DSpace Collection:
http://inet.vidyasagar.ac.in:8080/jspui/handle/123456789/1077
2024-03-28T13:55:03ZEvaluation of work related health problems of carpenters and an ergonomic intervention in the carpenter’s hand tool and workstation
http://inet.vidyasagar.ac.in:8080/jspui/handle/123456789/6313
Title: Evaluation of work related health problems of carpenters and an ergonomic intervention in the carpenter’s hand tool and workstation
Authors: Chatterjee, Mousumi
Abstract: Introduction: Carpentry is one of the common small-scale industries which contribute to
Indian economy. A cluster of carpentry workshop has been originated in different states of
India such as, West Bengal, Assam, Orissa, Madhya Pradesh, Rajasthan, Karnataka, Kerala
etc. Different districts of West Bengal, such as, Paschim Medinipur, Bankura, Purulia etc.
are the virtuous standby bunch zone of carpenters.
Carpentry task is an assemblage exertion work in a firmly corresponding method by some
carpenters. Every group is made up of2-3 numbers of varied workforces, executing diverse
categories of carpentry work. The main responsibilities are – (i) cutting the raw wood by
sawing, (ii) planning the wood for further preparation of furniture, (iii) designing and fine
cutting of wood by the chisel. According to the responsibilities the carpenters were divided
in to three major categories, viz. saw users, plane users and chisel users. They work in a
group and some of them were habituated to perform all three tasks.
Carpenters, who had to execute their task by exercising physical effort, were exposed to
some occupation associated health hazards and stresses. The significant contributing reasons
might be an improper procedure of work, unusual posture, extreme job pressure, physical
stresses, non-ergonomically designed workshop, and etc. The job associated strains might
have certain effects on the health and performance of the carpenters.
Some difficult postures adopted by the workers l i ke, bending, overstretching, squatting,
crouching, twisting etc. at the time of executing the carpentry task. Those kinds of posture
mostly lead to postural stress among the workers.
Some human factors related to the carpentry work were studied in this research work.
Priority has been given to appraise the general health status, occupation related MSD, work
posture, work-rest cycle, and physical variations of the carpenters. Carpenters had to execute
their task in a workstation which must be suitable to them and their tasks. It was required to assess the workstation from the ergonomics and human factors points of view. Ergonomic
intervention was necessary to reduce the extent of mismatch between the workers and
various components of the workstation. A number of hand operated tools were used by the
carpenters in their workshop. Ergonomics evaluation of those tools as well as ergonomics
modification of the hand tools might be required to ensure the better productivity and well
being of the workers.
The followings were the objectives of the present research study –
i. To assess the socioeconomic and nutritional status of the carpenters.
ii. To evaluate musculoskeletal disorders and the discomfort level of the carpenters.
iii. To evaluate the postural stress of the carpenters
iv. Ergonomic intervention for redesigning the conventional workstation and hand tool
(carpenters chisel) used by the carpenters.
Methods: To accomplish the said objectives the succeeding procedures were employed. The
whole study was conducted in different carpenter's workshops of Paschim Medinipur
districts of West Bengal state in India. For the execution of this research work 256 of male
(18-60 years) carpenters were chosen arbitrarily. All those selected subjects volunteered to
this study.
The carpenter’s socio-economic position was estimated by modified Kuppuswami scale (Raj
et.al. 2015). The workers educational status was appraised through questionnaire procedure
and nutritional status of the workers was assessed by using anthropometric guides like, body
mass index (BMI), body fat (BF%) etc. Anthropometric study (height, weight, BMI) was
made through standard measurement method (as per WHO, 1986 guidelines). Modified
‘Nordic’ questionnaire technique was applied for determining the occupation related
musculoskeletal disorder of carpenters. Discomfort or pain in different body parts of the
workers was rated through10-point Borg’s scale. By scheming the genuine work time and break time of entire work shift, the work-rest cycle was assessed. It was detected through
video-photography method from beginning to end of the work shift.
