nodular goiter (NG). All the patients from GD, GO, and NG were subclinical hyperthyroid. We analyzed the expression of Treg cell markers (CD4, CD25, CD127^-, Foxp3) on T cells and their ability to respond to IGF-1 stimulation. In patients with GD without GO, we found lowered percentages of CD4⁺ Foxp3⁺ cells, as compared to nodular goiter 1.77 vs. 5.42% (p=0.0276). Similarly, significantly reduced frequencies of CD4⁺CD25⁺CD127^-Foxp3⁺ and CD4⁺CD25⁺CD127^- cells were observed in GD patients as compared to nodular goiter patients with hyperthyreosis, (0.7 vs. 1.48%) (p=0.0071) and (14.5 vs. 37.2%) (p=0.0051), respectively. In GO with active GO, only the percentage of CD4⁺CD25⁺CD127^- cells was found to be decreased versus nodular goiter (9.35 vs. 37.2) (p=0.0275). Stimulation of PBMC derived from GO patients with IGF-1 resulted in significant increase of frequency of both CD4⁺ Foxp3⁺ and CD4⁺CD25⁺CD127^- Foxp3 cells. Decreased frequencies of peripheral blood CD4⁺CD25⁺CD127^-Foxp3⁺ in patients with GD and GO could be an useful marker of autoimmune process and perhaps a possible target for future therapies. This is the first study demonstrating Treg-enhancing effects of IGF-1. Thus IGF-1 can be accounted for modulating Treg cell-related action in GO.

Biomarkers of Environmental Enteropathy are Positively Associated with Immune Responses to an Oral Cholera Vaccine in Bangladeshi Children

Environmental enteropathy (EE) is a poorly understood condition that refers to chronic alterations in intestinal permeability, absorption, and inflammation, which mainly affects young children in resource-limited settings. Recently, EE has been linked to suboptimal oral vaccine responses in children, although immunological mechanisms are poorly defined. The objective of this study was to determine host factors associated with immune responses to an oral cholera vaccine (OCV). We measured antibody and memory T cell immune responses to cholera antigens, micronutrient markers in blood, and EE markers in blood and stool from 40 Bangladeshi children aged 3-14 years who received two doses of OCV given 14 days apart. EE markers included stool myeloperoxidase (MPO) and alpha anti-trypsin (AAT), and plasma endotoxin core antibody (EndoCab), intestinal fatty acid binding protein (i-FABP), and soluble CD14 (sCD14). We used multiple linear regression analysis with LASSO regularization to identify host factors, including EE markers, micronutrient (nutritional) status, age, and HAZ score, predictive for each response of interest. We found stool MPO to be positively associated with IgG antibody responses to the B subunit of cholera toxin (P = 0.03) and IgA responses to LPS (P = 0.02); plasma sCD14 to be positively associated with LPS IgG responses (P = 0.07); plasma i-FABP to be positively associated with LPS IgG responses (P = 0.01) and with memory T cell responses specific to cholera toxin (P = 0.01); stool AAT to be negatively associated with IL-10 (regulatory) T cell responses specific to cholera toxin (P = 0.02), and plasma EndoCab to be negatively associated with cholera toxin-specific memory T cell responses (P = 0.02). In summary, in a cohort of children 3-14 years old, we demonstrated that the majority of biomarkers of environmental enteropathy were positively associated with immune responses after vaccination with an OCV.

Risk Factors for Hyperlactataemia in HIV-Infected Patients, Aquitaine Cohort, 1999–2003

The objectives of our study were to describe the characteristics of a subset of patients who had been prescribed serum lactate in clinical practice within a large cohort of HIV-infected patients and to determine the factors associated with hyperlactataemia. Hyperlactataemia (⩾T2 mmol/l) was found in 219 [29% (95% confidence interval: 25.3–31.7)] of the 768 HIV-infected participants. In multivariate analysis (logistical regression), an increased risk of hyperlactataemia was associated with increasing age, CD4 count <500/mm3, triglycerides >2.2 mmol/L, lipoatrophy and stavudine use. In a second model coding for the NRTI-based drug combinations, only those including stavudine were associated with an increased risk of hyperlactataemia. In a third model including exposure duration to NRTIs, we estimated a 20% increased risk of hyperlactataemia per year of exposure to didanosine or stavudine. The risk of hyperlactataemia could increase over time in patients treated with these drugs and is also closely associated with increased age, decreased CD4 count, lipodystrophy and increased plasma triglycerides. It could be proposed that patients having one or more of these risk factors undergo regular monitoring of plasma lactate and renal function to prevent lactic acidosis.

