Neena Khanna

Disruption of HLA-DR raft, deregulations of Lck-ZAP-70-Cbl-b cross-talk and miR181a towards T cell hyporesponsiveness in leprosy.

Leprosy, a chronic human disease, results from infection of Mycobacterium leprae. Defective CMI and T cell hyporesponsiveness are the major hallmark of M. leprae pathogenesis. The present study demonstrates immunological-deregulations that eventually lead to T cell anergy/hyporesponsiveness in M. lepare infection. We firstly, evaluated the membrane fluidity and antigen-presenting-lipid-raft (HLA-DR) on macrophages of leprosy patients using fluorescence anisotropy and confocal microscopy, respectively. Increased membrane fluidity and raft-out localizations of over-expressed HLA-DR towards BL/LL pole are pinpointed as major defects, may be leading to defective antigen presentation in leprosy. Furthermore, altered expression and localization of Lck, ZAP-70, etc. and their deregulated cross talks with negative regulators (CD45, Cbl-b and SHP2) turned out to be the major putative reason(s) leading to T cell hyporesponsiveness in leprosy. Deregulations of Lck-ZAP-70 cross-talk in T cells were found to be associated with cholesterol-dependent-dismantling of HLA-DR rafts in macrophages in leprosy progression. Increased molecular interactions between Cbl-b and Lck/ZAP-70 and their subsequent degradation via ubiquitinization pathway, as result of high expression of Cbl-b, were turned out to be one of the principal underlying reason leading to T cell anergy in leprosy patients. Interestingly, overexpression of SHP2 due to gradual losses of miR181a and subsequent dephosphorylation of imperative T cell signaling molecules were emerged out as another important reason associated with prevailing T cell hyporesponsiveness during leprosy progression. Thus, this study for the first time pinpointed overexpression of Cbl-b and expressional losses of miR-181 as important hallmarks of progression of leprosy.

Adjuvant Role of Amniotic Membrane Transplantation in Acute Ocular Stevens-Johnson Syndrome: A Randomized Control Trial.

PURPOSE To evaluate the adjuvant role of amniotic membrane transplantation (AMT) in cases of acute ocular Stevens-Johnson syndrome (SJS). DESIGN Prospective randomized controlled clinical trial. PARTICIPANTS Twenty-five patients (50 eyes) with acute ocular SJS who presented within 4 weeks of onset of symptoms were recruited. METHODS The eyes were randomized into 2 groups that underwent either AMT with medical therapy (MT; n = 25) or standard MT alone (n = 25). The patients were evaluated at presentation and during follow-up at 1 week and 1, 3, and 6 months. The parameters evaluated were the best-corrected visual acuity (BCVA), Schirmer test, tear film breakup time (TBUT), conjunctival congestion, corneal haze, vascularization, conjunctivalization, and limbal stem cell involvement. Lid edema, symblepharon, ankyloblepharon, ectropion, entropion, trichiasis, and metaplastic lashes also were analyzed. MAIN OUTCOME MEASURES Maintenance of BCVA and stable ocular surface. RESULTS At the end of 6 months, the mean BCVA was significantly better in the AMT group (0.068±0.10 logMAR units) compared with the MT group (0.522±0.52 logMAR units; P = 0.042). The mean TBUT in the AMT and MT groups was 9.92±4.1 and 6.96±4.5 seconds, respectively (P = 0.015). The mean Schirmer test results in the AMT and MT groups were 15.4±6.3 and 8.64±5.4 mm, respectively (P < 0.001). Conjunctival congestion persisted in 44% (11/25) in the MT group compared with 4% (1/25) in the AMT group (P = 0.03) at the end of the 6-month follow-up. No case in the AMT group demonstrated corneal haze, limbal stem cell deficiency, symblepharon, ankyloblepharon, or lid-related complications. Among eyes in the MT group, corneal haze occurred in 44% (11/25; P = 0.001), corneal vascularization and conjunctivalization in 24% (6/25; P = 0.03), symblepharon in 16% (4/25; P = 0.12), ankyloblepharon in 4% (1/25; P = 1.00), ectropion and entropion in 8% (2/25; P = 0.47), and trichiasis and metaplastic lashes in 24% (6/25; P = 0.03) eyes. CONCLUSIONS Amniotic membrane transplantation is a useful adjunct to conventional MT in maintaining BCVA and a stable ocular surface in cases of acute ocular SJS. Furthermore, the adjunctive use of AMT also helps to prevent intermediate-term ocular cicatricial sequelae.