By using OWAS, RULA, REBA and QEC methods, the postural pattern of the carpenters
was assessed. In addition, direct observation, video photographic technique was also
employed. By determining of blood pressure and heart rate (HR) (during both resting and
working situations) cardiovascular status of the carpenters was estimated and from the
resting and mean working heart rate CSI (cardiovascular stress index) was calculated.
The whole body-center of gravity of the carpenters was determined by the segmental
method. Different body joint angles of the carpenters was measured by a digital goniometer.
the EMG study of different work posture of carpenters were evaluated by BioGraph Infiniti
system (Pate-1). The Pulmonary function parameters of the carpenters were evaluated by
using a digital spirometer. Different pulmonary parameters like, FVC FEV
1,
PEF and MVV-index were assessed. Furthermore, by using FEV
1
value <70%) the occurrence of COPD was determined.
FEF
25%-75%
/FVC value (minimum
Different hand tools were used by the carpenters for executing different tasks of carpentry
work. Carpenter’s chisel, which was one of the most frequent used tool of the carpenters,
was redesigned with an emphasis to the man- tool interface. Some of the steps followed for
redesigning the chisel were: (i) assessment of conventional chisel, (b) some concept of
design was developed and prototypes were prepared (c) restructured the conventional chisel
handle and (d) restructured chisel was evaluated by employing some methods such as
subjective evaluation, joint angle study, heart rate study and productivity study.
For optimizing the height of workstation for the plane users, some synchronized steps were
applied. In the beginning, the disadvantages or problems of the design of the conventional
workstation was evaluated by cross-examining the users, assessing BPD and determining
joint angles of the users and assessing the postural stress at the time of using the conventional workstation by study of EMG. Ultimate design of the workstation was executed by a psychophysical study, and by study of productivity. Results and Discussion: The results of the present research work represented that most of
the carpenters were belonging to lower socioeconomic category according to the modified
Kuppuswami scale. They had a poor nutritional status. Depending to Chronic Energy
Deficiency (CED) categorization ( WHO, 1995) it was found that a distinguished proportion
of carpenters were within the range of under nourished (<18.50 kg/m2) category.
Around82% of the carpenters were belongings to normotensive category and nearly15% of
the workers were within the hypotensive range.
The findings of occupation related musculoskeletal disorders exhibited that nearly all of the
body parts were affected during execution of carpentry tasks. Maximum pretentious body
segments were lower back (85.55%) and waist (78.52%), knee (69.14%), shoulder (69.14%)
and neck (61.72%) of carpenters in view of all tasks together. Significantly higher
prevalence of MSD was observed in some of the body parts of the carpenters. In all kinds of
carpentry tasks musculoskeletal problems were found in the lower back, wrist and knee
portion of the body, but problem was enormously predominant during chiseling and
planning task. Saw operators were extremely affected by knee problems. Problems in lower
back of the body were highly prevalent for chisel users (95.12%) and plane users (86.21%).
The prevalence of MSD was also observed very high in higher and lower experience groups
of carpenters than that of middle experience group workers.
The results of body part discomfort rating (BPD) exposed that the workers involved in
various carpentry tasks had different degrees of BPD. During chisel and plane operations,
severe pain (BPD>7) was found in shoulder and lower back of the body. Moderate level of
pain (BPD>4 to 7) was detected in neck and hand arm system among the workers involved
in all kinds of carpentry tasks. According to the work experience the of BPD rating was found to be greater in higher and lower experience group than that of middle experience
group. This ache or discomfort might be related to inappropriate working posture, poor work
environment along with high work load in the work place.
The most important factor in the job-related stress was the total duration of a work shift. The
work-rest cycle exhibited that the overall working time was around 8 to 9 hours including
rest pauses. The total time of work shift was the maximum in chisel operation followed by
the plane and saw operation.
The cardiovascular stress index (CSI) was high in different tasks of carpenters. The CSI and
work-rest period was found to be closely related. It was recommended that within the work
shift the carpenters might take more frequent short breaks instead of a long duration break.