Frequency of CD4+CD25+Foxp3+ cells in peripheral blood in relation to urinary bladder cancer malignancy indicators before and after surgical removal

Tumor cells communicate with stromal cells, including cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs), to form microenvironment inhibiting immune responses. Regulatory T cells (Tregs, CD4+CD25+FoxP3+) stimulate immune tolerance and facilitate tumor progression. We analyzed the changes in Treg frequencies assessed using flow cytometry in the peripheral blood of patients with urothelial bladder cancer before and after tumor-removal. Changes in Treg frequency were investigated in relation to clinicopathomorphological indicators of tumor malignancy and expression of RCAS1 on CAFs and TAMs. Higher Treg frequencies were observed in early phase of tumor growth (pTa-pT2), in larger tumors, with more aggressive type of invasion, and with expression of RCAS1. The later phase of tumor development, accompanied by a nonclassic differentiations and pT3-pT4 advancement, had lower number of tumor infiltrating lymphocytes (TILs) and lower Treg frequency. Furthermore, in pT2-pT4 tumors, a decreased post-surgery Treg frequency was associated with poorer prognosis: patients with the lowest frequency of Tregs died first. These findings strongly suggest that the Treg frequencies at later phase of tumor growth, associated with a low anti-tumor response, represent a new and important prognostic indicator in urinary bladder cancer.

[Immuknow and long term kidney graft]

INTRODUCTION

The survival of transplanted kidneys has improved over time, but there is an increased risk of neoplastic disease. In the long time follow up, non-melanoma skin cancers (NMSC) are the most frequent diseases and at the time of the occurrence of a NMSC we should evaluate a reduction or a change of IS. From a clinical point of view, the evaluation of immunosuppression is still a problem. The Immuknow assay may be of help in evaluating the immune response of transplanted patients. Here, by means of the ImmKnow assay, we tried to evaluate if long term renal transplant patients with NMSC are more immunosuppressed than patients without NMSC.

METHODS

33 long term kidney transplant patients, 16 with NMSC and 17 without NMSC, were recruited and blood samples were drawn at baseline, 4 months, 8 months and 12 months to check renal function, blood levels of cni and to perform immuknow assay.

RESULTS

most values of T CD4+ reactivity were comprised between (atp) 225 and 525 ng/ml as for an moderate immunosuppression. No major differences have been observed between the two groups. No correlation with blood level of CNI was detected. T CD4+ activity changed over time for both the groups. 3 patients of the group without NMSC had levels of CD4+ reactivity constantly under (ATP) 225 ng/ml, classified as low per manifacturers definition.

CONCLUSION

in our limited experience the measure of cell-mediated immunity by immuknow assay years after transplantation, has not evidenced any significant difference between patients positive for NMSC and negative patients. We observed variation of the CD4 reactivity with time, no correlation with the level of CNI and the useful identification of some cases of low levels of cell reactivity.

IL12p40 regulates functional development of human CD4+ T cells: enlightenment by the elevated expressions of IL12p40 in patients with inflammatory bowel diseases