CD4+CD25+ T regs with acetylated FoxP3 are associated with immune suppression in human leprosy

Leprosy is a chronic human disease that results from infection of Mycobacterium leprae. T reg cells have been shown to have important implications in various diseases. However, in leprosy, it is still unclear whether T regs can mediate immune suppression during progression of the disease. In the present study, we have proposed the putative mechanism leading to high proportion of T reg cells and investigated its significance in human leprosy. High levels of TGF-β followed by adaptation of FoxP3(+) naive and memory (CD4(+)CD45RA(+)/RO(+)) T cells were observed as the principal underlying factors leading to higher generation of T reg cells during disease progression. Furthermore, TGF-β was found to be associated with increased phosphorylation-mediated-nuclear-import of SMAD3 and NFAT towards BL/LL pole to facilitate FoxP3 expression in these cells, the same as justified after using nuclear inhibitors of SMAD3 (SIS3) and NFAT (cyclosporin A) in CD4(+)CD25(+) cells in the presence of TGF-β and IL-2. Interestingly, low ubiquitination of FoxP3 in T reg cells of BL/LL patients was revealed to be a major driving force in conferring stability to FoxP3 which in turn is linked to suppressive potential of T regs. The present study has also pinpointed the presence of CD4(+)CD25(+)IL-10(+) sub class of T regs (Tr1) in leprosy.

Th3 immune responses in the progression of leprosy via molecular cross-talks of TGF-β, CTLA-4 and Cbl-b.

Leprosy is a chronic human disease; primarily affecting skin, peripheral nerves, eyes, testis etc. Comprehensive-expressional-profiling of Th1-Th2-Th3 associated markers (84 genes) using qRT-PCR array, negated the previously prevailing notion, Th2 bias towards multibacillary stage of leprosy. High production TGF-β further supported the dearth of any immune response(s) in leprosy progression. Over expression of Cbl-b, could emerge as plausible reason for contributing T cell hyporesponsiveness, possibly by degradation of T cells signaling molecules. Anti-TGF-β treatments further confirm the TGF-β-dependent-Cbl-b overexpression in multibacillary patients. Diminished Cbl-b expression in CTLA-4 knockout studies using siRNA, provided other evidence towards T cell hyporesponsiveness. Further, high T cell proliferation and IL-2 production in PBMC cultures treated with anti-TGF-β and siRNA offers here a strategy to revert T cell hyporesponsiveness by downregulating Cbl-b expression in leprosy. Thus, this study negates Th2 bias and substantiates molecular cross-talk amongst TGF-β-CTLA-4-Cbl-b eventually leads to M. leprae persistence.

Acneiform eruptions after facial beauty treatment

Background Female patients in the post‐adolescent age group presented with predominantly deep‐seated nodules and a few comedones situated mainly on the cheeks. As most of these subjects related the onset of their symptoms to antecedent facial beauty treatment, we decided to study the clinical and histologic profile of these patients.

Facial melanoses: Indian perspective

Facial melanoses (FM) are a common presentation in Indian patients, causing cosmetic disfigurement with considerable psychological impact. Some of the well defined causes of FM include melasma, Riehls melanosis, Lichen planus pigmentosus, erythema dyschromicum perstans (EDP), erythrosis, and poikiloderma of Civatte. But there is considerable overlap in features amongst the clinical entities. Etiology in most of the causes is unknown, but some factors such as UV radiation in melasma, exposure to chemicals in EDP, exposure to allergens in Riehls melanosis are implicated. Diagnosis is generally based on clinical features. The treatment of FM includes removal of aggravating factors, vigorous photoprotection, and some form of active pigment reduction either with topical agents or physical modes of treatment. Topical agents include hydroquinone (HQ), which is the most commonly used agent, often in combination with retinoic acid, corticosteroids, azelaic acid, kojic acid, and glycolic acid. Chemical peels are important modalities of physical therapy, other forms include lasers and dermabrasion.

FoxP3 provides competitive fitness to CD4+CD25+ T cells in leprosy patients via transcriptional regulation