As per the results of different posture analysis procedures, the work postures adopted by the
carpenters had ‘moderate’ ‘to ‘very high’ levels of risk in different tasks of carpentry. The
workers were suffering from occupation associated health hazards, feasibly for extended
working periods along with assuming awkward postures. In this study it was observed that
three different postures were predominant for three different tasks of carpenters. Most of the
time the chisel users adopted forward bending posture while sitting with folded legs. The
plane users had to work in forward bending posture understanding condition. The
predominant posture of the saw users was the forward bending with one leg folded at upper
position. Prolonged squatting and bending postures were the main reasons for the occurrence
of MSD in the lower part of the body. From the results of postural assessment it was found
that the tasks of carpenters had a great risk and needed immediate corrective measures.
Results of the center of gravity showed that the location of CG was deviated from that of
reference position under normal erect posture. In EMG study there are vast deviation was
found in different muscle for different body posture which and also significant difference was found among in three different task of carpentry. The RMS values of EMG for fore arm
muscle was highest in stressed during chisel operation and for the biceps and triceps
muscles that RMS values was highest during plane operating task.
Further vital aspects of posture related stress was higher occurrence of job related
musculoskeletal disorders and rigorousness of discomfort rating. At the time of executing
different task of carpentry, the workers had to assume numerous types of difficult postures.
In different task of carpentry, the workers had to adopt different work posture. For chiseler
they had to adopt sitting with folded legs for about 85.50% of the total work time where
wise plane users and saw users had to adopted erect with forward bending and erect with one
leg folded at upper position (forward Bending) respectively for maximum time of the work
period.
The evaluation of blood pressure (BP) of carpenters indicated that approximately 82% of
workers were in normotensive category. The study of heart rate revealed that mean working
heart rate of the carpenters was120.86±9.90 and peak working heart rate was 129.04±8.77.
Depending on mean working heart rate, the work load of tasks of the workers was
categorized as light to heavy. The chiseling and sawing tasks were within the range of
moderate category.
The Cardiovascular stress index (CSI) of the woodworkers uncovered that they were
imposed to cardiovascular stress during performing out their diverse carpentry assignments.
There was a little variety in CSI among chisel users (CSI values 30.24) and plane users (CSI
esteem 33.07). Both of the work had high cardiovascular pressure. Be that as it may, CSI
estimation of saw activity (25.18) was beneath than other two tasks. The term of working
activity was discovered which was identified with the cardiovascular stress. The work-rest
pattern of various classes of woodworkers has been examined and its outcomes were
contrasted with the CSI values. The similar outcomes uncovered that more prominent the level of work time, more noteworthy was the CSI level and the other way around.
The results of the pulmonary function tests showed that all the pulmonary variables (FVC,
FEV
1
, FVC/FEV
1
average FVC, FEV
1
, EF
25%-75%
, PEF, and MVV-index) were below the normal range. The
, FVC/FEV
1
, PEF, EF
25%-75%
, and MVV-index were 3.21±0.41 litters,
3.04±0.56 litters, 82.12±9.43%, 6.65±1.07 litters/minute, 3.78±1.21 litters/minute and
84.16±13.0 litters/minute respectively. There was prevalence of COPD and other pulmonary
dysfunctions among the laborers. The diminished estimations of these pneumonic factors
may The lower score the pulmonary function variables might be because of long time
exposure of the wooden dust in the workstation. These problems were aggravated among the
workers those who were addicted to smoking.
Two ergonomic interventions were employed to lessen the work related health problems of
the carpenters.
In the first intervention the chisel, a commonly used hand tool, was evaluated and modified
the design of the tool from ergonomic point of view. The carpenters needed to hold the
chisel firmly using one of their hands during performing the work. During holding and
applying intense force, the chisel user felt distress at the various parts of the body, viz.,
fingers, palm, wrist and shoulder. An endeavor has been made to redesign the chisel handle
considering the human factors. The problems using the conventional handle interface was
assessed. Some design ideations were initiated to eliminate the drawbacks. As per proposed
ideations the size, shape and texture of the handle were modified and according to that four
prototype models were made. In such concepts hand dimensions of the carpenters were
incorporated. The psychophysical evaluation of the prototypes was made by means of paired
comparison test.