The proinflammatory effects of IL12p40 had been documented in the literature, and anti-IL12p40 treatment had been proved to be effective in therapy of Crohn disease (CD) in a phase 2b clinical trial. However, the precise role of IL12p40 in the pathogenesis of inflammatory bowel disease (IBD) was still poorly understood. In this study, we investigated the expressions of IL12p40 and its receptor interleukin-12 receptor β 1 both locally and systemically in IBD cases and healthy controls, and the contribution of IL12p40 in IBD pathogenesis. We found that the expression of IL12p40 was elevated both at messenger RNA and protein levels systematically and locally in IBD patients but more significantly in CD patients. Our genetic association study revealed that the polymorphisms of IL12B rs6887695 were associated with both CD and ulcerative colitis (UC) susceptibility in Chinese population, but did not affect the serum IL12p40 level in either CD patients or UC patients. In addition, CD4⁺ T cells isolated from peripheral blood of CD patients secreted the most abundant IL12p40 production, compared with the UC patients and healthy controls. We also found for the first time that neutralizing IL12p40 secretion could inhibit proliferation, enhance apoptosis, induce a G0/G1 arrest, restrain T helper 1 type immune responses, and promote chemokine C-C motif ligand 20-mediated migration of human CD4⁺ T cells, which might be the mechanisms why anti-IL12p40 treatment presented efficacy in CD.

Adherence, Quality of Life, and General Satisfaction with Co-formulated Zidovudine, Lamivudine, and Abacavir on Antiretroviral-Experienced Patients

PURPOSE

The main objective of the study was to evaluate patients' adherence to a fixed dose combination containing abacavir, zidovudine, and lamivudine (TZV) and to evaluate whether TZV might improve general satisfaction and quality of life (QOL) with anti-HIV treatment.

METHOD

Patients with viral load (VL) <400 copies switched their antiretroviral therapy to TZV. Adherence was assessed by patient self-report and medication accountability at week 24. General satisfaction was evaluated with 10-point Visual Analog Scale (VAS) at baseline and week 24. QOL was assessed with MOS-HIV questionnaire at baseline and weeks 12 and 24. Biochemical and hematological parameters were evaluated for safety reasons.

RESULTS

A total of 224 patients were included in the study. Overall, 81% (intent to treat [ITT]) and 98% (per protocol [PP]) of patients reported an adherence >95%, reaching 75% and 100% among the intravenous drug user population by ITT and PP analysis, respectively. General satisfaction was significantly higher at week 24 (90 +/- 14 vs. 53 +/- 26) in both ITT and PP populations (p<.0001). There were no statistically significant differences in QOL. Total cholesterol and triglycerides levels decreased significantly at week 24 compared to baseline (p<.05).

CONCLUSION

Patients who switched to TZV showed an increase in general satisfaction and high levels of adherence.

An association of hypochondroplasia and immune deficiency

A 4-year-old boy with hypochondroplasia was admitted to our clinic with complaints of bronchopneumonia. He also had immune deficiency characterized by low CD3, CD4 T-lymphocyte subsets and a low level of serum immunoglobulin A (IgA). The diagnosis of hypochondroplasia was made on clinical, radiological, and laboratory findings by the pediatric endocrinology department. The focus of our study is hypochondroplasia associated with immune deficiency which was unpublished in English medical literature previously.

Increased apoptosis of regulatory T cells in Crohn's disease

BACKGROUND/AIMS

Crohn's disease (CD) is characterized by a transmural often granulomatous Th1-driven inflammatory process hallmarked by an increased production of IL-12, TNF-alpha and IFN-gamma. Accumulating evidence suggests that the numerical defect within the regulatory T cell (Tregs) compartment might contribute to this imbalance between pro- and antiinflammatory factors. This study was aimed to investigate whether the numerical defect of Tregs observed in CD resulted from an increased apoptosis of these cells.

METHODOLOGY

The cytometric analysis was performed to evaluate the percentage of CD4 + FOXP3 + Tregs in peripheral blood of 55 investigated subjects, as well as to estimate the rate of Treg apoptosis.

RESULTS

The cytometric analysis showed a significantly lower percentage of Tregs in peripheral blood of CD patients compared with the healthy control group (P = 0.03) as well as an increased rate of apoptosis within this cell subpopulation (P = 0.000001). Interestingly, a significantly higher rate of Treg apoptosis was observed in female than male CD patients (P = 0.03).

DISCUSSION

Current data suggest that CD is associated with a numerical deficiency of the Treg compartment. Presented study indicates that an increased apoptosis might contribute to this numerical deficiency. A higher rate of Tregs apoptosis found in female patients might suggest the involvement of hormonal factors and possibly contribute to the female predominance observed in CD as well as to the tendency of female patients to develop a more severe form of the disease.