Leprosy is a chronic infectious disease caused by Mycobacterium leprae. FoxP3 have been shown to have important implications in various diseases. The present study describes the mechanism of action of FoxP3 in CD4+CD25+ T cells derived from leprosy patients. Increased molecular interactions of FoxP3 with histone deacetylases 7/9 in the nucleus of CD4+CD25+ T cells derived from borderline lepromatous leprosy/lepromatous leprosy (BL/LL) patients were found to be responsible for FoxP3‐driven immune suppression activities during the progression of leprosy. Further, downregulation of CTLA‐4 and CD25 genes in siFoxP3‐treated PBMCs derived from BL/LL patients elucidated the transcription‐activating nature of FoxP3. This observation was supported by direct binding of FoxP3 to the promoter region of the CTLA‐4 and CD25 genes, and FoxP3s molecular interaction with histone acetyl transferases. The study also revealed that the increased expression of miR155 in CD4+CD25+ cells from BL/LL governs the competitive fitness of these cells. Again, reduced Annexin V & propidium iodide staining and Nur77 expression, and concomitantly increased Ki‐67 positivity suggested that CD4+CD25+ cells derived from BL/LL patients are more competitively fit than those from borderline tuberculoid leprosy/tuberculoid leprosy and healthy controls. Taken together, the study shows the orchestration of FoxP3 leading to competitive fitness of Treg cells in leprosy.

IL-10 production from dendritic cells is associated with DC SIGN in human leprosy

The defective antigen presenting ability of antigen presenting cells (APCs) modulates host cytokines and co-stimulatory signals that may lead to severity of leprosy. In the present study, we sought to evaluate the phenotypic features of APCs along with whether DC SIGN (DC-specific intercellular adhesion molecule-grabbing nonintegrin) influences IL-10 production while moving from tuberculoid (BT/TT) to lepromatous (BL/LL) pole in leprosy pathogenesis. The study revealed an increased expression of DC SIGN on CD11c⁺ cells from BL/LL patients and an impaired form of CD83 (∼50 kDa). However, the cells after treatment with GM-CSF+IL-4+ManLAM showed an increased expression of similar form of CD83 on DCs. Upon treatment with ManLAM, DCs were found to show increased nuclear presence of NF-κB, thus leading to higher IL-10 production. High IL-10 production from ManLAM treated PBMCs further suggested the role of DC SIGN in subverting the DCs function towards BL/LL pole of leprosy. Anti-DC SIGN treatment resulting in restricted nuclear ingression of NF-κB as well as its acetylation along with enhanced T cell proliferation validated our findings. In conclusion, Mycobacterium leprae component triggers DC SIGN on DCs to induce production of IL-10 by modulating intracellular signalling pathway at the level of transcription factor NF-κB towards BL/LL pole of disease.

Association of TNF-α-(308(GG)), IL-10(-819(TT)), IL-10(-1082(GG)) and IL-1R1(+1970(CC)) genotypes with the susceptibility and progression of leprosy in North Indian population.

Leprosy is an infectious disease caused by M. leprae. We analyzed 48 cytokine polymorphisms in 13 (pro as well as anti-inflammatory) cytokine genes using PCR-SSP assay in 102 leprosy patients and 120 healthy controls with intent to find out a link between cytokine polymorphisms and disease susceptibility. TNF-α (-308) GG, IL-10 (-819) TT, IL-10 (-1082) GG and IL1R (+1970) CC genotypes are found to be predominant (p=0.01, p=0.02, p=0.0001 and p=0.001, respectively) in both tuberculoid as well as lepromatous leprosy patients. This observation suggests these genotypes as play the central role(s) in the progression of disease. CBA assay demonstrates the varied serum concentration of these cytokines with respect to their genotypes. The above genotypes appeared as high producer genotypes in our study. Even in presence of high produce genotypes, TNF-α level are found to be affected/masked by the presence of IL-10 in leprosy patients. Expressional masking of TNF-α is associated with the expression of IL-10 in these patients. This is one the negative impact of SNP-SNP interaction in leprosy patients. Therefore, we can conclude that cytokine gene polymorphisms determine the predisposition to the leprosy progression.

Post-kala-azar dermal leishmaniasis: a histopathological study.

BACKGROUND Post-kala-azar dermal leishmaniasis follows an attack of visceral leishmaniasis and is caused by the same organism, i.e. Leishmania donovani. METHODS In the present study, biopsy specimens from hypopigmented macules, nodules or plaques of 25 patients clinically diagnosed as PKDL were evaluated for epidermal and dermal changes and for the presence or absence of Leishmania donovani bodies (LDBs). RESULTS The hypopigmented macules showed a patchy perivascular and periappendageal infiltrate with no demonstrable LDBs in any of the biopsies. In the nodular and plaque lesions, the infiltrate was diffuse, beneath an atrophic epidermis (74%) and follicular plugging (95.6%) was seen in most biopsies. The infiltrate consisted of lymphocytes, histiocytes and plasma cells in decreasing order of presence. LDBs could be demonstrated in only 10 (43.5%) biopsy specimens from nodular and plaque lesions and were never numerous. CONCLUSIONS Histopathological features of PKDL are elucidated and discussed.