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<!--Generated by DFIN XBRL Instance Document - http://www.dfinsolutions.com/ - Version R3.0 - on 24-February-2024 [12:32:45] {AM}-->
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<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_AntiTakeoverProvisionsMember" xlink:label="loc_jhit_AntiTakeoverProvisionsMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_AntiTakeoverProvisionsMember" xml:lang="en-US">Anti Takeover Provisions [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_AntiTakeoverProvisionsMember" xlink:to="lab_jhit_AntiTakeoverProvisionsMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_BradyBondsRiskMember" xlink:label="loc_jhit_BradyBondsRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_BradyBondsRiskMember" xml:lang="en-US">Brady Bonds Risk [Member]</label>
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<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_CreditAndCounterpartyRiskMember" xlink:label="loc_jhit_CreditAndCounterpartyRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_CreditAndCounterpartyRiskMember" xml:lang="en-US">Credit And Counterparty Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_CreditAndCounterpartyRiskMember" xlink:to="lab_jhit_CreditAndCounterpartyRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_CurrencyRiskMember" xlink:label="loc_jhit_CurrencyRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_CurrencyRiskMember" xml:lang="en-US">Currency Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_CurrencyRiskMember" xlink:to="lab_jhit_CurrencyRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_DefensivePositionsRiskMember" xlink:label="loc_jhit_DefensivePositionsRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_DefensivePositionsRiskMember" xml:lang="en-US">Defensive Positions Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_DefensivePositionsRiskMember" xlink:to="lab_jhit_DefensivePositionsRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_DistributionRiskMember" xlink:label="loc_jhit_DistributionRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_DistributionRiskMember" xml:lang="en-US">Distribution Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_DistributionRiskMember" xlink:to="lab_jhit_DistributionRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_EconomicAndMarketEventsRiskMember" xlink:label="loc_jhit_EconomicAndMarketEventsRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_EconomicAndMarketEventsRiskMember" xml:lang="en-US">Economic And Market Events Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_EconomicAndMarketEventsRiskMember" xlink:to="lab_jhit_EconomicAndMarketEventsRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_EquitySecuritiesRiskMember" xlink:label="loc_jhit_EquitySecuritiesRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_EquitySecuritiesRiskMember" xml:lang="en-US">Equity Securities Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_EquitySecuritiesRiskMember" xlink:to="lab_jhit_EquitySecuritiesRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_ESGIntegrationRiskMember" xlink:label="loc_jhit_ESGIntegrationRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_ESGIntegrationRiskMember" xml:lang="en-US">ESG Integration Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_ESGIntegrationRiskMember" xlink:to="lab_jhit_ESGIntegrationRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_FixedIncomeSecuritiesRiskMember" xlink:label="loc_jhit_FixedIncomeSecuritiesRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_FixedIncomeSecuritiesRiskMember" xml:lang="en-US">Fixed Income Securities Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_FixedIncomeSecuritiesRiskMember" xlink:to="lab_jhit_FixedIncomeSecuritiesRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_FixedIncomeSecuritiesRiskOneMember" xlink:label="loc_jhit_FixedIncomeSecuritiesRiskOneMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_FixedIncomeSecuritiesRiskOneMember" xml:lang="en-US">Fixed Income Securities Risk One [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_FixedIncomeSecuritiesRiskOneMember" xlink:to="lab_jhit_FixedIncomeSecuritiesRiskOneMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_ForeignInvestmentRiskMember" xlink:label="loc_jhit_ForeignInvestmentRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_ForeignInvestmentRiskMember" xml:lang="en-US">Foreign Investment Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_ForeignInvestmentRiskMember" xlink:to="lab_jhit_ForeignInvestmentRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_HedgingDerivativesAndOtherStrategicTransactionsRiskMember" xlink:label="loc_jhit_HedgingDerivativesAndOtherStrategicTransactionsRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_HedgingDerivativesAndOtherStrategicTransactionsRiskMember" xml:lang="en-US">Hedging Derivatives And Other Strategic Transactions Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_HedgingDerivativesAndOtherStrategicTransactionsRiskMember" xlink:to="lab_jhit_HedgingDerivativesAndOtherStrategicTransactionsRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_IlliquidAndRestrictedSecuritiesRiskMember" xlink:label="loc_jhit_IlliquidAndRestrictedSecuritiesRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_IlliquidAndRestrictedSecuritiesRiskMember" xml:lang="en-US">Illiquid And Restricted Securities Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_IlliquidAndRestrictedSecuritiesRiskMember" xlink:to="lab_jhit_IlliquidAndRestrictedSecuritiesRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_LeverageRiskMember" xlink:label="loc_jhit_LeverageRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_LeverageRiskMember" xml:lang="en-US">Leverage Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_LeverageRiskMember" xlink:to="lab_jhit_LeverageRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_LowerRatedAndHighYieldFixedIncomeSecuritiesRiskMember" xlink:label="loc_jhit_LowerRatedAndHighYieldFixedIncomeSecuritiesRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_LowerRatedAndHighYieldFixedIncomeSecuritiesRiskMember" xml:lang="en-US">Lower