The administration of milk fermented by the probiotic Lactobacillus casei CRL 431 exerts an immunomodulatory effect against a breast tumour in a mouse model

Antitumour activity is one of the health-promoting effects attributed to probiotics specially analysed from preclinical models, mostly murine. Here, the effect of milk fermented by the probiotic bacterium Lactobacillus casei CRL 431, on a murine breast cancer model was analysed. Mice were fed with milk fermented by Lactobacillus casei or unfermented milk before and after tumour injection. Rate of tumour development, cytokines in serum, IgA, CD4, CD8, F4/80 and cytokines positive cells in mammary glands were determined. Microvasculature in the tumour tissues was monitored. The effect of fermented milk administration after tumour injection was also evaluated. It was observed that probiotic administration delayed or blocked tumour development. This effect was associated to modulation of the immune response triggered by the tumour. The area occupied by blood vessels decreased in the tumours from mice given fermented milk which agrees with their small tumours, and fewer side effects. Finally, it was observed that probiotic administration after tumour detection was also beneficial to delay the tumour growth. In conclusion, we showed in this study the potential of milk fermented by the probiotic Lactobacillus casei CRL431 to stimulate the immune response against this breast tumour, avoiding or delaying its growth when it was preventively administrated and also when the administration started after tumour cells injection.

[Clinical course and characteristics of cellular and humoral immunity in patients with allergic rhinitis]

In research the condition cellular and humoral immunity is defined at allergic rhinitis--AR (n = 45) for an estimation of mechanisms pathogeny this disease. The AR in 76% of cases has the hereditary nature mainly from outside mothers (36%), begins more often at children's and teenage age (88%) and in 44% is accompanied by other allergic pathology. In structure of a sensibilization of patients the allergic rhinitis the basic place is occupied with pollen, household, fungoid and epidermal allergens, allergic reaction (83% of cases) thus prevailed. As a result of the spent researches rising of relative quantity CD4+CD25+Foxp3+ regulatory T cells is taped, at the same time rising of an average level of the general IgE--(198,20 +/- 11,42) IU/ml is noted. In cytokine regulations at patients an allergic rhinitis rising IL-4 and depression IL-10 is noted. Thus, the conducted research suggests that an allergic rhinitis--disease with involving in process of regulation of the immune answer of certain type regulatory T of cells.

Viral escape from HIV-1 neutralizing antibodies drives increased plasma neutralization breadth through sequential recognition of multiple epitopes and immunotypes

Identifying the targets of broadly neutralizing antibodies to HIV-1 and understanding how these antibodies develop remain important goals in the quest to rationally develop an HIV-1 vaccine. We previously identified a participant in the CAPRISA Acute Infection Cohort (CAP257) whose plasma neutralized 84% of heterologous viruses. In this study we showed that breadth in CAP257 was largely due to the sequential, transient appearance of three distinct broadly neutralizing antibody specificities spanning the first 4.5 years of infection. The first specificity targeted an epitope in the V2 region of gp120 that was also recognized by strain-specific antibodies 7 weeks earlier. Specificity for the autologous virus was determined largely by a rare N167 antigenic variant of V2, with viral escape to the more common D167 immunotype coinciding with the development of the first wave of broadly neutralizing antibodies. Escape from these broadly neutralizing V2 antibodies through deletion of the glycan at N160 was associated with exposure of an epitope in the CD4 binding site that became the target for a second wave of broadly neutralizing antibodies. Neutralization by these CD4 binding site antibodies was almost entirely dependent on the glycan at position N276. Early viral escape mutations in the CD4 binding site drove an increase in wave two neutralization breadth, as this second wave of heterologous neutralization matured to recognize multiple immunotypes within this site. The third wave targeted a quaternary epitope that did not overlap any of the four known sites of vulnerability on the HIV-1 envelope and remains undefined. Altogether this study showed that the human immune system is capable of generating multiple broadly neutralizing antibodies in response to a constantly evolving viral population that exposes new targets as a consequence of escape from earlier neutralizing antibodies.

