Galectin-9 (Gal-9) and osteopontin (OPN) play immunomodulatory roles in tuberculosis and HIV infections. Evaluation of their levels as well as their interplay with different pro-inflammatory cytokines is critical to understand their role in immunopathogenesis of HIV/tuberculosis co-infection considering the complexity of the disease. Plasma levels of these proteins were measured by ELISAs in HIV-negative individuals with pulmonary (n = 21), extrapulmonary (n = 33), and latent tuberculosis (n = 22) and in HIV infected patients with pulmonary (n = 14), latent tuberculosis (n = 17), and without tuberculosis (n = 41). Levels of pro-inflammatory cytokines were estimated by Luminex assay. Receiver operated characteristic curve analysis was performed to evaluate discriminatory roles of these proteins. Spearman's correlation analysis was performed with the markers of HIV and tuberculosis disease progression to evaluate their immunopathogenic roles. Gal-9 and OPN levels were higher in HIV uninfected patients with active tuberculosis than with latent tuberculosis. Gal-9 but not OPN levels were higher in HIV infected patients with active tuberculosis than with latent tuberculosis. Area under curve for Galectin-9 was >0.9 in HIV/tuberculosis coinfection and extrapulmonary tuberculosis. OPN and IL-6 levels were higher in patients with severe chest X-ray grade indicating its association with severity of the disease and positively correlated with each other. Stronger positive and negative correlations of Gal-9 levels, respectively, with viral loads and CD4 cell counts in HIV infected patients were observed than OPN levels indicating their association with HIV disease progression. Thus, significantly elevated Gal-9 levels were reported for the first time in HIV/tuberculosis co-infection and extrapulmonary tuberculosis in our study than single infections with HIV and tuberculosis. The study indicated a need for further evaluation of monitoring role of Gal-9 for detection of developing tuberculosis in HIV infected individuals. The findings also indicated differential roles of Gal-9 and OPN in the pathogenesis of tuberculosis and HIV infections.

The emergence of novel variants of SARS-CoV-2 in several countries has been associated with increased transmissibility or reduced neutralization potential of antibodies against the Wuhan virus (wild type). From August 2021 onwards, India experienced a progressive decline in the number of active SARS-CoV-2 infections, indicative of a downward trend in the explosive second wave. This prospective study was conducted quarterly for one year (May 2020 to June 2021) at a tertiary care hospital in the city of Pune in western India. Receptor-binding domain (RBD, n = 319) and full genome (n = 20) sequences from viral-RNA-positive nasopharyngeal swabs of COVID-19 patients representing the first and second waves were used for analysis. No Brazilian, South African, or California variants were detected in this study. Until December 2020, only the wild-type strain was prevalent. Concurrent with the upsurge of the second wave in March 2021, 73% (33/45) of RBD sequences harboured L452R/E484Q mutations characteristic of the Kappa variant. In April 2021, co-circulation of Kappa (37%) and Delta (L452R/T478K, 59%) variants was recorded. During May and June 2021, the Delta variant became the predominant circulating variant, and this coincided with a significant decline in the number of COVID-19 cases. Of the 20 full genome sequences, six isolates each exhibited signature mutations of the Kappa and Delta variant. With several states witnessing a reduction in the number of COVID-19 cases, continuous monitoring of newer mutations and assessment of their effect on virus transmissibility and their impact on vaccinated or previously exposed individuals is necessary. Supplementary Information The online version contains supplementary material available at 10.1007/s00705-021-05320-7.

