Increased Frequency of Memory CD4+ T-Cell Responses in Individuals With Previously Treated Extrapulmonary Tuberculosis

Identification of diagnostic biomarkers correlate with immune infiltration in extra-pulmonary tuberculosis by integrating bioinformatics and machine learning

The diagnosis of tuberculosis depends on detecting Mycobacterium tuberculosis (Mtb). Unfortunately, recognizing patients with extrapulmonary tuberculosis (EPTB) remains challenging due to the insidious clinical presentation and poor performance of diagnostic tests. To identify biomarkers for EPTB, the GSE83456 dataset was screened for differentially expressed genes (DEGs), followed by a gene enrichment analysis. One hundred and ten DEGs were obtained, mainly enriched in inflammation and immune -related pathways. Weighted gene co-expression network analysis (WGCNA) was used to identify 10 co-expression modules. The turquoise module, correlating the most highly with EPTB, contained 96 DEGs. Further screening with the least absolute shrinkage and selection operator (LASSO) and support vector machine recursive feature elimination (SVM-RFE) narrowed down the 96 DEGs to five central genes. All five key genes were validated in the GSE144127 dataset. CARD17 and GBP5 had high diagnostic capacity, with AUC values were 0.763 (95% CI: 0.717-0.805) and 0.833 (95% CI: 0.793-0.869) respectively. Using single sample gene enrichment analysis (ssGSEA), we evaluated the infiltration of 28 immune cells in EPTB and explored their relationships with key genes. The results showed 17 immune cell subtypes with significant infiltrations in EPTB. CARD17, GBP5, HOOK1, LOC730167, and HIST1H4C were significantly associated with 16, 14, 12, 6, and 4 immune cell subtypes, respectively. The RT-qPCR results confirmed that the expression levels of GBP5 and CARD17 were higher in EPTB compared to control. In conclusion, CARD17 and GBP5 have high diagnostic efficiency for EPTB and are closely related to immune cell infiltration.

Mycobacterium tuberculosis impairs human memory CD4+ T cell recognition of M2 but not M1-like macrophages

Direct recognition of Mycobacterium tuberculosis (Mtb)-infected cells is required for protection by CD4+ T cells. While impaired T cell recognition of Mtb-infected macrophages was demonstrated in mice, data are lacking for humans. Using T cells and monocyte-derived macrophages (MDMs) from individuals with latent Mtb infection (LTBI), we quantified the frequency of memory CD4+ T cell activation in response to autologous MDMs infected with virulent Mtb. We observed robust T cell activation in response to Mtb infection of M1-like macrophages differentiated using GM-CSF, while M2-like macrophages differentiated using M-CSF were poorly recognized. However, non-infected GM-CSF and M-CSF MDMs loaded with exogenous antigens elicited similar CD4+ T cell activation. IL-10 was preferentially secreted by infected M-CSF MDMs, and neutralization improved T cell activation. These results suggest that preferential infection of macrophages with an M2-like phenotype limits T cell-mediated protection against Mtb. Vaccine development should focus on T cell recognition of Mtb-infected macrophages.

Immune disturbances in female genital tuberculosis and latent genital tuberculosis

BACKGROUND

Female genital tuberculosis (FGTB), an important clinical sub-type of extra-pulmonary tuberculosis (EPTB) is responsible for about 10% cases of infertility in India. Both FGTB and latent genital tuberculosis (LGTB) can cause infertility through blockage of fallopian tubes and through altered uterine endometrial receptivity.

AIMS

This review tries to elucidates the role of various immune factors in FGTB and LGTB.

CONTENT

Various immune disturbances are observed in FGTB and LGTB like growth factors and cytokines which inhibit implantation and several inflammatory signaling pathways like mitogen activated protein kinase (MAPK), natural killer (NK) cells, nuclear factor kappa-B (NF-KB), tumor necrosis factor (TNF), and toll like receptors (TLR) signaling are dysregulated. These altered immune factors and pathways may be detected in the endometrial biopsies at the early stages of disease before permanent damage. Prompt and adequate treatment with the four anti-tubercular drugs (rifampicin [R], isoniazid [H], pyrazinamide [Z], and ethambutol [E]) can increase pregnancy rates in some of these women. Assisted reproduction especially in-vitro fertilization and embryo transfer may be required for some women.

IMPLICATIONS

Inflammatory pathways identified from the gene profiling have enabled development of potential biomarkers for early diagnosis of FGTB. Immunomodulation and novel biotechniques like stem cell transplantation, nanoparticles and host directed therapies are being tried in selected patients of FGTB and LGTB with promising results.

Tuberculosis in international immigrants: profile and vulnerability of cases residing in the municipality of São Paulo, Brazil

Objective

To analyze the profile of immigrants with tuberculosis (TB) and to identify the associated vulnerability characteristics.

Methods

A cross-sectional study which used TB-WEB data from cases residing in São Paulo in 2016 (203 immigrants and 6,069 non-immigrants). The variables were analyzed using prevalence ratio and confidence intervals.

Results

Among the immigrant cases, 67% were Bolivians. When compared to non-immigrants, immigrants were younger and frequently indigenous or presenting yellow ethnicity. They were also associated with a higher education level. We observed less immigrants having extrapulmonary TB and comorbidities, such as HIV/AIDS, diabetes mellitus, or drug use. Compared to cured cases, immigrants were not associated with treatment default and death, but they were associated with transfer to another state/country.

Conclusions

Younger individuals and higher education levels were identified among immigrants, as well as a lower occurrence of comorbidities and drug use. It is believed that these results have led immigrants to more favorable outcomes of TB treatment.