A novel gut microbiome-immune axis influencing pathology in HCMV infected infants with neonatal cholestasis.

The interplay of active HCMV infection with gut dysbiosis in the immunopathology of cholestasis in neonates and infants remains unexplored. In this study, we evaluated gut microbiome profiles and immune dysfunction in a cohort of HCMV infected cholestatic infants (IgM positive, N = 21; IgM negative, N = 25) compared to healthy infants, N = 10. HCMV infected IgM positive individuals exhibited increased clinical severity in terms of liver dysfunction, altered CD4+: CD8+ ratio, and elevated Granzyme B levels in cellular immune subsets. Gut microbiome analysis revealed distinct and differential diversity and composition within infected groups aligned with clinical severity reflected through the increased abundance of Gammaproteobacteria, reduced Bifidobacteria, and a unique signature mapping to the HCMV infected IgM negative group. Correlation analyses revealed associations between Bifidobacterium breve, Gammaproteobacteria, Firmicutes, Clostridia, Finegoldia magna, Veillonella dispar, and Granzyme B expressing immune cell subsets. Our study describes a novel gut microbiome-immune axis that may influence disease severity in cholestatic infants with active HCMV infection.

Integrated immune monitoring of HCMV infection in pregnant women with complications and its association with adverse pregnancy outcomes.

Human Cytomegalovirus (HCMV) infection is associated with bad obstetric history (BOH) and adverse pregnancy outcomes (APO). Here, we characterized antiviral humoral profiles, systemic and virus specific cellular immune responses concurrently in pregnant women (n = 67) with complications including BOH and associated these signatures with pregnancy outcomes. Infection status was determined using nested blood PCR, seropositivity and IgG avidity by ELISA. Systemic and HCMV specific (pp65) cellular immune responses were evaluated by flow cytometry. Seropositivity was determined for other TORCH pathogens (n = 33) on samples with recorded pregnancy outcomes. This approach was more sensitive in detecting HCMV infection. Blood PCR positive participants, irrespective of their IgG avidity status, had higher cytotoxic potential in circulating CD8+ T cells (p < 0.05) suggesting that infection associated cellular dysfunction was uncoupled with avidity maturation of antiviral humoral responses. Also, impaired anamnestic degranulation of HCMV-pp65-specific T cells compared to HCMV blood PCR negative participants (p < 0.05) was observed. APO correlated with HCMV blood PCR positivity but not serostatus (p = 0.0039). Most HCMV IgM positive participants (5/6) were HCMV blood PCR positive with APO. None were found to be IgM positive for other TORCH pathogens. Multiple TORCH seropositivity however was significantly enriched in the APO group (p = 0.024). Generation of HCMV specific high avidity IgG antibodies had no bearing on APO (p = 0.9999). Our study highlights the utility of an integrated screening approach for antenatal HCMV infection in the context of BOH, where infection is associated with systemic and virus specific cellular immune dysfunction as well as APO.

Discordance between TST and QFT-TBGold Plus for Latent Tuberculosis Screening among Under-Five Children: An Interim Analysis.

AIM: To analyze the agreement between tuberculin skin test (TST) and fourth-generation QuantiFERON (QFT)-TB Gold Plus [interferon gamma (INF-γ) release assays (IGRA)] for latent tuberculosis infection (LTBI) diagnosis among under-five children who are undernourished and/or who have history of contact with active tuberculosis (TB) patients. METHODS: Children from the age group of 6 months to 5 years (undernourished or tuberculosis household contacts) were screened through anganwadis (government playschools) and TB Health posts from Mumbai, India during September 2019 to January 2021. Both TST and QFT-TB Gold Plus test were carried out to diagnose LTBI. RESULTS: Out of the total 299, 35 (11.7%) (95% CI 8.1-15.3%) children tested positive by IGRA (QFT-TB Gold Plus) and 68 (22.7%) (95% CI 18.0-27.4%) by TST, suggestive of moderate concordance (κ = 0.483) between both tests. IGRA and TST showed moderate concordance in children <24 months (κ = 0.478). Moreover, 26 (21.1%) children with TB contact had both TST and IGRA positive with moderate concordance (κ = 0.550). A fair concordance (κ = 0.396) was observed between IGRA and TST in undernourished children. Also, 45 (15.0%) children showed discordance of which 39 (13.0%) had positive TST but negative IGRA and 6 (2.0%) had negative TST but positive IGRA. CONCLUSIONS: The study strongly recommends both TST and QFT-TB Gold Plus test for the diagnosis of LTBI in under-five children. A moderate concordance in children <24 months endorses the reliability of QFT-TB Gold Plus in diagnosing LTBI in this age group. This study highlights the need for screening undernourished children for LTBI to consider repeating IGRA testing for TST positives as per the window period and risk of ongoing exposure.