Following adjustments were made to renovate the handle of the chisel.
i. The length of the handles was expanded for proper holding of the tool by considering the hand length of the users and the results of the paired comparison test.
ii. The diameter of the handles was modified according to the inner hand grip of the
users as well as the finding of the paired comparison test.
iii. The shape of the handle was selected from the best scores of the Paired comparison
test so that the slippage of the palm could be prevented.
iv. A rubber grip was incorporated at the gripping area of the handle for firm gripping
during working.
v. A safety guard made of thick rubber plate was fitted above the holding area of handle
for preventing mishit of the hammer.
The overhauled chisel was assessed by a few boundaries, The renovated chisel was
examined by some parameters, viz., prevalence of MSD, joint angle study, working pulse
rate and productivity study. The consequences of these investigations showed that the
redesigned chisel was more efficient, easy to operate and less stressful.
The second ergonomic intervention was the optimization of the height of the workstation for
performing various tasks of the carpenters, especially for the plane operators. The existing
height of the work surface of the plane operators was varied from one place to another. The
average height of the same was about 60.3 cm. Such conventional workstation produced
various musculoskeletal problems during doing the work. To find optimum height of the
workstation some prototype models of the workstation were made with varied
heights,viz.,65 cm, 70cm and 75 cm. Those prototypes were tested by paired comparison
test. The prototype which yielded the best score was selected for optimization of the height.
In addition to the 5
th
percentile value of the standing height of the users was also taken into
account. Further, EMG studies were conducted on shoulder and back muscles and found that
least myoelectric activities were noted. All the experimental studies revealed that the best
height of the workstation was 70.0cm. The optimized workstation was tested with by computing body joint angles, prevalence of MSD and body part discomfort rating. All
results were in favour of redesigned workstation. Moreover, productivity study was also
supported these findings.
Conclusion: From the above discussion, it could be inferred that the prevalence of work
related musculoskeletal issues (WRMSD) was observed among the woodworkers. They
were experiencing various WRMSD. The major affected body parts were the lower back,
wrist, shoulder, neck, and knee. The magnitude of pain or discomfort rating was also high in
those body sections.
The postural stress was high among the workers because of adopting awkward working
posture for a long time. The higher pervasiveness of MSD and occurrence of pain or
discomfort rate was related with the postural stress. The work related health hazards
alongside postural stress could be diminished by adjusting the work-rest cycle.
Proper usage of redesigned chisel and optimized workstation might relieve the carpenters
from work associated health hazards and enable them to achieve better productivity. Thus
the results of the study might provide well being of the carpenters.
,2021-11-22T00:00:00ZAnticancer efficacy of surface coated copper oxide nanoparticles: A mechanistic study comprising immunomodulation
http://inet.vidyasagar.ac.in:8080/jspui/handle/123456789/6267
Title: Anticancer efficacy of surface coated copper oxide nanoparticles: A mechanistic study comprising immunomodulation
Authors: Dey, Aditi
Abstract: In the current study, we synthesized Copper Oxide Nanoparticles (CuONPs) by chemical and
green synthesis methods. Several chemicals were used in the chemically synthesized method,
whereas in green method, water extract of Azadirachta indica (A. indica) leaves were used. In
case of both synthesis methods, Copper sulphate salt was used as a precursor. After completion
of synthesis, several physio-chemical techniques were used such as FT-IR, DLS, Surface Zeta
potential, EDX, XRD, SEM and TEM to confirm the synthesis of both nanoparticles. The GC
mass analysis was performed to know the bioactive components of water extracts of A. indica
leaves. The anti-oxidant property and radical scavenging property have been estimated by taking
ascorbic acid as a reference. The green synthesized CuONPs showed significant anti-oxidant and
radical scavenging activity, which may be due to bioactive components of A. indica leaf extracts.
Then the toxicity difference between the chemical CuONPs and green CuONPs was evaluated in
in vitro and in vivo models. The result showed that green CuONPs is less toxic compared to the
chemical one. However green CuONPs showed toxicity at higher doses. Hence from the toxicity
point of view, we selected green CuONPs for further study.