Increased soluble CD4 in serum of rheumatoid arthritis patients is generated by matrix metalloproteinase (MMP)-like proteinases

Higher soluble CD4 (sCD4) levels in serum have been detected in patients of infectious and chronic inflammatory diseases. However, how and why sCD4 is produced remains poorly understood. We establish sensitive ELISA and WB assays for sCD4 detection in conditioned medium of in vitro cell culture system and serum of chronic inflammatory patients. Serum samples from patients with systemic lupus erythematosus (SLE) (n = 79), rheumatoid arthritis (RA) (n = 59), ankylosing spondylitis (AS) (n = 25), gout (n = 31), and normal controls (n = 99) were analyzed using ELISA for sCD4 detection. Results from each assay were analyzed by the Kruskal-Wallis test. Dunn's multiple comparison post-test was then applied between groups. We confirm that cells expressing exogenous CD4 produce sCD4 in a constitutive and PMA-induced manner. Importantly, sCD4 production in a heterologous expression system is inhibited by GM6001 and TAPI-0, suggesting receptor shedding by matrix metalloproteinase (MMP)-like proteinases. Moreover, similar findings are recapitulated in human primary CD4(+) T cells. Finally, we show that serum sCD4 levels are increased in patients of chronic inflammatory diseases including RA and SLE, but not in those with gout. Intriguingly, sCD4 levels in RA patients are correlated positively with the disease activities and higher sCD4 levels seem to associate with poor prognosis. Taken together, we conclude that CD4 is shed from cell surface by a MMP-like sheddase and sCD4 level is closely related with the inflammatory condition in certain chronic diseases. Hence, sCD4 might be considered an important parameter for RA disease progression with potential diagnostic importance.

[Immune elements of pathogenesis of multiorgan failure syndrome in newborns]

Expression of clusters determination of T-cells immune links (CD4, CD8, CD95) and level of interferon-alpha at newborns with multiorgan failure syndrome were investigated. It were shown supressive character of immune reactions and reduction the level of interferon-alpha in this contingent of patients.

A clinical prediction score in addition to WHO criteria for anti-retroviral treatment failure in resource-limited settings--experience from Lesotho

Objective

To assess the positive predictive value (PPV) of a clinical score for viral failure among patients fulfilling the WHO-criteria for anti-retroviral treatment (ART) failure in rural Lesotho.

Methods

Patients fulfilling clinical and/or immunological WHO failure-criteria were enrolled. The score includes the following predictors: Prior ART exposure (1 point), CD4-count below baseline (1), 25% and 50% drop from peak CD4-count (1 and 2), hemoglobin drop≥1 g/dL (1), CD4 count<100/µl after 12 months (1), new onset papular pruritic eruption (1), and adherence<95% (3). A nurse assessed the score the day blood was drawn for viral load (VL). Reported confidence intervals (CI) were calculated using Wilsons method.

Results

Among 1'131 patients on ART≥6 months, 134 (11.8%) had immunological and/or clinical failure, 104 (78%) had blood drawn (13 died, 10 lost to follow-up, 7 did not show up). From 92 (88%) a result could be obtained (2 samples hemolysed, 10 lost). Out of these 92 patients 47 (51%) had viral failure (≥5000 copies), 27 (29%) viral suppression (<40) and 18 (20%) intermediate viremia (40–4999). Overall, 20 (22%) had a score≥5. A score≥5 had a PPV of 100% to detect a VL>40 copies (95%CI: 84–100), and of 90% to detect a VL≥5000 copies (70–97). Within the score, adherence<95%, CD4-count<100/µl and papular pruritic eruption were the strongest single predictors. Among 47 patients failing, 8 (17%) died before or within 4 weeks after being switched. Overall mortality was 4 (20%) among those with score≥5 and 4 (5%) if score<5 (OR 4.3; 95%CI: 0.96–18.84, p = 0.057).

Conclusion

A score≥5 among patients fulfilling WHO-criteria had a PPV of 100% for a detectable VL and 90% for viral failure. In settings without regular access to VL-testing, this PPV may be considered high enough to switch this patient-group to second-line treatment without confirmatory VL-test.