An enzyme-linked immunosorbent assay (ELISA) for the detection of IgG antibodies against the pandemic H1N1 2009 influenza A virus, employing a recombinant hemagglutinin protein of the virus, was compared to the hemagglutination inhibition (HI) test using 783 serum samples. The results showed a concordance of 98.4%, suggesting the utility of the ELISA in serosurveillance. Two hundred sixty-nine (100%) serum samples with an HI titer of >20 were ELISA reactive.Influenza viruses are negative-strand RNA viruses that belong to the family Orthomyxoviridae, which includes 4 genera, Influenzavirus A, B, and C and Thogotovirus. Influenza A viruses are widely distributed in nature and can infect a wide variety of mammals and birds. Based on the antigenicity of the two surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA), influenza A viruses have been classified into 16 HA and 9 NA subtypes. Of these, H1, H2, and H3 HA subtypes and N1 and N2 NA subtypes have circulated in human populations. In recent years, H5N1 virus of avian origin was expected to be a pandemic-causing pathogen (4). However, the first pandemic of this century was caused by a novel H1N1 influenza A virus of swine origin that emerged in 2009 (hereinafter called p-H1N1-09) (3, 5).Due to the circulation of several influenza A virus subtypes, cross-reactivity is a major problem in influenza virus serology. The inhibition of hemagglutination (HI) caused by antibodies to the HA of the virus is routinely used for assessing the prevalence of a specific virus in a community or an animal population.India was affected by the pandemic H1N1 influenza during the latter half of 2009 (2). In order to understand the degree of exposure of different populations to the virus, an extensive serosurvey was undertaken by the National Institute of Virology, Pune, India. The test of choice, HI, was performed as described earlier (1). Considering the requirement of fresh red blood cells and time and the cumbersome protocol, it was thought important to evaluate the utility of a recombinant HA protein enzyme-linked immunosorbent assay (ELISA) for the detection of p-H1N1-09 IgG antibodies as evidence of exposure to this novel virus.The HA gene of the p-H1N1-09 influenza virus isolated at the National Institute of Virology (A/India-Blore/NIV310/ 2009, GenBank accession no. GU292347) was PCR amplified, cloned into the pFastBac1 vector (Invitrogen) within the EcoRI and XhoI restriction sites, and expressed with a baculovirus expression system (Invitrogen) in an insect cell line. The sequence of the cloned HA was identical to that of the original isolate. The HA protein was purified by lentil lectin affinity chromatography (GE Healthcare) and used for ELISA.An indirect sandwich ELISA was performed. Briefly, a Maxisorb microtiter plate (Nunc) was coated with p-H1N1-09 HA protein, 2 g/well, and incubated at 37°C for 2 h. The plate was blocked with phosphate-buffered saline (PBS) containing 10% donor calf serum, 0.5% Tween 20, 0.5% gelatin (blocking solution) at 37°C for 30 min. A...

Highlights d Chronic HIV infection selectively impairs Mtb-specific effector cytokine responses d Chronic HIV infection augments Mtb-specific proinflammatory Th17 responses d HIV-induced changes in Mtb-specific cells are independent of viral load and MIP-1b d ART/ATT restore anti-inflammatory and dampen proinflammatory Th17 responses

Continued evolution of highly pathogenic H5N1 viruses causing high mortality in humans obviates need for broadly cross-reactive vaccines. For this, hemagglutinin (HA) inducing specific protective antibodies, highly conserved nucleoprotein (NP), and ectodomain of matrix (M2e) protein, either singly or in combination, were evaluated in BALB/c mice. Recombinant HA and NP (baculovirus system) and M2e (synthetic peptide) and 3 adjuvants, that is, liposomes, Mw (heat killed Mycobacterium w), and alum were utilized for the homologous virus challenge. Additional immunogens included liposome-encapsulated HA/NP proteins and corresponding DNAs. Mice groups received two doses of respective formulations given at 3-week intervals and challenged intranasally with 100LD50 of H5N1 virus strain. Dynamics of weight loss, lung viral load, titres of IgG-anti-HA, NP, and M2e antibodies (ELISA), and IgG-subtype analysis was done. Two doses of all the formulations led to 100% seroconversion against the immunogens evaluated (100% seroconversion after the first dose in majority). Antibody titres against the components were dependent on the adjuvant and combination. HA-driven Th2 response with all the adjuvants, balanced Th1/Th2 response to NP protein, and Th2-bias with alum were noted. Low anti-M2e antibody titres did not allow subtype analysis. On challenge, complete protection was observed with Mw-HA, alum-HA+NP, Lipo-HA+NP+M2e, alum-HA+NP+M2e, and HA-DP formulations with 12-fold, 8-fold, 720-fold, 17-fold, and no reduction, respectively, in lung viral load. In conclusion, the results identify several adjuvant-immunogen combinations conferring 100% protection in mice that need further evaluation in higher animals.