The in vitro and in vivo anticancer efficacy was evaluated using green synthesized CuONPs.
Breast cancer (MCF-7 cells) and cervical cancer (HeLa cells) were used throughout the study
and 4T1 cells were injected in subcutaneous abdominal mammary pad in Balb/c mice for solid
tumor model. Green CuONPs liberate Cu ions by leaching, which internalized inside the cancer
cells in a dose dependent manner. The liberated Cu ions were able to produce ROS which will
indirectly induce pro-inflammatory cytokines level and then apoptosis by mitochondrial and nonmitochondrial
mediated
pathway.
To reduce the toxicity of green CuONPs, its surface was coated with cationic biopolymer
Chitosan (CS) to reduce the toxicity and able to specifically target the cancer cells due to cationic
surface charge of CS as the cancer cells were negatively charged. CS has been chosen due to its
pH responsive nature that facilitates the release of Cu ions from CuONPs@CS in acidic cancer
cell environment. So, the release of Cu ions from CuONPs@CS in normal cells became reduced.
Surface coated green CuONPs (CuONPs@CS) showed significant apoptosis in cancer cells. The
underlying mechanism of apoptosis was investigated here. The surface coated NPs induced pro-inflammatory cytokines level and simultaneously reduced the level of the anti-inflammatory
cytokines. Immuno-histochemistry and cytokine analysis showed that the involvement of
cascade of Caspases is the key phenomenon of apoptosis. CuONPs@CS showed a significant
reduction of tumor weight after 30 days of treatment in mice model.
The CuONPs@CS being an immunostimulant was able to activate the cellular as well as
humoral immune response. The CD4+ expression and secretion of pro-inflammatory cytokines
indicated the activation of T cells and macrophages which destroyed the cancer cells in in vitro
and in vivo models. Alongside humoral immunity, response was triggered by the CuONPs@CS
through IgG response, which indicated the adjuvant role of the nano conjugate. Th1 (Type 1 and
Type 2 helper T cells) and Th2 cells were activated after the treatment with nano conjugate and
acts as an immunostimulant which would inhibit the proliferation of breast cancer (MCF-7) and
cervical cancer (HeLa) cells in in vitro and in vivo Balb/c mice model. The secretion of proinflammatory
cytokines
and
the
increase
in
CD4+
populations indicated the activation of
immune cells in the current study. Immunotherapy by the help of metal nano conjugate
(CuONPs@CS) can be an effective tool to wipe out the cancer cells from the system.
The CuONPs@CS was finally coated with folic acid to specifically target the cancer cells as the
folate receptor was overexpressed on cancer cells. Green synthesized CuONPs have widespread
anti-cancer activity, but the incompetent targeting ability of these metal based nanoparticles is
the main obstacle. To overcome this difficulty here we synthesized a folic acid (FA) and chitosan
(CS) coated nano vehicle to effectively diminish off-target effects by increasing intracellular NPs
concentration in cancer cells and subsequently reducing the burden of cytotoxicity against
normal lymphocytes. HeLa and MCF-7 cancer cells were used here as in vitro model, where
CuONPs@CS@FA internalized through folate receptor mediated endocytosis pathway.
Sustained release of NPs inside the cancer cells destroyed the mitochondrial membrane potential
and produced ROS which caused apoptosis. 4T1 cells induced solid tumor burden in Balb/c
mice, significantly reduced by CuONPs@CS@FA. Our multi layered coated conjugate could be
an effective NPs delivery system for anti-cancer therapy, without creating any severe toxicity
towards normal cells.
The overall study complies with the dynamic functional properties of surface coated CuONPs,
which acts as a smart tool to destroy the cancer cells without significant toxicity. The nano conjugate acts as a targeted NPs delivery system and immunostimulant, which can activate the
immune cells of our system.
