Biology subjects

Khatun, A.

Publications and source records attributed to Khatun, A..

4 recordsLinked to original sources

bioRxiv2025

Serosurveillance Studies of Peste des Petits Ruminants (PPR) Virus in Sheep and Goats in South Asia: A Systematic Review and Meta-analysis

BackgroundPeste des Petits Ruminants (PPR), also known as the goat plague, is one of the WOAH-listed A, highly contagious and economically important viral transboundary animal diseases affecting small ruminants, and having a significant impact on the global livestock industry and international animal traffic. ObjectiveThe present study aimed to use a systematic approach to assess the pooled seroprevalence of PPRV in sheep and goats in South Asia, through a systematic review and meta-analysis of published data. MethodsA thorough search on various databases was performed to identify published research articles published between January 2000 and June 2025 reporting the seroprevalence of PPRV in small ruminants in South Asia. The articles were chosen on the basis of specific inclusion and exclusion criteria. Since the heterogeneity among the studies was significant, the pooled seroprevalence was estimated via a random effects meta-analysis model, using Stata (v19) and R software (v4.5.0). ResultsIn sheep and goats, the estimated pooled seroprevalence of PPR was 42.4% (95% CI: 35.0-49.9), whereas it was 41.8% (95% CI: 33.7-50.1) in goats and 44.5% (95% CI: 37.0- 52.0) in sheep. Subgroup analysis revealed that the pooled seroprevalence of PPRV in sheep and goat by country and vaccination status was greater in Nepal (57.0%, 95% CI: 8.4-97.7) and in vaccinated animals (57.5%, 95% CI: 47.9-66.9). ConclusionThis study highlights the need for coordinated actions, including vaccination, surveillance, and strict biosecurity, to control and eradicate the disease effectively. Moreover, authorities should adopt evidence-based strategies to support the global goal of eradicating PPR by 2030, as recommended by the WOAH.

microbiology↗

bioRxiv2022

Delineating the transcriptional landscape and clonal diversity of virus- specific CD4 + T cells during chronic viral infection

CD4+ T cells responding to chronic viral infection often acquire a dysfunctional phenotype that is characterized by a progressive loss in Th1 differentiation and function, as well as an upregulation of multiple co-inhibitory receptors. Conversely, CD4+ T cells, and particularly Tfh cells, gradually increase their production of IL-21 during chronic viral infection, which is critical to sustain humoral immunity and also effector CD8+ T cell responses. Recent evidence further indicates that a memory-like CD4+ T cell population also develops in the face of persistent infection, although how the transcriptional landscape of this subset, along with the Th1 and Tfh cell subsets from chronic infection, differ from their acute infection counterparts remains unclear. Additionally, whether cell-intrinsic factors such as TCR usage influence CD4+ T cell fate commitment during chronic infection has not previously been studied. Herein, we perform single-cell RNA sequencing (scRNA-seq) combined with single-cell T cell receptor sequencing (scTCR-seq) on virus-specific CD4+ T cells during chronic lymphocytic choriomeningitis virus (LCMV) infection. We identify several transcriptionally distinct states among the Th1, Tfh, and memory-like T cell subsets that form at the peak of chronic infection, including the presence of a previously unrecognized Slamf7+ subset with cytolytic features, and show that the relative distribution of these populations differs substantially between acute and persistent LCMV infection. Moreover, while the progeny of most T cell clones displays membership within each of these transcriptionally unique populations, overall supporting a one cell-multiple fate model, a small fraction of clones display a biased cell fate decision, suggesting that TCR usage may impact CD4+ T cell development during chronic viral infection. Importantly, a comparative analysis further reveals both subset-specific and core gene expression programs that are differentially regulated between CD4+ T cells responding to acute and chronic viral infection. Together, these data may serve as a useful framework and allow for a detailed interrogation into the clonal distribution and transcriptional circuits underlying CD4+ T cell differentiation during chronic viral infection.

immunology↗

bioRxiv2021

Nonsterile immunity to cryptosporidiosis in infants is associated with mucosal IgA against the sporozoite and protection from malnutrition

We conducted a longitudinal study of cryptosporidiosis from birth to three years of age in an urban slum of Dhaka Bangladesh. Fecal DNA was extracted from monthly surveillance samples and diarrheal stool samples collected from 392 infants from birth to three years. A pan-Cryptosporidium qPCR assay was used to identify sub-clinical and symptomatic cryptosporidiosis. Anthropometric measurements were collected quarterly to assess child nutritional status. 31% (121/392) of children experienced a single and 57% (222/392) multiple infections with Cryptosporidium. Repeat infections had a lower burden of parasites in the stool (Cq slope = -1.85; p<0.0001) and were more likely to be sub-clinical (Chi square test for trend; p=0.01). Repeat infections were associated with the development of growth faltering (Pearson correlation = -0.18; p=0.0004). High levels of fecal IgA antibodies against the Cryptosporidium Cp23 sporozoite protein at one year of life were associated with a delay in reinfection and amelioration of growth faltering through three years of life (HAZ IgA high responders -1.323 {+/-} 0.932 versus HAZ -1.731 {+/-} 0.984 p=0.0001). We concluded that nonsterile immunity to cryptosporidiosis in young children was associated with high levels of mucosal IgA anti-Cp23 and protection from diarrhea and growth faltering. Authors SummaryCryptosporidium is one of the top causes of diarrhea and growth faltering in Bangladesh infants. We discovered that a prior infection resulted in incomplete immunity that protected from diarrhea and growth faltering but not infection and was associated with mucosal IgA against a sporozoite surface protein Cp23. The most important implication of these findings is that a cryptosporidiosis vaccine may not need to achieve complete protection from infection to have a beneficial impact on child health.

microbiology↗

bioRxiv2021

A reservoir of stem-like CD8 T cells in the tumor-draining lymph node maintains the ongoing anti-tumor immune response

"Stem-like" TCF1+ CD8+ T cells (TSL) are necessary for long-term maintenance of T cell responses and the efficacy of immunotherapy but, as tumors contain signals that should drive T-cell terminal-differentiation, how these cells are maintained in tumors remains unclear. We found that a small number of TCF1+ tumor-specific CD8+ T cells were present in tumors throughout development. Yet, most intratumoral T cells differentiated as tumors progressed, corresponding with an immunologic shift in the tumor microenvironment (TME) from "hot" to "cold". By contrast, most tumor-specific CD8+ T cells in tumor-draining lymph nodes (dLNs) had functions and gene expression signatures similar to TSL from chronic LCMV infection and this population was stable over time, despite the changes in the TME. dLN T cells were the precursors of their more-differentiated intratumoral counterparts, and maintenance of TCF1 by intratumoral T cells required continuous migration from dLNs. Finally, TSL CD8 T cells were also present in LNs from lung adenocarcinoma patients, suggesting this population is also relevant in human disease. Thus, we propose that the dLN TSL reservoir has a critical function during tumor development in sustaining antitumor T cells during tumor development and protecting them from the terminal differentiation that occurs in the TME.

immunology↗