The current study focuses on discordance and concordance between tuberculin skin test (TST) and fourth-generation QuantiFERON (QFT)-TB Gold Plus [interferon gamma (INF-γ) release assays (IGRA)] for latent tuberculosis infection (LTBI) diagnosis among at-risk under-five children who are underweight and/or who have history of contact with active tuberculosis patients. The IGRA prevalence came out to be 11.7% (95% CI 8.1­15.3%) whereas the TST prevalence turned out to be 22.7% (95% CI 18.0­27.4%). A stronger concordance was observed between IGRA and TST among the age group of 2 to 5 years, and a relatively fair one for children below the age of 1 year. The present study strongly recommends to include both TST and IGRA test for the diagnosis of LTBI with respect to Indian pediatric population. This study also suggests the importance of repetition of IGRA for TST positive patients. Another vital opinion that is showcased in the present study is the inclusion of undernourished pediatric population residing in at-risk areas like urban slums for routine LTBI screening programs.

Hepatic interferon γ and tumor necrosis factor a expression in infants with neonatal cholestasis and cytomegalovirus infection.

AIM OF THE STUDY: To determine the hepatic interferon γ (IFN-γ) and tumor necrosis factor α (TNF-α) levels in infants with neonatal cholestasis (NC) and associated cytomegalovirus (CMV) infection. MATERIAL AND METHODS: This study was conducted in 21 infants with NC over a period of 6 months from June 2017 to December 2017 to determine the hepatic IFN-γ and TNF-α levels in infants with NC and associated CMV infection. RESULTS: IFN-γ levels were positive in 16 (80%), low positive in 3 (16%) and negative in 1 (5%) patients. High positive and positive TNF-α levels were seen in 9 (56.3%) patients with positive liver CMV PCR and low positive levels were seen in 7 (43.7%) patients with positive liver CMV PCR (odds ratio [OR] = 2.6). Positive IFN-γ was present in 13 (81.3%) patients with positive liver CMV PCR and low positive or negative IFN-γ was seen in 3 (18.7%) patients with positive liver CMV PCR (OR = 2.2). Six (60%) patients with positive or high positive TNF-α levels in liver tissue had biliary atresia (BA) whereas 7 (77.7%) with low positive TNF-α levels had non-BA neonatal hepatitis (OR = 5.25). Six (37.5%) patients with positive IFN-γ had BA whereas 2 (50%) patients with low positive or negative IFN-γ had BA (OR = 0.6). CONCLUSIONS: There is high prevalence of CMV in liver tissues in patients with NC and elevated TNF-α and IFN-γ levels are seen in these patients. Elevated TNF-α is also seen in patients with BA. The association of elevated TNF-α, BA and CMV infection needs to be evaluated further.

Detection of Cytomegalovirus in Liver Tissue by Polymerase Chain Reaction in Infants With Neonatal Cholestasis.

AIM: Cytomegalovirus (CMV) is associated with neonatal cholestasis (NC). Diagnosis of CMV infection is most often based on either positive blood CMV IgM or CMV blood polymerase chain reaction (PCR). Isolation of CMV in liver tissues in patients with NC has rarely been reported. This study was undertaken to see if CMV is present in liver tissues of patients with NC and evaluate the correlation between positive CMV PCR in liver tissue with the serology and blood PCR. METHODS: This study was conducted in 31 infants with NC from June 2015 to December 2016. All patients underwent blood CMV IgM, blood CMV PCR and liver CMV PCR. Prevalence of CMV in NC based on positive liver CMV PCR was calculated. Sensitivity and specificity of the serologic markers and blood CMV PCR to identify CMV infection in the liver was determined. RESULTS: CMV IgM was positive in 13 (42%) patients, CMV IgG was positive in 26 (84%) patients and blood CMV PCR was positive in 23 (74%) patients. Liver CMV PCR was positive in 16 (52%) patients. Fifteen (48%) patients had biliary atresia (BA), 10 (32%) patients had neonatal hepatitis, 5 (16%) had paucity of bile ducts and 1 (3%) had ascending cholangitis. Of the 16 patients with positive liver CMV PCR, 8 (50%) had BA, 4 (25%) had neonatal hepatitis, 3 (19%) had paucity of bile ducts and 1 (6%) had ascending cholangitis. Sensitivity of blood CMV IgM in relation to liver CMV PCR was 69% and specificity was 61%. Sensitivity of blood CMV PCR was 61% and specificity was 71% when compared with liver CMV PCR. CONCLUSION: CMV is present in the liver tissues of more than half the patients with NC. Serology or blood CMV PCR is apparently not an accurate marker of CMV in the liver tissue. Also, CMV infection in children seems to be associated equally with BA or non-BA neonatal hepatitis.