Keywords: MCF-7, HeLa, Cytokines, apoptotic markers, Balb/c, Copper Oxide nanoparticles,
Reactive Oxygen Species, toxicity.2021-08-19T00:00:00ZEcological studies on fungi of Subarnarekha river, India with special reference to the role of Aspergillus penicillioides as bioremediator
http://inet.vidyasagar.ac.in:8080/jspui/handle/123456789/6143
Title: Ecological studies on fungi of Subarnarekha river, India with special reference to the role of Aspergillus penicillioides as bioremediator
Authors: Paria, Kishalay
Abstract: Rivers representing the lifeline of the human being is now under great threats generally due to
the different anthropogenic activities including large scale abstraction of river water for
agriculture, wasteland reclamation, afforestation, industrial activities, fishing and aquaculture,
wetland drainage operation of hydroelectric power stations etc. Bio-recalcitrant of the ores of
heavy metal as major result in disruption of ecological balances and ultimately push the
erstwhile pristine river into an eco-degraded landscape. Out of many rivers in India,
Subarnarekha (21°33′ to 23°32′ north latitude and 85°9′ to 87°27′ east longitude) is a
transboundary river which traverses through the landscapes of three states viz. Jharkhand, West
Bengal and Odisha, India. This research study was initiated with the prime objective to study
the ecology of benthic fungi which have the potential for bio-accumulation and bio- removal of
a persistent toxic substance such as heavy metals i.e. lead (Pb-II), cadmium (Cd- II) and
mercury (Hg-II). The study was aimed to record the ecological changes of the river temporarily
and spatially in fungal diversity and bio-potential for removing heavy metals from three eco-
contrasting astudy sites i.e. Muri (S-I), Sonakonia (S-II) and Talsari (S-III) through different
months (24) and seasons (6) of two (2) consecutive years (July, 2012-June, 2014) of
Subarnarekha river along with recorded hydro-biological parameters. From this study a total of
112 soil-inhabiting fungal isolates were recorded from different stretches of the Subarnarekha
river basin. Out of the major soil-inhabiting fungi of the river ecosystem, the fungal species,
Aspergillus penicillioides (F12) was found to exhibit the highest heavy metal tolerance activity.
This strain of fungus was identified by the ITS genetic system and deposited into the gene bank
(MN210327). It exhibited resistance against Hg (II) up to 200 ppm but Pb (II) and Cd (II) up to
1000 ppm. The heavy metal binding regions of fungus were determined by FTIR, SEM and
EDEX analysis. The specific extracts from (secondary metabolites from cultured media) this
species has also revealed antibacterial activities by proving their effectiveness as a potential inhibitor against human pathogenic gram-positive bacteria, Bacillus subtilis and Staphylococcus
aureus and gram-negative bacteria, Vibrio cholerae, and Escherichia coli.
The studied fungal strain A. penicillioides was seen to release higher quantity of
exopolysaccharide (EPS), which helps absorb heavy metals in maximum amount. In view of
such observation, such circumstance, it can be concluded that both EPS and biomass of fungal
strain are supposed to be responsible for the bioremediation of heavy metals from the riverian
flow. This study also emphasizes the optimization of processes of different physicochemical
parameters [pH, time (h) and temperature (°C)] by employing Box- Behnken Design (BBD) of
experiments, in order to achieve the bio-absorption capability of heavy metal [lead (Pb II)] from
Subarnarekha river estuary by EPS of Aspergillus penicillioids (MN210327). From statistical
analysis (ANOVA), the optimized bio-absorption (72.76%) of Pb (II) by EPS was obtained at
pH of 11, the temperature of 37.57 °C, for a period of 8 hours. Besides, the flocculating activity
was noted as the highest (88.4%) at a concentration of 0.5 mg/l EPS and the emulsifying
activity of EPS was found to be about 50%. The research findings of the present study indicate
that biomass and EPS of Aspergillus penicillioides can act as good emulsifier, flocculent and
heavy metals (Pb II, Cd II, Hg II) remediator. This study also offers the possibility of the
development of an alternative method for eco-sustainable bioremediation by fungal EPS which
can be applied in the wastewater treatment plant. Besides, seasonability for ecological
parameters for a transboundary river has been recorded with the establishment of some (sensitive
and tolerant) bioindicator of fungal strain as a part of biomonitoring of the ecological changes.