Expansion of CD4+CD25+FOXP3+ regulatory T cells in infants of mothers with type 1 diabetes

BACKGROUND

Reduced risk for type 1 diabetes (T1D) has been reported in the offspring of mothers with T1D when compared with children of affected fathers.

OBJECTIVE

To evaluate the hypothesis that exposure of the offspring to maternal insulin therapy induces regulatory mechanisms in utero, we compared the FOXP3 expressing regulatory T cells in cord blood (CB) of infants born to mothers with or without T1D.

SUBJECTS AND METHODS

Cord blood mononuclear cells (CBMCs) from 20 infants with maternal T1D and from 20 infants with an unaffected mother were analyzed for the numbers of CD4+CD25+FOXP3+ cells ex vivo and after in vitro stimulation with human insulin by flow cytometry. The mRNA expression of FOXP3, NFATc2, STIM1, interleukin (IL)-10, and transforming growth factor (TGF)-β was measured by real-time reverse transcription polymerase chain reaction.

RESULTS

The percentage of FOXP3+ cells in CD4+CD25(high) cells was higher in the CB of the infants with maternal T1D when compared with the infants of unaffected mothers (p = 0.023). After in vitro insulin stimulation an increase in the percentage of FOXP3+ cells in CD4+CD25(high) cells (p = 0.0002) as well as upregulation of FOXP3, NFATc2, STIM1, IL-10, and TGF-β transcripts in CBMCs (p < 0.013 for all; Wilcoxon test) was observed only in the offspring of mothers with T1D, in whom the disease-related PTPN22 allele was associated with reduced STIM1 and NFATc2 response in insulin-stimulated CBMCs (p = 0.007 and p = 0.014).

CONCLUSIONS

We suggest that maternal insulin treatment induces expansion of regulatory T cells in the fetus, which might contribute to the lower risk of diabetes in children with maternal vs. paternal diabetes.

Effects of valacyclovir on markers of disease progression in postpartum women co-infected with HIV-1 and herpes simplex virus-2

Objective

Herpes simplex virus type 2 (HSV-2) suppression has been shown to reduce HIV-1 disease progression in non-pregnant women and men, but effects on pregnant and postpartum women have not been described.

Methods

We analyzed data from a cohort of Kenyan women participating in a randomized clinical trial of HSV-2 suppression. Pregnant HIV-1-seropositive, HSV-2-seropositive women who were not eligible for antiretroviral therapy (WHO stage 1–2, CD4>250 cells/µl) were randomized to either 500 mg valacyclovir or placebo twice daily from 34 weeks gestation through 12 months postpartum. Women received zidovudine and single-dose nevirapine for prevention of mother-to-child HIV-1 transmission. HIV-1 progression markers, including CD4 count and plasma HIV-1 RNA levels, were measured serially. Multivariate linear regression was used to compare progression markers between study arms.

Results

Of 148 women randomized, 136 (92%) completed 12 months of postpartum follow-up. While adjusted mean CD4 count at 12 months (565 cells/µl placebo arm, 638 cells/µl valacyclovir arm) increased from antenatal levels in both arms, the mean CD4 count increase was 73 cells/µl higher in the valacyclovir arm than placebo arm (p = 0.03). Mean increase in CD4 count was 154 cells/µl in the valacyclovir arm, almost double the increase of 78 cells/µl in the placebo arm. At 12 months, adjusted HIV-1 RNA levels in the placebo arm increased by 0.66 log₁₀ copies/ml from baseline, and increased by only 0.21 log₁₀ copies/ml in the valacyclovir arm (0.40 log₁₀ copies/ml difference, p = 0.001).

Conclusion

Women randomized to valacyclovir suppressive therapy during pregnancy and postpartum had greater increases in CD4 counts and smaller increases in plasma HIV-1 RNA levels than women in the placebo arm. Valacyclovir suppression during pregnancy and breastfeeding may improve outcomes and delay antiretroviral therapy for HIV-1/HSV-2 co-infected women.