Evaluation of contraceptive potential of a novel epididymal sperm protein SFP2 in a mouse model.

PROBLEM: Sperm flagellar protein 2 (SFP2), which was earlier identified using a novel combinatorial approach, was evaluated for its contraceptive potential in mice. METHOD OF STUDY: Male mice were actively immunized with two synthetic peptides of SFP2. Antipeptide antibody was characterized by Western blot and indirect immunofluorescence. Immune response was monitored, and mating studies were performed 6 and 22 weeks post-immunization. RESULT: Antibodies to the SFP2 peptide 1 recognized a doublet at 220- to 230-kDa region only in the epididymal protein extract. Peptide 1 antibody recognized the cognate protein on spermatozoa from mouse, rat, and human. Histological analysis of testis and epididymis of the immunized mice indicated no deleterious effect. Incubation of sperm with the immune sera of peptide 1 caused significant reduction in motility and viability but did not agglutinate sperm. Only synthetic peptide 1 gave rise to high-level antibodies in all the immunized mice, which on mating resulted in reduced fertility rate (20%) when compared with PBS control animals (100%). The antibody levels in the immunized males declined by 22 weeks post-immunization, resulting in 100% reinstatement of fertility. CONCLUSION: These data provide an experimental basis for the development of effective contraceptive vaccine based on new epididymal target.

Identification and characterization of anti-microbial peptides from rabbit vaginal fluid.

Antimicrobial peptides (AMPs) serve as a first line of host defense and represent an important, though poorly understood components of the innate immune system. The present study was an attempt to identify and characterize the major molecules having anti-bacterial activities from the vaginal fluid of rabbit, Oryctologus cuniculus. AMPs from the rabbit vaginal fluid (RVF) were identified in the acid extracts of pooled RVF samples after RP-HPLC purification. The protein, RVFAMP was effective against gram negative (Escherichia coli and Pseudomonas aeruginosa) and gram positive (Staphylococcus aureus and Streptococcus pyogenes) bacteria. The results of acid urea-PAGE-gel overlay assay (AU-PAGE-GOA) demonstrated clear zone of growth inhibition of E. coli corresponding to 6 and 15 kDa protein bands. LC-MS data of these proteins indicated that 15 kDa protein consists of lysozyme, lipopolysaccharide binding protein (LBP), hemoglobin-α and ß subunits (Hb-α/ß), whereas 9 kDa protein band consists of transthyretin and calcyclin while uteroglobulin and neutrophil antibacterial peptide-5 (NAMP-5) are present in the 6 kDa protein band. Of the eight proteins, Hb-α derived protein was further characterized, as it showed the highest Probability Based Mowse Score (PBMS) of 288. A 25mer peptide, RVFHbαp was active against several clinical pathogens as demonstrated by minimum inhibitory concentration (MIC) and radial diffusion assays (RDA). The interaction of RVFHbαP with bacterial liposome membrane was assessed by calcein dye leakage assay. RVFHbαP did not show cytotoxicity against human endocervical cells (End1/E6E7) or erythrocytes. RT-PCR and immunofluorescence results revealed the expression of RVFHbαP mRNA and protein in rabbit vaginal tissue. To the best our knowledge, this is the first report describing the detection of AMPs in RVFs. In conclusion, these studies indicated that vaginal epithelial cells (VEC) derived RVFHbαP may have therapeutic potential in the management of reproductive well being of rabbits. The major reason for undertaking this study in rabbits is that, it forms an excellent in vivo model system for human's studies.

Chimeric T helper-B cell peptides induce protective response against Japanese encephalitis virus in mice.

Virus neutralizing MAb binding and T helper cell stimulating peptide epitopes from structural and non-structural proteins of Japanese encephalitis virus were delineated. It was observed that priming by T helper peptides potentiated neutralizing antibody response against JE virus. Immunization with chimeric T helper - B cell peptides could thus protect mice from lethal challenge with JE virus.