Rated And High Yield Fixed Income Securities Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_LowerRatedAndHighYieldFixedIncomeSecuritiesRiskMember" xlink:to="lab_jhit_LowerRatedAndHighYieldFixedIncomeSecuritiesRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_MarketDiscountRiskMember" xlink:label="loc_jhit_MarketDiscountRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_MarketDiscountRiskMember" xml:lang="en-US">Market Discount Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_MarketDiscountRiskMember" xlink:to="lab_jhit_MarketDiscountRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_MortgageBackedAndAssetBackedSecuritiesRiskMember" xlink:label="loc_jhit_MortgageBackedAndAssetBackedSecuritiesRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_MortgageBackedAndAssetBackedSecuritiesRiskMember" xml:lang="en-US">Mortgage Backed And Asset Backed Securities Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_MortgageBackedAndAssetBackedSecuritiesRiskMember" xlink:to="lab_jhit_MortgageBackedAndAssetBackedSecuritiesRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_OperationalAndCybersecurityRiskMember" xlink:label="loc_jhit_OperationalAndCybersecurityRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_OperationalAndCybersecurityRiskMember" xml:lang="en-US">Operational And Cybersecurity Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_OperationalAndCybersecurityRiskMember" xlink:to="lab_jhit_OperationalAndCybersecurityRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_PreferredAndConvertibleSecuritiesRiskMember" xlink:label="loc_jhit_PreferredAndConvertibleSecuritiesRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_PreferredAndConvertibleSecuritiesRiskMember" xml:lang="en-US">Preferred And Convertible Securities Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_PreferredAndConvertibleSecuritiesRiskMember" xlink:to="lab_jhit_PreferredAndConvertibleSecuritiesRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_RepurchaseAgreementRiskMember" xlink:label="loc_jhit_RepurchaseAgreementRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_RepurchaseAgreementRiskMember" xml:lang="en-US">Repurchase Agreement Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_RepurchaseAgreementRiskMember" xlink:to="lab_jhit_RepurchaseAgreementRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_ReverseRepurchaseAgreementRiskMember" xlink:label="loc_jhit_ReverseRepurchaseAgreementRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_ReverseRepurchaseAgreementRiskMember" xml:lang="en-US">Reverse Repurchase Agreement Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_ReverseRepurchaseAgreementRiskMember" xlink:to="lab_jhit_ReverseRepurchaseAgreementRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_SecondaryMarketForTheCommonSharesMember" xlink:label="loc_jhit_SecondaryMarketForTheCommonSharesMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_SecondaryMarketForTheCommonSharesMember" xml:lang="en-US">Secondary Market For The Common Shares [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_SecondaryMarketForTheCommonSharesMember" xlink:to="lab_jhit_SecondaryMarketForTheCommonSharesMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_SectorRiskMember" xlink:label="loc_jhit_SectorRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_SectorRiskMember" xml:lang="en-US">Sector Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_SectorRiskMember" xlink:to="lab_jhit_SectorRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_SovereignDebtObligationsRiskMember" xlink:label="loc_jhit_SovereignDebtObligationsRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_SovereignDebtObligationsRiskMember" xml:lang="en-US">Sovereign Debt Obligations Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_SovereignDebtObligationsRiskMember" xlink:to="lab_jhit_SovereignDebtObligationsRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_StrategyRisksMember" xlink:label="loc_jhit_StrategyRisksMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_StrategyRisksMember" xml:lang="en-US">Strategy Risks [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_StrategyRisksMember" xlink:to="lab_jhit_StrategyRisksMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_TaxRiskMember" xlink:label="loc_jhit_TaxRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_TaxRiskMember" xml:lang="en-US">Tax Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_TaxRiskMember" xlink:to="lab_jhit_TaxRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_USGovernmentSecuritiesRiskMember" xlink:label="loc_jhit_USGovernmentSecuritiesRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_USGovernmentSecuritiesRiskMember" xml:lang="en-US">U S Government Securities Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_USGovernmentSecuritiesRiskMember" xlink:to="lab_jhit_USGovernmentSecuritiesRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_WarrantsRiskMember" xlink:label="loc_jhit_WarrantsRiskMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_WarrantsRiskMember" xml:lang="en-US">Warrants Risk [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_WarrantsRiskMember" xlink:to="lab_jhit_WarrantsRiskMember" />
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_CommonSharesMember" xlink:label="loc_jhit_CommonSharesMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_CommonSharesMember" xml:lang="en-US">Common Shares [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_CommonSharesMember" xlink:to="lab_jhit_CommonSharesMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_jhit_CommonSharesMember" xml:lang="en-US">Common shares.</label>
<loc xlink:type="locator" xlink:href="jhit-20240220.xsd#jhit_PreferredSharesMember" xlink:label="loc_jhit_PreferredSharesMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_jhit_PreferredSharesMember" xml:lang="en-US">Preferred Shares [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_jhit_PreferredSharesMember" xlink:to="lab_jhit_PreferredSharesMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_jhit_PreferredSharesMember" xml:lang="en-US">Preferred shares.</label>
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