Keywords: Heavy metals; Flocculation; Emulsification; Box-Behnken design; Transboundary
River; Benthic fungi; Bioremediation; Bio-indicator.2021-07-26T00:00:00ZGeneration of novel anti-Leishmania vaccine
http://inet.vidyasagar.ac.in:8080/jspui/handle/123456789/5924
Title: Generation of novel anti-Leishmania vaccine
Authors: Zutshi, Shubhranshu
Abstract: Leishmaniasis is a neglected, tropical disease caused by the protozoan parasite Leishmania
which affects millions of people worldwide. During past many decades, numerous vaccine
candidates have been tested against various forms of leishmaniasis, but convincing results
are yet to be achieved. Selection of a judicious vaccine candidate from plethora of
antigenic proteins is a crucial step in designing an efficacious vaccine. In this study, we
identified virulence factors of Leishmania based on their expression levels inside
peritoneum-derived primary macrophages post-infection. NAD+ synthase, adenylate
kinase, LmjF_36_3850, phosphatidic acid phosphatase, thiol-dependent reductase 1,
LmjF_33_2620 was observed to be significantly down-regulated in avirulent as compared
to virulent strain, and were identified as probable virulence factors and potential vaccine
candidates. Hence, we cloned LmjF_36_3850 in pcDNA6/HisA and evaluated its
antigenicity and protective efficacy in L. major challenge model. DNA vaccination with
LmjF_36_3850 elicited IgG2a and IgG1 to similar extent and produced mixed Th
response. Upon s.c. challenge of 2x10 6 L. major stationary phase promastigotes,
vaccinated mice were unable to control disease progression and had higher parasit ic load in
draining lymph node. Expression levels of Th2 cytokines such as IL-4 and IL-10, co-
inhibitory molecule such as CTLA-4, were found to be higher in lymphocytes of DNA
vaccinated mice. Moreover, CSA re-stimulated lymphocytes from vaccinated mice after
challenge infection secrete less IFN-γ than controls and comparable levels of IL-10 as
compared to non-vaccinated, L. major-infected mice. Also, population of pro-parasitic IL-
4, IL-10 and IL-17 secreting Th2-, Treg- and Th17-TEM found to be higher; while population of IFN-γ secreting Th1-TEM and TCM cells, respectively, were cells were lower in LmjF_36_3850 vaccinated mice as compared to control groups. Thus, DNA vaccination
with LmjF_36_3850 was unable to protect mice from L. major challenge.
Next, to analyze the potential of Heterologous prime-boost (HPB) strategy against L.
major challenge, we cloned L. major adenylate kinase (LmAdeK) in pcDNA6/HisA and
pet28a+. We purified rAdeK by Ni-NTA affinity resin and analyzed immunogenicity and
protective efficacy of different groups. HPB vaccination with LmAdeK was able to elicit
higher levels of Th1-associated IgG2a antibody and lower IgG1 levels than other
vaccination strategies and control groups. IgG2a/IgG1 ratio was higher in HPB vaccinated
mice than other vaccinated groups and controls and was skewed towards Th1 type. Also,
IgG2a levels in HPB vaccinated mice were higher after five weeks of challenge infection.
HPB vaccinated mice were able to better control lesion progression in footpad and have
lower parasitic load in draining lymph node than other groups. Also, HPB vaccinated mice
had higher IFN-γ and lower IL-4, IL-10, CTLA-4 expression in lymphocytes of draining
lymph node. Moreover, HPB vaccinated mice had lower population of IL-17 and IL-10
secreting Th17-TEM, TCM and Treg-TEM lower repertoire of IL-4 secreting Th2-TEM
cells, respectively. HPB vaccinated mice have and CM cells, although levels of IFN-γ
secreting cells were lower than the rAdeK-vaccinated group. Hence, HPB vaccination
strategy was more effective in controlling disease progression and parasitic burden than
other vaccination strategies and contains higher IFN-γ expressing lymphocytes and
decreased population of pro-leishmanial cytokine secreting Th2-, Th17- and Treg- memory
cells. Thus, vaccination strategy plays a vital role in eliciting a host-protective immune
response.2021-03-03T00:00:00Z