Traditionally, the distribution of the Mycobacterium tuberculosis genotypes in India has been characterized by widespread prevalence of ancestral lineages (TbD1+ strains and variants) in the south and the modern forms (TbD1− CAS and variants) predominating in the north of India. The pattern was, however, not clearly known in the south-central region such as Hyderabad and the rest of the state of Andhra Pradesh where the prevalence of both tuberculosis (TB) and human immunodeficiency virus (HIV) infection is one of the highest in the country; this area has been the hotspot of TB vaccine trials. Spoligotyping of 101 clinical isolates obtained from Hyderabad and rural Andhra Pradesh confirmed the occurrence of major genogroups such as the ancestral (or the TbD1+ type or the East African Indian (EAI) type), the Central Asian (CAS) or Delhi type and the Beijing lineage in Andhra Pradesh. Sixty five different spoligotype patterns were observed for the isolates included in this study; these were further analyzed based on specific genetic signatures/mutations. It was found that the major genogroups, CAS and “ancestral,” were almost equally prevalent in our collection but followed a north-south compartmentalization as was also reported previously. However, we observed a significant presence of MANU lineage in south Andhra Pradesh, which was earlier reported to be overwhelmingly present in Mumbai. This study portrays genotypic diversity of M. tuberculosis from the Indian state of Andhra Pradesh and provides a much needed snapshot of the strain diversity that will be helpful in devising effective TB control programs in this part of the world.

SUMMARY We studied the factors that regulate IL-23 receptor expression and IL-17 production in human tuberculosis infection. Mycobacterium tuberculosis (M. tb)-stimulated CD4+ cells from tuberculosis patients secreted less IL-17 than did CD4+ cells from healthy tuberculin reactors (PPD+). M. tb cultured monocytes from tuberculosis patients and PPD+ donors expressed equal amounts of IL-23p19 mRNA and protein, suggesting that reduced IL-23 production is not responsible for decreased IL-17 production by tuberculosis patients. Freshly isolated and M. tb- stimulated CD4+ cells from tuberculosis patients had reduced IL-23 receptor and phosphorylated STAT3 (pSTAT3) expression, compared to PPD+ donors. STAT3 siRNA reduced IL-23 receptor expression, and IL-17 production by CD4+ cells from PPD+ donors. Tuberculosis patients had increased number of PD-1+ T cells compared to healthy PPD+ individuals. Anti-PD-1 antibody enhanced pSTAT3 and IL-23R expression and IL-17 production by M. tb cultured CD4+ cells of tuberculosis patients. Anti-tuberculosis therapy decreased PD-1 expression, increased IL-17 and IFN-γ production and pSTAT3, IL-23R expression. These findings demonstrate that increased PD-1 expression and decreased pSTAT3 expression reduces IL-23 receptor expression and IL-17 production by CD4+ cells of tuberculosis patients.

BackgroundHousehold contacts of diagnostically established tuberculosis (TB) patients are highly susceptible to disease development. It is surmised that cytokines perhaps play a synergistic and a prognostic role in the activation of the otherwise latent infection in these house hold contacts. Evaluation of the cytokines and any of their inherent polymorphisms might provide a useful diagnostic tool in evaluating the immune regulation and the progression of the disease. The cytokines thus released in a paracrine manner in serum may also provide an indirect measure of the cytokine function.ObjectiveThe present study was aimed to evaluate the levels of TNF-α, IL-10 & IL-6 cytokines and their correlation with genotype variants amongst tuberculosis patients and their household contacts.MethodsThe cytokine levels were estimated in serum by enzyme-linked immunosorbent assay (ELISA) and their polymorphisms were studied by amplification refractory mutation system polymerase chain reaction (ARMs PCR) in active pulmonary tuberculosis patients (APTB = 150), household contacts (HHC = 190), and healthy controls (HC = 150).ResultsThe median values of TNF-α cytokine were significantly high among APTB and HHC compared to HCs (P< 0.0001 and 0.0001). IL-6 levels also were elevated among APTB compared to HHC and HC, and a significant difference was observed between APTB and HHC at P<0.0001; APTB & HC at P< 0.04; HHC & HC at P< 0.01. The IL-10 levels were low in APTB compared to HHC and HCs and no significant difference was observed. TNF-α/IL-10 ratio was significant and indicated Th1 predominance in APTB and HHC. IL-6/IL-10 showed pronounced Th1 expression in APTB and Th2 in HHC and HC. The ROC analysis indicated that both IL-10 and IL-6 can be used to decide the risk of exposed individual to a disease. The results of multivariate analysis indicate that IL-10 (-1082) GA genotype was significantly associated with p<0.028 in APTB. No significant association was observed between genotypes, other serum cytokine levels and clinical characteristics between APTB, HHC and HCs.ConclusionLarge sample size with follow-up at different time points may further illuminate the role of IL-10 and IL-6 cytokines as a prognostic marker in house hold contacts.

Vitamin D, an immunomodulator of macrophage function, can activate human antimycobacterial activity. Vitamin D deficiency (VDD) is associated with an impaired mycobacterial immunity and susceptibility to tuberculosis. It has been found that vitamin D and its receptor may be essential for immune function. In this study, we examined the serum 25(OH) vitamin D levels and its receptor (VDR) polymorphisms with susceptibility to tuberculosis in patients, household contacts and healthy controls. Serum 25(OH) vitamin D levels were measured in 75 cases (25 patients, 25 household contacts and 25 healthy controls), and polymorphisms (BsmI and FokI) were carried out in 335 cases (110 patients, 110 household contacts and 115 healthy controls). The proportion of serum 25(OH) vitamin D deficiency and insufficiency was high in patients (44, 58%) and household contacts (40, 48%) compared to controls (48%). The BB and Bb genotypes of BsmI were significantly associated in patients (P < 0.014; OR: 0.509; CI: 0.265-0.876) (P < 0.001; OR: 2.351; CI: 1.368-4.041) and household contacts (P < 0.04; OR: 0.575; CI: 0.336-0.985); (P < 0.002; OR: À2.267; CI: 1.32-3.895) when compared to healthy controls. The diplotype and MDR analysis showed the high-risk genotypes of BsmI and FokI polymorphisms. Vitamin D deficiency and its association with VDR gene polymorphisms may be useful to identify the high-risk group individuals.